Usd module

Summary: The core client-facing module for authoring, compositing, and reading Universal Scene Description.

Classes:

`APISchemaBase`	The base class for all API schemas.
`AssetInfoKeys`
`Attribute`	Scenegraph object for authoring and retrieving numeric, string, and array valued data, sampled over time.
`AttributeQuery`	Object for efficiently making repeated queries for attribute values.
`ClipsAPI`	UsdClipsAPI is an API schema that provides an interface to a prim's clip metadata.
`CollectionAPI`	This is a general purpose API schema, used to describe a collection of heterogeneous objects within the scene."Objects"here may be prims or properties belonging to prims or other collections.
`CompositionArc`
`CrateInfo`	A class for introspecting the underlying qualities of .usdc'crate'files, for diagnostic purposes.
`EditContext`	A utility class to temporarily modify a stage's current EditTarget during an execution scope.
`EditTarget`	Defines a mapping from scene graph paths to Sdf spec paths in a SdfLayer where edits should be directed, or up to where to perform partial composition.
`Inherits`	A proxy class for applying listOp edits to the inherit paths list for a prim.
`InterpolationType`
`ListPosition`
`LoadPolicy`
`ModelAPI`	UsdModelAPI is an API schema that provides an interface to a prim's model qualities, if it does, in fact, represent the root prim of a model.
`Notice`	Container class for Usd notices
`Object`	Base class for Usd scenegraph objects, providing common API.
`Payloads`	UsdPayloads provides an interface to authoring and introspecting payloads.
`Prim`	UsdPrim is the sole persistent scenegraph object on a UsdStage, and is the embodiment of a"Prim"as described in the Universal Scene Description Composition Compendium
`PrimCompositionQuery`	Object for making optionally filtered composition queries about a prim.
`PrimDefinition`	Class representing the builtin definition of a prim given the schemas registered in the schema registry.
`PrimRange`	An forward-iterable range that traverses a subtree of prims rooted at a given prim in depth-first order.
`PrimTypeInfo`	Class that holds the full type information for a prim.
`Property`	Base class for UsdAttribute and UsdRelationship scenegraph objects.
`References`	UsdReferences provides an interface to authoring and introspecting references in Usd.
`Relationship`	A UsdRelationship creates dependencies between scenegraph objects by allowing a prim to target other prims, attributes, or relationships.
`ResolveInfo`	Container for information about the source of an attribute's value, i.e. the'resolved'location of the attribute.
`ResolveInfoSource`
`ResolveTarget`	Defines a subrange of nodes and layers within a prim's prim index to consider when performing value resolution for the prim's attributes.
`SchemaBase`	The base class for all schema types in Usd.
`SchemaKind`
`SchemaRegistry`	Singleton registry that provides access to schema type information and the prim definitions for registered Usd"IsA"and applied API schema types.
`Specializes`	A proxy class for applying listOp edits to the specializes list for a prim.
`Stage`	The outermost container for scene description, which owns and presents composed prims as a scenegraph, following the composition recipe recursively described in its associated"root layer".
`StageCache`	A strongly concurrency safe collection of UsdStageRefPtr s, enabling sharing across multiple clients and threads.
`StageCacheContext`	A context object that lets the UsdStage::Open() API read from or read from and write to a UsdStageCache instance during a scope of execution.
`StageCacheContextBlockType`
`StageLoadRules`	This class represents rules that govern payload inclusion on UsdStages.
`StagePopulationMask`	This class represents a mask that may be applied to a UsdStage to limit the set of UsdPrim s it populates.
`TimeCode`	Represent a time value, which may be either numeric, holding a double value, or a sentinel value UsdTimeCode::Default() .
`Tokens`
`Typed`	The base class for all typed schemas (those that can impart a typeName to a UsdPrim), and therefore the base class for all instantiable and"IsA"schemas.
`UsdCollectionMembershipQuery`	Represents a flattened view of a collection.
`UsdFileFormat`	File format for USD files.
`VariantSet`	A UsdVariantSet represents a single VariantSet in USD (e.g.
`VariantSets`	UsdVariantSets represents the collection of VariantSets that are present on a UsdPrim.
`ZipFile`	Class for reading a zip file.
`ZipFileWriter`	Class for writing a zip file.

class pxr.Usd.APISchemaBase

The base class for all API schemas.

An API schema provides an interface to a prim’s qualities, but does not specify a typeName for the underlying prim. The prim’s qualities include its inheritance structure, attributes, relationships etc. Since it cannot provide a typeName, an API schema is considered to be non-concrete.

To auto-generate an API schema using usdGenSchema, simply leave the typeName empty and make it inherit from”/APISchemaBase”or from another API schema. See UsdModelAPI, UsdClipsAPI and UsdCollectionAPI for examples.

API schemas are classified into applied and non-applied API schemas. The author of an API schema has to decide on the type of API schema at the time of its creation by setting customData[‘apiSchemaType’] in the schema definition (i.e. in the associated primSpec inside the schema.usda file). UsdAPISchemaBase implements methods that are used to record the application of an API schema on a USD prim.

If an API schema only provides an interface to set certain core bits of metadata (like UsdModelAPI, which sets model kind and UsdClipsAPI, which sets clips-related metadata) OR if the API schema can apply to any type of prim or only to a known fixed set of prim types OR if there is no use of recording the application of the API schema, in such cases, it would be better to make it a non-applied API schema. Examples of non-applied API schemas include UsdModelAPI, UsdClipsAPI, UsdShadeConnectableAPI and UsdGeomPrimvarsAPI.

If there is a need to discover (or record) whether a prim contains or subscribes to a given API schema, it would be advantageous to make the API schema be”applied”. In general, API schemas that add one or more properties to a prim should be tagged as applied API schemas. A public Apply() method is generated for applied API schemas by usdGenSchema. An applied API schema must be applied to a prim via a call to the generated Apply() method, for the schema object to evaluate to true when converted to a bool using the explicit bool conversion operator. Examples of applied API schemas include UsdCollectionAPI, UsdGeomModelAPI and UsdGeomMotionAPI

Methods:

GetSchemaAttributeNames

classmethod GetSchemaAttributeNames(includeInherited) -> list[str]

static GetSchemaAttributeNames()

classmethod GetSchemaAttributeNames(includeInherited) -> list[str]

Return a vector of names of all pre-declared attributes for this schema class and all its ancestor classes.

Does not include attributes that may be authored by custom/extended methods of the schemas involved.

Parameters: includeInherited (bool) –

class pxr.Usd.AssetInfoKeys

Attributes:

`identifier`
`name`
`payloadAssetDependencies`
`version`

identifier = 'identifier'

name = 'name'

payloadAssetDependencies = 'payloadAssetDependencies'

version = 'version'

class pxr.Usd.Attribute

Scenegraph object for authoring and retrieving numeric, string, and array valued data, sampled over time.

The allowed value types for UsdAttribute are dictated by the Sdf (“Scene Description Foundations”) core’s data model, which we summarize in Basic Datatypes for Scene Description Provided by Sdf.

Attribute Defining Qualities

In addition to its value type, an Attribute has two other defining qualities:

Variability Expresses whether an attribute is intended to have time samples ( GetVariability() == SdfVariabilityVarying ), or only a default ( GetVariability() == SdfVariabilityUniform ). For more on reasoning about time samples, see Value & Time-Sample Accessors.

Custom Determines whether an attribute belongs to a schema ( IsCustom() == false ), or is a user-defined, custom attribute. schema attributes will always be defined on a prim of the schema type, ans may possess fallback values from the schema, whereas custom attributes must always first be authored in order to be defined. Note that custom is actually an aspect of UsdProperty, as UsdRelationship can also be custom or provided by a schema.

Attribute Creation and Existence

One can always create an attribute generically via UsdPrim::CreateAttribute() , which ensures that an attribute”is defined”in the current UsdEditTarget. In order to author any metadata or a default or timesample for an attribute, it must first be defined. It is sufficient that the attribute be defined in any one of the layers participating in the stage’s current composition; for builtin attributes (those belonging to the owning prim’s defining schema, i.e. the most specific subclass of UsdTypedSchema for which prim.IsA<schema>() will evaluate to true) there need be no authored scene description, because a definition is provided by the prim’s schema definition.

Creating an attribute does not imply that the attribute has a value. More broadly, in the following code:

if (UsdAttribute attr = prim.GetAttribute(TfToken("myAttr"))){
   \.\.\.
}

The UsdAttribute passes the bool test, because it is defined; however, inside the clause, we have no guarantee that attr has a value.

Attribute Value Interpolation

UsdAttribute supports two interpolation behaviors when retrieving attribute values at times where no value is explicitly authored. The desired behavior may be specified via UsdStage::SetInterpolationType. That behavior will be used for all calls to UsdAttribute::Get.

The supported interpolation types are:

Held Attribute values are held constant between authored values. An attribute’s value will be equal to the nearest preceding authored value. If there is no preceding authored value, the value will be equal to the nearest subsequent value.

Linear Attribute values are linearly interpolated between authored values. Linear interpolation is only supported for certain data types. See USD_LINEAR_INTERPOLATION_TYPES for the list of these types. Types that do not support linear interpolation will use held interpolation instead.

Linear interpolation is done element-by-element for array, vector, and matrix data types. If linear interpolation is requested for two array values with different sizes, held interpolation will be used instead.

Attribute Value Blocking

While prims can effectively be removed from a scene by deactivating them, properties cannot. However, it is possible to block an attribute’s value, thus making the attribute behave as if it has a definition (and possibly metadata), but no authored value.

One blocks an attribute using UsdAttribute::Block() , which will block the attribute in the stage’s current UsdEditTarget, by authoring an SdfValueBlock in the attribute’s default, and only values authored in weaker layers than the editTarget will be blocked. If the value block is the strongest authored opinion for the attribute, the HasAuthoredValue() method will return false, and the HasValue() and Get() methods will only return true if the attribute possesses a fallback value from the prim’s schema.”Unblocking”a blocked attribute is as simple as setting a default or timeSample value for the attribute in the same or stronger layer.

The semantics of Value Clips necessitate the ability to selectively block an attribute’s value for only some intervals in its authored range of samples. One can block an attribute’s value at time t by calling attr.Set(SdfValueBlock, t) When an attribute is thusly”partially blocked”, UsdAttribute::Get() will succeed only for those time intervals whose left/earlier bracketing timeSample is not SdfValueBlock.

Due to this time-varying potential of value blocking, it may be the case that an attribute’s HasAuthoredValue() and HasValue() methods both return true (because they do not and cannot consider time- varying blocks), but Get() may yet return false over some intervals.

Attributes of type SdfAssetPath and UsdAttribute::Get()

If an attribute’s value type is SdfAssetPath or SdfAssetPathArray, Get() performs extra work to compute the resolved asset paths, using the layer that has the strongest value opinion as the anchor for”relative”asset paths. Both the unresolved and resolved results are available through SdfAssetPath::GetAssetPath() and SdfAssetPath::GetResolvedPath() , respectively.

Clients that call Get() on many asset-path-valued attributes may wish to employ an ArResolverScopedCache to improve asset path resolution performance.

Methods:

`AddConnection`(source, position)	Adds `source` to the list of connections, in the position specified by `position` .
`Block`()	Remove all time samples on an attribute and author a block `default` value.
`Clear`()	Clears the authored default value and all time samples for this attribute at the current EditTarget and returns true on success.
`ClearAtTime`(time)	Clear the authored value for this attribute at the given time, at the current EditTarget and return true on success.
`ClearColorSpace`()	Clears authored color-space value on the attribute.
`ClearConnections`()	Remove all opinions about the connections list from the current edit target.
`ClearDefault`()	Shorthand for ClearAtTime(UsdTimeCode::Default()).
`Get`(value, time)	Perform value resolution to fetch the value of this attribute at the requested UsdTimeCode `time` , which defaults to default.
`GetBracketingTimeSamples`(desiredTime, lower, ...)	Populate lower and upper with the next greater and lesser value relative to the desiredTime.
`GetColorSpace`()	Gets the color space in which the attribute is authored.
`GetConnections`(sources)	Compose this attribute's connections and fill `sources` with the result.
`GetNumTimeSamples`()	Returns the number of time samples that have been authored.
`GetResolveInfo`(time)	Perform value resolution to determine the source of the resolved value of this attribute at the requested UsdTimeCode `time` .
`GetRoleName`()	Return the roleName for this attribute's typeName.
`GetTimeSamples`(times)	Populates a vector with authored sample times.
`GetTimeSamplesInInterval`(interval, times)	Populates a vector with authored sample times in `interval` .
`GetTypeName`()	Return the"scene description"value type name for this attribute.
`GetUnionedTimeSamples`	classmethod GetUnionedTimeSamples(attrs, times) -> bool
`GetUnionedTimeSamplesInInterval`	classmethod GetUnionedTimeSamplesInInterval(attrs, interval, times) -> bool
`GetVariability`()	An attribute's variability expresses whether it is intended to have time-samples ( `SdfVariabilityVarying` ), or only a single default value ( `SdfVariabilityUniform` ).
`HasAuthoredConnections`()	Return true if this attribute has any authored opinions regarding connections.
`HasAuthoredValue`()	Return true if this attribute has either an authored default value or authored time samples.
`HasAuthoredValueOpinion`()	Deprecated
`HasColorSpace`()	Returns whether color-space is authored on the attribute.
`HasFallbackValue`()	Return true if this attribute has a fallback value provided by a registered schema.
`HasValue`()	Return true if this attribute has an authored default value, authored time samples or a fallback value provided by a registered schema.
`RemoveConnection`(source)	Removes `target` from the list of targets.
`Set`(value, time)	Set the value of this attribute in the current UsdEditTarget to `value` at UsdTimeCode `time` , which defaults to default.
`SetColorSpace`(colorSpace)	Sets the color space of the attribute to `colorSpace` .
`SetConnections`(sources)	Make the authoring layer's opinion of the connection list explicit, and set exactly to `sources` .
`SetTypeName`(typeName)	Set the value for typeName at the current EditTarget, return true on success, false if the value can not be written.
`SetVariability`(variability)	Set the value for variability at the current EditTarget, return true on success, false if the value can not be written.
`ValueMightBeTimeVarying`()	Return true if it is possible, but not certain, that this attribute's value changes over time, false otherwise.

AddConnection(source, position) → bool

Adds source to the list of connections, in the position specified by position .

Issue an error if source identifies a prototype prim or an object descendant to a prototype prim. It is not valid to author connections to these objects.

What data this actually authors depends on what data is currently authored in the authoring layer, with respect to list-editing semantics, which we will document soon

Parameters

source (Path) –
position (ListPosition) –

Block() → None

Remove all time samples on an attribute and author a block default value.

This causes the attribute to resolve as if there were no authored value opinions in weaker layers.

See Attribute Value Blocking for more information, including information on time-varying blocking.

Clear() → bool

Clears the authored default value and all time samples for this attribute at the current EditTarget and returns true on success.

Calling clear when either no value is authored or no spec is present, is a silent no-op returning true.

This method does not affect any other data authored on this attribute.

ClearAtTime(time) → bool

Clear the authored value for this attribute at the given time, at the current EditTarget and return true on success.

UsdTimeCode::Default() can be used to clear the default value.

Calling clear when either no value is authored or no spec is present, is a silent no-op returning true.

Parameters: time (TimeCode) –

ClearColorSpace() → bool

Clears authored color-space value on the attribute.

SetColorSpace()

ClearConnections() → bool: Remove all opinions about the connections list from the current edit target.

ClearDefault() → bool: Shorthand for ClearAtTime(UsdTimeCode::Default()).

Get(value, time) → bool

Perform value resolution to fetch the value of this attribute at the requested UsdTimeCode time , which defaults to default.

If no value is authored at time but values are authored at other times, this function will return an interpolated value based on the stage’s interpolation type. See Attribute Value Interpolation.

This templated accessor is designed for high performance data- streaming applications, allowing one to fetch data into the same container repeatedly, avoiding memory allocations when possible (VtArray containers will be resized as necessary to conform to the size of data being read).

This template is only instantiated for the valid scene description value types and their corresponding VtArray containers. See Basic Datatypes for Scene Description Provided by Sdf for the complete list of types.

Values are retrieved without regard to this attribute’s variability. For example, a uniform attribute may retrieve time sample values if any are authored. However, the USD_VALIDATE_VARIABILITY TF_DEBUG code will cause debug information to be output if values that are inconsistent with this attribute’s variability are retrieved. See UsdAttribute::GetVariability for more details.

true if there was a value to be read, it was of the type T requested, and we read it successfully - false otherwise. For more details, see TimeSamples, Defaults, and Value Resolution, and also Attributes of type SdfAssetPath and UsdAttribute::Get() for information on how to retrieve resolved asset paths from SdfAssetPath-valued attributes.

Parameters

value (T) –
time (TimeCode) –

Get(value, time) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Type-erased access, often not as efficient as typed access.

Parameters

value (VtValue) –
time (TimeCode) –

GetBracketingTimeSamples(desiredTime, lower, upper, hasTimeSamples) → bool

Populate lower and upper with the next greater and lesser value relative to the desiredTime.

Return false if no value exists or an error occurs, true if either a default value or timeSamples exist.

Use standard resolution semantics: if a stronger default value is authored over weaker time samples, the default value hides the underlying timeSamples.

1) If a sample exists at the desiredTime, set both upper and lower to desiredTime.

2) If samples exist surrounding, but not equal to the desiredTime, set lower and upper to the bracketing samples nearest to the desiredTime.

3) If the desiredTime is outside of the range of authored samples, clamp upper and lower to the nearest time sample.

4) If no samples exist, do not modify upper and lower and set hasTimeSamples to false.

In cases (1), (2) and (3), set hasTimeSamples to true.

All four cases above are considered to be successful, thus the return value will be true and no error message will be emitted.

Parameters

desiredTime (float) –
lower (float) –
upper (float) –
hasTimeSamples (bool) –

GetColorSpace() → str

Gets the color space in which the attribute is authored.

SetColorSpace() UsdStage Color Configuration API

GetConnections(sources) → bool

Compose this attribute’s connections and fill sources with the result.

All preexisting elements in sources are lost.

Returns true if any connection path opinions have been authored and no composition errors were encountered, returns false otherwise. Note that authored opinions may include opinions that clear the connections and a return value of true does not necessarily indicate that sources will contain any connection paths.

See Relationship Targets and Attribute Connections for details on behavior when targets point to objects beneath instance prims.

The result is not cached, and thus recomputed on each query.

Parameters: sources (list[Path]) –

GetNumTimeSamples() → int

Returns the number of time samples that have been authored.

This method uses the standard resolution semantics, so if a stronger default value is authored over weaker time samples, the default value will hide the underlying timesamples.

This function will query all value clips that may contribute time samples for this attribute, opening them if needed. This may be expensive, especially if many clips are involved.

GetResolveInfo(time) → ResolveInfo

Perform value resolution to determine the source of the resolved value of this attribute at the requested UsdTimeCode time .

Parameters: time (TimeCode) –

GetResolveInfo() -> ResolveInfo

Perform value resolution to determine the source of the resolved value of this attribute at any non-default time.

Often (i.e. unless the attribute is affected by Value Clips) the source of the resolved value does not vary over time. See UsdAttributeQuery as an example that takes advantage of this quality of value resolution.

GetRoleName() → str: Return the roleName for this attribute’s typeName.

GetTimeSamples(times) → bool

Populates a vector with authored sample times.

Returns false only on error.

This method uses the standard resolution semantics, so if a stronger default value is authored over weaker time samples, the default value will hide the underlying timesamples.

This function will query all value clips that may contribute time samples for this attribute, opening them if needed. This may be expensive, especially if many clips are involved. times

- on return, will contain the sorted, ascending timeSample ordinates. Any data in times will be lost, as this method clears times .

UsdAttribute::GetTimeSamplesInInterval

Parameters: times (list[float]) –

GetTimeSamplesInInterval(interval, times) → bool

Populates a vector with authored sample times in interval .

Returns false only on an error.

This function will only query the value clips that may contribute time samples for this attribute in the given interval, opening them if necessary. interval

- the GfInterval on which to gather time samples. times

- on return, will contain the sorted, ascending timeSample ordinates. Any data in times will be lost, as this method clears times .

UsdAttribute::GetTimeSamples

Parameters

interval (Interval) –
times (list[float]) –

GetTypeName() → ValueTypeName: Return the”scene description”value type name for this attribute.

static GetUnionedTimeSamples()

classmethod GetUnionedTimeSamples(attrs, times) -> bool

Populates the given vector, times with the union of all the authored sample times on all of the given attributes, attrs .

This function will query all value clips that may contribute time samples for the attributes in attrs , opening them if needed. This may be expensive, especially if many clips are involved. The accumulated sample times will be in sorted (increasing) order and will not contain any duplicates.

This clears any existing values in the times vector before accumulating sample times of the given attributes.

false if any of the attributes in attr are invalid or if there’s an error when fetching time-samples for any of the attributes.

UsdAttribute::GetTimeSamples

UsdAttribute::GetUnionedTimeSamplesInInterval

Parameters

attrs (list[Attribute]) –
times (list[float]) –

static GetUnionedTimeSamplesInInterval()

classmethod GetUnionedTimeSamplesInInterval(attrs, interval, times) -> bool

Populates the given vector, times with the union of all the authored sample times in the GfInterval, interval on all of the given attributes, attrs .

This function will only query the value clips that may contribute time samples for the attributes in attrs , in the given interval , opening them if necessary. The accumulated sample times will be in sorted (increasing) order and will not contain any duplicates.

This clears any existing values in the times vector before accumulating sample times of the given attributes.

false if any of the attributes in attr are invalid or if there’s an error fetching time-samples for any of the attributes.

UsdAttribute::GetTimeSamplesInInterval

UsdAttribute::GetUnionedTimeSamples

Parameters

attrs (list[Attribute]) –
interval (Interval) –
times (list[float]) –

GetVariability() → Variability

An attribute’s variability expresses whether it is intended to have time-samples ( SdfVariabilityVarying ), or only a single default value ( SdfVariabilityUniform ).

Variability is required meta-data of all attributes, and its fallback value is SdfVariabilityVarying.

HasAuthoredConnections() → bool

Return true if this attribute has any authored opinions regarding connections.

Note that this includes opinions that remove connections, so a true return does not necessarily indicate that this attribute has connections.

HasAuthoredValue() → bool

Return true if this attribute has either an authored default value or authored time samples.

If the attribute has been blocked, then return false

HasAuthoredValueOpinion() → bool

Deprecated

This method is deprecated because it returns true even when an attribute is blocked. Please use HasAuthoredValue() instead. If you truly need to know whether the attribute has any authored value opinions, including blocks, you can make the following query: attr.GetResolveInfo(). HasAuthoredValueOpinion()

Return true if this attribute has either an authored default value or authored time samples.

HasColorSpace() → bool

Returns whether color-space is authored on the attribute.

GetColorSpace()

HasFallbackValue() → bool: Return true if this attribute has a fallback value provided by a registered schema.

HasValue() → bool

Return true if this attribute has an authored default value, authored time samples or a fallback value provided by a registered schema.

If the attribute has been blocked, then return true if and only if it has a fallback value.

RemoveConnection(source) → bool

Removes target from the list of targets.

Issue an error if source identifies a prototype prim or an object descendant to a prototype prim. It is not valid to author connections to these objects.

Parameters: source (Path) –

Set(value, time) → bool

Set the value of this attribute in the current UsdEditTarget to value at UsdTimeCode time , which defaults to default.

Values are authored without regard to this attribute’s variability. For example, time sample values may be authored on a uniform attribute. However, the USD_VALIDATE_VARIABILITY TF_DEBUG code will cause debug information to be output if values that are inconsistent with this attribute’s variability are authored. See UsdAttribute::GetVariability for more details.

false and generate an error if type T does not match this attribute’s defined scene description type exactly, or if there is no existing definition for the attribute.

Parameters

value (T) –
time (TimeCode) –

Set(value, time) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. As a convenience, we allow the setting of string value typed attributes via a C string value.

Parameters

value (str) –
time (TimeCode) –

Set(value, time) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

value (VtValue) –
time (TimeCode) –

SetColorSpace(colorSpace) → None

Sets the color space of the attribute to colorSpace .

GetColorSpace() UsdStage Color Configuration API

Parameters: colorSpace (str) –

SetConnections(sources) → bool

Make the authoring layer’s opinion of the connection list explicit, and set exactly to sources .

Issue an error if source identifies a prototype prim or an object descendant to a prototype prim. It is not valid to author connections to these objects.

If any path in sources is invalid, issue an error and return false.

Parameters: sources (list[Path]) –

SetTypeName(typeName) → bool

Set the value for typeName at the current EditTarget, return true on success, false if the value can not be written.

Note that this value should not be changed as it is typically either automatically authored or provided by a property definition. This method is provided primarily for fixing invalid scene description.

Parameters: typeName (ValueTypeName) –

SetVariability(variability) → bool

Set the value for variability at the current EditTarget, return true on success, false if the value can not be written.

Note that this value should not be changed as it is typically either automatically authored or provided by a property definition. This method is provided primarily for fixing invalid scene description.

Parameters: variability (Variability) –

ValueMightBeTimeVarying() → bool

Return true if it is possible, but not certain, that this attribute’s value changes over time, false otherwise.

If this function returns false, it is certain that this attribute’s value remains constant over time.

This function is equivalent to checking if GetNumTimeSamples() >1, but may be more efficient since it does not actually need to get a full count of all time samples.

class pxr.Usd.AttributeQuery

Object for efficiently making repeated queries for attribute values.

Retrieving an attribute’s value at a particular time requires determining the source of strongest opinion for that value. Often (i.e. unless the attribute is affected by Value Clips) this source does not vary over time. UsdAttributeQuery uses this fact to speed up repeated value queries by caching the source information for an attribute. It is safe to use a UsdAttributeQuery for any attribute - if the attribute is affected by Value Clips, the performance gain will just be less.

Resolve targets

An attribute query can also be constructed for an attribute along with a UsdResolveTarget. A resolve target allows value resolution to consider only a subrange of the prim stack instead of the entirety of it. All of the methods of an attribute query created with a resolve target will perform value resolution within that resolve target. This can be useful for finding the value of an attribute resolved up to a particular layer or for determining if a value authored on layer would be overridden by a stronger opinion.

Thread safety

This object provides the basic thread-safety guarantee. Multiple threads may call the value accessor functions simultaneously.

Invalidation

This object does not listen for change notification. If a consumer is holding on to a UsdAttributeQuery, it is their responsibility to dispose of it in response to a resync change to the associated attribute. Failing to do so may result in incorrect values or crashes due to dereferencing invalid objects.

Methods:

`CreateQueries`	classmethod CreateQueries(prim, attrNames) -> list[AttributeQuery]
`Get`(value, time)	Perform value resolution to fetch the value of the attribute associated with this query at the requested UsdTimeCode `time` .
`GetAttribute`()	Return the attribute associated with this query.
`GetBracketingTimeSamples`(desiredTime, lower, ...)	Populate lower and upper with the next greater and lesser value relative to the desiredTime.
`GetNumTimeSamples`()	Returns the number of time samples that have been authored.
`GetTimeSamples`(times)	Populates a vector with authored sample times.
`GetTimeSamplesInInterval`(interval, times)	Populates a vector with authored sample times in `interval` .
`GetUnionedTimeSamples`	classmethod GetUnionedTimeSamples(attrQueries, times) -> bool
`GetUnionedTimeSamplesInInterval`	classmethod GetUnionedTimeSamplesInInterval(attrQueries, interval, times) -> bool
`HasAuthoredValue`()	Return true if this attribute has either an authored default value or authored time samples.
`HasAuthoredValueOpinion`()	Deprecated
`HasFallbackValue`()	Return true if the attribute associated with this query has a fallback value provided by a registered schema.
`HasValue`()	Return true if the attribute associated with this query has an authored default value, authored time samples or a fallback value provided by a registered schema.
`IsValid`()	Return true if this query is valid (i.e.
`ValueMightBeTimeVarying`()	Return true if it is possible, but not certain, that this attribute's value changes over time, false otherwise.

static CreateQueries()

classmethod CreateQueries(prim, attrNames) -> list[AttributeQuery]

Construct new queries for the attributes named in attrNames under the prim prim .

The objects in the returned vector will line up 1-to-1 with attrNames .

Parameters

prim (Prim) –
attrNames (list[str]) –

Get(value, time) → bool

Perform value resolution to fetch the value of the attribute associated with this query at the requested UsdTimeCode time .

UsdAttribute::Get

Parameters

value (T) –
time (TimeCode) –

Get(value, time) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Type-erased access, often not as efficient as typed access.

Parameters

value (VtValue) –
time (TimeCode) –

GetAttribute() → Attribute: Return the attribute associated with this query.

GetBracketingTimeSamples(desiredTime, lower, upper, hasTimeSamples) → bool

Populate lower and upper with the next greater and lesser value relative to the desiredTime.

UsdAttribute::GetBracketingTimeSamples

Parameters

desiredTime (float) –
lower (float) –
upper (float) –
hasTimeSamples (bool) –

GetNumTimeSamples() → int

Returns the number of time samples that have been authored.

UsdAttribute::GetNumTimeSamples

GetTimeSamples(times) → bool

Populates a vector with authored sample times.

Returns false only on error. Behaves identically to UsdAttribute::GetTimeSamples()

UsdAttributeQuery::GetTimeSamplesInInterval

Parameters: times (list[float]) –

GetTimeSamplesInInterval(interval, times) → bool

Populates a vector with authored sample times in interval .

Returns false only on an error.

Behaves identically to UsdAttribute::GetTimeSamplesInInterval()

Parameters

interval (Interval) –
times (list[float]) –

static GetUnionedTimeSamples()

classmethod GetUnionedTimeSamples(attrQueries, times) -> bool

Populates the given vector, times with the union of all the authored sample times on all of the given attribute-query objects, attrQueries .

Behaves identically to UsdAttribute::GetUnionedTimeSamples()

false if one or more attribute-queries in attrQueries are invalid or if there’s an error fetching time-samples for any of the attribute- query objects.

UsdAttribute::GetUnionedTimeSamples

UsdAttributeQuery::GetUnionedTimeSamplesInInterval

Parameters

attrQueries (list[AttributeQuery]) –
times (list[float]) –

static GetUnionedTimeSamplesInInterval()

classmethod GetUnionedTimeSamplesInInterval(attrQueries, interval, times) -> bool

Populates the given vector, times with the union of all the authored sample times in the GfInterval, interval on all of the given attribute-query objects, attrQueries .

Behaves identically to UsdAttribute::GetUnionedTimeSamplesInInterval()

false if one or more attribute-queries in attrQueries are invalid or if there’s an error fetching time-samples for any of the attribute- query objects.

UsdAttribute::GetUnionedTimeSamplesInInterval

Parameters

attrQueries (list[AttributeQuery]) –
interval (Interval) –
times (list[float]) –

HasAuthoredValue() → bool

Return true if this attribute has either an authored default value or authored time samples.

If the attribute has been blocked, then return false

UsdAttribute::HasAuthoredValue()

HasAuthoredValueOpinion() → bool

Deprecated

This method is deprecated because it returns true even when an attribute is blocked. Please use HasAuthoredValue() instead. If you truly need to know whether the attribute has any authored value opinions, including blocks, you can make the following query: query.GetAttribute().GetResolveInfo(). HasAuthoredValueOpinion()

Return true if this attribute has either an authored default value or authored time samples.

HasFallbackValue() → bool

Return true if the attribute associated with this query has a fallback value provided by a registered schema.

UsdAttribute::HasFallbackValue

HasValue() → bool

Return true if the attribute associated with this query has an authored default value, authored time samples or a fallback value provided by a registered schema.

UsdAttribute::HasValue

IsValid() → bool

Return true if this query is valid (i.e.

it is associated with a valid attribute), false otherwise.

ValueMightBeTimeVarying() → bool

Return true if it is possible, but not certain, that this attribute’s value changes over time, false otherwise.

UsdAttribute::ValueMightBeTimeVarying

class pxr.Usd.ClipsAPI

UsdClipsAPI is an API schema that provides an interface to a prim’s clip metadata. Clips are a”value resolution”feature that allows one to specify a sequence of usd files (clips) to be consulted, over time, as a source of varying overrides for the prims at and beneath this prim in namespace.

SetClipAssetPaths() establishes the set of clips that can be consulted. SetClipActive() specifies the ordering of clip application over time (clips can be repeated), while SetClipTimes() specifies time-mapping from stage-time to clip-time for the clip active at a given stage-time, which allows for time-dilation and repetition of clips. Finally, SetClipPrimPath() determines the path within each clip that will map to this prim, i.e. the location within the clip at which we will look for opinions for this prim.

The clip asset paths, times and active metadata can also be specified through template clip metadata. This can be desirable when your set of assets is very large, as the template metadata is much more concise. SetClipTemplateAssetPath() establishes the asset identifier pattern of the set of clips to be consulted. SetClipTemplateStride() , SetClipTemplateEndTime() , and SetClipTemplateStartTime() specify the range in which USD will search, based on the template. From the set of resolved asset paths, times and active will be derived internally.

A prim may have multiple”clip sets” named sets of clips that each have their own values for the metadata described above. For example, a prim might have a clip set named”Clips_1”that specifies some group of clip asset paths, and another clip set named”Clips_2”that uses an entirely different set of clip asset paths. These clip sets are composed across composition arcs, so clip sets for a prim may be defined in multiple sublayers or references, for example. Individual metadata for a given clip set may be sparsely overridden.

Important facts about clips:

Within the layerstack in which clips are established, the opinions within the clips will be weaker than any local opinions in the layerstack, but em stronger than varying opinions coming across references and variants.

We will never look for metadata or default opinions in clips when performing value resolution on the owning stage, since these quantities must be time-invariant. This leads to the common structure in which we reference a model asset on a prim, and then author clips at the same site: the asset reference will provide the topology and unvarying data for the model, while the clips will provide the time-sampled animation.

For further information, see Sequencable, Re-timable Animated”Value Clips”

Methods:

`ComputeClipAssetPaths`(clipSet)	Computes and resolves the list of clip asset paths used by the clip set named `clipSet` .
`GenerateClipManifest`(clipSet, ...)	Create a clip manifest containing entries for all attributes in the value clips for clip set `clipSet` .
`GenerateClipManifestFromLayers`	classmethod GenerateClipManifestFromLayers(clipLayers, clipPrimPath) -> Layer
`Get`	classmethod Get(stage, path) -> ClipsAPI
`GetClipActive`(activeClips, clipSet)	List of pairs (time, clip index) indicating the time on the stage at which the clip in the clip set named `clipSet` specified by the clip index is active.
`GetClipAssetPaths`(assetPaths, clipSet)	List of asset paths to the clips in the clip set named `clipSet` .
`GetClipManifestAssetPath`(manifestAssetPath, ...)	Asset path for the clip manifest for the clip set named `clipSet` .
`GetClipPrimPath`(primPath, clipSet)	Path to the prim in the clips in the clip set named `clipSet` from which time samples will be read.
`GetClipSets`(clipSets)	ListOp that may be used to affect how opinions from clip sets are applied during value resolution.
`GetClipTemplateActiveOffset`(...)	A double representing the offset value used by USD when determining the active period for each clip.
`GetClipTemplateAssetPath`(...)	A template string representing a set of assets to be used as clips for the clip set named `clipSet` .
`GetClipTemplateEndTime`(clipTemplateEndTime, ...)	A double which indicates the end of the range USD will use to to search for asset paths for the clip set named `clipSet` .
`GetClipTemplateStartTime`(...)	A double which indicates the start of the range USD will use to search for asset paths for the clip set named `clipSet` .
`GetClipTemplateStride`(clipTemplateStride, ...)	A double representing the increment value USD will use when searching for asset paths for the clip set named `clipSet` .
`GetClipTimes`(clipTimes, clipSet)	List of pairs (stage time, clip time) indicating the time in the active clip in the clip set named `clipSet` that should be consulted for values at the corresponding stage time.
`GetClips`(clips)	Dictionary that contains the definition of the clip sets on this prim.
`GetInterpolateMissingClipValues`(interpolate, ...)	param interpolate
`GetSchemaAttributeNames`	classmethod GetSchemaAttributeNames(includeInherited) -> list[str]
`SetClipActive`(activeClips, clipSet)	Set the active clip metadata for the clip set named `clipSet` .
`SetClipAssetPaths`(assetPaths, clipSet)	Set the clip asset paths for the clip set named `clipSet` .
`SetClipManifestAssetPath`(manifestAssetPath, ...)	Set the clip manifest asset path for this prim.
`SetClipPrimPath`(primPath, clipSet)	Set the clip prim path for the clip set named `clipSet` .
`SetClipSets`(clipSets)	Set the clip sets list op for this prim.
`SetClipTemplateActiveOffset`(...)	Set the clip template offset for the clip set named `clipSet` .
`SetClipTemplateAssetPath`(...)	Set the clip template asset path for the clip set named `clipSet` .
`SetClipTemplateEndTime`(clipTemplateEndTime, ...)	Set the template end time for the clipset named `clipSet` .
`SetClipTemplateStartTime`(...)	Set the template start time for the clip set named `clipSet` .
`SetClipTemplateStride`(clipTemplateStride, ...)	Set the template stride for the clip set named `clipSet` .
`SetClipTimes`(clipTimes, clipSet)	Set the clip times metadata for this prim.
`SetClips`(clips)	Set the clips dictionary for this prim.
`SetInterpolateMissingClipValues`(interpolate, ...)	Set whether missing clip values are interpolated from surrounding clips.

ComputeClipAssetPaths(clipSet) → VtArray[AssetPath]

Computes and resolves the list of clip asset paths used by the clip set named clipSet .

This is the same list of paths that would be used during value resolution.

If the clip set is defined using template clip metadata, this function will compute the asset paths based on the template parameters. Otherwise this function will use the authored clipAssetPaths.

Parameters: clipSet (str) –

ComputeClipAssetPaths() -> VtArray[AssetPath]

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

GenerateClipManifest(clipSet, writeBlocksForClipsWithMissingValues) → Layer

Create a clip manifest containing entries for all attributes in the value clips for clip set clipSet .

This returns an anonymous layer that can be exported and reused (

SetClipManifestAssetPath). If writeBlocksForClipsWithMissingValues is true , the generated manifest will have value blocks authored for each attribute at the activation times of clips that do not contain time samples for that attribute. This accelerates searches done when the interpolation of missing clip values is enabled. See GetInterpolateMissingClipValues and Interpolating Missing Values in Clip Set for more details.

Returns an invalid SdfLayerRefPtr on failure.

Parameters

clipSet (str) –
writeBlocksForClipsWithMissingValues (bool) –

GenerateClipManifest(writeBlocksForClipsWithMissingValues) -> Layer

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: writeBlocksForClipsWithMissingValues (bool) –

static GenerateClipManifestFromLayers()

classmethod GenerateClipManifestFromLayers(clipLayers, clipPrimPath) -> Layer

Create a clip manifest containing entries for all attributes in the given clipLayers that belong to the prim at clipPrimPath and all descendants.

This returns an anonymous layer that can be exported and reused (

SetClipManifestAssetPath). Returns an invalid SdfLayerRefPtr on failure.

Parameters

clipLayers (list[Layer]) –
clipPrimPath (Path) –

static Get()

classmethod Get(stage, path) -> ClipsAPI

Return a UsdClipsAPI holding the prim adhering to this schema at path on stage .

If no prim exists at path on stage , or if the prim at that path does not adhere to this schema, return an invalid schema object. This is shorthand for the following:

UsdClipsAPI(stage->GetPrimAtPath(path));

Parameters

stage (Stage) –
path (Path) –

GetClipActive(activeClips, clipSet) → bool

List of pairs (time, clip index) indicating the time on the stage at which the clip in the clip set named clipSet specified by the clip index is active.

For instance, a value of [(0.0, 0), (20.0, 1)] indicates that clip 0 is active at time 0 and clip 1 is active at time 20.

Parameters

activeClips (Vec2dArray) –
clipSet (str) –

GetClipActive(activeClips) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: activeClips (Vec2dArray) –

GetClipAssetPaths(assetPaths, clipSet) → bool

List of asset paths to the clips in the clip set named clipSet .

This list is unordered, but elements in this list are referred to by index in other clip-related fields.

Parameters

assetPaths (VtArray[AssetPath]) –
clipSet (str) –

GetClipAssetPaths(assetPaths) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: assetPaths (VtArray[AssetPath]) –

GetClipManifestAssetPath(manifestAssetPath, clipSet) → bool

Asset path for the clip manifest for the clip set named clipSet .

The clip manifest indicates which attributes have time samples authored in the clips specified on this prim. During value resolution, clips will only be examined if the attribute exists and is declared as varying in the manifest. See Clip Manifest for more details.

For instance, if this prim’s path is</Prim_1>, the clip prim path is</Prim>, and we want values for the attribute</Prim_1.size>, we will only look within this prim’s clips if the attribute</Prim.size>exists and is varying in the manifest.

Parameters

manifestAssetPath (AssetPath) –
clipSet (str) –

GetClipManifestAssetPath(manifestAssetPath) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: manifestAssetPath (AssetPath) –

GetClipPrimPath(primPath, clipSet) → bool

Path to the prim in the clips in the clip set named clipSet from which time samples will be read.

This prim’s path will be substituted with this value to determine the final path in the clip from which to read data. For instance, if this prims’path is’/Prim_1’, the clip prim path is’/Prim’, and we want to get values for the attribute’/Prim_1.size’. The clip prim path will be substituted in, yielding’/Prim.size’, and each clip will be examined for values at that path.

Parameters

primPath (str) –
clipSet (str) –

GetClipPrimPath(primPath) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: primPath (str) –

GetClipSets(clipSets) → bool

ListOp that may be used to affect how opinions from clip sets are applied during value resolution.

By default, clip sets in a layer stack are examined in lexicographical order by name for attribute values during value resolution. The clip sets listOp can be used to reorder the clip sets in a layer stack or remove them entirely from consideration during value resolution without modifying the clips dictionary.

This is not the list of clip sets that are authored on this prim. To retrieve that information, use GetClips to examine the clips dictionary directly.

This function returns the clip sets listOp from the current edit target.

Parameters: clipSets (StringListOp) –

GetClipTemplateActiveOffset(clipTemplateActiveOffset, clipSet) → bool

A double representing the offset value used by USD when determining the active period for each clip.

Parameters

clipTemplateActiveOffset (float) –
clipSet (str) –

GetClipTemplateActiveOffset(clipTemplateActiveOffset) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: clipTemplateActiveOffset (float) –

GetClipTemplateAssetPath(clipTemplateAssetPath, clipSet) → bool

A template string representing a set of assets to be used as clips for the clip set named clipSet .

This string can be of two forms:

integer frames: path/basename.###.usd

subinteger frames: path/basename.##.##.usd.

For the integer portion of the specification, USD will take a particular time, determined by the template start time, stride, and end time, and pad it with zeros up to the number of hashes provided so long as the number of hashes is greater than the digits required to specify the integer value.

For instance:

time = 12, template asset path = foo.##.usd =>foo.12.usd time = 12, template asset path = foo.###.usd =>foo.012.usd time = 333, template asset path = foo.#.usd =>foo.333.usd

In the case of subinteger portion of a specifications, USD requires the specification to be exact.

For instance:

time = 1.15, template asset path = foo.#.###.usd =>foo.1.150.usd time = 1.145, template asset path = foo.#.##.usd =>foo.1.15.usd time = 1.1, template asset path = foo.#.##.usd =>foo.1.10.usd

Note that USD requires that hash groups be adjacent in the string, and that there only be one or two such groups.

Parameters

clipTemplateAssetPath (str) –
clipSet (str) –

GetClipTemplateAssetPath(clipTemplateAssetPath) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: clipTemplateAssetPath (str) –

GetClipTemplateEndTime(clipTemplateEndTime, clipSet) → bool

A double which indicates the end of the range USD will use to to search for asset paths for the clip set named clipSet .

This value is inclusive in that range.

GetClipTemplateAssetPath.

Parameters

clipTemplateEndTime (float) –
clipSet (str) –

GetClipTemplateEndTime(clipTemplateEndTime) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: clipTemplateEndTime (float) –

GetClipTemplateStartTime(clipTemplateStartTime, clipSet) → bool

A double which indicates the start of the range USD will use to search for asset paths for the clip set named clipSet .

This value is inclusive in that range.

GetClipTemplateAssetPath.

Parameters

clipTemplateStartTime (float) –
clipSet (str) –

GetClipTemplateStartTime(clipTemplateStartTime) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: clipTemplateStartTime (float) –

GetClipTemplateStride(clipTemplateStride, clipSet) → bool

A double representing the increment value USD will use when searching for asset paths for the clip set named clipSet .

GetClipTemplateAssetPath.

Parameters

clipTemplateStride (float) –
clipSet (str) –

GetClipTemplateStride(clipTemplateStride) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: clipTemplateStride (float) –

GetClipTimes(clipTimes, clipSet) → bool

List of pairs (stage time, clip time) indicating the time in the active clip in the clip set named clipSet that should be consulted for values at the corresponding stage time.

During value resolution, this list will be sorted by stage time; times will then be linearly interpolated between consecutive entries. For instance, for clip times [(0.0, 0.0), (10.0, 20.0)], at stage time 0, values from the active clip at time 0 will be used, at stage time 5, values from the active clip at time 10, and at stage time 10, clip values at time 20.

Parameters

clipTimes (Vec2dArray) –
clipSet (str) –

GetClipTimes(clipTimes) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: clipTimes (Vec2dArray) –

GetClips(clips) → bool

Dictionary that contains the definition of the clip sets on this prim.

Each entry in this dictionary defines a clip set: the entry’s key is the name of the clip set and the entry’s value is a dictionary containing the metadata that specifies the clips in the set.

See UsdClipsAPIInfoKeys for the keys used for each clip set’s dictionary, or use the other API to set or get values for a given clip set.

Parameters: clips (VtDictionary) –

GetInterpolateMissingClipValues(interpolate, clipSet) → bool

Parameters

interpolate (bool) –
clipSet (str) –

GetInterpolateMissingClipValues(interpolate) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

Parameters: interpolate (bool) –

static GetSchemaAttributeNames()

classmethod GetSchemaAttributeNames(includeInherited) -> list[str]

Return a vector of names of all pre-declared attributes for this schema class and all its ancestor classes.

Does not include attributes that may be authored by custom/extended methods of the schemas involved.

Parameters: includeInherited (bool) –

SetClipActive(activeClips, clipSet) → bool

Set the active clip metadata for the clip set named clipSet .

GetClipActive()

Parameters

activeClips (Vec2dArray) –
clipSet (str) –

SetClipActive(activeClips) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: activeClips (Vec2dArray) –

SetClipAssetPaths(assetPaths, clipSet) → bool

Set the clip asset paths for the clip set named clipSet .

GetClipAssetPaths()

Parameters

assetPaths (VtArray[AssetPath]) –
clipSet (str) –

SetClipAssetPaths(assetPaths) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: assetPaths (VtArray[AssetPath]) –

SetClipManifestAssetPath(manifestAssetPath, clipSet) → bool

Set the clip manifest asset path for this prim.

GetClipManifestAssetPath()

Parameters

manifestAssetPath (AssetPath) –
clipSet (str) –

SetClipManifestAssetPath(manifestAssetPath) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: manifestAssetPath (AssetPath) –

SetClipPrimPath(primPath, clipSet) → bool

Set the clip prim path for the clip set named clipSet .

GetClipPrimPath()

Parameters

primPath (str) –
clipSet (str) –

SetClipPrimPath(primPath) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: primPath (str) –

SetClipSets(clipSets) → bool

Set the clip sets list op for this prim.

GetClipSets

Parameters: clipSets (StringListOp) –

SetClipTemplateActiveOffset(clipTemplateActiveOffset, clipSet) → bool

Set the clip template offset for the clip set named clipSet .

GetClipTemplateActiveOffset

Parameters

clipTemplateActiveOffset (float) –
clipSet (str) –

SetClipTemplateActiveOffset(clipTemplateActiveOffset) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: clipTemplateActiveOffset (float) –

SetClipTemplateAssetPath(clipTemplateAssetPath, clipSet) → bool

Set the clip template asset path for the clip set named clipSet .

GetClipTemplateAssetPath

Parameters

clipTemplateAssetPath (str) –
clipSet (str) –

SetClipTemplateAssetPath(clipTemplateAssetPath) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: clipTemplateAssetPath (str) –

SetClipTemplateEndTime(clipTemplateEndTime, clipSet) → bool

Set the template end time for the clipset named clipSet .

GetClipTemplateEndTime()

Parameters

clipTemplateEndTime (float) –
clipSet (str) –

SetClipTemplateEndTime(clipTemplateEndTime) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: clipTemplateEndTime (float) –

SetClipTemplateStartTime(clipTemplateStartTime, clipSet) → bool

Set the template start time for the clip set named clipSet .

GetClipTemplateStartTime

Parameters

clipTemplateStartTime (float) –
clipSet (str) –

SetClipTemplateStartTime(clipTemplateStartTime) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: clipTemplateStartTime (float) –

SetClipTemplateStride(clipTemplateStride, clipSet) → bool

Set the template stride for the clip set named clipSet .

GetClipTemplateStride()

Parameters

clipTemplateStride (float) –
clipSet (str) –

SetClipTemplateStride(clipTemplateStride) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: clipTemplateStride (float) –

SetClipTimes(clipTimes, clipSet) → bool

Set the clip times metadata for this prim.

GetClipTimes()

Parameters

clipTimes (Vec2dArray) –
clipSet (str) –

SetClipTimes(clipTimes) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

UsdClipsAPISetNames

Parameters: clipTimes (Vec2dArray) –

SetClips(clips) → bool

Set the clips dictionary for this prim.

GetClips

Parameters: clips (VtDictionary) –

SetInterpolateMissingClipValues(interpolate, clipSet) → bool

Set whether missing clip values are interpolated from surrounding clips.

Parameters

interpolate (bool) –
clipSet (str) –

SetInterpolateMissingClipValues(interpolate) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This function operates on the default clip set.

Parameters: interpolate (bool) –

class pxr.Usd.CollectionAPI

This is a general purpose API schema, used to describe a collection of heterogeneous objects within the scene.”Objects”here may be prims or properties belonging to prims or other collections. It’s an add-on schema that can be applied many times to a prim with different collection names.

A collection allows an enumeration of a set of paths to include and a set of paths to exclude. Whether the descendants of an included path are members of a collection are decided by its expansion rule (see below). If the collection excludes paths that are not descendents of included paths, the collection implicitly includes the root path</>. If such a collection also includes paths that are not descendants of the excluded paths, it is considered invalid, since the intention is ambiguous.

All the properties authored by the schema are namespaced under”collection:”. The given name of the collection provides additional namespacing for the various per-collection properties, which include the following:

uniform token collection: *collectionName* :expansionRule - specified how the paths that are included in the collection must be expanded to determine its members. Possible values include:

explicitOnly - only paths in the includes rel targets and not in the excludes rel targets belong to the collection.

expandPrims - all the prims at or below the includes rel- targets (and not under the excludes rel-targets) belong to the collection. Any property paths included in the collection would, of course, also be honored. This is the default behavior as it satisfies most use cases.

expandPrimsAndProperties - like expandPrims, but also includes all properties on all matched prims. We’re still not quite sure what the use cases are for this, but you can use it to capture a whole lot of UsdObjects very concisely.

bool collection: *collectionName* :includeRoot - boolean attribute indicating whether the pseudo-root path</>should be counted as one of the included target paths. The fallback is false. This separate attribute is required because relationships cannot directly target the root.

rel collection: *collectionName* :includes - specifies a list of targets that are included in the collection. This can target prims or properties directly. A collection can insert the rules of another collection by making its includes relationship target the collection:{collectionName} property on the owning prim of the collection to be included. Such a property may not (and typically does not) exist on the UsdStage, but it is the path that is used to refer to the collection. It is important to note that including another collection does not guarantee the contents of that collection will be in the final collection; instead, the rules are merged. This means, for example, an exclude entry may exclude a portion of the included collection. When a collection includes one or more collections, the order in which targets are added to the includes relationship may become significant, if there are conflicting opinions about the same path. Targets that are added later are considered to be stronger than earlier targets for the same path.

rel collection: *collectionName* :excludes - specifies a list of targets that are excluded below the included paths in this collection. This can target prims or properties directly, but cannot target another collection. This is to keep the membership determining logic simple, efficient and easier to reason about. Finally, it is invalid for a collection to exclude paths that are not included in it. The presence of such”orphaned”excluded paths will not affect the set of paths included in the collection, but may affect the performance of querying membership of a path in the collection (see UsdCollectionAPI::MembershipQuery::IsPathIncluded) or of enumerating the objects belonging to the collection (see UsdCollectionAPI::GetIncludedObjects).

Implicit inclusion

In some scenarios it is useful to express a collection that includes everything except certain paths. To support this, a collection that has an exclude that is not a descendent of any include will include the root path</>.

Creating collections in C++

For any described attribute Fallback Value or Allowed Values below that are text/tokens, the actual token is published and defined in UsdTokens. So to set an attribute to the value”rightHanded”, use UsdTokens->rightHanded as the value.

Methods:

`Apply`	classmethod Apply(prim, name) -> CollectionAPI
`BlockCollection`()	Blocks the targets of the includes and excludes relationships of the collection, making it<* empty if"includeRoot"is false (or unset) or.
`CanApply`	classmethod CanApply(prim, name, whyNot) -> bool
`CanContainPropertyName`	classmethod CanContainPropertyName(name) -> bool
`ComputeIncludedObjects`	classmethod ComputeIncludedObjects(query, stage, pred) -> set[Object]
`ComputeIncludedPaths`	classmethod ComputeIncludedPaths(query, stage, pred) -> SdfPathSet
`ComputeMembershipQuery`()	Computes and returns a UsdCollectionMembershipQuery object which can be used to query inclusion or exclusion of paths in the collection.
`CreateExcludesRel`()	See GetExcludesRel() , and also Create vs Get Property Methods for when to use Get vs Create.
`CreateExpansionRuleAttr`(defaultValue, ...)	See GetExpansionRuleAttr() , and also Create vs Get Property Methods for when to use Get vs Create.
`CreateIncludeRootAttr`(defaultValue, ...)	See GetIncludeRootAttr() , and also Create vs Get Property Methods for when to use Get vs Create.
`CreateIncludesRel`()	See GetIncludesRel() , and also Create vs Get Property Methods for when to use Get vs Create.
`ExcludePath`(pathToExclude)	Excludes or removes the given path, `pathToExclude` from the collection.
`Get`	classmethod Get(stage, path) -> CollectionAPI
`GetAll`	classmethod GetAll(prim) -> list[CollectionAPI]
`GetAllCollections`	classmethod GetAllCollections(prim) -> list[CollectionAPI]
`GetCollection`	classmethod GetCollection(stage, collectionPath) -> CollectionAPI
`GetCollectionPath`()	Returns the canonical path that represents this collection.
`GetExcludesRel`()	Specifies a list of targets that are excluded below the included paths in this collection.
`GetExpansionRuleAttr`()	Specifies how the paths that are included in the collection must be expanded to determine its members.
`GetIncludeRootAttr`()	Boolean attribute indicating whether the pseudo-root path</>should be counted as one of the included target paths.
`GetIncludesRel`()	Specifies a list of targets that are included in the collection.
`GetName`()	Returns the name of this multiple-apply schema instance.
`GetNamedCollectionPath`	classmethod GetNamedCollectionPath(prim, collectionName) -> Path
`GetSchemaAttributeNames`	classmethod GetSchemaAttributeNames(includeInherited) -> list[str]
`HasNoIncludedPaths`()	Returns true if the collection has nothing included in it.
`IncludePath`(pathToInclude)	Includes or adds the given path, `pathToInclude` in the collection.
`IsCollectionAPIPath`	classmethod IsCollectionAPIPath(path, name) -> bool
`IsSchemaPropertyBaseName`	classmethod IsSchemaPropertyBaseName(baseName) -> bool
`ResetCollection`()	Resets the collection by clearing both the includes and excludes targets of the collection in the current UsdEditTarget.
`Validate`(reason)	Validates the collection by checking the following rules:

static Apply()

classmethod Apply(prim, name) -> CollectionAPI

Applies this multiple-apply API schema to the given prim along with the given instance name, name .

This information is stored by adding”CollectionAPI:<i>name</i>”to the token-valued, listOp metadata apiSchemas on the prim. For example, if name is’instance1’, the token’CollectionAPI:instance1’is added to’apiSchemas’.

A valid UsdCollectionAPI object is returned upon success. An invalid (or empty) UsdCollectionAPI object is returned upon failure. See UsdPrim::ApplyAPI() for conditions resulting in failure.

UsdPrim::GetAppliedSchemas()

UsdPrim::HasAPI()

UsdPrim::CanApplyAPI()

UsdPrim::ApplyAPI()

UsdPrim::RemoveAPI()

Parameters

prim (Prim) –
name (str) –

BlockCollection() → bool

Blocks the targets of the includes and excludes relationships of the collection, making it<* empty if”includeRoot”is false (or unset) or.

include everything if”includeRoot”is true. (assuming there are no opinions in stronger edit targets).

static CanApply()

classmethod CanApply(prim, name, whyNot) -> bool

Returns true if this multiple-apply API schema can be applied, with the given instance name, name , to the given prim .

If this schema can not be a applied the prim, this returns false and, if provided, populates whyNot with the reason it can not be applied.

Note that if CanApply returns false, that does not necessarily imply that calling Apply will fail. Callers are expected to call CanApply before calling Apply if they want to ensure that it is valid to apply a schema.

UsdPrim::GetAppliedSchemas()

UsdPrim::HasAPI()

UsdPrim::CanApplyAPI()

UsdPrim::ApplyAPI()

UsdPrim::RemoveAPI()

Parameters

prim (Prim) –
name (str) –
whyNot (str) –

static CanContainPropertyName()

classmethod CanContainPropertyName(name) -> bool

Test whether a given name contains the”collection:”prefix.

Parameters: name (str) –

static ComputeIncludedObjects()

classmethod ComputeIncludedObjects(query, stage, pred) -> set[Object]

Returns all the usd objects that satisfy the predicate, pred in the collection represented by the UsdCollectionMembershipQuery object, query .

The results depends on the load state of the UsdStage, stage .

Parameters

query (UsdCollectionMembershipQuery) –
stage (UsdStageWeak) –
pred (_PrimFlagsPredicate) –

static ComputeIncludedPaths()

classmethod ComputeIncludedPaths(query, stage, pred) -> SdfPathSet

Returns all the paths that satisfy the predicate, pred in the collection represented by the UsdCollectionMembershipQuery object, query .

The result depends on the load state of the UsdStage, stage .

Parameters

query (UsdCollectionMembershipQuery) –
stage (UsdStageWeak) –
pred (_PrimFlagsPredicate) –

ComputeMembershipQuery() → UsdCollectionMembershipQuery

Computes and returns a UsdCollectionMembershipQuery object which can be used to query inclusion or exclusion of paths in the collection.

ComputeMembershipQuery(query) -> None

Populates the UsdCollectionMembershipQuery object with data from this collection, so it can be used to query inclusion or exclusion of paths.

Parameters: query (UsdCollectionMembershipQuery) –

CreateExcludesRel() → Relationship: See GetExcludesRel() , and also Create vs Get Property Methods for when to use Get vs Create.

CreateExpansionRuleAttr(defaultValue, writeSparsely) → Attribute

See GetExpansionRuleAttr() , and also Create vs Get Property Methods for when to use Get vs Create.

If specified, author defaultValue as the attribute’s default, sparsely (when it makes sense to do so) if writeSparsely is true - the default for writeSparsely is false .

Parameters

defaultValue (VtValue) –
writeSparsely (bool) –

CreateIncludeRootAttr(defaultValue, writeSparsely) → Attribute

See GetIncludeRootAttr() , and also Create vs Get Property Methods for when to use Get vs Create.

If specified, author defaultValue as the attribute’s default, sparsely (when it makes sense to do so) if writeSparsely is true - the default for writeSparsely is false .

Parameters

defaultValue (VtValue) –
writeSparsely (bool) –

CreateIncludesRel() → Relationship: See GetIncludesRel() , and also Create vs Get Property Methods for when to use Get vs Create.

ExcludePath(pathToExclude) → bool

Excludes or removes the given path, pathToExclude from the collection.

If the collection is empty, the collection becomes one that includes all paths except the givne path. Otherwise, this does nothing if the path is not included in the collection.

This does not modify the expansion-rule of the collection. Hence, if the expansionRule is expandPrims or expandPrimsAndProperties, then the descendants of pathToExclude will also be excluded from the collection, unless explicitly included.

UsdCollectionAPI::IncludePath()

Parameters: pathToExclude (Path) –

static Get()

classmethod Get(stage, path) -> CollectionAPI

Return a UsdCollectionAPI holding the prim adhering to this schema at path on stage .

If no prim exists at path on stage , or if the prim at that path does not adhere to this schema, return an invalid schema object. path must be of the format<path>.collection:name.

This is shorthand for the following:

TfToken name = SdfPath::StripNamespace(path.GetToken());
UsdCollectionAPI(
    stage->GetPrimAtPath(path.GetPrimPath()), name);

Parameters

stage (Stage) –
path (Path) –

Get(prim, name) -> CollectionAPI

Return a UsdCollectionAPI with name name holding the prim prim .

Shorthand for UsdCollectionAPI(prim, name);

Parameters

prim (Prim) –
name (str) –

static GetAll()

classmethod GetAll(prim) -> list[CollectionAPI]

Return a vector of all named instances of UsdCollectionAPI on the given prim .

Parameters: prim (Prim) –

static GetAllCollections()

classmethod GetAllCollections(prim) -> list[CollectionAPI]

Returns all the named collections on the given USD prim.

Deprecated

Use GetAll(prim) instead.

Parameters: prim (Prim) –

static GetCollection()

classmethod GetCollection(stage, collectionPath) -> CollectionAPI

Returns the collection represented by the given collection path, collectionPath on the given USD stage.

Parameters

stage (Stage) –
collectionPath (Path) –

GetCollection(prim, name) -> CollectionAPI

Returns the schema object representing a collection named name on the given prim .

Parameters

prim (Prim) –
name (str) –

GetCollectionPath() → Path

Returns the canonical path that represents this collection.

This points to a property named”collection:{collectionName}”on the prim defining the collection (which won’t really exist as a property on the UsdStage, but will be used to refer to the collection). This is the path to be used to”include”this collection in another collection.

GetExcludesRel() → Relationship

Specifies a list of targets that are excluded below the included paths in this collection.

This can target prims or properties directly, but cannot target another collection. This is to keep the membership determining logic simple, efficient and easier to reason about. Finally, it is invalid for a collection to exclude paths that are not included in it. The presence of such”orphaned”excluded paths will not affect the set of paths included in the collection, but may affect the performance of querying membership of a path in the collection (see UsdCollectionAPI::MembershipQuery::IsPathIncluded) or of enumerating the objects belonging to the collection (see UsdCollectionAPI::GetIncludedObjects).

GetExpansionRuleAttr() → Attribute

Specifies how the paths that are included in the collection must be expanded to determine its members.

Declaration

uniform token expansionRule ="expandPrims"

C++ Type

TfToken

Usd Type

SdfValueTypeNames->Token

Variability

SdfVariabilityUniform

Allowed Values

explicitOnly, expandPrims, expandPrimsAndProperties

GetIncludeRootAttr() → Attribute

Boolean attribute indicating whether the pseudo-root path</>should be counted as one of the included target paths.

The fallback is false. This separate attribute is required because relationships cannot directly target the root.

Declaration

uniform bool includeRoot

C++ Type

bool

Usd Type

SdfValueTypeNames->Bool

Variability

SdfVariabilityUniform

GetIncludesRel() → Relationship

Specifies a list of targets that are included in the collection.

This can target prims or properties directly. A collection can insert the rules of another collection by making its includes relationship target the collection:{collectionName} property on the owning prim of the collection to be included

GetName() → str: Returns the name of this multiple-apply schema instance.

static GetNamedCollectionPath()

classmethod GetNamedCollectionPath(prim, collectionName) -> Path

Returns the canonical path to the collection named, name on the given prim, prim .

GetCollectionPath()

Parameters

prim (Prim) –
collectionName (str) –

static GetSchemaAttributeNames()

classmethod GetSchemaAttributeNames(includeInherited) -> list[str]

Return a vector of names of all pre-declared attributes for this schema class and all its ancestor classes.

Does not include attributes that may be authored by custom/extended methods of the schemas involved.

Parameters: includeInherited (bool) –

GetSchemaAttributeNames(includeInherited, instanceName) -> list[str]

Return a vector of names of all pre-declared attributes for this schema class and all its ancestor classes for a given instance name.

Does not include attributes that may be authored by custom/extended methods of the schemas involved. The names returned will have the proper namespace prefix.

Parameters

includeInherited (bool) –
instanceName (str) –

HasNoIncludedPaths() → bool

Returns true if the collection has nothing included in it.

This requires both that the includes relationship have no target paths, and that the includeRoot attribute be false. Note that there may be cases where the collection has no objects included in it even when HasNoIncludedPaths() returns false. For example, if the included objects are unloaded or if the included objects are also excluded.

IncludePath(pathToInclude) → bool

Includes or adds the given path, pathToInclude in the collection.

This does nothing if the path is already included in the collection.

This does not modify the expansion-rule of the collection. Hence, if the expansionRule is expandPrims or expandPrimsAndProperties, then the descendants of pathToInclude will be also included in the collection unless explicitly excluded.

UsdCollectionAPI::ExcludePath()

Parameters: pathToInclude (Path) –

static IsCollectionAPIPath()

classmethod IsCollectionAPIPath(path, name) -> bool

Checks if the given path path is of an API schema of type CollectionAPI.

If so, it stores the instance name of the schema in name and returns true. Otherwise, it returns false.

Parameters

path (Path) –
name (str) –

static IsSchemaPropertyBaseName()

classmethod IsSchemaPropertyBaseName(baseName) -> bool

Checks if the given name baseName is the base name of a property of CollectionAPI.

Parameters: baseName (str) –

ResetCollection() → bool

Resets the collection by clearing both the includes and excludes targets of the collection in the current UsdEditTarget.

This does not modify the”includeRoot”attribute which is used to include or exclude everything (i.e. the pseudoRoot) in the USD stage.

Validate(reason) → bool

Validates the collection by checking the following rules:

a collection’s expansionRule should be one of”explicitOnly”,”expandPrims”or”expandPrimsAndProperties”.

a collection should not have have a circular dependency on another collection.

a collection should not have both includes and excludes among its top-level rules

Parameters: reason (str) –

class pxr.Usd.CompositionArc

Methods:

`GetArcType`
`GetIntroducingLayer`
`GetIntroducingListEditor`
`GetIntroducingNode`
`GetIntroducingPrimPath`
`GetTargetLayer`
`GetTargetNode`
`GetTargetPrimPath`
`HasSpecs`
`IsAncestral`
`IsImplicit`
`IsIntroducedInRootLayerPrimSpec`
`IsIntroducedInRootLayerStack`
`MakeResolveTargetStrongerThan`
`MakeResolveTargetUpTo`

GetArcType()

GetIntroducingLayer()

GetIntroducingListEditor()

GetIntroducingNode()

GetIntroducingPrimPath()

GetTargetLayer()

GetTargetNode()

GetTargetPrimPath()

HasSpecs()

IsAncestral()

IsImplicit()

IsIntroducedInRootLayerPrimSpec()

IsIntroducedInRootLayerStack()

MakeResolveTargetStrongerThan()

MakeResolveTargetUpTo()

class pxr.Usd.CrateInfo

A class for introspecting the underlying qualities of .usdc’crate’files, for diagnostic purposes.

Classes:

`Section`
`SummaryStats`

Methods:

`GetFileVersion`()	Return the file version.
`GetSections`()	Return the named file sections, their location and sizes in the file.
`GetSoftwareVersion`()	Return the software version.
`GetSummaryStats`()	Return summary statistics structure for this file.
`Open`	classmethod Open(fileName) -> CrateInfo

class Section

Attributes:

`name`
`size`
`start`

property name

property size

property start

class SummaryStats

Attributes:

`numSpecs`
`numUniqueFieldSets`
`numUniqueFields`
`numUniquePaths`
`numUniqueStrings`
`numUniqueTokens`

property numSpecs

property numUniqueFieldSets

property numUniqueFields

property numUniquePaths

property numUniqueStrings

property numUniqueTokens

GetFileVersion() → str: Return the file version.

GetSections() → list[Section]: Return the named file sections, their location and sizes in the file.

GetSoftwareVersion() → str: Return the software version.

GetSummaryStats() → SummaryStats: Return summary statistics structure for this file.

static Open()

classmethod Open(fileName) -> CrateInfo

Attempt to open and read fileName .

Parameters: fileName (str) –

class pxr.Usd.EditContext

A utility class to temporarily modify a stage’s current EditTarget during an execution scope.

This is an”RAII”-like object meant to be used as an automatic local variable. Upon construction, it sets a given stage’s EditTarget, and upon destruction it restores the stage’s EditTarget to what it was previously.

Example usage, temporarily overriding a stage’s EditTarget to direct an edit to the stage’s session layer. When the ctx object expires, it restores the stage’s EditTarget to whatever it was previously.

void SetVisState(const UsdPrim  & prim, bool vis) {
    UsdEditContext ctx(prim.GetStage(),
                       prim.GetStage()->GetSessionLayer());
    prim.GetAttribute("visible").Set(vis);
}

Threading Note

When one thread is mutating a UsdStage, it is unsafe for any other thread to either query or mutate it. Using this class with a stage in such a way that it modifies the stage’s EditTarget constitutes a mutation.

class pxr.Usd.EditTarget

Defines a mapping from scene graph paths to Sdf spec paths in a SdfLayer where edits should be directed, or up to where to perform partial composition.

A UsdEditTarget can represent an arbitrary point in a composition graph for the purposes of placing edits and resolving values. This enables editing and resolving across references, classes, variants, and payloads.

In the simplest case, an EditTarget represents a single layer in a stage’s local LayerStack. In this case, the mapping that transforms scene graph paths to spec paths in the layer is the identity function. That is, the UsdAttribute path’/World/Foo.avar’would map to the SdfPropertySpec path’/World/Foo.avar’.

For a more complex example, suppose’/World/Foo’in’Shot.usda’is a reference to’/Model’in’Model.usda’. One can construct a UsdEditTarget that maps scene graph paths from the’Shot.usda’stage across the reference to the appropriate paths in the’Model.usda’layer. For example, the UsdAttribute ‘/World/Foo.avar’would map to the SdfPropertySpec ‘/Model.avar’. Paths in the stage composed at’Shot.usda’that weren’t prefixed by’/World/Foo’would not have a valid mapping to’Model.usda’.

EditTargets may also work for any other kind of arc or series of arcs. This allows for editing across variants, classes, and payloads, or in a variant on the far side of a reference, for example.

In addition to mapping scene paths to spec paths for editing, EditTargets may also be used to identify points in the composition graph for partial composition. Though it doesn’t currently exist, a UsdCompose API that takes UsdEditTarget arguments may someday be provided.

For convenience and deployment ease, SdfLayerHandles will implicitly convert to UsdEditTargets. A UsdEditTarget constructed in this way means direct opinions in a layer in a stage’s local LayerStack.

Methods:

`ComposeOver`(weaker)	Return a new EditTarget composed over weaker.
`ForLocalDirectVariant`	classmethod ForLocalDirectVariant(layer, varSelPath) -> EditTarget
`GetLayer`()	Return the layer this EditTarget contains.
`GetMapFunction`()	Returns the PcpMapFunction representing the map from source specs (including any variant selections) to the stage.
`GetPrimSpecForScenePath`(scenePath)	Convenience function for getting the PrimSpec in the edit target's layer for scenePath.
`GetPropertySpecForScenePath`(scenePath)	param scenePath
`GetSpecForScenePath`(scenePath)	param scenePath
`IsNull`()	Return true if this EditTarget is null.
`IsValid`()	Return true if this EditTarget is valid, false otherwise.
`MapToSpecPath`(scenePath)	Map the provided scenePath into a SdfSpec path for the EditTarget's layer, according to the EditTarget's mapping.

ComposeOver(weaker) → EditTarget

Return a new EditTarget composed over weaker.

This is typically used to make an EditTarget”explicit”. For example, an edit target with a layer but with no mapping and no LayerStack identifier indicates a layer in the local LayerStack of a composed scene. However, an EditTarget with the same layer but an explicit identity mapping and the LayerStack identifier of the composed scene may be desired. This can be obtained by composing a partial (e.g. layer only) EditTarget over an explicit EditTarget with layer, mapping and layer stack identifier.

Parameters: weaker (EditTarget) –

static ForLocalDirectVariant()

classmethod ForLocalDirectVariant(layer, varSelPath) -> EditTarget

Convenience constructor for editing a direct variant in a local LayerStack.

The varSelPath must be a prim variant selection path (see SdfPath::IsPrimVariantSelectionPath() ).

Parameters

layer (Layer) –
varSelPath (Path) –

GetLayer() → Layer

Return the layer this EditTarget contains.

GetLayer() -> Layer

GetMapFunction() → MapFunction: Returns the PcpMapFunction representing the map from source specs (including any variant selections) to the stage.

GetPrimSpecForScenePath(scenePath) → PrimSpec

Convenience function for getting the PrimSpec in the edit target’s layer for scenePath.

This is equivalent to target.GetLayer()->GetPrimAtPath(target.MapToSpecPath(scenePath)) if target has a valid layer. If this target IsNull or there is no valid mapping from scenePath to a SdfPrimSpec path in the layer, return null.

Parameters: scenePath (Path) –

GetPropertySpecForScenePath(scenePath) → PropertySpec

Parameters: scenePath (Path) –

GetSpecForScenePath(scenePath) → Spec

Parameters: scenePath (Path) –

IsNull() → bool

Return true if this EditTarget is null.

Null EditTargets map paths unchanged, and have no layer or LayerStack identifier.

IsValid() → bool

Return true if this EditTarget is valid, false otherwise.

Edit targets are considered valid when they have a layer.

MapToSpecPath(scenePath) → Path

Map the provided scenePath into a SdfSpec path for the EditTarget’s layer, according to the EditTarget’s mapping.

Null edit targets and EditTargets for which IsLocalLayer are true return scenePath unchanged.

Parameters: scenePath (Path) –

class pxr.Usd.Inherits

A proxy class for applying listOp edits to the inherit paths list for a prim.

All paths passed to the UsdInherits API are expected to be in the namespace of the owning prim’s stage. Subroot prim inherit paths will be translated from this namespace to the namespace of the current edit target, if necessary. If a path cannot be translated, a coding error will be issued and no changes will be made. Root prim inherit paths will not be translated.

Methods:

`AddInherit`(primPath, position)	Adds a path to the inheritPaths listOp at the current EditTarget, in the position specified by `position` .
`ClearInherits`()	Removes the authored inheritPaths listOp edits at the current edit target.
`GetAllDirectInherits`()	Return all the paths in this prim's stage's local layer stack that would compose into this prim via direct inherits (excluding prim specs that would be composed into this prim due to inherits authored on ancestral prims) in strong-to-weak order.
`GetPrim`()	Return the prim this object is bound to.
`RemoveInherit`(primPath)	Removes the specified path from the inheritPaths listOp at the current EditTarget.
`SetInherits`(items)	Explicitly set the inherited paths, potentially blocking weaker opinions that add or remove items, returning true on success, false if the edit could not be performed.

AddInherit(primPath, position) → bool

Adds a path to the inheritPaths listOp at the current EditTarget, in the position specified by position .

Parameters

primPath (Path) –
position (ListPosition) –

ClearInherits() → bool: Removes the authored inheritPaths listOp edits at the current edit target.

GetAllDirectInherits() → list[Path]

Return all the paths in this prim’s stage’s local layer stack that would compose into this prim via direct inherits (excluding prim specs that would be composed into this prim due to inherits authored on ancestral prims) in strong-to-weak order.

Note that there currently may not be any scene description at these paths on the stage. This returns all the potential places that such opinions could appear.

GetPrim() → Prim

Return the prim this object is bound to.

GetPrim() -> Prim

RemoveInherit(primPath) → bool

Removes the specified path from the inheritPaths listOp at the current EditTarget.

Parameters: primPath (Path) –

SetInherits(items) → bool

Explicitly set the inherited paths, potentially blocking weaker opinions that add or remove items, returning true on success, false if the edit could not be performed.

Parameters: items (list[Path]) –

class pxr.Usd.InterpolationType

Methods:

GetValueFromName

Attributes:

allValues

static GetValueFromName()

allValues = (Usd.InterpolationTypeHeld, Usd.InterpolationTypeLinear)

class pxr.Usd.ListPosition

Methods:

GetValueFromName

Attributes:

allValues

static GetValueFromName()

allValues = (Usd.ListPositionFrontOfPrependList, Usd.ListPositionBackOfPrependList, Usd.ListPositionFrontOfAppendList, Usd.ListPositionBackOfAppendList)

class pxr.Usd.LoadPolicy

Methods:

GetValueFromName

Attributes:

allValues

static GetValueFromName()

allValues = (Usd.LoadWithDescendants, Usd.LoadWithoutDescendants)

class pxr.Usd.ModelAPI

UsdModelAPI is an API schema that provides an interface to a prim’s model qualities, if it does, in fact, represent the root prim of a model.

The first and foremost model quality is its kind, i.e. the metadata that establishes it as a model (See KindRegistry). UsdModelAPI provides various methods for setting and querying the prim’s kind, as well as queries (also available on UsdPrim) for asking what category of model the prim is. See Kind and Model-ness.

UsdModelAPI also provides access to a prim’s assetInfo data. While any prim can host assetInfo, it is common that published (referenced) assets are packaged as models, therefore it is convenient to provide access to the one from the other.

Classes:

KindValidation

Option for validating queries to a prim's kind metadata.

Methods:

`Get`	classmethod Get(stage, path) -> ModelAPI
`GetAssetIdentifier`(identifier)	Returns the model's asset identifier as authored in the composed assetInfo dictionary.
`GetAssetInfo`(info)	Returns the model's composed assetInfo dictionary.
`GetAssetName`(assetName)	Returns the model's asset name from the composed assetInfo dictionary.
`GetAssetVersion`(version)	Returns the model's resolved asset version.
`GetKind`(kind)	Retrieve the authored `kind` for this prim.
`GetPayloadAssetDependencies`(assetDeps)	Returns the list of asset dependencies referenced inside the payload of the model.
`GetSchemaAttributeNames`	classmethod GetSchemaAttributeNames(includeInherited) -> list[str]
`IsGroup`()	Return true if this prim represents a model group, based on its kind metadata.
`IsKind`(baseKind, validation)	Return true if the prim's kind metadata is or inherits from `baseKind` as defined by the Kind Registry.
`IsModel`()	Return true if this prim represents a model, based on its kind metadata.
`SetAssetIdentifier`(identifier)	Sets the model's asset identifier to the given asset path, `identifier` .
`SetAssetInfo`(info)	Sets the model's assetInfo dictionary to `info` in the current edit target.
`SetAssetName`(assetName)	Sets the model's asset name to `assetName` .
`SetAssetVersion`(version)	Sets the model's asset version string.
`SetKind`(kind)	Author a `kind` for this prim, at the current UsdEditTarget.
`SetPayloadAssetDependencies`(assetDeps)	Sets the list of external asset dependencies referenced inside the payload of a model.

Attributes:

`KindValidationModelHierarchy`
`KindValidationNone`

class KindValidation

Option for validating queries to a prim’s kind metadata.

IsKind()

Methods:

GetValueFromName

Attributes:

allValues

static GetValueFromName()

allValues = (Usd.ModelAPI.KindValidationNone, Usd.ModelAPI.KindValidationModelHierarchy)

static Get()

classmethod Get(stage, path) -> ModelAPI

Return a UsdModelAPI holding the prim adhering to this schema at path on stage .

If no prim exists at path on stage , or if the prim at that path does not adhere to this schema, return an invalid schema object. This is shorthand for the following:

UsdModelAPI(stage->GetPrimAtPath(path));

Parameters

stage (Stage) –
path (Path) –

GetAssetIdentifier(identifier) → bool

Returns the model’s asset identifier as authored in the composed assetInfo dictionary.

The asset identifier can be used to resolve the model’s root layer via the asset resolver plugin.

Parameters: identifier (AssetPath) –

GetAssetInfo(info) → bool

Returns the model’s composed assetInfo dictionary.

The asset info dictionary is used to annotate models with various data related to asset management. For example, asset name, identifier, version etc.

The elements of this dictionary are composed element-wise, and are nestable.

Parameters: info (VtDictionary) –

GetAssetName(assetName) → bool

Returns the model’s asset name from the composed assetInfo dictionary.

The asset name is the name of the asset, as would be used in a database query.

Parameters: assetName (str) –

GetAssetVersion(version) → bool

Returns the model’s resolved asset version.

If you publish assets with an embedded version, then you may receive that version string. You may, however, cause your authoring tools to record the resolved version at the time at which a reference to the asset was added to an aggregate, at the referencing site. In such a pipeline, this API will always return that stronger opinion, even if the asset is republished with a newer version, and even though that newer version may be the one that is resolved when the UsdStage is opened.

Parameters: version (str) –

GetKind(kind) → bool

Retrieve the authored kind for this prim.

To test whether the returned kind matches a particular known”clientKind”:

TfToken kind;

bool isClientKind = UsdModelAPI(prim).GetKind(&kind) and
                    KindRegistry::IsA(kind, clientKind);

true if there was an authored kind that was successfully read, otherwise false.

The Kind module for further details on how to use Kind for classification, and how to extend the taxonomy.

Parameters: kind (str) –

GetPayloadAssetDependencies(assetDeps) → bool

Returns the list of asset dependencies referenced inside the payload of the model.

This typically contains identifiers of external assets that are referenced inside the model’s payload. When the model is created, this list is compiled and set at the root of the model. This enables efficient dependency analysis without the need to include the model’s payload.

Parameters: assetDeps (VtArray[AssetPath]) –

static GetSchemaAttributeNames()

classmethod GetSchemaAttributeNames(includeInherited) -> list[str]

Return a vector of names of all pre-declared attributes for this schema class and all its ancestor classes.

Does not include attributes that may be authored by custom/extended methods of the schemas involved.

Parameters: includeInherited (bool) –

IsGroup() → bool: Return true if this prim represents a model group, based on its kind metadata.

IsKind(baseKind, validation) → bool

Return true if the prim’s kind metadata is or inherits from baseKind as defined by the Kind Registry.

If validation is KindValidationModelHierarchy (the default), then this also ensures that if baseKind is a model, the prim conforms to the rules of model hierarchy, as defined by IsModel. If set to KindValidationNone, no additional validation is done.

IsModel and IsGroup are preferrable to IsKind(“model”) as they are optimized for fast traversal.

If a prim’s model hierarchy is not valid, it is possible that that prim.IsModel() and prim.IsKind(“model”, Usd.ModelAPI.KindValidationNone) return different answers. (As a corallary, this is also true for for prim.IsGroup())

Parameters

baseKind (str) –
validation (KindValidation) –

IsModel() → bool: Return true if this prim represents a model, based on its kind metadata.

SetAssetIdentifier(identifier) → None

Sets the model’s asset identifier to the given asset path, identifier .

GetAssetIdentifier()

Parameters: identifier (AssetPath) –

SetAssetInfo(info) → None

Sets the model’s assetInfo dictionary to info in the current edit target.

Parameters: info (VtDictionary) –

SetAssetName(assetName) → None

Sets the model’s asset name to assetName .

GetAssetName()

Parameters: assetName (str) –

SetAssetVersion(version) → None

Sets the model’s asset version string.

GetAssetVersion()

Parameters: version (str) –

SetKind(kind) → bool

Author a kind for this prim, at the current UsdEditTarget.

true if kind was successully authored, otherwise false.

Parameters: kind (str) –

SetPayloadAssetDependencies(assetDeps) → None

Sets the list of external asset dependencies referenced inside the payload of a model.

GetPayloadAssetDependencies()

Parameters: assetDeps (VtArray[AssetPath]) –

KindValidationModelHierarchy = Usd.ModelAPI.KindValidationModelHierarchy

KindValidationNone = Usd.ModelAPI.KindValidationNone

class pxr.Usd.Notice

Container class for Usd notices

Classes:

`LayerMutingChanged`
`ObjectsChanged`
`StageContentsChanged`
`StageEditTargetChanged`
`StageNotice`

class LayerMutingChanged

Methods:

`GetMutedLayers`
`GetUnmutedLayers`

GetMutedLayers()

GetUnmutedLayers()

class ObjectsChanged

Methods:

`AffectedObject`
`ChangedInfoOnly`
`GetChangedFields`
`GetChangedInfoOnlyPaths`
`GetFastUpdates`
`GetResyncedPaths`
`HasChangedFields`
`ResyncedObject`

AffectedObject()

ChangedInfoOnly()

GetChangedFields()

GetChangedInfoOnlyPaths()

GetFastUpdates()

GetResyncedPaths()

HasChangedFields()

ResyncedObject()

class StageContentsChanged

class StageEditTargetChanged

class StageNotice

Methods:

GetStage

GetStage()

class pxr.Usd.Object

Base class for Usd scenegraph objects, providing common API.

The commonality between the three types of scenegraph objects in Usd ( UsdPrim, UsdAttribute, UsdRelationship) is that they can all have metadata. Other objects in the API ( UsdReferences, UsdVariantSets, etc.) simply are kinds of metadata.

UsdObject ‘s API primarily provides schema for interacting with the metadata common to all the scenegraph objects, as well as generic access to metadata.

section Usd_UsdObject_Lifetime Lifetime Management and Object Validity

Every derived class of UsdObject supports explicit detection of object validity through an explicit-bool operator, so client code should always be able use objects safely, even across edits to the owning UsdStage. UsdObject classes also perform some level of validity checking upon every use, in order to facilitate debugging of unsafe code, although we reserve the right to activate that behavior only in debug builds, if it becomes compelling to do so for performance reasons. This per-use checking will cause a fatal error upon failing the inline validity check, with an error message describing the namespace location of the dereferenced object on its owning UsdStage.

Methods:

`ClearAssetInfo`()	Clear the authored opinion for this object's assetInfo dictionary at the current EditTarget.
`ClearAssetInfoByKey`(keyPath)	Clear the authored opinion identified by `keyPath` in this object's assetInfo dictionary at the current EditTarget.
`ClearCustomData`()	Clear the authored opinion for this object's customData dictionary at the current EditTarget.
`ClearCustomDataByKey`(keyPath)	Clear the authored opinion identified by `keyPath` in this object's customData dictionary at the current EditTarget.
`ClearDocumentation`()	Clears this object's documentation (metadata) in the current EditTarget (only).
`ClearHidden`()	Clears the opinion for"Hidden"at the current EditTarget.
`ClearMetadata`(key)	Clears the authored key's value at the current EditTarget, returning false on error.
`ClearMetadataByDictKey`(key, keyPath)	Clear any authored value identified by `key` and `keyPath` at the current EditTarget.
`GetAllAuthoredMetadata`()	Resolve and return all user-authored metadata on this object, sorted lexicographically.
`GetAllMetadata`()	Resolve and return all metadata (including both authored and fallback values) on this object, sorted lexicographically.
`GetAssetInfo`()	Return this object's composed assetInfo dictionary.
`GetAssetInfoByKey`(keyPath)	Return the element identified by `keyPath` in this object's composed assetInfo dictionary.
`GetCustomData`()	Return this object's composed customData dictionary.
`GetCustomDataByKey`(keyPath)	Return the element identified by `keyPath` in this object's composed customData dictionary.
`GetDescription`()	Return a string that provides a brief summary description of the object.
`GetDocumentation`()	Return this object's documentation (metadata).
`GetMetadata`(key, value)	Resolve the requested metadatum named `key` into `value` , returning true on success.
`GetMetadataByDictKey`(key, keyPath, value)	Resolve the requested dictionary sub-element `keyPath` of dictionary-valued metadatum named `key` into `value` , returning true on success.
`GetName`()	Return the full name of this object, i.e.
`GetNamespaceDelimiter`	classmethod GetNamespaceDelimiter() -> char
`GetPath`()	Return the complete scene path to this object on its UsdStage, which may (UsdPrim) or may not (all other subclasses) return a cached result.
`GetPrim`()	Return this object if it is a prim, otherwise return this object's nearest owning prim.
`GetPrimPath`()	Return this object's path if this object is a prim, otherwise this object's nearest owning prim's path.
`GetStage`()	Return the stage that owns the object, and to whose state and lifetime this object's validity is tied.
`HasAssetInfo`()	Return true if there are any authored or fallback opinions for this object's assetInfo dictionary, false otherwise.
`HasAssetInfoKey`(keyPath)	Return true if there are any authored or fallback opinions for the element identified by `keyPath` in this object's assetInfo dictionary, false otherwise.
`HasAuthoredAssetInfo`()	Return true if there are any authored opinions (excluding fallback) for this object's assetInfo dictionary, false otherwise.
`HasAuthoredAssetInfoKey`(keyPath)	Return true if there are any authored opinions (excluding fallback) for the element identified by `keyPath` in this object's assetInfo dictionary, false otherwise.
`HasAuthoredCustomData`()	Return true if there are any authored opinions (excluding fallback) for this object's customData dictionary, false otherwise.
`HasAuthoredCustomDataKey`(keyPath)	Return true if there are any authored opinions (excluding fallback) for the element identified by `keyPath` in this object's customData dictionary, false otherwise.
`HasAuthoredDocumentation`()	Returns true if documentation was explicitly authored and GetMetadata() will return a meaningful value for documentation.
`HasAuthoredHidden`()	Returns true if hidden was explicitly authored and GetMetadata() will return a meaningful value for Hidden.
`HasAuthoredMetadata`(key)	Returns true if the key has an authored value, false if no value was authored or the only value available is a prim's metadata fallback.
`HasAuthoredMetadataDictKey`(key, keyPath)	Return true if there exists any authored opinion (excluding fallbacks) for `key` and `keyPath` .
`HasCustomData`()	Return true if there are any authored or fallback opinions for this object's customData dictionary, false otherwise.
`HasCustomDataKey`(keyPath)	Return true if there are any authored or fallback opinions for the element identified by `keyPath` in this object's customData dictionary, false otherwise.
`HasMetadata`(key)	Returns true if the key has a meaningful value, that is, if GetMetadata() will provide a value, either because it was authored or because a prim's metadata fallback will be provided.
`HasMetadataDictKey`(key, keyPath)	Return true if there exists any authored or fallback opinion for `key` and `keyPath` .
`IsHidden`()	Gets the value of the'hidden'metadata field, false if not authored.
`IsValid`()	Return true if this is a valid object, false otherwise.
`SetAssetInfo`(customData)	Author this object's assetInfo dictionary to `assetInfo` at the current EditTarget.
`SetAssetInfoByKey`(keyPath, value)	Author the element identified by `keyPath` in this object's assetInfo dictionary at the current EditTarget.
`SetCustomData`(customData)	Author this object's customData dictionary to `customData` at the current EditTarget.
`SetCustomDataByKey`(keyPath, value)	Author the element identified by `keyPath` in this object's customData dictionary at the current EditTarget.
`SetDocumentation`(doc)	Sets this object's documentation (metadata).
`SetHidden`(hidden)	Sets the value of the'hidden'metadata field.
`SetMetadata`(key, value)	Set metadatum `key's` value to `value` .
`SetMetadataByDictKey`(key, keyPath, value)	Author `value` to the field identified by `key` and `keyPath` at the current EditTarget.

ClearAssetInfo() → None

Clear the authored opinion for this object’s assetInfo dictionary at the current EditTarget.

Do nothing if there is no such authored opinion.

ClearAssetInfoByKey(keyPath) → None

Clear the authored opinion identified by keyPath in this object’s assetInfo dictionary at the current EditTarget.

The keyPath is a’:’-separated path identifying a value in subdictionaries. Do nothing if there is no such authored opinion.

Parameters: keyPath (str) –

ClearCustomData() → None

Clear the authored opinion for this object’s customData dictionary at the current EditTarget.

Do nothing if there is no such authored opinion.

ClearCustomDataByKey(keyPath) → None

Clear the authored opinion identified by keyPath in this object’s customData dictionary at the current EditTarget.

The keyPath is a’:’-separated path identifying a value in subdictionaries. Do nothing if there is no such authored opinion.

Parameters: keyPath (str) –

ClearDocumentation() → bool

Clears this object’s documentation (metadata) in the current EditTarget (only).

Returns true on success.

ClearHidden() → bool: Clears the opinion for”Hidden”at the current EditTarget.

ClearMetadata(key) → bool

Clears the authored key’s value at the current EditTarget, returning false on error.

If no value is present, this method is a no-op and returns true. It is considered an error to call ClearMetadata when no spec is present for this UsdObject, i.e. if the object has no presence in the current UsdEditTarget.

General Metadata in USD

Parameters: key (str) –

ClearMetadataByDictKey(key, keyPath) → bool

Clear any authored value identified by key and keyPath at the current EditTarget.

The keyPath is a’:’-separated path identifying a path in subdictionaries stored in the metadata field at key . Return true if the value is cleared successfully, false otherwise.

Dictionary-valued Metadata

Parameters

key (str) –
keyPath (str) –

GetAllAuthoredMetadata() → UsdMetadataValueMap

Resolve and return all user-authored metadata on this object, sorted lexicographically.

This method does not return field keys for composition arcs, such as references, inherits, payloads, sublayers, variants, or primChildren, nor does it return the default value or timeSamples.

GetAllMetadata() → UsdMetadataValueMap

Resolve and return all metadata (including both authored and fallback values) on this object, sorted lexicographically.

This method does not return field keys for composition arcs, such as references, inherits, payloads, sublayers, variants, or primChildren, nor does it return the default value or timeSamples.

GetAssetInfo() → VtDictionary

Return this object’s composed assetInfo dictionary.

The asset info dictionary is used to annotate objects representing the root-prims of assets (generally organized as models) with various data related to asset management. For example, asset name, root layer identifier, asset version etc.

The elements of this dictionary are composed element-wise, and are nestable.

There is no means to query an assetInfo field’s valuetype other than fetching the value and interrogating it.

GetAssetInfoByKey()

GetAssetInfoByKey(keyPath) → VtValue

Return the element identified by keyPath in this object’s composed assetInfo dictionary.

The keyPath is a’:’-separated path identifying a value in subdictionaries. This is in general more efficient than composing the entire assetInfo dictionary than pulling out one sub-element.

Parameters: keyPath (str) –

GetCustomData() → VtDictionary

Return this object’s composed customData dictionary.

CustomData is”custom metadata”, a place for applications and users to put uniform data that is entirely dynamic and subject to no schema known to Usd. Unlike metadata like’hidden’,’displayName’etc, which must be declared in code or a data file that is considered part of one’s Usd distribution (e.g. a plugInfo.json file) to be used, customData keys and the datatypes of their corresponding values are ad hoc. No validation will ever be performed that values for the same key in different layers are of the same type - strongest simply wins.

Dictionaries like customData are composed element-wise, and are nestable.

There is no means to query a customData field’s valuetype other than fetching the value and interrogating it.

GetCustomDataByKey()

GetCustomDataByKey(keyPath) → VtValue

Return the element identified by keyPath in this object’s composed customData dictionary.

The keyPath is a’:’-separated path identifying a value in subdictionaries. This is in general more efficient than composing the entire customData dictionary and then pulling out one sub-element.

Parameters: keyPath (str) –

GetDescription() → str

Return a string that provides a brief summary description of the object.

This method, along with IsValid() /bool_operator, is always safe to call on a possibly-expired object, and the description will specify whether the object is valid or expired, along with a few other bits of data.

GetDocumentation() → str

Return this object’s documentation (metadata).

This returns the empty string if no documentation has been set.

SetDocumentation()

GetMetadata(key, value) → bool

Resolve the requested metadatum named key into value , returning true on success.

false if key was not resolvable, or if value's type T differed from that of the resolved metadatum.

For any composition-related metadata, as enumerated in GetAllMetadata() , this method will return only the strongest opinion found, not applying the composition rules used by Pcp to process the data. For more processed/composed views of composition data, please refer to the specific interface classes, such as UsdReferences, UsdInherits, UsdVariantSets, etc.

General Metadata in USD

Parameters

key (str) –
value (T) –

GetMetadata(key, value) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Type-erased access.

Parameters

key (str) –
value (VtValue) –

GetMetadataByDictKey(key, keyPath, value) → bool

Resolve the requested dictionary sub-element keyPath of dictionary-valued metadatum named key into value , returning true on success.

If you know you neeed just a small number of elements from a dictionary, accessing them element-wise using this method can be much less expensive than fetching the entire dictionary with GetMetadata(key).

false if key was not resolvable, or if value's type T differed from that of the resolved metadatum. The keyPath is a’:’-separated path addressing an element in subdictionaries.

Dictionary-valued Metadata

Parameters

key (str) –
keyPath (str) –
value (T) –

GetMetadataByDictKey(key, keyPath, value) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

key (str) –
keyPath (str) –
value (VtValue) –

GetName() → str

Return the full name of this object, i.e.

the last component of its SdfPath in namespace.

This is equivalent to, but generally cheaper than, GetPath() .GetNameToken()

static GetNamespaceDelimiter(): classmethod GetNamespaceDelimiter() -> char

GetPath() → Path: Return the complete scene path to this object on its UsdStage, which may (UsdPrim) or may not (all other subclasses) return a cached result.

GetPrim() → Prim: Return this object if it is a prim, otherwise return this object’s nearest owning prim.

GetPrimPath() → Path

Return this object’s path if this object is a prim, otherwise this object’s nearest owning prim’s path.

Equivalent to GetPrim() . GetPath() .

GetStage() → UsdStageWeak: Return the stage that owns the object, and to whose state and lifetime this object’s validity is tied.

HasAssetInfo() → bool: Return true if there are any authored or fallback opinions for this object’s assetInfo dictionary, false otherwise.

HasAssetInfoKey(keyPath) → bool

Return true if there are any authored or fallback opinions for the element identified by keyPath in this object’s assetInfo dictionary, false otherwise.

The keyPath is a’:’-separated path identifying a value in subdictionaries.

Parameters: keyPath (str) –

HasAuthoredAssetInfo() → bool: Return true if there are any authored opinions (excluding fallback) for this object’s assetInfo dictionary, false otherwise.

HasAuthoredAssetInfoKey(keyPath) → bool

Return true if there are any authored opinions (excluding fallback) for the element identified by keyPath in this object’s assetInfo dictionary, false otherwise.

The keyPath is a’:’-separated path identifying a value in subdictionaries.

Parameters: keyPath (str) –

HasAuthoredCustomData() → bool: Return true if there are any authored opinions (excluding fallback) for this object’s customData dictionary, false otherwise.

HasAuthoredCustomDataKey(keyPath) → bool

Return true if there are any authored opinions (excluding fallback) for the element identified by keyPath in this object’s customData dictionary, false otherwise.

The keyPath is a’:’-separated path identifying a value in subdictionaries.

Parameters: keyPath (str) –

HasAuthoredDocumentation() → bool: Returns true if documentation was explicitly authored and GetMetadata() will return a meaningful value for documentation.

HasAuthoredHidden() → bool

Returns true if hidden was explicitly authored and GetMetadata() will return a meaningful value for Hidden.

Note that IsHidden returns a fallback value (false) when hidden is not authored.

HasAuthoredMetadata(key) → bool

Returns true if the key has an authored value, false if no value was authored or the only value available is a prim’s metadata fallback.

Parameters: key (str) –

HasAuthoredMetadataDictKey(key, keyPath) → bool

Return true if there exists any authored opinion (excluding fallbacks) for key and keyPath .

The keyPath is a’:’-separated path identifying a value in subdictionaries stored in the metadata field at key .

Dictionary-valued Metadata

Parameters

key (str) –
keyPath (str) –

HasCustomData() → bool: Return true if there are any authored or fallback opinions for this object’s customData dictionary, false otherwise.

HasCustomDataKey(keyPath) → bool

Return true if there are any authored or fallback opinions for the element identified by keyPath in this object’s customData dictionary, false otherwise.

The keyPath is a’:’-separated path identifying a value in subdictionaries.

Parameters: keyPath (str) –

HasMetadata(key) → bool

Returns true if the key has a meaningful value, that is, if GetMetadata() will provide a value, either because it was authored or because a prim’s metadata fallback will be provided.

Parameters: key (str) –

HasMetadataDictKey(key, keyPath) → bool

Return true if there exists any authored or fallback opinion for key and keyPath .

The keyPath is a’:’-separated path identifying a value in subdictionaries stored in the metadata field at key .

Dictionary-valued Metadata

Parameters

key (str) –
keyPath (str) –

IsHidden() → bool

Gets the value of the’hidden’metadata field, false if not authored.

When an object is marked as hidden, it is an indicator to clients who generically display objects (such as GUI widgets) that this object should not be included, unless explicitly asked for. Although this is just a hint and thus up to each application to interpret, we use it primarily as a way of simplifying hierarchy displays, by hiding only the representation of the object itself, not its subtree, instead”pulling up”everything below it one level in the hierarchical nesting.

Note again that this is a hint for UI only - it should not be interpreted by any renderer as making a prim invisible to drawing.

IsValid() → bool: Return true if this is a valid object, false otherwise.

SetAssetInfo(customData) → None

Author this object’s assetInfo dictionary to assetInfo at the current EditTarget.

Parameters: customData (VtDictionary) –

SetAssetInfoByKey(keyPath, value) → None

Author the element identified by keyPath in this object’s assetInfo dictionary at the current EditTarget.

The keyPath is a’:’-separated path identifying a value in subdictionaries.

Parameters

keyPath (str) –
value (VtValue) –

SetCustomData(customData) → None

Author this object’s customData dictionary to customData at the current EditTarget.

Parameters: customData (VtDictionary) –

SetCustomDataByKey(keyPath, value) → None

Author the element identified by keyPath in this object’s customData dictionary at the current EditTarget.

The keyPath is a’:’-separated path identifying a value in subdictionaries.

Parameters

keyPath (str) –
value (VtValue) –

SetDocumentation(doc) → bool

Sets this object’s documentation (metadata). Returns true on success.

Parameters: doc (str) –

SetHidden(hidden) → bool

Sets the value of the’hidden’metadata field.

See IsHidden() for details.

Parameters: hidden (bool) –

SetMetadata(key, value) → bool

Set metadatum key's value to value .

false if value's type does not match the schema type for key .

General Metadata in USD

Parameters

key (str) –
value (T) –

SetMetadata(key, value) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

key (str) –
value (VtValue) –

SetMetadataByDictKey(key, keyPath, value) → bool

Author value to the field identified by key and keyPath at the current EditTarget.

The keyPath is a’:’-separated path identifying a value in subdictionaries stored in the metadata field at key . Return true if the value is authored successfully, false otherwise.

Dictionary-valued Metadata

Parameters

key (str) –
keyPath (str) –
value (T) –

SetMetadataByDictKey(key, keyPath, value) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

key (str) –
keyPath (str) –
value (VtValue) –

class pxr.Usd.Payloads

UsdPayloads provides an interface to authoring and introspecting payloads. Payloads behave the same as Usd references except that payloads can be optionally loaded.

Methods:

`AddInternalPayload`(primPath, layerOffset, ...)	Add an internal payload to the specified prim.
`AddPayload`(payload, position)	Adds a payload to the payload listOp at the current EditTarget, in the position specified by `position` .
`ClearPayloads`()	Removes the authored payload listOp edits at the current EditTarget.
`GetPrim`()	Return the prim this object is bound to.
`RemovePayload`(ref)	Removes the specified payload from the payloads listOp at the current EditTarget.
`SetPayloads`(items)	Explicitly set the payloads, potentially blocking weaker opinions that add or remove items.

AddInternalPayload(primPath, layerOffset, position) → bool

Add an internal payload to the specified prim.

Internal Payloads

Parameters

primPath (Path) –
layerOffset (LayerOffset) –
position (ListPosition) –

AddPayload(payload, position) → bool

Adds a payload to the payload listOp at the current EditTarget, in the position specified by position .

Why adding references may fail for explanation of expectations on payload and what return values and errors to expect, and ListOps and List Editing for details on list editing and composition of listOps.

Parameters

payload (Payload) –
position (ListPosition) –

AddPayload(identifier, primPath, layerOffset, position) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

identifier (str) –
primPath (Path) –
layerOffset (LayerOffset) –
position (ListPosition) –

AddPayload(identifier, layerOffset, position) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Payloads Without Prim Paths

Parameters

identifier (str) –
layerOffset (LayerOffset) –
position (ListPosition) –

ClearPayloads() → bool

Removes the authored payload listOp edits at the current EditTarget.

The same caveats for Remove() apply to Clear(). In fact, Clear() may actually increase the number of composed payloads, if the listOp being cleared contained the”remove”operator.

ListOps and List Editing

GetPrim() → Prim

Return the prim this object is bound to.

GetPrim() -> Prim

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

RemovePayload(ref) → bool

Removes the specified payload from the payloads listOp at the current EditTarget.

This does not necessarily eliminate the payload completely, as it may be added or set in another layer in the same LayerStack as the current EditTarget.

ListOps and List Editing

Parameters: ref (Payload) –

SetPayloads(items) → bool

Explicitly set the payloads, potentially blocking weaker opinions that add or remove items.

Why adding payloads may fail for explanation of expectations on items and what return values and errors to expect, and ListOps and List Editing for details on list editing and composition of listOps.

Parameters: items (list[Payload]) –

class pxr.Usd.Prim

UsdPrim is the sole persistent scenegraph object on a UsdStage, and is the embodiment of a”Prim”as described in the Universal Scene Description Composition Compendium

A UsdPrim is the principal container of other types of scene description. It provides API for accessing and creating all of the contained kinds of scene description, which include:

UsdVariantSets - all VariantSets on the prim ( GetVariantSets() , GetVariantSet() )

UsdReferences - all references on the prim ( GetReferences() )

UsdInherits - all inherits on the prim ( GetInherits() )

UsdSpecializes - all specializes on the prim ( GetSpecializes() ) As well as access to the API objects for properties contained within the prim - UsdPrim as well as all of the following classes are subclasses of UsdObject :

UsdProperty - generic access to all attributes and relationships. A UsdProperty can be queried and cast to a UsdAttribute or UsdRelationship using UsdObject::Is<>() and UsdObject::As<>() . ( GetPropertyNames() , GetProperties() , GetPropertiesInNamespace() , GetPropertyOrder() , SetPropertyOrder() )

UsdAttribute - access to default and timesampled attribute values, as well as value resolution information, and attribute- specific metadata ( CreateAttribute() , GetAttribute() , GetAttributes() , HasAttribute() )

UsdRelationship - access to authoring and resolving relationships to other prims and properties ( CreateRelationship() , GetRelationship() , GetRelationships() , HasRelationship() ) UsdPrim also provides access to iteration through its prim children, optionally making use of the prim predicates facility ( GetChildren() , GetAllChildren() , GetFilteredChildren() ).

Management

Clients acquire UsdPrim objects, which act like weak/guarded pointers to persistent objects owned and managed by their originating UsdStage. We provide the following guarantees for a UsdPrim acquired via UsdStage::GetPrimAtPath() or UsdStage::OverridePrim() or UsdStage::DefinePrim() :

As long as no further mutations to the structure of the UsdStage are made, the UsdPrim will still be valid. Loading and Unloading are considered structural mutations.

When the UsdStage ‘s structure is mutated, the thread performing the mutation will receive a UsdNotice::ObjectsChanged notice after the stage has been reconfigured, which provides details as to what prims may have been created or destroyed, and what prims may simply have changed in some structural way. Prim access in”reader”threads should be limited to GetPrimAtPath() , which will never cause a mutation to the Stage or its layers.

Please refer to UsdNotice for a listing of the events that could cause UsdNotice::ObjectsChanged to be emitted.

Methods:

`AddAppliedSchema`(appliedSchemaName)	Adds the applied API schema name token `appliedSchemaName` to the apiSchemas metadata for this prim at the current edit target.
`ApplyAPI`()	Applies a single-apply API schema with the given C++ type'SchemaType'to this prim in the current edit target.
`CanApplyAPI`(whyNot)	}@
`ClearActive`()	Remove the authored'active'opinion at the current EditTarget.
`ClearChildrenReorder`()	Remove the opinion for the metadata used to reorder children of this prim at the current EditTarget.
`ClearInstanceable`()	Remove the authored'instanceable'opinion at the current EditTarget.
`ClearPayload`()	Deprecated
`ClearPropertyOrder`()	Remove the opinion for propertyOrder metadata on this prim at the current EditTarget.
`ClearTypeName`()	Clear the opinion for this Prim's typeName at the current edit target.
`ComputeExpandedPrimIndex`()	Compute the prim index containing all sites that could contribute opinions to this prim.
`CreateAttribute`(name, typeName, custom, ...)	Author scene description for the attribute named attrName at the current EditTarget if none already exists.
`CreateRelationship`(relName, custom)	Author scene description for the relationship named relName at the current EditTarget if none already exists.
`FindAllAttributeConnectionPaths`(pred, ...)	Search the prim subtree rooted at this prim for attributes for which `predicate` returns true, collect their connection source paths and return them in an arbitrary order.
`FindAllRelationshipTargetPaths`(pred, ...)	Search the prim subtree rooted at this prim for relationships for which `predicate` returns true, collect their target paths and return them in an arbitrary order.
`GetAllChildren`()	Return all this prim's children as an iterable range.
`GetAllChildrenNames`()	Return the names of the child prims in the order they appear when iterating over GetAllChildren.
`GetAppliedSchemas`()	Return a vector containing the names of API schemas which have been applied to this prim.
`GetAttribute`(attrName)	Return a UsdAttribute with the name attrName.
`GetAttributeAtPath`(path)	Returns the attribute at `path` on the same stage as this prim.
`GetAttributes`()	Like GetProperties() , but exclude all relationships from the result.
`GetAuthoredAttributes`()	Like GetAttributes() , but exclude attributes without authored scene description from the result.
`GetAuthoredProperties`(predicate)	Return this prim's properties (attributes and relationships) that have authored scene description, ordered by name according to the strongest propertyOrder statement in scene description if one exists, otherwise ordered according to TfDictionaryLessThan.
`GetAuthoredPropertiesInNamespace`(namespaces)	Like GetPropertiesInNamespace() , but exclude properties that do not have authored scene description from the result.
`GetAuthoredPropertyNames`(predicate)	Return this prim's property names (attributes and relationships) that have authored scene description, ordered according to the strongest propertyOrder statement in scene description if one exists, otherwise ordered according to TfDictionaryLessThan.
`GetAuthoredRelationships`()	Like GetRelationships() , but exclude relationships without authored scene description from the result.
`GetChild`(name)	Return this prim's direct child named `name` if it has one, otherwise return an invalid UsdPrim.
`GetChildren`()	Return this prim's active, loaded, defined, non-abstract children as an iterable range.
`GetChildrenNames`()	Return the names of the child prims in the order they appear when iterating over GetChildren.
`GetChildrenReorder`()	Return the strongest opinion for the metadata used to reorder children of this prim.
`GetFilteredChildren`(predicate)	Return a subset of all of this prim's children filtered by `predicate` as an iterable range.
`GetFilteredChildrenNames`(predicate)	Return the names of the child prims in the order they appear when iterating over GetFilteredChildren( `predicate` ).
`GetFilteredNextSibling`(predicate)	Return this prim's next sibling that matches `predicate` if it has one, otherwise return the invalid UsdPrim.
`GetInherits`()	Return a UsdInherits object that allows one to add, remove, or mutate inherits at the currently set UsdEditTarget.
`GetInstances`()	If this prim is a prototype prim, returns all prims that are instances of this prototype.
`GetNextSibling`()	Return this prim's next active, loaded, defined, non-abstract sibling if it has one, otherwise return an invalid UsdPrim.
`GetObjectAtPath`(path)	Returns the object at `path` on the same stage as this prim.
`GetParent`()	Return this prim's parent prim.
`GetPayloads`()	Return a UsdPayloads object that allows one to add, remove, or mutate payloads at the currently set UsdEditTarget.
`GetPrimAtPath`(path)	Returns the prim at `path` on the same stage as this prim.
`GetPrimDefinition`()	Return this prim's definition based on the prim's type if the type is a registered prim type.
`GetPrimInPrototype`()	If this prim is an instance proxy, return the UsdPrim for the corresponding prim in the instance's prototype.
`GetPrimIndex`()	Return the cached prim index containing all sites that can contribute opinions to this prim.
`GetPrimStack`()	Return all the authored SdfPrimSpecs that may contain opinions for this prim in order from strong to weak.
`GetPrimStackWithLayerOffsets`()	Return all the authored SdfPrimSpecs that may contain opinions for this prim in order from strong to weak paired with the cumulative layer offset from the stage's root layer to the layer containing the prim spec.
`GetPrimTypeInfo`()	Return the prim's full type info composed from its type name, applied API schemas, and any fallback types defined on the stage for unrecognized prim type names.
`GetProperties`(predicate)	Return all of this prim's properties (attributes and relationships), including all builtin properties, ordered by name according to the strongest propertyOrder statement in scene description if one exists, otherwise ordered according to TfDictionaryLessThan.
`GetPropertiesInNamespace`(namespaces)	Return this prim's properties that are inside the given property namespace ordered according to the strongest propertyOrder statement in scene description if one exists, otherwise ordered according to TfDictionaryLessThan.
`GetProperty`(propName)	Return a UsdProperty with the name propName.
`GetPropertyAtPath`(path)	Returns the property at `path` on the same stage as this prim.
`GetPropertyNames`(predicate)	Return all of this prim's property names (attributes and relationships), including all builtin properties.
`GetPropertyOrder`()	Return the strongest propertyOrder metadata value authored on this prim.
`GetPrototype`()	If this prim is an instance, return the UsdPrim for the corresponding prototype.
`GetReferences`()	Return a UsdReferences object that allows one to add, remove, or mutate references at the currently set UsdEditTarget.
`GetRelationship`(relName)	Return a UsdRelationship with the name relName.
`GetRelationshipAtPath`(path)	Returns the relationship at `path` on the same stage as this prim.
`GetRelationships`()	Like GetProperties() , but exclude all attributes from the result.
`GetSpecializes`()	Return a UsdSpecializes object that allows one to add, remove, or mutate specializes at the currently set UsdEditTarget.
`GetSpecifier`()	Return this prim's composed specifier.
`GetTypeName`()	Return this prim's composed type name.
`GetVariantSet`(variantSetName)	Retrieve a specifically named VariantSet for editing or constructing a UsdEditTarget.
`GetVariantSets`()	Return a UsdVariantSets object representing all the VariantSets present on this prim.
`HasAPI`()	Using HasAPI in C++
`HasAttribute`(attrName)	Return true if this prim has an attribute named `attrName` , false otherwise.
`HasAuthoredActive`()	Return true if this prim has an authored opinion for'active', false otherwise.
`HasAuthoredInherits`()	Return true if this prim has any authored inherits.
`HasAuthoredInstanceable`()	Return true if this prim has an authored opinion for'instanceable', false otherwise.
`HasAuthoredPayloads`()	Return true if this prim has any authored payloads.
`HasAuthoredReferences`()	Return true if this prim has any authored references.
`HasAuthoredSpecializes`()	Returns true if this prim has any authored specializes.
`HasAuthoredTypeName`()	Return true if a typeName has been authored.
`HasDefiningSpecifier`()	Return true if this prim has a specifier of type SdfSpecifierDef or SdfSpecifierClass.
`HasPayload`()	Deprecated
`HasProperty`(propName)	Return true if this prim has an property named `propName` , false otherwise.
`HasRelationship`(relName)	Return true if this prim has a relationship named `relName` , false otherwise.
`HasVariantSets`()	Return true if this prim has any authored VariantSets.
`IsA`()	Return true if the prim's schema type, is or inherits schema type T.
`IsAbstract`()	Return true if this prim or any of its ancestors is a class.
`IsActive`()	Return true if this prim is active, meaning neither it nor any of its ancestors have active=false.
`IsDefined`()	Return true if this prim and all its ancestors have defining specifiers, false otherwise.
`IsGroup`()	Return true if this prim is a model group based on its kind metadata, false otherwise.
`IsInPrototype`()	Return true if this prim is a prototype prim or a descendant of a prototype prim, false otherwise.
`IsInstance`()	Return true if this prim is an instance of a prototype, false otherwise.
`IsInstanceProxy`()	Return true if this prim is an instance proxy, false otherwise.
`IsInstanceable`()	Return true if this prim has been marked as instanceable.
`IsLoaded`()	Return true if this prim is active, and either it is loadable and it is loaded, or its nearest loadable ancestor is loaded, or it has no loadable ancestor; false otherwise.
`IsModel`()	Return true if this prim is a model based on its kind metadata, false otherwise.
`IsPathInPrototype`	classmethod IsPathInPrototype(path) -> bool
`IsPrototype`()	Return true if this prim is an instancing prototype prim, false otherwise.
`IsPrototypePath`	classmethod IsPrototypePath(path) -> bool
`IsPseudoRoot`()	Returns true if the prim is the pseudo root.
`Load`(policy)	Load this prim, all its ancestors, and by default all its descendants.
`MakeResolveTargetStrongerThanEditTarget`(...)	Creates and returns a resolve target that, when passed to a UsdAttributeQuery for one of this prim's attributes, causes value resolution to only consider specs that are stronger than the spec that would be authored for this prim when using the given `editTarget` .
`MakeResolveTargetUpToEditTarget`(editTarget)	Creates and returns a resolve target that, when passed to a UsdAttributeQuery for one of this prim's attributes, causes value resolution to only consider weaker specs up to and including the spec that would be authored for this prim when using the given `editTarget` .
`RemoveAPI`()	Removes a single-apply API schema with the given C++ type'SchemaType'from this prim in the current edit target.
`RemoveAppliedSchema`(appliedSchemaName)	Removes the applied API schema name token `appliedSchemaName` from the apiSchemas metadata for this prim at the current edit target.
`RemoveProperty`(propName)	Remove all scene description for the property with the given `propName` in the current UsdEditTarget.
`SetActive`(active)	Author'active'metadata for this prim at the current EditTarget.
`SetChildrenReorder`(order)	Author an opinion for the metadata used to reorder children of this prim at the current EditTarget.
`SetInstanceable`(instanceable)	Author'instanceable'metadata for this prim at the current EditTarget.
`SetPayload`(payload)	Deprecated
`SetPropertyOrder`(order)	Author an opinion for propertyOrder metadata on this prim at the current EditTarget.
`SetSpecifier`(specifier)	Author an opinion for this Prim's specifier at the current edit target.
`SetTypeName`(typeName)	Author this Prim's typeName at the current EditTarget.
`Unload`()	Unloads this prim and all its descendants.

AddAppliedSchema(appliedSchemaName) → bool

Adds the applied API schema name token appliedSchemaName to the apiSchemas metadata for this prim at the current edit target.

For multiple-apply schemas the name token should include the instance name for the applied schema, for example’CollectionAPI:plasticStuff’.

The name will only be added if the list operation at the edit target does not already have this applied schema in its explicit, prepended, or appended lists and is always added to the end of either the prepended or explicit items.

Returns true upon success or if the API schema is already applied in the current edit target.

An error is issued and false returned for any of the following conditions:

this prim is not a valid prim for editing

this prim is valid, but cannot be reached or overridden in the current edit target

the schema name cannot be added to the apiSchemas listOp metadata Unlike ApplyAPI this method does not require that the name token refer to a valid API schema type. ApplyAPI is the preferred method for applying valid API schemas.

Parameters: appliedSchemaName (str) –

ApplyAPI() → bool

Applies a single-apply API schema with the given C++ type’SchemaType’to this prim in the current edit target.

This information is stored by adding the API schema’s name token to the token-valued, listOp metadata apiSchemas on this prim.

Returns true upon success or if the API schema is already applied in the current edit target.

An error is issued and false returned for any of the following conditions:

this prim is not a valid prim for editing

this prim is valid, but cannot be reached or overridden in the current edit target

the schema name cannot be added to the apiSchemas listOp metadata

ApplyAPI(schemaType) -> bool

Non-templated overload of the templated ApplyAPI above.

This function behaves exactly like the templated ApplyAPI except for the runtime schemaType validation which happens at compile time in the templated version. This method is provided for python clients. Use of the templated ApplyAPI is preferred.

Parameters: schemaType (Type) –

ApplyAPI(instanceName) -> bool

Applies a multiple-apply API schema with the given C++ type’SchemaType’and instance name instanceName to this prim in the current edit target.

This information is stored in the token-valued, listOp metadata apiSchemas on this prim. For example, if SchemaType is’ UsdCollectionAPI ‘and instanceName is’plasticStuff’, the name’CollectionAPI:plasticStuff’is added to the’apiSchemas’listOp metadata.

Returns true upon success or if the API schema is already applied with this instanceName in the current edit target.

An error is issued and false returned for any of the following conditions:

instanceName is empty

this prim is not a valid prim for editing

this prim is valid, but cannot be reached or overridden in the current edit target

the schema name cannot be added to the apiSchemas listOp metadata

Parameters: instanceName (str) –

ApplyAPI(schemaType, instanceName) -> bool

Non-templated overload of the templated ApplyAPI above.

This function behaves exactly like the templated ApplyAPI except for the runtime schemaType validation which happens at compile time in the templated version. This method is provided for python clients. Use of the templated ApplyAPI is preferred.

Parameters

schemaType (Type) –
instanceName (str) –

CanApplyAPI(whyNot) → bool

}@

Returns whether a single-apply API schema with the given C++ type’SchemaType’can be applied to this prim. If the return value is false, and whyNot is provided, the reason the schema cannot be applied is written to whyNot.

Whether the schema can be applied is determined by the schema type definition which may specify that the API schema can only be applied to certain prim types.

The return value of this function only indicates whether it would be valid to apply this schema to the prim. It has no bearing on whether calling ApplyAPI will be successful or not.

Parameters: whyNot (str) –

CanApplyAPI(schemaType, whyNot) -> bool

Non-templated overload of the templated CanApplyAPI above.

This function behaves exactly like the templated CanApplyAPI except for the runtime schemaType validation which happens at compile time in the templated version. This method is provided for python clients. Use of the templated CanApplyAPI is preferred.

Parameters

schemaType (Type) –
whyNot (str) –

CanApplyAPI(instanceName, whyNot) -> bool

Returns whether a multiple-apply API schema with the given C++ type’SchemaType’can be applied to this prim with the given instanceName .

If the return value is false, and whyNot is provided, the reason the schema cannot be applied is written to whyNot.

Whether the schema can be applied is determined by the schema type definition which may specify that the API schema can only be applied to certain prim types. It also determines whether the instance name is a valid instance name for the multiple apply schema.

The return value of this function only indicates whether it would be valid to apply this schema to the prim. It has no bearing on whether calling ApplyAPI will be successful or not.

Parameters

instanceName (str) –
whyNot (str) –

CanApplyAPI(schemaType, instanceName, whyNot) -> bool

Non-templated overload of the templated CanApplyAPI above.

This function behaves exactly like the templated CanApplyAPI except for the runtime schemaType validation which happens at compile time in the templated version. This method is provided for python clients. Use of the templated CanApplyAPI is preferred.

Parameters

schemaType (Type) –
instanceName (str) –
whyNot (str) –

ClearActive() → bool

Remove the authored’active’opinion at the current EditTarget.

Do nothing if there is no authored opinion.

See How”active”Affects Prims on a UsdStage for the effects of activating or deactivating a prim.

ClearChildrenReorder() → None: Remove the opinion for the metadata used to reorder children of this prim at the current EditTarget.

ClearInstanceable() → bool

Remove the authored’instanceable’opinion at the current EditTarget.

Do nothing if there is no authored opinion.

ClearPayload() → bool

Deprecated

Clears the payload at the current EditTarget for this prim. Return false if the payload could not be cleared.

ClearPropertyOrder() → None: Remove the opinion for propertyOrder metadata on this prim at the current EditTarget.

ClearTypeName() → bool: Clear the opinion for this Prim’s typeName at the current edit target.

ComputeExpandedPrimIndex() → PrimIndex

Compute the prim index containing all sites that could contribute opinions to this prim.

This function is similar to UsdPrim::GetPrimIndex. However, the returned prim index includes all sites that could possibly contribute opinions to this prim, not just the sites that currently do so. This is useful in certain situations; for example, this could be used to generate a list of sites where clients could make edits to affect this prim, or for debugging purposes.

This function may be relatively slow, since it will recompute the prim index on every call. Clients should prefer UsdPrim::GetPrimIndex unless the additional site information is truly needed.

CreateAttribute(name, typeName, custom, variability) → Attribute

Author scene description for the attribute named attrName at the current EditTarget if none already exists.

Return a valid attribute if scene description was successfully authored or if it already existed, return invalid attribute otherwise. Note that the supplied typeName and custom arguments are only used in one specific case. See below for details.

Suggested use:

if (UsdAttribute myAttr = prim.CreateAttribute(\.\.\.)) {
   // success.
}

To call this, GetPrim() must return a valid prim.

If a spec for this attribute already exists at the current edit target, do nothing.

If a spec for attrName of a different spec type (e.g. a relationship) exists at the current EditTarget, issue an error.

If name refers to a builtin attribute according to the prim’s definition, author an attribute spec with required metadata from the definition.

If name refers to a builtin relationship, issue an error.

If there exists an absolute strongest authored attribute spec for attrName, author an attribute spec at the current EditTarget by copying required metadata from that strongest spec.

If there exists an absolute strongest authored relationship spec for attrName, issue an error.

Otherwise author an attribute spec at the current EditTarget using the provided typeName and custom for the required metadata fields. Note that these supplied arguments are only ever used in this particular circumstance, in all other cases they are ignored.

Parameters

name (str) –
typeName (ValueTypeName) –
custom (bool) –
variability (Variability) –

CreateAttribute(name, typeName, variability) -> Attribute

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Create a custom attribute with name , typeName and variability .

Parameters

name (str) –
typeName (ValueTypeName) –
variability (Variability) –

CreateAttribute(nameElts, typeName, custom, variability) -> Attribute

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This overload of CreateAttribute() accepts a vector of name components used to construct a namespaced property name.

For details, see Names, Namespace Ordering, and Property Namespaces

Parameters

nameElts (list[str]) –
typeName (ValueTypeName) –
custom (bool) –
variability (Variability) –

CreateAttribute(nameElts, typeName, variability) -> Attribute

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Create a custom attribute with nameElts , typeName , and variability .

Parameters

nameElts (list[str]) –
typeName (ValueTypeName) –
variability (Variability) –

CreateRelationship(relName, custom) → Relationship

Author scene description for the relationship named relName at the current EditTarget if none already exists.

Return a valid relationship if scene description was successfully authored or if it already existed, return an invalid relationship otherwise.

Suggested use:

if (UsdRelationship myRel = prim.CreateRelationship(\.\.\.)) {
   // success.
}

To call this, GetPrim() must return a valid prim.

If a spec for this relationship already exists at the current edit target, do nothing.

If a spec for relName of a different spec type (e.g. an attribute) exists at the current EditTarget, issue an error.

If name refers to a builtin relationship according to the prim’s definition, author a relationship spec with required metadata from the definition.

If name refers to a builtin attribute, issue an error.

If there exists an absolute strongest authored relationship spec for relName, author a relationship spec at the current EditTarget by copying required metadata from that strongest spec.

If there exists an absolute strongest authored attribute spec for relName, issue an error.

Otherwise author a uniform relationship spec at the current EditTarget, honoring custom .

Parameters

relName (str) –
custom (bool) –

CreateRelationship(nameElts, custom) -> Relationship

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. This overload of CreateRelationship() accepts a vector of name components used to construct a namespaced property name.

For details, see Names, Namespace Ordering, and Property Namespaces

Parameters

nameElts (list[str]) –
custom (bool) –

FindAllAttributeConnectionPaths(pred, recurseOnSources) → list[Path]

Search the prim subtree rooted at this prim for attributes for which predicate returns true, collect their connection source paths and return them in an arbitrary order.

If recurseOnSources is true, act as if this function was invoked on the connected prims and owning prims of connected properties also and return the union.

Parameters

pred (function[bool( Attribute )]) –
recurseOnSources (bool) –

FindAllRelationshipTargetPaths(pred, recurseOnTargets) → list[Path]

Search the prim subtree rooted at this prim for relationships for which predicate returns true, collect their target paths and return them in an arbitrary order.

If recurseOnTargets is true, act as if this function was invoked on the targeted prims and owning prims of targeted properties also (but not of forwarding relationships) and return the union.

Parameters

pred (function[bool( Relationship )]) –
recurseOnTargets (bool) –

GetAllChildren() → SiblingRange: Return all this prim’s children as an iterable range.

GetAllChildrenNames() → list[str]: Return the names of the child prims in the order they appear when iterating over GetAllChildren.

GetAppliedSchemas() → list[str]

Return a vector containing the names of API schemas which have been applied to this prim.

This includes both the authored API schemas applied using the Apply() method on the particular schema class as well as any built-in API schemas that are automatically included through the prim type’s prim definition. To get only the authored API schemas use GetPrimTypeInfo instead.

GetAttribute(attrName) → Attribute

Return a UsdAttribute with the name attrName.

The attribute returned may or may not actually exist so it must be checked for validity. Suggested use:

if (UsdAttribute myAttr = prim.GetAttribute("myAttr")) {
   // myAttr is safe to use.
   // Edits to the owning stage requires subsequent validation.
} else {
   // myAttr was not defined/authored
}

Parameters: attrName (str) –

GetAttributeAtPath(path) → Attribute

Returns the attribute at path on the same stage as this prim.

If path is relative, it will be anchored to the path of this prim.

There is no guarantee that this method returns an attribute on this prim. This is only guaranteed if path is a purely relative property path.

GetAttribute(const TfToken&) const

UsdStage::GetAttributeAtPath(const SdfPath&) const

Parameters: path (Path) –

GetAttributes() → list[Attribute]: Like GetProperties() , but exclude all relationships from the result.

GetAuthoredAttributes() → list[Attribute]

Like GetAttributes() , but exclude attributes without authored scene description from the result.

See UsdProperty::IsAuthored() .

GetAuthoredProperties(predicate) → list[Property]

Return this prim’s properties (attributes and relationships) that have authored scene description, ordered by name according to the strongest propertyOrder statement in scene description if one exists, otherwise ordered according to TfDictionaryLessThan.

If a valid predicate is passed in, then only authored properties whose names pass the predicate are included in the result. This is useful if the client is interested only in a subset of authored properties on the prim. For example, only the ones in a given namespace or only the ones needed to compute a value.

GetProperties()

UsdProperty::IsAuthored()

Parameters: predicate (PropertyPredicateFunc) –

GetAuthoredPropertiesInNamespace(namespaces) → list[Property]

Like GetPropertiesInNamespace() , but exclude properties that do not have authored scene description from the result.

See UsdProperty::IsAuthored() .

For details of namespaced properties, see Names, Namespace Ordering, and Property Namespaces

Parameters: namespaces (list[str]) –

GetAuthoredPropertiesInNamespace(namespaces) -> list[Property]

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. namespaces must be an already-concatenated ordered set of namespaces, and may or may not terminate with the namespace-separator character.

If namespaces is empty, this method is equivalent to GetAuthoredProperties() .

Parameters: namespaces (str) –

GetAuthoredPropertyNames(predicate) → list[str]

Return this prim’s property names (attributes and relationships) that have authored scene description, ordered according to the strongest propertyOrder statement in scene description if one exists, otherwise ordered according to TfDictionaryLessThan.

If a valid predicate is passed in, then only the authored properties whose names pass the predicate are included in the result. This is useful if the client is interested only in a subset of authored properties on the prim. For example, only the ones in a given namespace or only the ones needed to compute a value.

GetPropertyNames()

UsdProperty::IsAuthored()

Parameters: predicate (PropertyPredicateFunc) –

GetAuthoredRelationships() → list[Relationship]

Like GetRelationships() , but exclude relationships without authored scene description from the result.

See UsdProperty::IsAuthored() .

GetChild(name) → Prim

Return this prim’s direct child named name if it has one, otherwise return an invalid UsdPrim.

Equivalent to:

prim.GetStage()->GetPrimAtPath(prim.GetPath().AppendChild(name))

Parameters: name (str) –

GetChildren() → SiblingRange

Return this prim’s active, loaded, defined, non-abstract children as an iterable range.

Equivalent to:

GetFilteredChildren(UsdPrimDefaultPredicate)

See Prim predicate flags and UsdPrimDefaultPredicate for more information.

GetChildrenNames() → list[str]: Return the names of the child prims in the order they appear when iterating over GetChildren.

GetChildrenReorder() → list[str]

Return the strongest opinion for the metadata used to reorder children of this prim.

Due to how reordering of prim children is composed, this value cannot be relied on to get the actual order of the prim’s children. Use GetChidrenNames, GetAllChildrenNames, GetFilteredChildrenNames to get the true child order if needed.

GetFilteredChildren(predicate) → SiblingRange

Return a subset of all of this prim’s children filtered by predicate as an iterable range.

The predicate is generated by combining a series of prim flag terms with either&&or || and !.

Example usage:

// Get all active model children.
GetFilteredChildren(UsdPrimIsActive && UsdPrimIsModel);

// Get all model children that pass the default predicate.
GetFilteredChildren(UsdPrimDefaultPredicate && UsdPrimIsModel);

If this prim is an instance, no children will be returned unless UsdTraverseInstanceProxies is used to allow instance proxies to be returned, or if this prim is itself an instance proxy.

See Prim predicate flags and UsdPrimDefaultPredicate for more information.

Parameters: predicate (_PrimFlagsPredicate) –

GetFilteredChildrenNames(predicate) → list[str]

Return the names of the child prims in the order they appear when iterating over GetFilteredChildren( predicate ).

Parameters: predicate (_PrimFlagsPredicate) –

GetFilteredNextSibling(predicate) → Prim

Return this prim’s next sibling that matches predicate if it has one, otherwise return the invalid UsdPrim.

See Prim predicate flags and UsdPrimDefaultPredicate for more information.

Parameters: predicate (_PrimFlagsPredicate) –

GetInherits() → Inherits

Return a UsdInherits object that allows one to add, remove, or mutate inherits at the currently set UsdEditTarget.

While the UsdInherits object has no methods for listing the currently authored inherits on a prim, one can use a UsdPrimCompositionQuery to query the inherits arcs that are composed by this prim.

UsdPrimCompositionQuery::GetDirectInherits

GetInstances() → list[Prim]

If this prim is a prototype prim, returns all prims that are instances of this prototype.

Otherwise, returns an empty vector.

Note that this function will return prims in prototypes for instances that are nested beneath other instances.

GetNextSibling() → Prim

Return this prim’s next active, loaded, defined, non-abstract sibling if it has one, otherwise return an invalid UsdPrim.

Equivalent to:

GetFilteredNextSibling(UsdPrimDefaultPredicate)

See Prim predicate flags and UsdPrimDefaultPredicate for more information.

GetObjectAtPath(path) → Object

Returns the object at path on the same stage as this prim.

If path is is relative, it will be anchored to the path of this prim.

UsdStage::GetObjectAtPath(const SdfPath&) const

Parameters: path (Path) –

GetParent() → Prim

Return this prim’s parent prim.

Return an invalid UsdPrim if this is a root prim.

GetPayloads() → Payloads

Return a UsdPayloads object that allows one to add, remove, or mutate payloads at the currently set UsdEditTarget.

While the UsdPayloads object has no methods for listing the currently authored payloads on a prim, one can use a UsdPrimCompositionQuery to query the payload arcs that are composed by this prim.

GetPrimAtPath(path) → Prim

Returns the prim at path on the same stage as this prim.

If path is is relative, it will be anchored to the path of this prim.

UsdStage::GetPrimAtPath(const SdfPath&) const

Parameters: path (Path) –

GetPrimDefinition() → PrimDefinition

Return this prim’s definition based on the prim’s type if the type is a registered prim type.

Returns an empty prim definition if it is not.

GetPrimInPrototype() → Prim

If this prim is an instance proxy, return the UsdPrim for the corresponding prim in the instance’s prototype.

Otherwise, return an invalid UsdPrim.

GetPrimIndex() → PrimIndex

Return the cached prim index containing all sites that can contribute opinions to this prim.

The prim index can be used to examine the composition arcs and scene description sites that can contribute to this prim’s property and metadata values.

The prim index returned by this function is optimized and may not include sites that do not contribute opinions to this prim. Use UsdPrim::ComputeExpandedPrimIndex to compute a prim index that includes all possible sites that could contribute opinions.

This prim index will be empty for prototype prims. This ensures that these prims do not provide any attribute or metadata values. For all other prims in prototypes, this is the prim index that was chosen to be shared with all other instances. In either case, the prim index’s path will not be the same as the prim’s path.

Prim indexes may be invalidated by changes to the UsdStage and cannot detect if they are expired. Clients should avoid keeping copies of the prim index across such changes, which include scene description changes or changes to load state.

GetPrimStack() → list[PrimSpec]

Return all the authored SdfPrimSpecs that may contain opinions for this prim in order from strong to weak.

This does not include all the places where contributing prim specs could potentially be created; rather, it includes only those prim specs that already exist. To discover all the places that prim specs could be authored that would contribute opinions, see”Composition Structure”

Use this method for debugging and diagnostic purposes. It is not advisable to retain a PrimStack for expedited metadata value resolution, since not all metadata resolves with simple”strongestopinion wins”semantics.

GetPrimStackWithLayerOffsets() → list[tuple[PrimSpec, LayerOffset]]

Return all the authored SdfPrimSpecs that may contain opinions for this prim in order from strong to weak paired with the cumulative layer offset from the stage’s root layer to the layer containing the prim spec.

This behaves exactly the same as UsdPrim::GetPrimStack with the addition of providing the cumulative layer offset of each spec’s layer.

Use this method for debugging and diagnostic purposes. It is not advisable to retain a PrimStack for expedited metadata value resolution, since not all metadata resolves with simple”strongestopinion wins”semantics.

GetPrimTypeInfo() → PrimTypeInfo

Return the prim’s full type info composed from its type name, applied API schemas, and any fallback types defined on the stage for unrecognized prim type names.

The returned type structure contains the”true”schema type used to create this prim’s prim definition and answer the IsA query. This value is cached and efficient to query. The cached values are guaranteed to exist for (at least) as long as the prim’s stage is open.

GetTypeName

GetAppliedSchemas

Fallback Prim Types

GetProperties(predicate) → list[Property]

Return all of this prim’s properties (attributes and relationships), including all builtin properties, ordered by name according to the strongest propertyOrder statement in scene description if one exists, otherwise ordered according to TfDictionaryLessThan.

If a valid predicate is passed in, then only properties whose names pass the predicate are included in the result. This is useful if the client is interested only in a subset of properties on the prim. For example, only the ones in a given namespace or only the ones needed to compute a value.

To obtain only either attributes or relationships, use either GetAttributes() or GetRelationships() .

To determine whether a property is either an attribute or a relationship, use the UsdObject::As() and UsdObject::Is() methods in C++:

// Use As<>() to obtain a subclass instance.
if (UsdAttribute attr = property.As<UsdAttribute>()) {
    // use attribute 'attr'.
else if (UsdRelationship rel = property.As<UsdRelationship>()) {
    // use relationship 'rel'.
}

// Use Is<>() to discriminate only.
if (property.Is<UsdAttribute>()) {
    // property is an attribute.
}

In Python, use the standard isinstance() function:

if isinstance(property, Usd.Attribute):
    # property is a Usd.Attribute.
elif isinstance(property, Usd.Relationship):
    # property is a Usd.Relationship.

GetAuthoredProperties()

UsdProperty::IsAuthored()

Parameters: predicate (PropertyPredicateFunc) –

GetPropertiesInNamespace(namespaces) → list[Property]

Return this prim’s properties that are inside the given property namespace ordered according to the strongest propertyOrder statement in scene description if one exists, otherwise ordered according to TfDictionaryLessThan.

A namespaces argument whose elements are [“ri”,”attribute”] will return all the properties under the namespace”ri:attribute”, i.e.”ri:attribute:*”. An empty namespaces argument is equivalent to GetProperties() .

For details of namespaced properties, see Names, Namespace Ordering, and Property Namespaces

Parameters: namespaces (list[str]) –

GetPropertiesInNamespace(namespaces) -> list[Property]

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. namespaces must be an already-concatenated ordered set of namespaces, and may or may not terminate with the namespace-separator character.

If namespaces is empty, this method is equivalent to GetProperties() .

Parameters: namespaces (str) –

GetProperty(propName) → Property

Return a UsdProperty with the name propName.

The property returned may or may not actually exist so it must be checked for validity. Suggested use:

if (UsdProperty myProp = prim.GetProperty("myProp")) {
   // myProp is safe to use.
   // Edits to the owning stage requires subsequent validation.
} else {
   // myProp was not defined/authored
}

Parameters: propName (str) –

GetPropertyAtPath(path) → Property

Returns the property at path on the same stage as this prim.

If path is relative, it will be anchored to the path of this prim.

There is no guarantee that this method returns a property on this prim. This is only guaranteed if path is a purely relative property path.

GetProperty(const TfToken&) const

UsdStage::GetPropertyAtPath(const SdfPath&) const

Parameters: path (Path) –

GetPropertyNames(predicate) → list[str]

Return all of this prim’s property names (attributes and relationships), including all builtin properties.

If a valid predicate is passed in, then only properties whose names pass the predicate are included in the result. This is useful if the client is interested only in a subset of properties on the prim. For example, only the ones in a given namespace or only the ones needed to compute a value.

GetAuthoredPropertyNames()

UsdProperty::IsAuthored()

Parameters: predicate (PropertyPredicateFunc) –

GetPropertyOrder() → list[str]: Return the strongest propertyOrder metadata value authored on this prim.

GetPrototype() → Prim

If this prim is an instance, return the UsdPrim for the corresponding prototype.

Otherwise, return an invalid UsdPrim.

GetReferences() → References

Return a UsdReferences object that allows one to add, remove, or mutate references at the currently set UsdEditTarget.

While the UsdReferences object has no methods for listing the currently authored references on a prim, one can use a UsdPrimCompositionQuery to query the reference arcs that are composed by this prim.

UsdPrimCompositionQuery::GetDirectReferences

GetRelationship(relName) → Relationship

Return a UsdRelationship with the name relName.

The relationship returned may or may not actually exist so it must be checked for validity. Suggested use:

if (UsdRelationship myRel = prim.GetRelationship("myRel")) {
   // myRel is safe to use.
   // Edits to the owning stage requires subsequent validation.
} else {
   // myRel was not defined/authored
}

Parameters: relName (str) –

GetRelationshipAtPath(path) → Relationship

Returns the relationship at path on the same stage as this prim.

If path is relative, it will be anchored to the path of this prim.

There is no guarantee that this method returns a relationship on this prim. This is only guaranteed if path is a purely relative property path.

GetRelationship(const TfToken&) const

UsdStage::GetRelationshipAtPath(const SdfPath&) const

Parameters: path (Path) –

GetRelationships() → list[Relationship]: Like GetProperties() , but exclude all attributes from the result.

GetSpecializes() → Specializes

Return a UsdSpecializes object that allows one to add, remove, or mutate specializes at the currently set UsdEditTarget.

While the UsdSpecializes object has no methods for listing the currently authored specializes on a prim, one can use a UsdPrimCompositionQuery to query the specializes arcs that are composed by this prim.

GetSpecifier() → Specifier: Return this prim’s composed specifier.

GetTypeName() → str

Return this prim’s composed type name.

This value is cached and is efficient to query. Note that this is just the composed type name as authored and may not represent the full type of the prim and its prim definition. If you need to reason about the actual type of the prim, use GetPrimTypeInfo instead as it accounts for recognized schemas, applied API schemas, fallback types, etc.

GetVariantSet(variantSetName) → VariantSet

Retrieve a specifically named VariantSet for editing or constructing a UsdEditTarget.

This is a shortcut for

prim.GetVariantSets().GetVariantSet(variantSetName)

Parameters: variantSetName (str) –

GetVariantSets() → VariantSets

Return a UsdVariantSets object representing all the VariantSets present on this prim.

The returned object also provides the API for adding new VariantSets to the prim.

HasAPI() → enable_if[T.schemaKind != SchemaKind.MultipleApplyAPI, bool].type

Using HasAPI in C++

UsdPrim prim = stage->OverridePrim("/path/to/prim");
MyDomainBozAPI = MyDomainBozAPI::Apply(prim);
assert(prim.HasAPI<MyDomainBozAPI>());

UsdCollectionAPI collAPI = UsdCollectionAPI::Apply(prim,
        /\*instanceName\*/ TfToken("geom"))
assert(prim.HasAPI<UsdCollectionAPI>()
assert(prim.HasAPI<UsdCollectionAPI>(/\*instanceName\*/ TfToken("geom")))

The python version of this method takes as an argument the TfType of the API schema class. Similar validation of the schema type is performed in python at run-time and a coding error is issued if the given type is not a valid applied API schema.

Using HasAPI in Python

 prim = stage.OverridePrim("/path/to/prim")
 bozAPI = MyDomain.BozAPI.Apply(prim)
 assert prim.HasAPI(MyDomain.BozAPI)

 collAPI = Usd.CollectionAPI.Apply(prim, "geom")
 assert(prim.HasAPI(Usd.CollectionAPI))
 assert(prim.HasAPI(Usd.CollectionAPI, instanceName="geom"))

Return true if the UsdPrim has had a single API schema represented by

the C++ class type T applied to it through the Apply() method provided on the API schema class.

HasAPI(instanceName) -> enable_if[T.schemaKind== SchemaKind.MultipleApplyAPI, bool].type

Return true if the UsdPrim has had a multiple-apply API schema represented by the C++ class type T applied to it through the Apply() method provided on the API schema class.

instanceName , if non-empty is used to determine if a particular instance of a multiple-apply API schema (eg. UsdCollectionAPI) has been applied to the prim, otherwise this returns true if any instance of the multiple-apply API has been applied.

Parameters: instanceName (str) –

HasAPI(schemaType, instanceName) -> bool

Return true if a prim has an API schema with TfType schemaType .

instanceName , if non-empty is used to determine if a particular instance of a multiple-apply API schema (eg. UsdCollectionAPI) has been applied to the prim. A coding error is issued if a non-empty instanceName is passed in and T represents a single-apply API schema.

This function behaves exactly like the templated HasAPI functions except for the runtime schemaType validation which happens at compile time in the templated versions. This method is provided for python clients. Use of the templated HasAPI functions are preferred.

Parameters

schemaType (Type) –
instanceName (str) –

HasAttribute(attrName) → bool

Return true if this prim has an attribute named attrName , false otherwise.

Parameters: attrName (str) –

HasAuthoredActive() → bool

Return true if this prim has an authored opinion for’active’, false otherwise.

See How”active”Affects Prims on a UsdStage for what it means for a prim to be active.

HasAuthoredInherits() → bool: Return true if this prim has any authored inherits.

HasAuthoredInstanceable() → bool: Return true if this prim has an authored opinion for’instanceable’, false otherwise.

HasAuthoredPayloads() → bool: Return true if this prim has any authored payloads.

HasAuthoredReferences() → bool: Return true if this prim has any authored references.

HasAuthoredSpecializes() → bool: Returns true if this prim has any authored specializes.

HasAuthoredTypeName() → bool: Return true if a typeName has been authored.

HasDefiningSpecifier() → bool

Return true if this prim has a specifier of type SdfSpecifierDef or SdfSpecifierClass.

SdfIsDefiningSpecifier

HasPayload() → bool

Deprecated

Return true if a payload is present on this prim.

Payloads: Impact of Using and Not Using

HasProperty(propName) → bool

Return true if this prim has an property named propName , false otherwise.

Parameters: propName (str) –

HasRelationship(relName) → bool

Return true if this prim has a relationship named relName , false otherwise.

Parameters: relName (str) –

HasVariantSets() → bool

Return true if this prim has any authored VariantSets.

this connotes only the existence of one of more VariantSets, not that such VariantSets necessarily contain any variants or variant opinions.

IsA() → bool

Return true if the prim’s schema type, is or inherits schema type T.

GetPrimTypeInfo

UsdPrimTypeInfo::GetSchemaType

Fallback Prim Types

IsA(schemaType) -> bool

Return true if the prim’s schema type is or inherits schemaType .

GetPrimTypeInfo

UsdPrimTypeInfo::GetSchemaType

Fallback Prim Types

Parameters: schemaType (Type) –

IsAbstract() → bool: Return true if this prim or any of its ancestors is a class.

IsActive() → bool

Return true if this prim is active, meaning neither it nor any of its ancestors have active=false.

Return false otherwise.

See How”active”Affects Prims on a UsdStage for what it means for a prim to be active.

IsDefined() → bool

Return true if this prim and all its ancestors have defining specifiers, false otherwise.

SdfIsDefiningSpecifier.

IsGroup() → bool

Return true if this prim is a model group based on its kind metadata, false otherwise.

If this prim is a group, it is also necessarily a model.

IsInPrototype() → bool

Return true if this prim is a prototype prim or a descendant of a prototype prim, false otherwise.

IsPrototype

IsInstance() → bool

Return true if this prim is an instance of a prototype, false otherwise.

If this prim is an instance, calling GetPrototype() will return the UsdPrim for the corresponding prototype prim.

IsInstanceProxy() → bool

Return true if this prim is an instance proxy, false otherwise.

An instance proxy prim represents a descendent of an instance prim.

IsInstanceable() → bool

Return true if this prim has been marked as instanceable.

Note that this is not the same as IsInstance() . A prim may return true for IsInstanceable() and false for IsInstance() if this prim is not active or if it is marked as instanceable but contains no instanceable data.

IsLoaded() → bool: Return true if this prim is active, and either it is loadable and it is loaded, or its nearest loadable ancestor is loaded, or it has no loadable ancestor; false otherwise.

IsModel() → bool: Return true if this prim is a model based on its kind metadata, false otherwise.

static IsPathInPrototype()

classmethod IsPathInPrototype(path) -> bool

Return true if the given path identifies a prototype prim or a prim or property descendant of a prototype prim, false otherwise.

IsPrototypePath

Parameters: path (Path) –

IsPrototype() → bool

Return true if this prim is an instancing prototype prim, false otherwise.

IsInPrototype

static IsPrototypePath()

classmethod IsPrototypePath(path) -> bool

Return true if the given path identifies a prototype prim, false otherwise.

This function will return false for prim and property paths that are descendants of a prototype prim path.

IsPathInPrototype

Parameters: path (Path) –

IsPseudoRoot() → bool

Returns true if the prim is the pseudo root.

Equivalent to

prim.GetPath() == SdfPath::AbsoluteRootPath()

Load(policy) → None

Load this prim, all its ancestors, and by default all its descendants.

If loadPolicy is UsdLoadWithoutDescendants, then load only this prim and its ancestors.

See UsdStage::Load for additional details.

Parameters: policy (LoadPolicy) –

MakeResolveTargetStrongerThanEditTarget(editTarget) → ResolveTarget

Creates and returns a resolve target that, when passed to a UsdAttributeQuery for one of this prim’s attributes, causes value resolution to only consider specs that are stronger than the spec that would be authored for this prim when using the given editTarget .

If the edit target would not affect any specs that could contribute to this prim, a null resolve target is returned.

Parameters: editTarget (EditTarget) –

MakeResolveTargetUpToEditTarget(editTarget) → ResolveTarget

Creates and returns a resolve target that, when passed to a UsdAttributeQuery for one of this prim’s attributes, causes value resolution to only consider weaker specs up to and including the spec that would be authored for this prim when using the given editTarget .

If the edit target would not affect any specs that could contribute to this prim, a null resolve target is returned.

Parameters: editTarget (EditTarget) –

RemoveAPI() → bool

Removes a single-apply API schema with the given C++ type’SchemaType’from this prim in the current edit target.

This is done by removing the API schema’s name token from the token- valued, listOp metadata apiSchemas on this prim as well as authoring an explicit deletion of schema name from the listOp.

Returns true upon success or if the API schema is already deleted in the current edit target.

An error is issued and false returned for any of the following conditions:

this prim is not a valid prim for editing

this prim is valid, but cannot be reached or overridden in the current edit target

the schema name cannot be deleted in the apiSchemas listOp metadata

RemoveAPI(schemaType) -> bool

Non-templated overload of the templated RemoveAPI above.

This function behaves exactly like the templated RemoveAPI except for the runtime schemaType validation which happens at compile time in the templated version. This method is provided for python clients. Use of the templated RemoveAPI is preferred.

Parameters: schemaType (Type) –

RemoveAPI(instanceName) -> bool

Removes a multiple-apply API schema with the given C++ type’SchemaType’and instance name instanceName from this prim in the current edit target.

This is done by removing the instanced schema name token from the token-valued, listOp metadata apiSchemas on this prim as well as authoring an explicit deletion of the name from the listOp. For example, if SchemaType is’ UsdCollectionAPI ‘and instanceName is’plasticStuff’, the name’CollectionAPI:plasticStuff’is deleted from the’apiSchemas’listOp metadata.

Returns true upon success or if the API schema with this instanceName is already deleted in the current edit target.

An error is issued and false returned for any of the following conditions:

instanceName is empty

this prim is not a valid prim for editing

this prim is valid, but cannot be reached or overridden in the current edit target

the schema name cannot be deleted in the apiSchemas listOp metadata

Parameters: instanceName (str) –

RemoveAPI(schemaType, instanceName) -> bool

Non-templated overload of the templated RemoveAPI above.

This function behaves exactly like the templated RemoveAPI except for the runtime schemaType validation which happens at compile time in the templated version. This method is provided for python clients. Use of the templated RemoveAPI is preferred.

Parameters

schemaType (Type) –
instanceName (str) –

RemoveAppliedSchema(appliedSchemaName) → bool

Removes the applied API schema name token appliedSchemaName from the apiSchemas metadata for this prim at the current edit target.

For multiple-apply schemas the name token should include the instance name for the applied schema, for example’CollectionAPI:plasticStuff’

For an explicit list operation, this removes the applied schema name from the explicit items list if it was present. For a non-explicit list operation, this will remove any occurrence of the applied schema name from the prepended and appended item as well as adding it to the deleted items list.

Returns true upon success or if the API schema is already deleted in the current edit target.

An error is issued and false returned for any of the following conditions:

this prim is not a valid prim for editing

this prim is valid, but cannot be reached or overridden in the current edit target

the schema name cannot be deleted in the apiSchemas listOp metadata Unlike RemoveAPI this method does not require that the name token refer to a valid API schema type. RemoveAPI is the preferred method for removing valid API schemas.

Parameters: appliedSchemaName (str) –

RemoveProperty(propName) → bool

Remove all scene description for the property with the given propName in the current UsdEditTarget.

Return true if the property is removed, false otherwise.

Because this method can only remove opinions about the property from the current EditTarget, you may generally find it more useful to use UsdAttribute::Block() , which will ensure that all values from the EditTarget and weaker layers for the property will be ignored.

Parameters: propName (str) –

SetActive(active) → bool

Author’active’metadata for this prim at the current EditTarget.

See How”active”Affects Prims on a UsdStage for the effects of activating or deactivating a prim.

Parameters: active (bool) –

SetChildrenReorder(order) → None

Author an opinion for the metadata used to reorder children of this prim at the current EditTarget.

Parameters: order (list[str]) –

SetInstanceable(instanceable) → bool

Author’instanceable’metadata for this prim at the current EditTarget.

Parameters: instanceable (bool) –

SetPayload(payload) → bool

Deprecated

Author payload metadata for this prim at the current edit target. Return true on success, false if the value could not be set.

Payloads: Impact of Using and Not Using

Parameters: payload (Payload) –

SetPayload(assetPath, primPath) -> bool

Deprecated

Shorthand for SetPayload(SdfPayload(assetPath, primPath)).

Parameters

assetPath (str) –
primPath (Path) –

SetPayload(layer, primPath) -> bool

Deprecated

Shorthand for SetPayload( SdfPayload (layer->GetIdentifier(), primPath)).

Parameters

layer (Layer) –
primPath (Path) –

SetPropertyOrder(order) → None

Author an opinion for propertyOrder metadata on this prim at the current EditTarget.

Parameters: order (list[str]) –

SetSpecifier(specifier) → bool

Author an opinion for this Prim’s specifier at the current edit target.

Parameters: specifier (Specifier) –

SetTypeName(typeName) → bool

Author this Prim’s typeName at the current EditTarget.

Parameters: typeName (str) –

Unload() → None

Unloads this prim and all its descendants.

See UsdStage::Unload for additional details.

class pxr.Usd.PrimCompositionQuery

Object for making optionally filtered composition queries about a prim. It creates a list of strength ordering UsdPrimCompositionQueryArc that can be filtered by a combination of criteria and returned.

Invalidation

This object does not listen for change notification. If a consumer is holding on to a UsdPrimCompositionQuery, it is their responsibility to dispose of it in response to a resync change to the associated prim. Failing to do so may result in incorrect values or crashes due to dereferencing invalid objects.

Classes:

`ArcIntroducedFilter`	Choices for filtering composition arcs based on where the arc is introduced.
`ArcTypeFilter`	Choices for filtering composition arcs based on arc type.
`DependencyTypeFilter`	Choices for filtering composition arcs on dependency type.
`Filter`
`HasSpecsFilter`	Choices for filtering composition arcs on whether the node contributes specs to the prim.

Methods:

`GetCompositionArcs`()	Return a list of composition arcs for this query's prim using the current query filter.
`GetDirectInherits`	classmethod GetDirectInherits(prim) -> PrimCompositionQuery
`GetDirectReferences`	classmethod GetDirectReferences(prim) -> PrimCompositionQuery
`GetDirectRootLayerArcs`	classmethod GetDirectRootLayerArcs(prim) -> PrimCompositionQuery

Attributes:

filter

Filter

class ArcIntroducedFilter

Choices for filtering composition arcs based on where the arc is introduced.

Attributes:

`All`
`IntroducedInRootLayerPrimSpec`
`IntroducedInRootLayerStack`
`names`
`values`

All = pxr.Usd.ArcIntroducedFilter.All

IntroducedInRootLayerPrimSpec = pxr.Usd.ArcIntroducedFilter.IntroducedInRootLayerPrimSpec

IntroducedInRootLayerStack = pxr.Usd.ArcIntroducedFilter.IntroducedInRootLayerStack

names = {'All': pxr.Usd.ArcIntroducedFilter.All, 'IntroducedInRootLayerPrimSpec': pxr.Usd.ArcIntroducedFilter.IntroducedInRootLayerPrimSpec, 'IntroducedInRootLayerStack': pxr.Usd.ArcIntroducedFilter.IntroducedInRootLayerStack}

values = {0: pxr.Usd.ArcIntroducedFilter.All, 1: pxr.Usd.ArcIntroducedFilter.IntroducedInRootLayerStack, 2: pxr.Usd.ArcIntroducedFilter.IntroducedInRootLayerPrimSpec}

class ArcTypeFilter

Choices for filtering composition arcs based on arc type.

Attributes:

`All`
`Inherit`
`InheritOrSpecialize`
`NotInheritOrSpecialize`
`NotReferenceOrPayload`
`NotVariant`
`Payload`
`Reference`
`ReferenceOrPayload`
`Specialize`
`Variant`
`names`
`values`

All = pxr.Usd.ArcTypeFilter.All

Inherit = pxr.Usd.ArcTypeFilter.Inherit

InheritOrSpecialize = pxr.Usd.ArcTypeFilter.InheritOrSpecialize

NotInheritOrSpecialize = pxr.Usd.ArcTypeFilter.NotInheritOrSpecialize

NotReferenceOrPayload = pxr.Usd.ArcTypeFilter.NotReferenceOrPayload

NotVariant = pxr.Usd.ArcTypeFilter.NotVariant

Payload = pxr.Usd.ArcTypeFilter.Payload

Reference = pxr.Usd.ArcTypeFilter.Reference

ReferenceOrPayload = pxr.Usd.ArcTypeFilter.ReferenceOrPayload

Specialize = pxr.Usd.ArcTypeFilter.Specialize

Variant = pxr.Usd.ArcTypeFilter.Variant

names = {'All': pxr.Usd.ArcTypeFilter.All, 'Inherit': pxr.Usd.ArcTypeFilter.Inherit, 'InheritOrSpecialize': pxr.Usd.ArcTypeFilter.InheritOrSpecialize, 'NotInheritOrSpecialize': pxr.Usd.ArcTypeFilter.NotInheritOrSpecialize, 'NotReferenceOrPayload': pxr.Usd.ArcTypeFilter.NotReferenceOrPayload, 'NotVariant': pxr.Usd.ArcTypeFilter.NotVariant, 'Payload': pxr.Usd.ArcTypeFilter.Payload, 'Reference': pxr.Usd.ArcTypeFilter.Reference, 'ReferenceOrPayload': pxr.Usd.ArcTypeFilter.ReferenceOrPayload, 'Specialize': pxr.Usd.ArcTypeFilter.Specialize, 'Variant': pxr.Usd.ArcTypeFilter.Variant}

values = {0: pxr.Usd.ArcTypeFilter.All, 1: pxr.Usd.ArcTypeFilter.Reference, 2: pxr.Usd.ArcTypeFilter.Payload, 3: pxr.Usd.ArcTypeFilter.Inherit, 4: pxr.Usd.ArcTypeFilter.Specialize, 5: pxr.Usd.ArcTypeFilter.Variant, 6: pxr.Usd.ArcTypeFilter.ReferenceOrPayload, 7: pxr.Usd.ArcTypeFilter.InheritOrSpecialize, 8: pxr.Usd.ArcTypeFilter.NotReferenceOrPayload, 9: pxr.Usd.ArcTypeFilter.NotInheritOrSpecialize, 10: pxr.Usd.ArcTypeFilter.NotVariant}

class DependencyTypeFilter

Choices for filtering composition arcs on dependency type.

This can be direct (arc introduced at the prim’s level in namespace) or ancestral (arc introduced by a namespace parent of the prim).

Attributes:

`All`
`Ancestral`
`Direct`
`names`
`values`

All = pxr.Usd.DependencyTypeFilter.All

Ancestral = pxr.Usd.DependencyTypeFilter.Ancestral

Direct = pxr.Usd.DependencyTypeFilter.Direct

names = {'All': pxr.Usd.DependencyTypeFilter.All, 'Ancestral': pxr.Usd.DependencyTypeFilter.Ancestral, 'Direct': pxr.Usd.DependencyTypeFilter.Direct}

values = {0: pxr.Usd.DependencyTypeFilter.All, 1: pxr.Usd.DependencyTypeFilter.Direct, 2: pxr.Usd.DependencyTypeFilter.Ancestral}

class Filter

Attributes:

`arcIntroducedFilter`
`arcTypeFilter`
`dependencyTypeFilter`
`hasSpecsFilter`

property arcIntroducedFilter

property arcTypeFilter

property dependencyTypeFilter

property hasSpecsFilter

class HasSpecsFilter

Choices for filtering composition arcs on whether the node contributes specs to the prim.

Attributes:

`All`
`HasNoSpecs`
`HasSpecs`
`names`
`values`

All = pxr.Usd.HasSpecsFilter.All

HasNoSpecs = pxr.Usd.HasSpecsFilter.HasNoSpecs

HasSpecs = pxr.Usd.HasSpecsFilter.HasSpecs

names = {'All': pxr.Usd.HasSpecsFilter.All, 'HasNoSpecs': pxr.Usd.HasSpecsFilter.HasNoSpecs, 'HasSpecs': pxr.Usd.HasSpecsFilter.HasSpecs}

values = {0: pxr.Usd.HasSpecsFilter.All, 1: pxr.Usd.HasSpecsFilter.HasSpecs, 2: pxr.Usd.HasSpecsFilter.HasNoSpecs}

GetCompositionArcs() → list[UsdPrimCompositionQueryArc]

Return a list of composition arcs for this query’s prim using the current query filter.

The composition arcs are always returned in order from strongest to weakest regardless of the filter.

static GetDirectInherits()

classmethod GetDirectInherits(prim) -> PrimCompositionQuery

Returns a prim composition query for the given prim with a preset filter that only returns inherit arcs that are not ancestral.

Parameters: prim (Prim) –

static GetDirectReferences()

classmethod GetDirectReferences(prim) -> PrimCompositionQuery

Returns a prim composition query for the given prim with a preset filter that only returns reference arcs that are not ancestral.

Parameters: prim (Prim) –

static GetDirectRootLayerArcs()

classmethod GetDirectRootLayerArcs(prim) -> PrimCompositionQuery

Returns a prim composition query for the given prim with a preset filter that only returns direct arcs that were introduced by opinions defined in a layer in the root layer stack.

Parameters: prim (Prim) –

property filter

Filter

Return a copy of the current filter parameters.

type : None

Change the filter for this query.

Type: type

class pxr.Usd.PrimDefinition

Class representing the builtin definition of a prim given the schemas registered in the schema registry.

It provides access to the the builtin properties and metadata of a prim whose type is defined by this definition.

Instances of this class can only be created by the UsdSchemaRegistry.

Methods:

`FlattenTo`(layer, path, newSpecSpecifier)	Copies the contents of this prim definition to a prim spec on the given `layer` at the given `path` .
`GetAppliedAPISchemas`()	Return the list of names of the API schemas that have been applied to this prim definition in order.
`GetAttributeFallbackValue`(attrName, value)	Retrieves the fallback value for the attribute named `attrName` and stores it in `value` if possible.
`GetDocumentation`()	Returns the documentation metadata defined by the prim definition for the prim itself.
`GetMetadata`(key, value)	Retrieves the fallback value for the metadata field named `key` , that is defined by this prim definition for the prim itself and stores it in `value` if possible.
`GetMetadataByDictKey`(key, keyPath, value)	Retrieves the value at `keyPath` from the fallback dictionary value for the dictionary metadata field named `key` , that is defined by this prim definition for the prim itself, and stores it in `value` if possible.
`GetPropertyDocumentation`(propName)	Returns the documentation metadata defined by the prim definition for the property named `propName` if it exists.
`GetPropertyMetadata`(propName, key, value)	Retrieves the fallback value for the metadata field named `key` , that is defined by this prim definition for the property named `propName` , and stores it in `value` if possible.
`GetPropertyMetadataByDictKey`(propName, key, ...)	Retrieves the value at `keyPath` from the fallback dictionary value for the dictionary metadata field named `key` , that is defined by this prim definition for the property named `propName` , and stores it in `value` if possible.
`GetPropertyNames`()	Return the list of names of builtin properties for this prim definition.
`GetSchemaAttributeSpec`(attrName)	This is a convenience method.
`GetSchemaPropertySpec`(propName)	Return the property spec that defines the fallback for the property named propName on prims of this prim definition's type.
`GetSchemaRelationshipSpec`(relName)	This is a convenience method.
`ListMetadataFields`()	Returns the list of names of metadata fields that are defined by this prim definition for the prim itself.
`ListPropertyMetadataFields`(propName)	Returns the list of names of metadata fields that are defined by this prim definition for property `propName` if a property named `propName` exists.

FlattenTo(layer, path, newSpecSpecifier) → bool

Copies the contents of this prim definition to a prim spec on the given layer at the given path .

This includes the entire property spec for each of this definition’s built-in properties as well as all of this definition’s prim metadata.

If the prim definition represents a concrete prim type, the type name of the prim spec is set to the the type name of this prim definition. Otherwise the type name is set to empty. The’apiSchemas’metadata on the prim spec will always be explicitly set to the combined list of all API schemas applied to this prim definition, i.e. the list returned by UsdPrimDefinition::GetAppliedAPISchemas. Note that if this prim definition is an API schema prim definition (see UsdSchemaRegistry::FindAppliedAPIPrimDefinition) then’apiSchemas’will be empty as this prim definition does not”have”an applied API because instead it”is”an applied API.

If there is no prim spec at the given path , a new prim spec is created at that path with the specifier newSpecSpecifier . Any necessary ancestor specs will be created as well but they will always be created as overs. If a spec does exist at path , then all of its properties and schema allowed metadata are cleared before it is populated from the prim definition.

Parameters

layer (Layer) –
path (Path) –
newSpecSpecifier (Specifier) –

FlattenTo(parent, name, newSpecSpecifier) -> Prim

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Copies the contents of this prim definition to a prim spec at the current edit target for a prim with the given name under the prim parent .

Parameters

parent (Prim) –
name (str) –
newSpecSpecifier (Specifier) –

FlattenTo(prim, newSpecSpecifier) -> Prim

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Copies the contents of this prim definition to a prim spec at the current edit target for the given prim .

Parameters

prim (Prim) –
newSpecSpecifier (Specifier) –

GetAppliedAPISchemas() → list[str]: Return the list of names of the API schemas that have been applied to this prim definition in order.

GetAttributeFallbackValue(attrName, value) → bool

Retrieves the fallback value for the attribute named attrName and stores it in value if possible.

Returns true if the attribute exists in this prim definition and it has a fallback value defined. Returns false otherwise.

Parameters

attrName (str) –
value (T) –

GetDocumentation() → str: Returns the documentation metadata defined by the prim definition for the prim itself.

GetMetadata(key, value) → bool

Retrieves the fallback value for the metadata field named key , that is defined by this prim definition for the prim itself and stores it in value if possible.

Returns true if a fallback value is defined for the given metadata key . Returns false otherwise.

Parameters

key (str) –
value (T) –

GetMetadataByDictKey(key, keyPath, value) → bool

Retrieves the value at keyPath from the fallback dictionary value for the dictionary metadata field named key , that is defined by this prim definition for the prim itself, and stores it in value if possible.

Returns true if a fallback dictionary value is defined for the given metadata key and it contains a value at keyPath . Returns false otherwise.

Parameters

key (str) –
keyPath (str) –
value (T) –

GetPropertyDocumentation(propName) → str

Returns the documentation metadata defined by the prim definition for the property named propName if it exists.

Parameters: propName (str) –

GetPropertyMetadata(propName, key, value) → bool

Retrieves the fallback value for the metadata field named key , that is defined by this prim definition for the property named propName , and stores it in value if possible.

Returns true if a fallback value is defined for the given metadata key for the named property. Returns false otherwise.

Parameters

propName (str) –
key (str) –
value (T) –

GetPropertyMetadataByDictKey(propName, key, keyPath, value) → bool

Retrieves the value at keyPath from the fallback dictionary value for the dictionary metadata field named key , that is defined by this prim definition for the property named propName , and stores it in value if possible.

Returns true if a fallback dictionary value is defined for the given metadata key for the named property and it contains a value at keyPath . Returns false otherwise.

Parameters

propName (str) –
key (str) –
keyPath (str) –
value (T) –

GetPropertyNames() → list[str]: Return the list of names of builtin properties for this prim definition.

GetSchemaAttributeSpec(attrName) → AttributeSpec

This is a convenience method.

It is shorthand for TfDynamic_cast<SdfAttributeSpecHandle>( GetSchemaPropertySpec(primType, attrName));

Parameters: attrName (str) –

GetSchemaPropertySpec(propName) → PropertySpec

Return the property spec that defines the fallback for the property named propName on prims of this prim definition’s type.

Return null if there is no such property spec.

Parameters: propName (str) –

GetSchemaRelationshipSpec(relName) → RelationshipSpec

This is a convenience method.

It is shorthand for TfDynamic_cast<SdfRelationshipSpecHandle>( GetSchemaPropertySpec(primType, relName));

Parameters: relName (str) –

ListMetadataFields() → list[str]: Returns the list of names of metadata fields that are defined by this prim definition for the prim itself.

ListPropertyMetadataFields(propName) → list[str]

Returns the list of names of metadata fields that are defined by this prim definition for property propName if a property named propName exists.

Parameters: propName (str) –

class pxr.Usd.PrimRange

An forward-iterable range that traverses a subtree of prims rooted at a given prim in depth-first order.

In addition to depth-first order, UsdPrimRange provides the optional ability to traverse in depth-first pre- and post-order wher prims appear twice in the range; first before all descendants and then again immediately after all descendants. This is useful for maintaining state associated with subtrees, in a stack-like fashion. See UsdPrimRange::iterator::IsPostVisit() to detect when an iterator is visiting a prim for the second time.

There are several constructors providing different levels of configurability; ultimately, one can provide a prim predicate for a custom iteration, just as one would use UsdPrim::GetFilteredChildren() in a custom recursion.

Why would one want to use a UsdPrimRange rather than just iterating over the results of UsdPrim::GetFilteredDescendants() ? Primarily, if one of the following applies:

You need to perform pre-and-post-order processing

You may want to prune sub-trees from processing (see UsdPrimRange::iterator::PruneChildren() )

You want to treat the root prim itself uniformly with its descendents (GetFilteredDescendants() will not return the root prim itself, while UsdPrimRange will - see UsdPrimRange::Stage for an exception). Using UsdPrimRange in C++

UsdPrimRange provides standard container-like semantics. For example:

// simple range-for iteration
for (UsdPrim prim: UsdPrimRange(rootPrim)) {
    ProcessPrim(prim);
}

// using stl algorithms
std::vector<UsdPrim> meshes;
auto range = stage->Traverse();
std::copy_if(range.begin(), range.end(), std::back_inserter(meshes),
             [](UsdPrim const &) { return prim.IsA<UsdGeomMesh>(); });

// iterator-based iterating, with subtree pruning
UsdPrimRange range(rootPrim);
for (auto iter = range.begin(); iter != range.end(); ++iter) {
    if (UsdModelAPI(\*iter).GetKind() == KindTokens->component) {
        iter.PruneChildren();
    }
    else {
        nonComponents.push_back(\*iter);
    }
}

Using Usd.PrimRange in python

The python wrapping for PrimRange is python-iterable, so it can used directly as the object of a”for x in...”clause; however in that usage one loses access to PrimRange methods such as PruneChildren() and IsPostVisit(). Simply create the iterator outside the loop to overcome this limitation. Finally, in python, prim predicates must be combined with bit-wise operators rather than logical operators because the latter are not overridable.

# simple iteration
for prim in Usd.PrimRange(rootPrim):
    ProcessPrim(prim)

# filtered range using iterator to invoke iterator methods
it = iter(Usd.PrimRange.Stage(stage, Usd.PrimIsLoaded  &  ~Usd.PrimIsAbstract))
for prim in it:
    if Usd.ModelAPI(prim).GetKind() == Kind.Tokens.component:
        it.PruneChildren()
    else:
        nonComponents.append(prim)

Finally, since iterators in python are not directly dereferencable, we provide the python only methods GetCurrentPrim() and IsValid(), documented in the python help system.

Methods:

`AllPrims`	classmethod AllPrims(start) -> PrimRange
`AllPrimsPreAndPostVisit`	classmethod AllPrimsPreAndPostVisit(start) -> PrimRange
`IsValid`	true if the iterator is not yet exhausted
`PreAndPostVisit`	classmethod PreAndPostVisit(start) -> PrimRange
`Stage`	classmethod Stage(stage, predicate) -> PrimRange

static AllPrims()

classmethod AllPrims(start) -> PrimRange

Construct a PrimRange that traverses the subtree rooted at start in depth-first order, visiting all prims (including deactivated, undefined, and abstract prims).

Parameters: start (Prim) –

static AllPrimsPreAndPostVisit()

classmethod AllPrimsPreAndPostVisit(start) -> PrimRange

Construct a PrimRange that traverses the subtree rooted at start in depth-first order, visiting all prims (including deactivated, undefined, and abstract prims) with pre- and post-order visitation.

Pre- and post-order visitation means that each prim appears twice in the range; not only prior to all its descendants as with an ordinary traversal but also immediately following its descendants. This lets client code maintain state for subtrees. See UsdPrimRange::iterator::IsPostVisit() .

Parameters: start (Prim) –

IsValid(): true if the iterator is not yet exhausted

static PreAndPostVisit()

classmethod PreAndPostVisit(start) -> PrimRange

Create a PrimRange that traverses the subtree rooted at start in depth-first order, visiting prims that pass the default predicate (as defined by UsdPrimDefaultPredicate) with pre- and post-order visitation.

Pre- and post-order visitation means that each prim appears twice in the range; not only prior to all its descendants as with an ordinary traversal but also immediately following its descendants. This lets client code maintain state for subtrees. See UsdPrimRange::iterator::IsPostVisit() .

Parameters: start (Prim) –

PreAndPostVisit(start, predicate) -> PrimRange

Create a PrimRange that traverses the subtree rooted at start in depth-first order, visiting prims that pass predicate with pre- and post-order visitation.

Pre- and post-order visitation means that each prim appears twice in the range; not only prior to all its descendants as with an ordinary traversal but also immediately following its descendants. This lets client code maintain state for subtrees. See UsdPrimRange::iterator::IsPostVisit() .

Parameters

start (Prim) –
predicate (_PrimFlagsPredicate) –

static Stage()

classmethod Stage(stage, predicate) -> PrimRange

Create a PrimRange that traverses all the prims on stage , and visits those that pass the default predicate (as defined by UsdPrimDefaultPredicate).

Parameters

stage (Stage) –
predicate (_PrimFlagsPredicate) –

class pxr.Usd.PrimTypeInfo

Class that holds the full type information for a prim.

It holds the type name, applied API schema names, and possibly a mapped schema type name which represent a unique full type. The info this holds is used to cache and provide the”real”schema type for the prim’s type name regardless of whether it is a recognized prim type or not. The optional”mapped schema type name”is used to obtain a valid schema type for an unrecognized prim type name if the stage provides a fallback type for the unrecognized type. This class also provides access to the prim definition that defines all the built-in properties and metadata of a prim of this type.

Methods:

`GetAppliedAPISchemas`()	Returns the list of applied API schemas, directly authored on the prim, that impart additional properties on its prim definition.
`GetEmptyPrimType`	classmethod GetEmptyPrimType() -> PrimTypeInfo
`GetPrimDefinition`()	Returns the prim definition associated with this prim type's schema type and applied API schemas.
`GetSchemaType`()	Returns the TfType of the actual concrete schema that prims of this type will use to create their prim definition.
`GetSchemaTypeName`()	Returns the type name associated with the schema type returned from GetSchemaType.
`GetTypeName`()	Returns the concrete prim type name.

GetAppliedAPISchemas() → list[str]

Returns the list of applied API schemas, directly authored on the prim, that impart additional properties on its prim definition.

This does NOT include the applied API schemas that may be defined in the conrete prim type’s prim definition..

static GetEmptyPrimType()

classmethod GetEmptyPrimType() -> PrimTypeInfo

Returns the empty prim type info.

GetPrimDefinition() → PrimDefinition: Returns the prim definition associated with this prim type’s schema type and applied API schemas.

GetSchemaType() → Type

Returns the TfType of the actual concrete schema that prims of this type will use to create their prim definition.

Typically, this will be the type registered in the schema registry for the concrete prim type returned by GetTypeName. But if the stage provided this type info with a fallback type because the prim type name is not a recognized schema, this will return the provided fallback schema type instead.

Fallback Prim Types

GetSchemaTypeName() → str

Returns the type name associated with the schema type returned from GetSchemaType.

This will always be equivalent to calling UsdSchemaRegistry::GetConcreteSchemaTypeName on the type returned by GetSchemaType and will typically be the same as GetTypeName as long as the prim type name is a recognized prim type.

Fallback Prim Types

GetTypeName() → str: Returns the concrete prim type name.

class pxr.Usd.Property

Base class for UsdAttribute and UsdRelationship scenegraph objects.

UsdProperty has a bool conversion operator that validates that the property IsDefined() and thus valid for querying and authoring values and metadata. This is a fairly expensive query that we do not cache, so if client code retains UsdProperty objects it should manage its object validity closely for performance. An ideal pattern is to listen for UsdNotice::StageContentsChanged notifications, and revalidate/refetch retained UsdObjects only then and otherwise use them without validity checking.

Methods:

`ClearDisplayGroup`()	Clears this property's display group (metadata) in the current EditTarget (only).
`ClearDisplayName`()	Clears this property's display name (metadata) in the current EditTarget (only).
`FlattenTo`(parent)	Flattens this property to a property spec with the same name beneath the given `parent` prim in the edit target of its owning stage.
`GetBaseName`()	Return this property's name with all namespace prefixes removed, i.e.
`GetDisplayGroup`()	Return this property's display group (metadata).
`GetDisplayName`()	Return this property's display name (metadata).
`GetNamespace`()	Return this property's complete namespace prefix.
`GetNestedDisplayGroups`()	Return this property's displayGroup as a sequence of groups to be nested, or an empty vector if displayGroup is empty or not authored.
`GetPropertyStack`(time)	Returns a strength-ordered list of property specs that provide opinions for this property.
`GetPropertyStackWithLayerOffsets`(time)	Returns a strength-ordered list of property specs that provide opinions for this property paired with the cumulative layer offset from the stage's root layer to the layer containing the property spec.
`HasAuthoredDisplayGroup`()	Returns true if displayGroup was explicitly authored and GetMetadata() will return a meaningful value for displayGroup.
`HasAuthoredDisplayName`()	Returns true if displayName was explicitly authored and GetMetadata() will return a meaningful value for displayName.
`IsAuthored`()	Return true if there are any authored opinions for this property in any layer that contributes to this stage, false otherwise.
`IsAuthoredAt`(editTarget)	Return true if there is an SdfPropertySpec authored for this property at the given editTarget, otherwise return false.
`IsCustom`()	Return true if this is a custom property (i.e., not part of a prim schema).
`IsDefined`()	Return true if this is a builtin property or if the strongest authored SdfPropertySpec for this property's path matches this property's dynamic type.
`SetCustom`(isCustom)	Set the value for custom at the current EditTarget, return true on success, false if the value can not be written.
`SetDisplayGroup`(displayGroup)	Sets this property's display group (metadata).
`SetDisplayName`(name)	Sets this property's display name (metadata).
`SetNestedDisplayGroups`(nestedGroups)	Sets this property's display group (metadata) to the nested sequence.
`SplitName`()	Return this property's name elements including namespaces and its base name as the final element.

ClearDisplayGroup() → bool

Clears this property’s display group (metadata) in the current EditTarget (only).

Returns true on success.

ClearDisplayName() → bool

Clears this property’s display name (metadata) in the current EditTarget (only).

Returns true on success.

FlattenTo(parent) → Property

Flattens this property to a property spec with the same name beneath the given parent prim in the edit target of its owning stage.

The parent prim may belong to a different stage than this property’s owning stage.

Flattening authors all authored resolved values and metadata for this property into the destination property spec. If this property is a builtin property, fallback values and metadata will also be authored if the destination property has a different fallback value or no fallback value, or if the destination property has an authored value that overrides its fallback.

Attribute connections and relationship targets that target an object beneath this property’s owning prim will be remapped to target objects beneath the destination parent prim.

If the destination spec already exists, it will be overwritten.

UsdStage::Flatten

Parameters: parent (Prim) –

FlattenTo(parent, propName) -> Property

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Flattens this property to a property spec with the given propName beneath the given parent prim in the edit target of its owning stage.

The parent prim may belong to a different stage than this property’s owning stage.

Parameters

parent (Prim) –
propName (str) –

FlattenTo(property) -> Property

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Flattens this property to a property spec for the given property in the edit target of its owning prim’s stage.

The property owning prim may belong to a different stage than this property’s owning stage.

Parameters: property (Property) –

GetBaseName() → str

Return this property’s name with all namespace prefixes removed, i.e.

the last component of the return value of GetName()

This is generally the property’s”client name”; property namespaces are often used to group related properties together. The namespace prefixes the property name but many consumers will care only about un- namespaced name, i.e. its BaseName. For more information, see Names, Namespace Ordering, and Property Namespaces

GetDisplayGroup() → str

Return this property’s display group (metadata).

This returns the empty token if no display group has been set.

SetDisplayGroup()

GetDisplayName() → str

Return this property’s display name (metadata).

This returns the empty string if no display name has been set.

SetDisplayName()

GetNamespace() → str

Return this property’s complete namespace prefix.

Return the empty token if this property has no namespaces.

This is the complement of GetBaseName() , although it does not contain a trailing namespace delimiter

GetNestedDisplayGroups() → list[str]: Return this property’s displayGroup as a sequence of groups to be nested, or an empty vector if displayGroup is empty or not authored.

GetPropertyStack(time) → list[PropertySpec]

Returns a strength-ordered list of property specs that provide opinions for this property.

If time is UsdTimeCode::Default() , or this property is a UsdRelationship (which are never affected by clips), we will not consider value clips for opinions. For any other time , for a UsdAttribute, clips whose samples may contribute an opinion will be included. These specs are ordered from strongest to weakest opinion, although if time requires interpolation between two adjacent clips, both clips will appear, sequentially.

The results returned by this method are meant for debugging and diagnostic purposes. It is not advisable to retain a PropertyStack for the purposes of expedited value resolution for properties, since the makeup of an attribute’s PropertyStack may itself be time-varying. To expedite repeated value resolution of attributes, you should instead retain a UsdAttributeQuery .

UsdClipsAPI

Parameters: time (TimeCode) –

GetPropertyStackWithLayerOffsets(time) → list[tuple[PropertySpec, LayerOffset]]

Returns a strength-ordered list of property specs that provide opinions for this property paired with the cumulative layer offset from the stage’s root layer to the layer containing the property spec.

This behaves exactly the same as UsdProperty::GetPropertyStack with the addition of providing the cumulative layer offset of each spec’s layer.

The results returned by this method are meant for debugging and diagnostic purposes. It is not advisable to retain a PropertyStack for the purposes of expedited value resolution for properties, since the makeup of an attribute’s PropertyStack may itself be time-varying. To expedite repeated value resolution of attributes, you should instead retain a UsdAttributeQuery .

Parameters: time (TimeCode) –

HasAuthoredDisplayGroup() → bool: Returns true if displayGroup was explicitly authored and GetMetadata() will return a meaningful value for displayGroup.

HasAuthoredDisplayName() → bool: Returns true if displayName was explicitly authored and GetMetadata() will return a meaningful value for displayName.

IsAuthored() → bool: Return true if there are any authored opinions for this property in any layer that contributes to this stage, false otherwise.

IsAuthoredAt(editTarget) → bool

Return true if there is an SdfPropertySpec authored for this property at the given editTarget, otherwise return false.

Note that this method does not do partial composition. It does not consider whether authored scene description exists at editTarget or weaker, only exactly at the given editTarget.

Parameters: editTarget (EditTarget) –

IsCustom() → bool

Return true if this is a custom property (i.e., not part of a prim schema).

The’custom’modifier in USD serves the same function as Alembic’s’userProperties’, which is to say as a categorization for ad hoc client data not formalized into any schema, and therefore not carrying an expectation of specific processing by consuming applications.

IsDefined() → bool

Return true if this is a builtin property or if the strongest authored SdfPropertySpec for this property’s path matches this property’s dynamic type.

That is, SdfRelationshipSpec in case this is a UsdRelationship, and SdfAttributeSpec in case this is a UsdAttribute. Return false if this property’s prim has expired.

For attributes, a true return does not imply that this attribute possesses a value, only that has been declared, is of a certain type and variability, and that it is safe to use to query and author values and metadata.

SetCustom(isCustom) → bool

Set the value for custom at the current EditTarget, return true on success, false if the value can not be written.

Note that this value should not be changed as it is typically either automatically authored or provided by a property definition. This method is provided primarily for fixing invalid scene description.

Parameters: isCustom (bool) –

SetDisplayGroup(displayGroup) → bool

Sets this property’s display group (metadata).

Returns true on success.

DisplayGroup provides UI hinting for grouping related properties together for display. We define a convention for specifying nesting of groups by recognizing the property namespace separator in displayGroup as denoting group-nesting.

SetNestedDisplayGroups()

Parameters: displayGroup (str) –

SetDisplayName(name) → bool

Sets this property’s display name (metadata).

Returns true on success.

DisplayName is meant to be a descriptive label, not necessarily an alternate identifier; therefore there is no restriction on which characters can appear in it.

Parameters: name (str) –

SetNestedDisplayGroups(nestedGroups) → bool

Sets this property’s display group (metadata) to the nested sequence.

Returns true on success.

A displayGroup set with this method can still be retrieved with GetDisplayGroup() , with the namespace separator embedded in the result. If nestedGroups is empty, we author an empty string for displayGroup.

SetDisplayGroup()

Parameters: nestedGroups (list[str]) –

SplitName() → list[str]: Return this property’s name elements including namespaces and its base name as the final element.

class pxr.Usd.References

UsdReferences provides an interface to authoring and introspecting references in Usd.

References are the primary operator for”encapsulated aggregation”of scene description. aggregation means that references let us build up rich scenes by composing scene description recorded in a (most often) different layer. A scene can reference the same layer many times at different locations in a scene’s namespace. Referenced scene description can be overridden in the referencing (or stronger) layers, allowing each instance of the reference to be directly customized/overridden. Encapsulated means that regardless of how much scene description is in the referenced layer, only the scene description under and composed from (via other composition arcs in the referenced layer) the targeted prim will be composed into the aggregate scene. Multiple references to the same layer will result in the layer being opened and retained in memory only once, although each referencing prim will compose unique prim indices for the tree rooted at the referenced prim.

Important Qualities and Effective Use of References

Any prim can host zero, one or multiple references

References are list editable; that is, they compose differently than ordinary properties and metadata. In any given LayerStack, each authored reference operation at the same SdfPath location in each layer (i.e. on the same prim) will compose into an aggregate result by adding to, removing from, or replacing”weaker”references.

References can target the same LayerStack in which they are authored, as long as doing so does not introduce a cycle in the composition graph. See Expressing”internal”references to the containing LayerStack

The identifier component of a reference in the provided API can be a resolvable asset-path to some external layer, empty, in which case the reference targets the root layer of the LayerStack containing the referencing layer, or the identifier of an existing anonymous, in- memory-only SdfLayer. Care should be exercised in the latter case: calling Export() on an anonymous layer to serialize it to a file will not attempt to replace any references to anonymous layers with references to file-backed layers.

Opinions brought in by reference on an ancestor prim are weaker than opinions brought in by references on a descendant prim.

References may omit the target prim path if the referenced layer has the’defaultPrim’metadata set. In this case, the reference targets the’defaultPrim’in the referenced layer. A layer’s defaultPrim can be authored and accessed on a UsdStage whose root layer is the layer in question: see UsdStage::GetDefaultPrim() and UsdStage::SetDefaultPrim() . One can also author defaultPrim directly on an SdfLayer - see SdfLayer::GetDefaultPrim() , SdfLayer::SetDefaultPrim() .

References may omit the identifier specifying the referenced layer. This creates an”internal”reference. During composition, the referenced layer will be resolved to the root layer of the LayerStack containing the layer where the reference was authored. See AddInternalReference() .

References may target any prim in a layer. In the simplest and most common case, a root prim in a layer will be referenced. However, referencing sub-root prims can be useful in a variety of other cases; for example, a user might organize prims into a meaningful hierarchy in a layer for display purposes, then use sub-root references to reference a selection from that hierarchy into a scene.

Sub-root references have subtle behaviors with respect to opinions and composition arcs authored on ancestors of the referenced prim. Users should carefully consider this when deciding whether to use sub-root references. These issues can be avoided by not authoring any properties or metadata on ancestors of prims that are meant to be referenced.

Consider the following example:

\* shot.usda                                 | \* asset.usda
                                            |
#usda 1.0                                   | #usda 1.0
                                            |
over "Class"                                | class "Class"
{                                           | {
    over "B"                                | }
    {                                       |
        over "Model"                        | def "A" (
        {                                   |    inherits = </Class>
            int a = 3                       | )
        }                                   | {
    }                                       |     token purpose = "render"
}                                           |
                                            |     def "B" (
over "A"                                    |        variantSets = "type"
{                                           |        variants = {
    over "B" (                              |             string type = "a"
        # variant selection won't be used   |        }
        variants = {                        |     )
            string type = "b"               |     {
        }                                   |         variantSet "type" = {
    )                                       |             "a" {
    {                                       |                 def "Model"
    }                                       |                 {
}                                           |                     int a = 1
                                            |                 }
def "ReferencedModel" (                     |             }
    references = @./asset.usda@</A/B/Model> |             "b" {
)                                           |                 def "Model"
{                                           |                 {
}                                           |                     int a = 2
                                            |                 }
                                            |             }
                                            |         }
                                            |     }
                                            | }

 - Property and metadata opinions on the ancestors of the referenced
   prim *are not* present in the composed stage and will never contribute
   to any computations. In this example, the opinion for the attribute
   /A.purpose in asset.usda will never be visible in the UsdStage for
   shot.usda.

 - Property and metadata opinions due to ancestral composition arcs
   *are* present in the composed stage. In this example, the attribute
   /Class/B/Model.a in shot.usda will be present in the UsdStage for
   shot.usda, even though the inherit arc is authored on an ancestor of
   the referenced prim.

 - A consequence of these rules is that users might not be able to
   override ancestral variant selections that affect the referenced prim.
   In this example, the Model prim being referenced comes from the
   variant selection {type=a} on prim /A/B in asset.usda. The {type=b}
   variant cannot be selected in shot.usda, even if prims with the same
   hierarchy happen to exist there. There are various workarounds for
   this; in this example, the {type=b} variant selection could be
   authored on /Class/B/Model in shot.usda instead because of the inherit
   arc that was established on prim /A.

AddReference() and SetReferences() can each fail for a number of reasons. If one of the specified prim targets for one of the references is not a prim, we will generate an error, fail to author any scene description, and return false . If anything goes wrong in attempting to write the reference, we also return false, and the reference will also remain unauthored. Otherwise, if the reference was successfully authored, we will return true . A successful reference authoring operation may still generate composition errors! Just because the reference you specified was syntactically correct and therefore successfully authored, does not imply it was meaningful. If you wish to ensure that the reference you are about to author will be meaningfully consumable by your stage, you are strongly encouraged to ensure it will resolve to an actual file by using UsdStage::ResolveIdentifierToEditTarget() before authoring the reference.

When adding an internal reference, the given prim path is expected to be in the namespace of the owning prim’s stage. Sub-root prim paths will be translated from this namespace to the namespace of the current edit target, if necessary. If a path cannot be translated, a coding error will be issued and no changes will be made. Non-sub-root paths will not be translated.

Immediately upon successful authoring of the reference (before returning from AddReference() , RemoveReference() , ClearReferences() , or SetReferences() ), the UsdStage on which the reference was authored will recompose the subtree rooted at the prim hosting the reference. If the provided identifier does not resolve to a layer that is already opened or that can be opened in the usd format, or if the provided primPath is not an actual prim in that layer, the stage’s recomposition will fail, and pass on composition errors to the client.

Methods:

`AddInternalReference`(primPath, layerOffset, ...)	Add an internal reference to the specified prim.
`AddReference`(ref, position)	Adds a reference to the reference listOp at the current EditTarget, in the position specified by `position` .
`ClearReferences`()	Removes the authored reference listOp edits at the current EditTarget.
`GetPrim`()	Return the prim this object is bound to.
`RemoveReference`(ref)	Removes the specified reference from the references listOp at the current EditTarget.
`SetReferences`(items)	Explicitly set the references, potentially blocking weaker opinions that add or remove items.

AddInternalReference(primPath, layerOffset, position) → bool

Add an internal reference to the specified prim.

Internal References

Parameters

primPath (Path) –
layerOffset (LayerOffset) –
position (ListPosition) –

AddReference(ref, position) → bool

Adds a reference to the reference listOp at the current EditTarget, in the position specified by position .

Why adding references may fail for explanation of expectations on ref and what return values and errors to expect, and ListOps and List Editing for details on list editing and composition of listOps.

Parameters

ref (Reference) –
position (ListPosition) –

AddReference(identifier, primPath, layerOffset, position) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

identifier (str) –
primPath (Path) –
layerOffset (LayerOffset) –
position (ListPosition) –

AddReference(identifier, layerOffset, position) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

References Without Prim Paths

Parameters

identifier (str) –
layerOffset (LayerOffset) –
position (ListPosition) –

ClearReferences() → bool

Removes the authored reference listOp edits at the current EditTarget.

The same caveats for Remove() apply to Clear(). In fact, Clear() may actually increase the number of composed references, if the listOp being cleared contained the”remove”operator.

ListOps and List Editing

GetPrim() → Prim

Return the prim this object is bound to.

GetPrim() -> Prim

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

RemoveReference(ref) → bool

Removes the specified reference from the references listOp at the current EditTarget.

This does not necessarily eliminate the reference completely, as it may be added or set in another layer in the same LayerStack as the current EditTarget.

ListOps and List Editing

Parameters: ref (Reference) –

SetReferences(items) → bool

Explicitly set the references, potentially blocking weaker opinions that add or remove items.

Why adding references may fail for explanation of expectations on ref and what return values and errors to expect, and ListOps and List Editing for details on list editing and composition of listOps.

Parameters: items (list[Reference]) –

class pxr.Usd.Relationship

A UsdRelationship creates dependencies between scenegraph objects by allowing a prim to target other prims, attributes, or relationships.

Relationship Characteristics

A UsdRelationship is a pointer to other objects, which are named by their scenegraph paths. When authoring relationships, the target parameters should be scenegraph paths in the composed namespace of the UsdStage into which you are authoring. If your edits are targeted to a different layer, across various composition arcs (because you specified a non-default UsdEditTarget), the target’s path will be automatically translated into the proper namespace.

A single UsdRelationship can target multiple other objects, which can be of UsdPrim, UsdAttribute, or UsdRelationship type. UsdRelationship participates in”list editing”, which means that stronger layers in a composed scene can add, remove, or reorder targets authored on the relationship in weaker layers without stomping the weaker opinions, although stomping behavior is still possible, via SetTargets() .

An authored relationship creates a dependency of the targeting prim on the targeted prim(s). We consider these dependencies to be”loaddependencies”, which means that when we load the targeting prim’s”load group”, we will also load the targeted prims’load groups, to ensure that all the data required to render the model containing the targeting prim is composed and available.

Like UsdAttribute, UsdRelationship objects are meant to be ephemeral, live on the stack, and be cheap to refetch from their owning UsdPrim.

Unlike UsdAttribute s, which can either be uniform over all time or vary in value over time, UsdRelationship is always uniform.

Relationship Restrictions

When authoring relationship targets in a stage’s local LayerStack, all target paths are legal (Note we may restrict this prior to launch to only allowing targeting of already-extant scenegraph objects). However, a relationship target that is legal in a local LayerStack may become unreachable when the stage’s root layer is referenced into an aggregate, and will cause an error when attempting to load/compose the aggregate.

This can happen because references encapsulate just the tree whose root is targeted in the reference - no other scene description in the referenced layer will be composed into the aggregate. So if some descendant prim of the referenced root targets a relationship to another tree in the same layer, that relationship would dangle, and the client will error in GetTargets() or GetForwardedTargets() .

Authoring targets to objects within prototypes is not allowed, since prototype prims do not have a stable identity across runs. Consumers must author targets to the object within an instance instead.

Relationships authored in a descendent prim of a referenced prim may not target the referenced prim itself or any of its immediate child properties if the referencing prim is instanceable. Allowing this would break the ability for this relationship to be instanced and shared by multiple instances it would force consumers of relationships within prototypes to resolve targets in the context of each of that prototype’s instances.

Relationship Forwarding

Because a relationship can target another relationship, we can and do provide the ability to resolve chained or forwarded relationships. This can be useful in several situations, including:

Combining relationships with VariantSets to create demultiplexers. A prim can host a relationship that serves as a”binding post”for other prims to target. The prim also hosts a”bindingVariant” UsdVariantSet whose variants each modulate the target of the binding-post relationship. We can now change the forwarded target of all prims targeting the binding-post by simply switching the bindingVariant VariantSet. We will work through this example in the USD reference manual.

Defining a relationship as part of a model’s interface (so that it can be targeted in model hierarchy with no models loaded), which, inside the model’s payload, forwards to prims useful to a client, the set of which may vary depending on the model’s configured VariantSets.

Methods:

`AddTarget`(target, position)	Adds `target` to the list of targets, in the position specified by `position` .
`ClearTargets`(removeSpec)	Remove all opinions about the target list from the current edit target.
`GetForwardedTargets`(targets)	Compose this relationship's ultimate targets, taking into account"relationship forwarding", and fill `targets` with the result.
`GetTargets`(targets)	Compose this relationship's targets and fill `targets` with the result.
`HasAuthoredTargets`()	Returns true if any target path opinions have been authored.
`RemoveTarget`(target)	Removes `target` from the list of targets.
`SetTargets`(targets)	Make the authoring layer's opinion of the targets list explicit, and set exactly to `targets` .

AddTarget(target, position) → bool

Adds target to the list of targets, in the position specified by position .

Passing paths to prototype prims or any other objects in prototypes will cause an error to be issued. It is not valid to author targets to these objects.

What data this actually authors depends on what data is currently authored in the authoring layer, with respect to list-editing semantics, which we will document soon

Parameters

target (Path) –
position (ListPosition) –

ClearTargets(removeSpec) → bool

Remove all opinions about the target list from the current edit target.

Only remove the spec if removeSpec is true (leave the spec to preserve meta-data we may have intentionally authored on the relationship)

Parameters: removeSpec (bool) –

GetForwardedTargets(targets) → bool

Compose this relationship’s ultimate targets, taking into account”relationship forwarding”, and fill targets with the result.

All preexisting elements in targets are lost. This method never inserts relationship paths in targets .

Returns true if any of the visited relationships that are not”purely forwarding”has an authored opinion for its target paths and no composition errors were encountered while computing any targets. Purely forwarding, in this context, means the relationship has at least one target but all of its targets are paths to other relationships. Note that authored opinions may include opinions that clear the targets and a return value of true does not necessarily indicate that targets will not be empty.

Returns false otherwise. When composition errors occur, this function continues to collect successfully composed targets, but returns false to indicate to the caller that errors occurred.

When a forwarded target cannot be determined, e.g. due to a composition error, no value is returned for that target; the alternative would be to return the relationship path at which the forwarded targets could not be composed, however this would require all callers of GetForwardedTargets() to account for unexpected relationship paths being returned with the expected target results. For example, a particular caller may expect only prim paths in the target vector, but when composition errors occur, relationships would be included, potentially triggering additional down stream errors.

See Relationship Forwarding for details on the semantics.

The result is not cached, so will be recomputed on every query.

Parameters: targets (list[Path]) –

GetTargets(targets) → bool

Compose this relationship’s targets and fill targets with the result.

All preexisting elements in targets are lost.

Returns true if any target path opinions have been authored and no composition errors were encountered, returns false otherwise. Note that authored opinions may include opinions that clear the targets and a return value of true does not necessarily indicate that targets will contain any target paths.

See Relationship Targets and Attribute Connections for details on behavior when targets point to objects beneath instance prims.

The result is not cached, so will be recomputed on every query.

Parameters: targets (list[Path]) –

HasAuthoredTargets() → bool

Returns true if any target path opinions have been authored.

Note that this may include opinions that clear targets and may not indicate that target paths will exist for this relationship.

RemoveTarget(target) → bool

Removes target from the list of targets.

Passing paths to prototype prims or any other objects in prototypes will cause an error to be issued. It is not valid to author targets to these objects.

Parameters: target (Path) –

SetTargets(targets) → bool

Make the authoring layer’s opinion of the targets list explicit, and set exactly to targets .

Passing paths to prototype prims or any other objects in prototypes will cause an error to be issued. It is not valid to author targets to these objects.

If any target in targets is invalid, no targets will be authored and this function will return false.

Parameters: targets (list[Path]) –

class pxr.Usd.ResolveInfo

Container for information about the source of an attribute’s value, i.e. the’resolved’location of the attribute.

For more details, see TimeSamples, Defaults, and Value Resolution.

Methods:

`GetNode`()	Return the node within the containing PcpPrimIndex that provided the resolved value opinion.
`GetSource`()	Return the source of the associated attribute's value.
`ValueIsBlocked`()	Return true if this UsdResolveInfo represents an attribute whose value is blocked.

GetNode() → NodeRef: Return the node within the containing PcpPrimIndex that provided the resolved value opinion.

GetSource() → ResolveInfoSource: Return the source of the associated attribute’s value.

ValueIsBlocked() → bool

Return true if this UsdResolveInfo represents an attribute whose value is blocked.

UsdAttribute::Block()

class pxr.Usd.ResolveInfoSource

Methods:

GetValueFromName

Attributes:

allValues

static GetValueFromName()

allValues = (Usd.ResolveInfoSourceNone, Usd.ResolveInfoSourceFallback, Usd.ResolveInfoSourceDefault, Usd.ResolveInfoSourceTimeSamples, Usd.ResolveInfoSourceValueClips)

class pxr.Usd.ResolveTarget

Defines a subrange of nodes and layers within a prim’s prim index to consider when performing value resolution for the prim’s attributes. A resolve target can then be passed to UsdAttributeQuery during its construction to have all of the queries made by the UsdAttributeQuery use the resolve target’s subrange for their value resolution.

Resolve targets can be created via methods on UsdPrimCompositionQueryArc to to limit value resolution to a subrange of the prim’s composed specs that are no stronger that arc, or a subrange of specs that is strictly stronger than that arc (optionally providing a particular layer within the arc’s layer stack to further limit the range of specs).

Alternatively, resolve targets can also be created via methods on UsdPrim that can limit value resolution to either up to or stronger than the spec that would be edited when setting a value for the prim using the given UsdEditTarget.

Unlike UsdEditTarget, a UsdResolveTarget is only relevant to the prim it is created for and can only be used in a UsdAttributeQuery for attributes on this prim.

Invalidation

This object does not listen for change notification. If a consumer is holding on to a UsdResolveTarget, it is their responsibility to dispose of it in response to a resync change to the associated prim. Failing to do so may result in incorrect values or crashes due to dereferencing invalid objects.

Methods:

`GetPrimIndex`()	Get the prim index of the resolve target.
`GetStartLayer`()	Returns the layer in the layer stack of the start node that value resolution with this resolve target will start at.
`GetStartNode`()	Returns the node that value resolution with this resolve target will start at.
`GetStopLayer`()	Returns the layer in the layer stack of the stop node that value resolution with this resolve target will stop at.
`GetStopNode`()	Returns the node that value resolution with this resolve target will stop at when the"stop at"layer is reached.
`IsNull`()	Returns true if this is a null resolve target.

GetPrimIndex() → PrimIndex: Get the prim index of the resolve target.

GetStartLayer() → Layer: Returns the layer in the layer stack of the start node that value resolution with this resolve target will start at.

GetStartNode() → NodeRef: Returns the node that value resolution with this resolve target will start at.

GetStopLayer() → Layer: Returns the layer in the layer stack of the stop node that value resolution with this resolve target will stop at.

GetStopNode() → NodeRef: Returns the node that value resolution with this resolve target will stop at when the”stop at”layer is reached.

IsNull() → bool: Returns true if this is a null resolve target.

class pxr.Usd.SchemaBase

The base class for all schema types in Usd.

Schema objects hold a UsdPrim internally and provide a layer of specific named API atop the underlying scene graph.

Schema objects are polymorphic but they are intended to be created as automatic local variables, so they may be passed and returned by- value. This leaves them subject to slicing. This means that if one passes a SpecificSchema instance to a function that takes a UsdSchemaBase by-value, all the polymorphic behavior specific to SpecificSchema is lost.

To avoid slicing, it is encouraged that functions taking schema object arguments take them by const& if const access is sufficient, otherwise by non-const pointer.

Methods:

`GetPath`()	Shorthand for GetPrim() -> GetPath() .
`GetPrim`()	Return this schema object's held prim.
`GetSchemaAttributeNames`	classmethod GetSchemaAttributeNames(includeInherited) -> list[str]
`GetSchemaClassPrimDefinition`()	Return the prim definition associated with this schema instance if one exists, otherwise return null.
`GetSchemaKind`()	Returns the kind of schema this class is.
`IsAPISchema`()	Returns whether this is an API schema or not.
`IsAppliedAPISchema`()	Returns whether this is an applied API schema or not.
`IsConcrete`()	Returns whether or not this class corresponds to a concrete instantiable prim type in scene description.
`IsMultipleApplyAPISchema`()	Returns whether this is an applied API schema or not.
`IsTyped`()	Returns whether or not this class inherits from UsdTyped.

GetPath() → Path: Shorthand for GetPrim() -> GetPath() .

GetPrim() → Prim: Return this schema object’s held prim.

static GetSchemaAttributeNames()

classmethod GetSchemaAttributeNames(includeInherited) -> list[str]

Parameters: includeInherited (bool) –

GetSchemaClassPrimDefinition() → PrimDefinition

Return the prim definition associated with this schema instance if one exists, otherwise return null.

This does not use the held prim’s type. To get the held prim instance’s definition, use UsdPrim::GetPrimDefinition() .

UsdPrim::GetPrimDefinition()

GetSchemaKind() → SchemaKind: Returns the kind of schema this class is.

IsAPISchema() → bool: Returns whether this is an API schema or not.

IsAppliedAPISchema() → bool

Returns whether this is an applied API schema or not.

If this returns true this class will have an Apply() method

IsConcrete() → bool

Returns whether or not this class corresponds to a concrete instantiable prim type in scene description.

If this is true, GetStaticPrimDefinition() will return a valid prim definition with a non-empty typeName.

IsMultipleApplyAPISchema() → bool

Returns whether this is an applied API schema or not.

If this returns true the constructor, Get and Apply methods of this class will take in the name of the API schema instance.

IsTyped() → bool

Returns whether or not this class inherits from UsdTyped.

Types which inherit from UsdTyped can impart a typename on a UsdPrim.

class pxr.Usd.SchemaKind

Attributes:

`AbstractBase`
`AbstractTyped`
`ConcreteTyped`
`Invalid`
`MultipleApplyAPI`
`NonAppliedAPI`
`SingleApplyAPI`
`names`
`values`

AbstractBase = pxr.Usd.SchemaKind.AbstractBase

AbstractTyped = pxr.Usd.SchemaKind.AbstractTyped

ConcreteTyped = pxr.Usd.SchemaKind.ConcreteTyped

Invalid = pxr.Usd.SchemaKind.Invalid

MultipleApplyAPI = pxr.Usd.SchemaKind.MultipleApplyAPI

NonAppliedAPI = pxr.Usd.SchemaKind.NonAppliedAPI

SingleApplyAPI = pxr.Usd.SchemaKind.SingleApplyAPI

names = {'AbstractBase': pxr.Usd.SchemaKind.AbstractBase, 'AbstractTyped': pxr.Usd.SchemaKind.AbstractTyped, 'ConcreteTyped': pxr.Usd.SchemaKind.ConcreteTyped, 'Invalid': pxr.Usd.SchemaKind.Invalid, 'MultipleApplyAPI': pxr.Usd.SchemaKind.MultipleApplyAPI, 'NonAppliedAPI': pxr.Usd.SchemaKind.NonAppliedAPI, 'SingleApplyAPI': pxr.Usd.SchemaKind.SingleApplyAPI}

values = {0: pxr.Usd.SchemaKind.Invalid, 1: pxr.Usd.SchemaKind.AbstractBase, 2: pxr.Usd.SchemaKind.AbstractTyped, 3: pxr.Usd.SchemaKind.ConcreteTyped, 4: pxr.Usd.SchemaKind.NonAppliedAPI, 5: pxr.Usd.SchemaKind.SingleApplyAPI, 6: pxr.Usd.SchemaKind.MultipleApplyAPI}

class pxr.Usd.SchemaRegistry

Singleton registry that provides access to schema type information and the prim definitions for registered Usd”IsA”and applied API schema types. It also contains the data from the generated schemas that is used by prim definitions to provide properties and fallbacks.

The data contained herein comes from the generatedSchema.usda file (generated when a schema.usda file is processed by usdGenSchema) of each schema-defining module. The registry expects each schema type to be represented as a single prim spec with its inheritance flattened, i.e. the prim spec contains a union of all its local and class inherited property specs and metadata fields.

It is used by the Usd core, via UsdPrimDefinition, to determine how to create scene description for unauthored”built-in”properties of schema classes, to enumerate all properties for a given schema class, and finally to provide fallback values for unauthored built-in properties.

Methods:

`BuildComposedPrimDefinition`(primType, ...)	Composes and returns a new UsdPrimDefinition from the given `primType` and list of `appliedSchemas` .
`FindAppliedAPIPrimDefinition`(typeName)	Finds the prim definition for the given `typeName` token if `typeName` is a registered applied API schema type.
`FindConcretePrimDefinition`(typeName)	Finds the prim definition for the given `typeName` token if `typeName` is a registered concrete typed schema type.
`GetAPISchemaCanOnlyApplyToTypeNames`	classmethod GetAPISchemaCanOnlyApplyToTypeNames(apiSchemaName, instanceName) -> list[str]
`GetAPISchemaTypeName`	classmethod GetAPISchemaTypeName(schemaType) -> str
`GetAPITypeFromSchemaTypeName`	classmethod GetAPITypeFromSchemaTypeName(typeName) -> Type
`GetAutoApplyAPISchemas`	classmethod GetAutoApplyAPISchemas() -> map[str, list[str]]
`GetConcreteSchemaTypeName`	classmethod GetConcreteSchemaTypeName(schemaType) -> str
`GetConcreteTypeFromSchemaTypeName`	classmethod GetConcreteTypeFromSchemaTypeName(typeName) -> Type
`GetEmptyPrimDefinition`()	Returns the empty prim definition.
`GetFallbackPrimTypes`()	Returns a dictionary mapping concrete schema prim type names to a VtTokenArray of fallback prim type names if fallback types are defined for the schema type in its registered schema.
`GetMultipleApplyNameTemplateBaseName`	classmethod GetMultipleApplyNameTemplateBaseName(nameTemplate) -> str
`GetSchemaKind`	classmethod GetSchemaKind(schemaType) -> SchemaKind
`GetSchemaTypeName`	classmethod GetSchemaTypeName(schemaType) -> str
`GetTypeFromName`	classmethod GetTypeFromName(typeName) -> Type
`GetTypeFromSchemaTypeName`	classmethod GetTypeFromSchemaTypeName(typeName) -> Type
`GetTypeNameAndInstance`	classmethod GetTypeNameAndInstance(apiSchemaName) -> tuple[str, str]
`IsAbstract`	classmethod IsAbstract(primType) -> bool
`IsAllowedAPISchemaInstanceName`	classmethod IsAllowedAPISchemaInstanceName(apiSchemaName, instanceName) -> bool
`IsAppliedAPISchema`	classmethod IsAppliedAPISchema(apiSchemaType) -> bool
`IsConcrete`	classmethod IsConcrete(primType) -> bool
`IsDisallowedField`	classmethod IsDisallowedField(fieldName) -> bool
`IsMultipleApplyAPISchema`	classmethod IsMultipleApplyAPISchema(apiSchemaType) -> bool
`IsMultipleApplyNameTemplate`	classmethod IsMultipleApplyNameTemplate(nameTemplate) -> bool
`IsTyped`	classmethod IsTyped(primType) -> bool
`MakeMultipleApplyNameInstance`	classmethod MakeMultipleApplyNameInstance(nameTemplate, instanceName) -> str
`MakeMultipleApplyNameTemplate`	classmethod MakeMultipleApplyNameTemplate(namespacePrefix, baseName) -> str

Attributes:

expired

True if this object has expired, False otherwise.

BuildComposedPrimDefinition(primType, appliedAPISchemas) → PrimDefinition

Composes and returns a new UsdPrimDefinition from the given primType and list of appliedSchemas .

This prim definition will contain a union of properties from the registered prim definitions of each of the provided types.

Parameters

primType (str) –
appliedAPISchemas (list[str]) –

FindAppliedAPIPrimDefinition(typeName) → PrimDefinition

Finds the prim definition for the given typeName token if typeName is a registered applied API schema type.

Returns null if it is not.

Parameters: typeName (str) –

FindConcretePrimDefinition(typeName) → PrimDefinition

Finds the prim definition for the given typeName token if typeName is a registered concrete typed schema type.

Returns null if it is not.

Parameters: typeName (str) –

static GetAPISchemaCanOnlyApplyToTypeNames()

classmethod GetAPISchemaCanOnlyApplyToTypeNames(apiSchemaName, instanceName) -> list[str]

Returns a list of prim type names that the given apiSchemaName can only be applied to.

A non-empty list indicates that the API schema can only be applied to prim that are or derive from prim type names in the list. If the list is empty, the API schema can be applied to prims of any type.

If a non-empty instanceName is provided, this will first look for a list of”can only apply to”names specific to that instance of the API schema and return that if found. If a list is not found for the specific instance, it will fall back to looking for a”can only apply to”list for just the schema name itself.

Parameters

apiSchemaName (str) –
instanceName (str) –

static GetAPISchemaTypeName()

classmethod GetAPISchemaTypeName(schemaType) -> str

Return the type name in the USD schema for API schema types only from the given registered schemaType .

Parameters: schemaType (Type) –

static GetAPITypeFromSchemaTypeName()

classmethod GetAPITypeFromSchemaTypeName(typeName) -> Type

Return the TfType of the schema corresponding to the given API schema type name typeName .

This the inverse of GetAPISchemaTypeNAme.

Parameters: typeName (str) –

static GetAutoApplyAPISchemas()

classmethod GetAutoApplyAPISchemas() -> map[str, list[str]]

Returns a map of the names of all registered auto apply API schemas to the list of type names each is registered to be auto applied to.

The list of type names to apply to will directly match what is specified in the plugin metadata for each schema type. While auto apply schemas do account for the existence and validity of the type names and expand to include derived types of the listed types, the type lists returned by this function do not.

static GetConcreteSchemaTypeName()

classmethod GetConcreteSchemaTypeName(schemaType) -> str

Return the type name in the USD schema for concrete prim types only from the given registered schemaType .

Parameters: schemaType (Type) –

static GetConcreteTypeFromSchemaTypeName()

classmethod GetConcreteTypeFromSchemaTypeName(typeName) -> Type

Return the TfType of the schema corresponding to the given concrete prim type name typeName .

This the inverse of GetConcreteSchemaTypeName.

Parameters: typeName (str) –

GetEmptyPrimDefinition() → PrimDefinition: Returns the empty prim definition.

GetFallbackPrimTypes() → VtDictionary

Returns a dictionary mapping concrete schema prim type names to a VtTokenArray of fallback prim type names if fallback types are defined for the schema type in its registered schema.

The standard use case for this to provide schema defined metadata that can be saved with a stage to inform an older version of USD - that may not have some schema types - as to which types it can used instead when encountering a prim of one these types.

UsdStage::WriteFallbackPrimTypes

Fallback Prim Types

static GetMultipleApplyNameTemplateBaseName()

classmethod GetMultipleApplyNameTemplateBaseName(nameTemplate) -> str

Returns the base name for the multiple apply schema name template nameTemplate .

The base name is the substring of the given name template that comes after the instance name placeholder and the subsequent namespace delimiter. If the given property name does not contain the instance name placeholder, it is not a name template and the name template is returned as is.

Parameters: nameTemplate (str) –

static GetSchemaKind()

classmethod GetSchemaKind(schemaType) -> SchemaKind

Returns the kind of the schema the given schemaType represents.

This returns UsdSchemaKind::Invalid if schemaType is not a valid schema type or if the kind cannot be determined from type’s plugin information.

Parameters: schemaType (Type) –

GetSchemaKind(typeName) -> SchemaKind

Returns the kind of the schema the given typeName represents.

This returns UsdSchemaKind::Invalid if typeName is not a valid schema type name or if the kind cannot be determined from type’s plugin information.

Parameters: typeName (str) –

static GetSchemaTypeName()

classmethod GetSchemaTypeName(schemaType) -> str

Return the type name in the USD schema for prims or API schemas of the given registered schemaType .

Parameters: schemaType (Type) –

GetSchemaTypeName() -> str

Return the type name in the USD schema for prims or API schemas of the given registered SchemaType .

static GetTypeFromName()

classmethod GetTypeFromName(typeName) -> Type

Finds the TfType of a schema with typeName .

This is primarily for when you have been provided Schema typeName (perhaps from a User Interface or Script) and need to identify if a prim’s type inherits/is that typeName. If the type name IS known, then using the schema class is preferred.

# This code attempts to match all prims on a stage to a given
# user specified type, making the traditional schema based idioms not
# applicable.
data = parser.parse_args()
tfType = UsdSchemaRegistry.GetTypeFromName(data.type)
matchedPrims = [p for p in stage.Traverse() if p.IsA(tfType)]

It’s worth noting that GetTypeFromName(“Sphere”) == GetTypeFromName(“UsdGeomSphere”), as this function resolves both the Schema’s C++ class name and any registered aliases from a modules plugInfo.json file. However, GetTypeFromName(“Boundable”) != GetTypeFromName(“UsdGeomBoundable”) because type aliases don’t get registered for abstract schema types.

Parameters: typeName (str) –

static GetTypeFromSchemaTypeName()

classmethod GetTypeFromSchemaTypeName(typeName) -> Type

Return the TfType of the schema corresponding to the given prim or API schema name typeName .

This the inverse of GetSchemaTypeName.

Parameters: typeName (str) –

static GetTypeNameAndInstance()

classmethod GetTypeNameAndInstance(apiSchemaName) -> tuple[str, str]

Returns the schema type name and the instance name parsed from the given apiSchemaName .

apiSchemaName is the name of an applied schema as it appears in the list of applied schemas on a prim. For single-apply API schemas the name will just be the schema type name. For multiple-apply schemas the name should include the schema type name and the applied instance name separated by a namespace delimiter, for example’CollectionAPI:plasticStuff’.

This function returns the separated schema type name and instance name component tokens if possible, otherwise it returns the apiSchemaName as the type name and an empty instance name.

Note that no validation is done on the returned tokens. Clients are advised to use GetTypeFromSchemaTypeName() to validate the typeName token.

UsdPrim::AddAppliedSchema(const TfToken&) const

UsdPrim::GetAppliedSchemas() const

Parameters: apiSchemaName (str) –

static IsAbstract()

classmethod IsAbstract(primType) -> bool

Returns true if the prim type primType is an abstract schema type and, unlike a concrete type, is not instantiable in scene description.

Parameters: primType (Type) –

IsAbstract(primType) -> bool

Returns true if the prim type primType is an abstract schema type and, unlike a concrete type, is not instantiable in scene description.

Parameters: primType (str) –

static IsAllowedAPISchemaInstanceName()

classmethod IsAllowedAPISchemaInstanceName(apiSchemaName, instanceName) -> bool

Returns true if the given instanceName is an allowed instance name for the multiple apply API schema named apiSchemaName .

Any instance name that matches the name of a property provided by the API schema is disallowed and will return false. If the schema type has plugin metadata that specifies allowed instance names, then only those specified names are allowed for the schema type. If the instance name is empty or the API is not a multiple apply schema, this will return false.

Parameters

apiSchemaName (str) –
instanceName (str) –

static IsAppliedAPISchema()

classmethod IsAppliedAPISchema(apiSchemaType) -> bool

Returns true if apiSchemaType is an applied API schema type.

Parameters: apiSchemaType (Type) –

IsAppliedAPISchema(apiSchemaType) -> bool

Returns true if apiSchemaType is an applied API schema type.

Parameters: apiSchemaType (str) –

static IsConcrete()

classmethod IsConcrete(primType) -> bool

Returns true if the prim type primType is instantiable in scene description.

Parameters: primType (Type) –

IsConcrete(primType) -> bool

Returns true if the prim type primType is instantiable in scene description.

Parameters: primType (str) –

static IsDisallowedField()

classmethod IsDisallowedField(fieldName) -> bool

Returns true if the field fieldName cannot have fallback values specified in schemas.

Fields are generally disallowed because their fallback values aren’t used. For instance, fallback values for composition arcs aren’t used during composition, so allowing them to be set in schemas would be misleading.

Parameters: fieldName (str) –

static IsMultipleApplyAPISchema()

classmethod IsMultipleApplyAPISchema(apiSchemaType) -> bool

Returns true if apiSchemaType is a multiple-apply API schema type.

Parameters: apiSchemaType (Type) –

IsMultipleApplyAPISchema(apiSchemaType) -> bool

Returns true if apiSchemaType is a multiple-apply API schema type.

Parameters: apiSchemaType (str) –

static IsMultipleApplyNameTemplate()

classmethod IsMultipleApplyNameTemplate(nameTemplate) -> bool

Returns true if nameTemplate is a multiple apply schema name template.

The given nameTemplate is a name template if and only if it contains the instance name place holder”__INSTANCE_NAME__”as an exact match as one of the tokenized components of the name tokenized by the namespace delimiter.

Parameters: nameTemplate (str) –

static IsTyped()

classmethod IsTyped(primType) -> bool

Returns true if the prim type primType inherits from UsdTyped.

Parameters: primType (Type) –

static MakeMultipleApplyNameInstance()

classmethod MakeMultipleApplyNameInstance(nameTemplate, instanceName) -> str

Returns an instance of a multiple apply schema name from the given nameTemplate for the given instanceName .

The returned name is created by replacing the instance name placeholder”__INSTANCE_NAME__”in the name template with the given instance name. If the instance name placeholder is not found in nameTemplate , then the name template is not multiple apply name template and is returned as is.

Note that the instance name placeholder must be found as an exact full word match with one of the tokenized components of the name template, when tokenized by the namespace delimiter, in order for it to be treated as a placeholder and substituted with the instance name.

Parameters

nameTemplate (str) –
instanceName (str) –

static MakeMultipleApplyNameTemplate()

classmethod MakeMultipleApplyNameTemplate(namespacePrefix, baseName) -> str

Creates a name template that can represent a property or API schema that belongs to a multiple apply schema and will therefore have multiple instances with different names.

The name template is created by joining the namespacePrefix , the instance name placeholder”__INSTANCE_NAME__”, and the baseName using the namespace delimiter. Therefore the returned name template will be of one of the following forms depending on whether either of the inputs is empty:

namespacePrefix: INSTANCE_NAME :baseName

namespacePrefix: INSTANCE_NAME

INSTANCE_NAME :baseName

INSTANCE_NAME

Name templates can be passed to MakeMultipleApplyNameInstance along with an instance name to create the name for a particular instance.

Parameters

namespacePrefix (str) –
baseName (str) –

property expired: True if this object has expired, False otherwise.

class pxr.Usd.Specializes

A proxy class for applying listOp edits to the specializes list for a prim.

All paths passed to the UsdSpecializes API are expected to be in the namespace of the owning prim’s stage. Subroot prim specializes paths will be translated from this namespace to the namespace of the current edit target, if necessary. If a path cannot be translated, a coding error will be issued and no changes will be made. Root prim specializes paths will not be translated.

Methods:

`AddSpecialize`(primPath, position)	Adds a path to the specializes listOp at the current EditTarget, in the position specified by `position` .
`ClearSpecializes`()	Removes the authored specializes listOp edits at the current edit target.
`GetPrim`()	Return the prim this object is bound to.
`RemoveSpecialize`(primPath)	Removes the specified path from the specializes listOp at the current EditTarget.
`SetSpecializes`(items)	Explicitly set specializes paths, potentially blocking weaker opinions that add or remove items, returning true on success, false if the edit could not be performed.

AddSpecialize(primPath, position) → bool

Adds a path to the specializes listOp at the current EditTarget, in the position specified by position .

Parameters

primPath (Path) –
position (ListPosition) –

ClearSpecializes() → bool: Removes the authored specializes listOp edits at the current edit target.

GetPrim() → Prim

Return the prim this object is bound to.

GetPrim() -> Prim

RemoveSpecialize(primPath) → bool

Removes the specified path from the specializes listOp at the current EditTarget.

Parameters: primPath (Path) –

SetSpecializes(items) → bool

Explicitly set specializes paths, potentially blocking weaker opinions that add or remove items, returning true on success, false if the edit could not be performed.

Parameters: items (list[Path]) –

class pxr.Usd.Stage

The outermost container for scene description, which owns and presents composed prims as a scenegraph, following the composition recipe recursively described in its associated”root layer”.

USD derives its persistent-storage scalability by combining and reusing simple compositions into richer aggregates using referencing and layering with sparse overrides. Ultimately, every composition (i.e.”scene”) is identifiable by its root layer, i.e. the .usd file, and a scene is instantiated in an application on a UsdStage that presents a composed view of the scene’s root layer. Each simple composition referenced into a larger composition could be presented on its own UsdStage, at the same (or not) time that it is participating in the larger composition on its own UsdStage; all of the underlying layers will be shared by the two stages, while each maintains its own scenegraph of composed prims.

A UsdStage has sole ownership over the UsdPrim ‘s with which it is populated, and retains shared ownership (with other stages and direct clients of SdfLayer ‘s, via the Sdf_LayerRegistry that underlies all SdfLayer creation methods) of layers. It provides roughly five categories of API that address different aspects of scene management:

Stage lifetime management methods for constructing and initially populating a UsdStage from an existing layer file, or one that will be created as a result, in memory or on the filesystem.

Load/unload working set management methods that allow you to specify which payloads should be included and excluded from the stage’s composition.

Variant management methods to manage policy for which variant to use when composing prims that provide a named variant set, but do not specify a selection.

Prim access, creation, and mutation methods that allow you to find, create, or remove a prim identified by a path on the stage. This group also provides methods for efficiently traversing the prims on the stage.

Layers and EditTargets methods provide access to the layers in the stage’s root LayerStack (i.e. the root layer and all of its recursive sublayers), and the ability to set a UsdEditTarget into which all subsequent mutations to objects associated with the stage (e.g. prims, properties, etc) will go.

Serialization methods for”flattening”a composition (to varying degrees), and exporting a completely flattened view of the stage to a string or file. These methods can be very useful for targeted asset optimization and debugging, though care should be exercized with large scenes, as flattening defeats some of the benefits of referenced scene description, and may produce very large results, especially in file formats that do not support data de-duplication, like the usda ASCII format!

Stage Session Layers

Each UsdStage can possess an optional”session layer”. The purpose of a session layer is to hold ephemeral edits that modify a UsdStage ‘s contents or behavior in a way that is useful to the client, but should not be considered as permanent mutations to be recorded upon export. A very common use of session layers is to make variant selections, to pick a specific LOD or shading variation, for example. The session layer is also frequently used to perform interactive vising/invsning of geometry and assets in the scene. A session layer, if present, contributes to a UsdStage ‘s identity, for purposes of stage-caching, etc.

Classes:

InitialLoadSet

Specifies the initial set of prims to load when opening a UsdStage.

Methods:

`ClearDefaultPrim`()	Clear the default prim layer metadata in this stage's root layer.
`ClearMetadata`(key)	Clear the value of stage metadatum `key` , if the stage's current UsdEditTarget is the root or session layer.
`ClearMetadataByDictKey`(key, keyPath)	Clear any authored value identified by `key` and `keyPath` at the current EditTarget.
`CreateClassPrim`(rootPrimPath)	Author an SdfPrimSpec with specifier == SdfSpecifierClass for the class at root prim path `path` at the current EditTarget.
`CreateInMemory`	classmethod CreateInMemory(load) -> Stage
`CreateNew`	classmethod CreateNew(identifier, load) -> Stage
`DefinePrim`(path, typeName)	Attempt to ensure a UsdPrim at `path` is defined (according to UsdPrim::IsDefined() ) on this stage.
`ExpandPopulationMask`(relPred, attrPred)	Expand this stage's population mask to include the targets of all relationships that pass `relPred` and connections to all attributes that pass `attrPred` recursively.
`Export`(filename, addSourceFileComment, args)	Writes out the composite scene as a single flattened layer into filename.
`ExportToString`(result, addSourceFileComment)	Writes the composite scene as a flattened Usd text representation into the given string.
`FindLoadable`(rootPath)	Returns an SdfPathSet of all paths that can be loaded.
`Flatten`(addSourceFileComment)	Returns a single, anonymous, merged layer for this composite scene.
`GetAttributeAtPath`(path)	Return the UsdAttribute at `path` , or an invalid UsdAttribute if none exists.
`GetColorConfigFallbacks`	classmethod GetColorConfigFallbacks(colorConfiguration, colorManagementSystem) -> None
`GetColorConfiguration`()	Returns the default color configuration used to interpret the per- attribute color-spaces in the composed USD stage.
`GetColorManagementSystem`()	Sets the name of the color management system to be used for loading and interpreting the color configuration file.
`GetDefaultPrim`()	Return the root UsdPrim on this stage whose name is the root layer's defaultPrim metadata's value.
`GetEditTarget`()	Return the stage's EditTarget.
`GetEditTargetForLocalLayer`(i)	Return a UsdEditTarget for editing the layer at index i in the layer stack.
`GetEndTimeCode`()	Returns the stage's end timeCode.
`GetFramesPerSecond`()	Returns the stage's framesPerSecond value.
`GetGlobalVariantFallbacks`	classmethod GetGlobalVariantFallbacks() -> PcpVariantFallbackMap
`GetInterpolationType`()	Returns the interpolation type used during value resolution for all attributes on this stage.
`GetLayerStack`(includeSessionLayers)	Return this stage's local layers in strong-to-weak order.
`GetLoadRules`()	Return the stage's current UsdStageLoadRules governing payload inclusion.
`GetLoadSet`()	Returns a set of all loaded paths.
`GetMetadata`(key, value)	Return in `value` an authored or fallback value (if one was defined for the given metadatum) for Stage metadatum `key` .
`GetMetadataByDictKey`(key, keyPath, value)	Resolve the requested dictionary sub-element `keyPath` of dictionary-valued metadatum named `key` , returning the resolved value.
`GetMutedLayers`()	Returns a vector of all layers that have been muted on this stage.
`GetObjectAtPath`(path)	Return the UsdObject at `path` , or an invalid UsdObject if none exists.
`GetPathResolverContext`()	Return the path resolver context for all path resolution during composition of this stage.
`GetPopulationMask`()	Return this stage's population mask.
`GetPrimAtPath`(path)	Return the UsdPrim at `path` , or an invalid UsdPrim if none exists.
`GetPropertyAtPath`(path)	Return the UsdProperty at `path` , or an invalid UsdProperty if none exists.
`GetPrototypes`()	Returns all native instancing prototype prims.
`GetPseudoRoot`()	Return the stage's"pseudo-root"prim, whose name is defined by Usd.
`GetRelationshipAtPath`(path)	Return the UsdAttribute at `path` , or an invalid UsdAttribute if none exists.
`GetRootLayer`()	Return this stage's root layer.
`GetSessionLayer`()	Return this stage's root session layer.
`GetStartTimeCode`()	Returns the stage's start timeCode.
`GetTimeCodesPerSecond`()	Returns the stage's timeCodesPerSecond value.
`GetUsedLayers`(includeClipLayers)	Return a vector of all of the layers currently consumed by this stage, as determined by the composition arcs that were traversed to compose and populate the stage.
`HasAuthoredMetadata`(key)	Returns `true` if the key has an authored value, `false` if no value was authored or the only value available is the SdfSchema 's metadata fallback.
`HasAuthoredMetadataDictKey`(key, keyPath)	Return true if there exists any authored opinion (excluding fallbacks) for `key` and `keyPath` .
`HasAuthoredTimeCodeRange`()	Returns true if the stage has both start and end timeCodes authored in the session layer or the root layer of the stage.
`HasDefaultPrim`()	Return true if this stage's root layer has an authored opinion for the default prim layer metadata.
`HasLocalLayer`(layer)	Return true if layer is one of the layers in this stage's local, root layerStack.
`HasMetadata`(key)	Returns true if the key has a meaningful value, that is, if GetMetadata() will provide a value, either because it was authored or because the Stage metadata was defined with a meaningful fallback value.
`HasMetadataDictKey`(key, keyPath)	Return true if there exists any authored or fallback opinion for `key` and `keyPath` .
`IsLayerMuted`(layerIdentifier)	Returns true if the layer specified by `layerIdentifier` is muted in this cache, false otherwise.
`IsSupportedFile`	classmethod IsSupportedFile(filePath) -> bool
`Load`(path, policy)	Modify this stage's load rules to load the prim at `path` , its ancestors, and all of its descendants if `policy` is UsdLoadWithDescendants.
`LoadAndUnload`(loadSet, unloadSet, policy)	Unload and load the given path sets.
`MuteAndUnmuteLayers`(muteLayers, unmuteLayers)	Mute and unmute the layers identified in `muteLayers` and `unmuteLayers` .
`MuteLayer`(layerIdentifier)	Mute the layer identified by `layerIdentifier` .
`Open`	classmethod Open(filePath, load) -> Stage
`OpenMasked`	classmethod OpenMasked(filePath, mask, load) -> Stage
`OverridePrim`(path)	Attempt to ensure a UsdPrim at `path` exists on this stage.
`Reload`()	Calls SdfLayer::Reload on all layers contributing to this stage, except session layers and sublayers of session layers.
`RemovePrim`(path)	Remove all scene description for the given `path` and its subtree in the current UsdEditTarget.
`ResolveIdentifierToEditTarget`(identifier)	Resolve the given identifier using this stage's ArResolverContext and the layer of its GetEditTarget() as an anchor for relative references (e.g.
`Save`()	Calls SdfLayer::Save on all dirty layers contributing to this stage except session layers and sublayers of session layers.
`SaveSessionLayers`()	Calls SdfLayer::Save on all dirty session layers and sublayers of session layers contributing to this stage.
`SetColorConfigFallbacks`	classmethod SetColorConfigFallbacks(colorConfiguration, colorManagementSystem) -> None
`SetColorConfiguration`(colorConfig)	Sets the default color configuration to be used to interpret the per- attribute color-spaces in the composed USD stage.
`SetColorManagementSystem`(cms)	Sets the name of the color management system used to interpret the color configuration file pointed at by the colorConfiguration metadata.
`SetDefaultPrim`(prim)	Set the default prim layer metadata in this stage's root layer.
`SetEditTarget`(editTarget)	Set the stage's EditTarget.
`SetEndTimeCode`(arg1)	Sets the stage's end timeCode.
`SetFramesPerSecond`(framesPerSecond)	Sets the stage's framesPerSecond value.
`SetGlobalVariantFallbacks`	classmethod SetGlobalVariantFallbacks(fallbacks) -> None
`SetInterpolationType`(interpolationType)	Sets the interpolation type used during value resolution for all attributes on this stage.
`SetLoadRules`(rules)	Set the UsdStageLoadRules to govern payload inclusion on this stage.
`SetMetadata`(key, value)	Set the value of Stage metadatum `key` to `value` , if the stage's current UsdEditTarget is the root or session layer.
`SetMetadataByDictKey`(key, keyPath, value)	Author `value` to the field identified by `key` and `keyPath` at the current EditTarget.
`SetPopulationMask`(mask)	Set this stage's population mask and recompose the stage.
`SetStartTimeCode`(arg1)	Sets the stage's start timeCode.
`SetTimeCodesPerSecond`(timeCodesPerSecond)	Sets the stage's timeCodesPerSecond value.
`Traverse`()	Traverse the active, loaded, defined, non-abstract prims on this stage depth-first.
`TraverseAll`()	Traverse all the prims on this stage depth-first.
`Unload`(path)	Modify this stage's load rules to unload the prim and its descendants specified by `path` .
`UnmuteLayer`(layerIdentifier)	Unmute the layer identified by `layerIdentifier` if it had previously been muted.
`WriteFallbackPrimTypes`()	Writes the fallback prim types defined in the schema registry to the stage as dictionary valued fallback prim type metadata.

Attributes:

`LoadAll`
`LoadNone`
`expired`	True if this object has expired, False otherwise.

class InitialLoadSet

Specifies the initial set of prims to load when opening a UsdStage.

Methods:

GetValueFromName

Attributes:

allValues

static GetValueFromName()

allValues = (Usd.Stage.LoadAll, Usd.Stage.LoadNone)

ClearDefaultPrim() → None

Clear the default prim layer metadata in this stage’s root layer.

This is shorthand for:

 stage->GetRootLayer()->ClearDefaultPrim();

Note that this function always authors to the stage's root layer. To

author to a different layer, use the SdfLayer::SetDefaultPrim() API.

ClearMetadata(key) → bool

Clear the value of stage metadatum key , if the stage’s current UsdEditTarget is the root or session layer.

If the current EditTarget is any other layer, raise a coding error.

true if authoring was successful, false otherwise. Generates a coding error if key is not allowed as layer metadata.

General Metadata in USD

Parameters: key (str) –

ClearMetadataByDictKey(key, keyPath) → bool

Clear any authored value identified by key and keyPath at the current EditTarget.

The keyPath is a’:’-separated path identifying a path in subdictionaries stored in the metadata field at key . If keyPath is empty, no action is taken.

true if the value is cleared successfully, false otherwise. Generates a coding error if key is not allowed as layer metadata.

Dictionary-valued Metadata

Parameters

key (str) –
keyPath (str) –

CreateClassPrim(rootPrimPath) → Prim

Author an SdfPrimSpec with specifier == SdfSpecifierClass for the class at root prim path path at the current EditTarget.

The current EditTarget must have UsdEditTarget::IsLocalLayer() == true.

The given path must be an absolute, root prim path that does not contain any variant selections.

If a defined ( UsdPrim::IsDefined() ) non-class prim already exists at path , issue an error and return an invalid UsdPrim.

If it is impossible to author the necessary PrimSpec, issue an error and return an invalid UsdPrim.

Parameters: rootPrimPath (Path) –

static CreateInMemory()

classmethod CreateInMemory(load) -> Stage

Creates a new stage only in memory, analogous to creating an anonymous SdfLayer.

If pathResolverContext is provided it will be bound when creating the root layer at identifier and whenever asset path resolution is done for this stage, regardless of what other context may be bound at that time. Otherwise Usd will create the root layer with no context bound, then create a context for all future asset path resolution for the stage by calling ArResolver::CreateDefaultContext.

The initial set of prims to load on the stage can be specified using the load parameter.

UsdStage::InitialLoadSet. Invoking an overload that does not take a sessionLayer argument will create a stage with an anonymous in- memory session layer. To create a stage without a session layer, pass TfNullPtr (or None in python) as the sessionLayer argument.

Parameters: load (InitialLoadSet) –

CreateInMemory(identifier, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

identifier (str) –
load (InitialLoadSet) –

CreateInMemory(identifier, pathResolverContext, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

identifier (str) –
pathResolverContext (ResolverContext) –
load (InitialLoadSet) –

CreateInMemory(identifier, sessionLayer, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

identifier (str) –
sessionLayer (Layer) –
load (InitialLoadSet) –

CreateInMemory(identifier, sessionLayer, pathResolverContext, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

identifier (str) –
sessionLayer (Layer) –
pathResolverContext (ResolverContext) –
load (InitialLoadSet) –

static CreateNew()

classmethod CreateNew(identifier, load) -> Stage

Create a new stage with root layer identifier , destroying potentially existing files with that identifier; it is considered an error if an existing, open layer is present with this identifier.

SdfLayer::CreateNew() Invoking an overload that does not take a sessionLayer argument will create a stage with an anonymous in- memory session layer. To create a stage without a session layer, pass TfNullPtr (or None in python) as the sessionLayer argument. The initial set of prims to load on the stage can be specified using the load parameter.

UsdStage::InitialLoadSet. If pathResolverContext is provided it will be bound when creating the root layer at identifier and whenever asset path resolution is done for this stage, regardless of what other context may be bound at that time. Otherwise Usd will create the root layer with no context bound, then create a context for all future asset path resolution for the stage by calling ArResolver::CreateDefaultContextForAsset with the root layer’s repository path if the layer has one, otherwise its resolved path.

Parameters

identifier (str) –
load (InitialLoadSet) –

CreateNew(identifier, sessionLayer, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

identifier (str) –
sessionLayer (Layer) –
load (InitialLoadSet) –

CreateNew(identifier, sessionLayer, pathResolverContext, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

identifier (str) –
sessionLayer (Layer) –
pathResolverContext (ResolverContext) –
load (InitialLoadSet) –

CreateNew(identifier, pathResolverContext, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

identifier (str) –
pathResolverContext (ResolverContext) –
load (InitialLoadSet) –

DefinePrim(path, typeName) → Prim

Attempt to ensure a UsdPrim at path is defined (according to UsdPrim::IsDefined() ) on this stage.

If a prim at path is already defined on this stage and typeName is empty or equal to the existing prim’s typeName, return that prim. Otherwise author an SdfPrimSpec with specifier == SdfSpecifierDef and typeName for the prim at path at the current EditTarget. Author SdfPrimSpec s with specifier == SdfSpecifierDef and empty typeName at the current EditTarget for any nonexistent, or existing but not Defined ancestors.

The given path must be an absolute prim path that does not contain any variant selections.

If it is impossible to author any of the necessary PrimSpecs (for example, in case path cannot map to the current UsdEditTarget ‘s namespace or one of the ancestors of path is inactive on the UsdStage), issue an error and return an invalid UsdPrim.

Note that this method may return a defined prim whose typeName does not match the supplied typeName , in case a stronger typeName opinion overrides the opinion at the current EditTarget.

Parameters

path (Path) –
typeName (str) –

ExpandPopulationMask(relPred, attrPred) → None

Expand this stage’s population mask to include the targets of all relationships that pass relPred and connections to all attributes that pass attrPred recursively.

If relPred is null, include all relationship targets; if attrPred is null, include all connections.

This function can be used, for example, to expand a population mask for a given prim to include bound materials, if those bound materials are expressed as relationships or attribute connections.

See also UsdPrim::FindAllRelationshipTargetPaths() and UsdPrim::FindAllAttributeConnectionPaths() .

Parameters

relPred (function[bool( Relationship )]) –
attrPred (function[bool( Attribute )]) –

Export(filename, addSourceFileComment, args) → bool

Writes out the composite scene as a single flattened layer into filename.

If addSourceFileComment is true, a comment in the output layer will mention the input layer it was generated from.

See UsdStage::Flatten for details of the flattening transformation.

Parameters

filename (str) –
addSourceFileComment (bool) –
args (Layer.FileFormatArguments) –

ExportToString(result, addSourceFileComment) → bool

Writes the composite scene as a flattened Usd text representation into the given string.

If addSourceFileComment is true, a comment in the output layer will mention the input layer it was generated from.

See UsdStage::Flatten for details of the flattening transformation.

Parameters

result (str) –
addSourceFileComment (bool) –

FindLoadable(rootPath) → SdfPathSet

Returns an SdfPathSet of all paths that can be loaded.

Note that this method does not return paths to inactive prims as they cannot be loaded.

The set returned includes loaded and unloaded paths. To determine the set of unloaded paths, one can diff this set with the current load set, for example:

SdfPathSet loaded = stage->GetLoadSet(),
           all = stage->FindLoadable(),
           result;
std::set_difference(loaded.begin(), loaded.end(),
                    all.begin(), all.end(),
                    std::inserter(result, result.end()));

See Working Set Management for more information.

Parameters: rootPath (Path) –

Flatten(addSourceFileComment) → Layer

Returns a single, anonymous, merged layer for this composite scene.

Specifically, this function removes most composition metadata and authors the resolved values for each object directly into the flattened layer.

All VariantSets are removed and only the currently selected variants will be present in the resulting layer.

Class prims will still exist, however all inherits arcs will have been removed and the inherited data will be copied onto each child object. Composition arcs authored on the class itself will be flattened into the class.

Flatten preserves scenegraph instancing by creating independent roots for each prototype currently composed on this stage, and adding a single internal reference arc on each instance prim to its corresponding prototype.

Time samples across sublayer offsets will will have the time offset and scale applied to each time index.

Finally, any deactivated prims will be pruned from the result.

Parameters: addSourceFileComment (bool) –

GetAttributeAtPath(path) → Attribute

Return the UsdAttribute at path , or an invalid UsdAttribute if none exists.

This is equivalent to

stage.GetObjectAtPath(path).As<UsdAttribute>();

GetObjectAtPath(const SdfPath&) const

Parameters: path (Path) –

static GetColorConfigFallbacks()

classmethod GetColorConfigFallbacks(colorConfiguration, colorManagementSystem) -> None

Returns the global fallback values of’colorConfiguration’and’colorManagementSystem’.

These are set in the plugInfo.json file of a plugin, but can be overridden by calling the static method SetColorConfigFallbacks() .

The python wrapping of this method returns a tuple containing (colorConfiguration, colorManagementSystem).

SetColorConfigFallbacks, Color Configuration API

Parameters

colorConfiguration (AssetPath) –
colorManagementSystem (str) –

GetColorConfiguration() → AssetPath

Returns the default color configuration used to interpret the per- attribute color-spaces in the composed USD stage.

Color Configuration API

GetColorManagementSystem() → str

Sets the name of the color management system to be used for loading and interpreting the color configuration file.

Color Configuration API

GetDefaultPrim() → Prim

Return the root UsdPrim on this stage whose name is the root layer’s defaultPrim metadata’s value.

Return an invalid prim if there is no such prim or if the root layer’s defaultPrim metadata is unset or is not a valid prim name. Note that this function only examines this stage’s rootLayer. It does not consider sublayers of the rootLayer. See also SdfLayer::GetDefaultPrim() .

GetEditTarget() → EditTarget: Return the stage’s EditTarget.

GetEditTargetForLocalLayer(i) → EditTarget

Return a UsdEditTarget for editing the layer at index i in the layer stack.

This edit target will incorporate any layer time offset that applies to the sublayer.

Parameters: i (int) –

GetEditTargetForLocalLayer(layer) -> EditTarget

Return a UsdEditTarget for editing the given local layer.

If the given layer appears more than once in the layer stack, the time offset to the first occurrence will be used.

Parameters: layer (Layer) –

GetEndTimeCode() → float

Returns the stage’s end timeCode.

If the stage has an associated session layer with an end timeCode opinion, this value is returned. Otherwise, the end timeCode opinion from the root layer is returned.

GetFramesPerSecond() → float

Returns the stage’s framesPerSecond value.

This makes an advisory statement about how the contained data can be most usefully consumed and presented. It’s primarily an indication of the expected playback rate for the data, but a timeline editing tool might also want to use this to decide how to scale and label its timeline.

The default value of framesPerSecond is 24.

static GetGlobalVariantFallbacks()

classmethod GetGlobalVariantFallbacks() -> PcpVariantFallbackMap

Get the global variant fallback preferences used in new UsdStages.

GetInterpolationType() → InterpolationType: Returns the interpolation type used during value resolution for all attributes on this stage.

GetLayerStack(includeSessionLayers) → list[Layer]

Return this stage’s local layers in strong-to-weak order.

If includeSessionLayers is true, return the linearized strong-to- weak sublayers rooted at the stage’s session layer followed by the linearized strong-to-weak sublayers rooted at this stage’s root layer. If includeSessionLayers is false, omit the sublayers rooted at this stage’s session layer.

Parameters: includeSessionLayers (bool) –

GetLoadRules() → StageLoadRules

Return the stage’s current UsdStageLoadRules governing payload inclusion.

See Working Set Management for more information.

GetLoadSet() → SdfPathSet

Returns a set of all loaded paths.

The paths returned are both those that have been explicitly loaded and those that were loaded as a result of dependencies, ancestors or descendants of explicitly loaded paths.

This method does not return paths to inactive prims.

See Working Set Management for more information.

GetMetadata(key, value) → bool

Return in value an authored or fallback value (if one was defined for the given metadatum) for Stage metadatum key .

Order of resolution is session layer, followed by root layer, else fallback to the SdfSchema.

true if we successfully retrieved a value of the requested type; false if key is not allowed as layer metadata or no value was found. Generates a coding error if we retrieved a stored value of a type other than the requested type

General Metadata in USD

Parameters

key (str) –
value (T) –

GetMetadata(key, value) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

key (str) –
value (VtValue) –

GetMetadataByDictKey(key, keyPath, value) → bool

Resolve the requested dictionary sub-element keyPath of dictionary-valued metadatum named key , returning the resolved value.

If you know you need just a small number of elements from a dictionary, accessing them element-wise using this method can be much less expensive than fetching the entire dictionary with GetMetadata(key).

true if we successfully retrieved a value of the requested type; false if key is not allowed as layer metadata or no value was found. Generates a coding error if we retrieved a stored value of a type other than the requested type The keyPath is a’:’-separated path addressing an element in subdictionaries. If keyPath is empty, returns an empty VtValue.

Parameters

key (str) –
keyPath (str) –
value (T) –

GetMetadataByDictKey(key, keyPath, value) -> bool

overload

Parameters

key (str) –
keyPath (str) –
value (VtValue) –

GetMutedLayers() → list[str]: Returns a vector of all layers that have been muted on this stage.

GetObjectAtPath(path) → Object

Return the UsdObject at path , or an invalid UsdObject if none exists.

If path indicates a prim beneath an instance, returns an instance proxy prim if a prim exists at the corresponding path in that instance’s prototype. If path indicates a property beneath a child of an instance, returns a property whose parent prim is an instance proxy prim.

Example:

if (UsdObject obj = stage->GetObjectAtPath(path)) {
    if (UsdPrim prim = obj.As<UsdPrim>()) {
        // Do things with prim
    }
    else if (UsdProperty prop = obj.As<UsdProperty>()) {
        // Do things with property. We can also cast to
        // UsdRelationship or UsdAttribute using this same pattern.
    }
}
else {
    // No object at specified path
}

Parameters: path (Path) –

GetPathResolverContext() → ResolverContext

Return the path resolver context for all path resolution during composition of this stage.

Useful for external clients that want to resolve paths with the same context as this stage, or create new stages with the same context.

GetPopulationMask() → StagePopulationMask: Return this stage’s population mask.

GetPrimAtPath(path) → Prim

Return the UsdPrim at path , or an invalid UsdPrim if none exists.

If path indicates a prim beneath an instance, returns an instance proxy prim if a prim exists at the corresponding path in that instance’s prototype.

Unlike OverridePrim() and DefinePrim() , this method will never author scene description, and therefore is safe to use as a”reader”in the Usd multi-threading model.

Parameters: path (Path) –

GetPropertyAtPath(path) → Property

Return the UsdProperty at path , or an invalid UsdProperty if none exists.

This is equivalent to

stage.GetObjectAtPath(path).As<UsdProperty>();

GetObjectAtPath(const SdfPath&) const

Parameters: path (Path) –

GetPrototypes() → list[Prim]: Returns all native instancing prototype prims.

GetPseudoRoot() → Prim

Return the stage’s”pseudo-root”prim, whose name is defined by Usd.

The stage’s named root prims are namespace children of this prim, which exists to make the namespace hierarchy a tree instead of a forest. This simplifies algorithms that want to traverse all prims.

A UsdStage always has a pseudo-root prim, unless there was an error opening or creating the stage, in which case this method returns an invalid UsdPrim.

GetRelationshipAtPath(path) → Relationship

Return the UsdAttribute at path , or an invalid UsdAttribute if none exists.

This is equivalent to

stage.GetObjectAtPath(path).As<UsdRelationship>();

GetObjectAtPath(const SdfPath&) const

Parameters: path (Path) –

GetRootLayer() → Layer: Return this stage’s root layer.

GetSessionLayer() → Layer: Return this stage’s root session layer.

GetStartTimeCode() → float

Returns the stage’s start timeCode.

If the stage has an associated session layer with a start timeCode opinion, this value is returned. Otherwise, the start timeCode opinion from the root layer is returned.

GetTimeCodesPerSecond() → float

Returns the stage’s timeCodesPerSecond value.

The timeCodesPerSecond value scales the time ordinate for the samples contained in the stage to seconds. If timeCodesPerSecond is 24, then a sample at time ordinate 24 should be viewed exactly one second after the sample at time ordinate 0.

Like SdfLayer::GetTimeCodesPerSecond, this accessor uses a dynamic fallback to framesPerSecond. The order of precedence is:

timeCodesPerSecond from session layer

timeCodesPerSecond from root layer

framesPerSecond from session layer

framesPerSecond from root layer

fallback value of 24

GetUsedLayers(includeClipLayers) → list[Layer]

Return a vector of all of the layers currently consumed by this stage, as determined by the composition arcs that were traversed to compose and populate the stage.

The list of consumed layers will change with the stage’s load-set and variant selections, so the return value should be considered only a snapshot. The return value will include the stage’s session layer, if it has one. If includeClipLayers is true, we will also include all of the layers that this stage has had to open so far to perform value resolution of attributes affected by Value Clips

Parameters: includeClipLayers (bool) –

HasAuthoredMetadata(key) → bool

Returns true if the key has an authored value, false if no value was authored or the only value available is the SdfSchema ‘s metadata fallback.

If a value for a metadatum not legal to author on layers is present in the root or session layer (which could happen through hand-editing or use of certain low-level API’s), this method will still return false .

Parameters: key (str) –

HasAuthoredMetadataDictKey(key, keyPath) → bool

Return true if there exists any authored opinion (excluding fallbacks) for key and keyPath .

The keyPath is a’:’-separated path identifying a value in subdictionaries stored in the metadata field at key . If keyPath is empty, returns false .

Dictionary-valued Metadata

Parameters

key (str) –
keyPath (str) –

HasAuthoredTimeCodeRange() → bool: Returns true if the stage has both start and end timeCodes authored in the session layer or the root layer of the stage.

HasDefaultPrim() → bool

Return true if this stage’s root layer has an authored opinion for the default prim layer metadata.

This is shorthand for:

 stage->GetRootLayer()->HasDefaultPrim();

Note that this function only consults the stage's root layer. To

consult a different layer, use the SdfLayer::HasDefaultPrim() API.

HasLocalLayer(layer) → bool

Return true if layer is one of the layers in this stage’s local, root layerStack.

Parameters: layer (Layer) –

HasMetadata(key) → bool

Returns true if the key has a meaningful value, that is, if GetMetadata() will provide a value, either because it was authored or because the Stage metadata was defined with a meaningful fallback value.

Returns false if key is not allowed as layer metadata.

Parameters: key (str) –

HasMetadataDictKey(key, keyPath) → bool

Return true if there exists any authored or fallback opinion for key and keyPath .

The keyPath is a’:’-separated path identifying a value in subdictionaries stored in the metadata field at key . If keyPath is empty, returns false .

Returns false if key is not allowed as layer metadata.

Dictionary-valued Metadata

Parameters

key (str) –
keyPath (str) –

IsLayerMuted(layerIdentifier) → bool

Returns true if the layer specified by layerIdentifier is muted in this cache, false otherwise.

See documentation on MuteLayer for details on how layerIdentifier is compared to the layers that have been muted.

Parameters: layerIdentifier (str) –

static IsSupportedFile()

classmethod IsSupportedFile(filePath) -> bool

Indicates whether the specified file is supported by UsdStage.

This function is a cheap way to determine whether a file might be open-able with UsdStage::Open. It is purely based on the given filePath and does not open the file or perform analysis on the contents. As such, UsdStage::Open may still fail even if this function returns true.

Parameters: filePath (str) –

Load(path, policy) → Prim

Modify this stage’s load rules to load the prim at path , its ancestors, and all of its descendants if policy is UsdLoadWithDescendants.

If policy is UsdLoadWithoutDescendants, then payloads on descendant prims are not loaded.

See Working Set Management for more information.

Parameters

path (Path) –
policy (LoadPolicy) –

LoadAndUnload(loadSet, unloadSet, policy) → None

Unload and load the given path sets.

The effect is as if the unload set were processed first followed by the load set.

This is equivalent to calling UsdStage::Unload for each item in the unloadSet followed by UsdStage::Load for each item in the loadSet, however this method is more efficient as all operations are committed in a single batch. The policy argument is described in the documentation for Load() .

See Working Set Management for more information.

Parameters

loadSet (SdfPathSet) –
unloadSet (SdfPathSet) –
policy (LoadPolicy) –

MuteAndUnmuteLayers(muteLayers, unmuteLayers) → None

Mute and unmute the layers identified in muteLayers and unmuteLayers .

This is equivalent to calling UsdStage::UnmuteLayer for each layer in unmuteLayers followed by UsdStage::MuteLayer for each layer in muteLayers , however this method is more efficient as all operations are committed in a single batch.

Parameters

muteLayers (list[str]) –
unmuteLayers (list[str]) –

MuteLayer(layerIdentifier) → None

Mute the layer identified by layerIdentifier .

Muted layers are ignored by the stage; they do not participate in value resolution or composition and do not appear in any LayerStack. If the root layer of a reference or payload LayerStack is muted, the behavior is as if the muted layer did not exist, which means a composition error will be generated.

A canonical identifier for each layer in layersToMute will be computed using ArResolver::CreateIdentifier using the stage’s root layer as the anchoring asset. Any layer encountered during composition with the same identifier will be considered muted and ignored.

Note that muting a layer will cause this stage to release all references to that layer. If no other client is holding on to references to that layer, it will be unloaded. In this case, if there are unsaved edits to the muted layer, those edits are lost. Since anonymous layers are not serialized, muting an anonymous layer will cause that layer and its contents to be lost in this case.

Muting a layer that has not been used by this stage is not an error. If that layer is encountered later, muting will take effect and that layer will be ignored.

The root layer of this stage may not be muted; attempting to do so will generate a coding error.

Parameters: layerIdentifier (str) –

static Open()

classmethod Open(filePath, load) -> Stage

Attempt to find a matching existing stage in a cache if UsdStageCacheContext objects exist on the stack.

Failing that, create a new stage and recursively compose prims defined within and referenced by the layer at filePath , which must already exist.

The initial set of prims to load on the stage can be specified using the load parameter.

UsdStage::InitialLoadSet. If pathResolverContext is provided it will be bound when opening the root layer at filePath and whenever asset path resolution is done for this stage, regardless of what other context may be bound at that time. Otherwise Usd will open the root layer with no context bound, then create a context for all future asset path resolution for the stage by calling ArResolver::CreateDefaultContextForAsset with the layer’s repository path if the layer has one, otherwise its resolved path.

Parameters

filePath (str) –
load (InitialLoadSet) –

Open(filePath, pathResolverContext, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

filePath (str) –
pathResolverContext (ResolverContext) –
load (InitialLoadSet) –

Open(rootLayer, load) -> Stage

Open a stage rooted at rootLayer .

Attempt to find a stage that matches the passed arguments in a UsdStageCache if UsdStageCacheContext objects exist on the calling stack. If a matching stage is found, return that stage. Otherwise, create a new stage rooted at rootLayer .

Invoking an overload that does not take a sessionLayer argument will create a stage with an anonymous in-memory session layer. To create a stage without a session layer, pass TfNullPtr (or None in python) as the sessionLayer argument.

The initial set of prims to load on the stage can be specified using the load parameter.

UsdStage::InitialLoadSet. If pathResolverContext is provided it will be bound when whenever asset path resolution is done for this stage, regardless of what other context may be bound at that time. Otherwise Usd will create a context for all future asset path resolution for the stage by calling ArResolver::CreateDefaultContextForAsset with the layer’s repository path if the layer has one, otherwise its resolved path.

When searching for a matching stage in bound UsdStageCache s, only the provided arguments matter for cache lookup. For example, if only a root layer (or a root layer file path) is provided, the first stage found in any cache that has that root layer is returned. So, for example if you require that the stage have no session layer, you must explicitly specify TfNullPtr (or None in python) for the sessionLayer argument.

Parameters

rootLayer (Layer) –
load (InitialLoadSet) –

Open(rootLayer, sessionLayer, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

rootLayer (Layer) –
sessionLayer (Layer) –
load (InitialLoadSet) –

Open(rootLayer, pathResolverContext, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

rootLayer (Layer) –
pathResolverContext (ResolverContext) –
load (InitialLoadSet) –

Open(rootLayer, sessionLayer, pathResolverContext, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

rootLayer (Layer) –
sessionLayer (Layer) –
pathResolverContext (ResolverContext) –
load (InitialLoadSet) –

static OpenMasked()

classmethod OpenMasked(filePath, mask, load) -> Stage

Create a new stage and recursively compose prims defined within and referenced by the layer at filePath which must already exist, subject to mask .

These OpenMasked() methods do not automatically consult or populate UsdStageCache s.

The initial set of prims to load on the stage can be specified using the load parameter.

UsdStage::InitialLoadSet. If pathResolverContext is provided it will be bound when opening the root layer at filePath and whenever asset path resolution is done for this stage, regardless of what other context may be bound at that time. Otherwise Usd will open the root layer with no context bound, then create a context for all future asset path resolution for the stage by calling ArResolver::CreateDefaultContextForAsset with the layer’s repository path if the layer has one, otherwise its resolved path.

Parameters

filePath (str) –
mask (StagePopulationMask) –
load (InitialLoadSet) –

OpenMasked(filePath, pathResolverContext, mask, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

filePath (str) –
pathResolverContext (ResolverContext) –
mask (StagePopulationMask) –
load (InitialLoadSet) –

OpenMasked(rootLayer, mask, load) -> Stage

Open a stage rooted at rootLayer and with limited population subject to mask .

These OpenMasked() methods do not automatically consult or populate UsdStageCache s.

Invoking an overload that does not take a sessionLayer argument will create a stage with an anonymous in-memory session layer. To create a stage without a session layer, pass TfNullPtr (or None in python) as the sessionLayer argument.

The initial set of prims to load on the stage can be specified using the load parameter.

UsdStage::InitialLoadSet. If pathResolverContext is provided it will be bound when whenever asset path resolution is done for this stage, regardless of what other context may be bound at that time. Otherwise Usd will create a context for all future asset path resolution for the stage by calling ArResolver::CreateDefaultContextForAsset with the layer’s repository path if the layer has one, otherwise its resolved path.

Parameters

rootLayer (Layer) –
mask (StagePopulationMask) –
load (InitialLoadSet) –

OpenMasked(rootLayer, sessionLayer, mask, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

rootLayer (Layer) –
sessionLayer (Layer) –
mask (StagePopulationMask) –
load (InitialLoadSet) –

OpenMasked(rootLayer, pathResolverContext, mask, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

rootLayer (Layer) –
pathResolverContext (ResolverContext) –
mask (StagePopulationMask) –
load (InitialLoadSet) –

OpenMasked(rootLayer, sessionLayer, pathResolverContext, mask, load) -> Stage

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

rootLayer (Layer) –
sessionLayer (Layer) –
pathResolverContext (ResolverContext) –
mask (StagePopulationMask) –
load (InitialLoadSet) –

OverridePrim(path) → Prim

Attempt to ensure a UsdPrim at path exists on this stage.

If a prim already exists at path , return it. Otherwise author SdfPrimSpecs with specifier == SdfSpecifierOver and empty typeName at the current EditTarget to create this prim and any nonexistent ancestors, then return it.

The given path must be an absolute prim path that does not contain any variant selections.

If it is impossible to author any of the necessary PrimSpecs, (for example, in case path cannot map to the current UsdEditTarget ‘s namespace) issue an error and return an invalid UsdPrim.

If an ancestor of path identifies an inactive prim, author scene description as described above but return an invalid prim, since the resulting prim is descendant to an inactive prim.

Parameters: path (Path) –

Reload() → None

Calls SdfLayer::Reload on all layers contributing to this stage, except session layers and sublayers of session layers.

This includes non-session sublayers, references and payloads. Note that reloading anonymous layers clears their content, so invoking Reload() on a stage constructed via CreateInMemory() will clear its root layer.

This method is considered a mutation, which has potentially global effect! Unlike the various Load() methods whose actions affect only this stage, Reload() may cause layers to change their contents, and because layers are global resources shared by potentially many Stages, calling Reload() on one stage may result in a mutation to any number of stages. In general, unless you are highly confident your stage is the only consumer of its layers, you should only call Reload() when you are assured no other threads may be reading from any Stages.

RemovePrim(path) → bool

Remove all scene description for the given path and its subtree in the current UsdEditTarget.

This method does not do what you might initially think! Calling this function will not necessarily cause the UsdPrim at path on this stage to disappear. Completely eradicating a prim from a composition can be an involved process, involving edits to many contributing layers, some of which (in many circumstances) will not be editable by a client. This method is a surgical instrument that can be used iteratively to effect complete removal of a prim and its subtree from namespace, assuming the proper permissions are acquired, but more commonly it is used to perform layer-level operations; e.g.: ensuring that a given layer (as expressed by a UsdEditTarget) provides no opinions for a prim and its subtree.

Generally, if your eye is attracted to this method, you probably want to instead use UsdPrim::SetActive(false), which will provide the composed effect of removing the prim and its subtree from the composition, without actually removing any scene description, which as a bonus, means that the effect is reversible at a later time!

Parameters: path (Path) –

ResolveIdentifierToEditTarget(identifier) → str

Resolve the given identifier using this stage’s ArResolverContext and the layer of its GetEditTarget() as an anchor for relative references (e.g.

@./siblingFile.usd@).

a non-empty string containing either the same identifier that was passed in (if the identifier refers to an already-opened layer or an”anonymous”, in-memory layer), or a resolved layer filepath. If the identifier was not resolvable, return the empty string.

Parameters: identifier (str) –

Save() → None

Calls SdfLayer::Save on all dirty layers contributing to this stage except session layers and sublayers of session layers.

This function will emit a warning and skip each dirty anonymous layer it encounters, since anonymous layers cannot be saved with SdfLayer::Save. These layers must be manually exported by calling SdfLayer::Export.

SaveSessionLayers() → None

Calls SdfLayer::Save on all dirty session layers and sublayers of session layers contributing to this stage.

This function will emit a warning and skip each dirty anonymous layer it encounters, since anonymous layers cannot be saved with SdfLayer::Save. These layers must be manually exported by calling SdfLayer::Export.

static SetColorConfigFallbacks()

classmethod SetColorConfigFallbacks(colorConfiguration, colorManagementSystem) -> None

Sets the global fallback values of color configuration metadata which includes the’colorConfiguration’asset path and the name of the color management system.

This overrides any fallback values authored in plugInfo files.

If the specified value of colorConfiguration or colorManagementSystem is empty, then the corresponding fallback value isn’t set. In other words, for this call to have an effect, at least one value must be non-empty. Additionally, these can’t be reset to empty values.

GetColorConfigFallbacks() Color Configuration API

Parameters

colorConfiguration (AssetPath) –
colorManagementSystem (str) –

SetColorConfiguration(colorConfig) → None

Sets the default color configuration to be used to interpret the per- attribute color-spaces in the composed USD stage.

This is specified as asset path which can be resolved to the color spec file.

Color Configuration API

Parameters: colorConfig (AssetPath) –

SetColorManagementSystem(cms) → None

Sets the name of the color management system used to interpret the color configuration file pointed at by the colorConfiguration metadata.

Color Configuration API

Parameters: cms (str) –

SetDefaultPrim(prim) → None

Set the default prim layer metadata in this stage’s root layer.

This is shorthand for:

 stage->GetRootLayer()->SetDefaultPrim(prim.GetName());

Note that this function always authors to the stage's root layer. To

author to a different layer, use the SdfLayer::SetDefaultPrim() API.

Parameters: prim (Prim) –

SetEditTarget(editTarget) → None

Set the stage’s EditTarget.

If editTarget.IsLocalLayer(), check to see if it’s a layer in this stage’s local LayerStack. If not, issue an error and do nothing. If editTarget is invalid, issue an error and do nothing. If editTarget differs from the stage’s current EditTarget, set the EditTarget and send UsdNotice::StageChangedEditTarget. Otherwise do nothing.

Parameters: editTarget (EditTarget) –

SetEndTimeCode(arg1) → None

Sets the stage’s end timeCode.

The end timeCode is set in the current EditTarget, if it is the root layer of the stage or the session layer associated with the stage. If the current EditTarget is neither, a warning is issued and the end timeCode is not set.

Parameters: arg1 (float) –

SetFramesPerSecond(framesPerSecond) → None

Sets the stage’s framesPerSecond value.

The framesPerSecond value is set in the current EditTarget, if it is the root layer of the stage or the session layer associated with the stage. If the current EditTarget is neither, a warning is issued and no value is set.

GetFramesPerSecond()

Parameters: framesPerSecond (float) –

static SetGlobalVariantFallbacks()

classmethod SetGlobalVariantFallbacks(fallbacks) -> None

Set the global variant fallback preferences used in new UsdStages.

This overrides any fallbacks configured in plugin metadata, and only affects stages created after this call.

This does not affect existing UsdStages.

Parameters: fallbacks (PcpVariantFallbackMap) –

SetInterpolationType(interpolationType) → None

Sets the interpolation type used during value resolution for all attributes on this stage.

Changing this will cause a UsdNotice::StageContentsChanged notice to be sent, as values at times where no samples are authored may have changed.

Parameters: interpolationType (InterpolationType) –

SetLoadRules(rules) → None

Set the UsdStageLoadRules to govern payload inclusion on this stage.

This rebuilds the stage’s entire prim hierarchy to follow rules .

Note that subsequent calls to Load() , Unload() , LoadAndUnload() will modify this stages load rules as described in the documentation for those member functions.

See Working Set Management for more information.

Parameters: rules (StageLoadRules) –

SetMetadata(key, value) → bool

Set the value of Stage metadatum key to value , if the stage’s current UsdEditTarget is the root or session layer.

If the current EditTarget is any other layer, raise a coding error.

true if authoring was successful, false otherwise. Generates a coding error if key is not allowed as layer metadata.

General Metadata in USD

Parameters

key (str) –
value (T) –

SetMetadata(key, value) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

key (str) –
value (VtValue) –

SetMetadataByDictKey(key, keyPath, value) → bool

Author value to the field identified by key and keyPath at the current EditTarget.

The keyPath is a’:’-separated path identifying a value in subdictionaries stored in the metadata field at key . If keyPath is empty, no action is taken.

true if the value is authored successfully, false otherwise. Generates a coding error if key is not allowed as layer metadata.

Dictionary-valued Metadata

Parameters

key (str) –
keyPath (str) –
value (T) –

SetMetadataByDictKey(key, keyPath, value) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

key (str) –
keyPath (str) –
value (VtValue) –

SetPopulationMask(mask) → None

Set this stage’s population mask and recompose the stage.

Parameters: mask (StagePopulationMask) –

SetStartTimeCode(arg1) → None

Sets the stage’s start timeCode.

The start timeCode is set in the current EditTarget, if it is the root layer of the stage or the session layer associated with the stage. If the current EditTarget is neither, a warning is issued and the start timeCode is not set.

Parameters: arg1 (float) –

SetTimeCodesPerSecond(timeCodesPerSecond) → None

Sets the stage’s timeCodesPerSecond value.

The timeCodesPerSecond value is set in the current EditTarget, if it is the root layer of the stage or the session layer associated with the stage. If the current EditTarget is neither, a warning is issued and no value is set.

GetTimeCodesPerSecond()

Parameters: timeCodesPerSecond (float) –

Traverse() → PrimRange

Traverse the active, loaded, defined, non-abstract prims on this stage depth-first.

Traverse() returns a UsdPrimRange, which allows low-latency traversal, with the ability to prune subtrees from traversal. It is python iterable, so in its simplest form, one can do:

for prim in stage.Traverse():
    print prim.GetPath()

If either a pre-and-post-order traversal or a traversal rooted at a particular prim is desired, construct a UsdPrimRange directly.

This is equivalent to UsdPrimRange::Stage() .

Traverse(predicate) -> PrimRange

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Traverse the prims on this stage subject to predicate .

This is equivalent to UsdPrimRange::Stage() .

Parameters: predicate (_PrimFlagsPredicate) –

TraverseAll() → PrimRange

Traverse all the prims on this stage depth-first.

Traverse()

UsdPrimRange::Stage()

Unload(path) → None

Modify this stage’s load rules to unload the prim and its descendants specified by path .

See Working Set Management for more information.

Parameters: path (Path) –

UnmuteLayer(layerIdentifier) → None

Unmute the layer identified by layerIdentifier if it had previously been muted.

Parameters: layerIdentifier (str) –

WriteFallbackPrimTypes() → None

Writes the fallback prim types defined in the schema registry to the stage as dictionary valued fallback prim type metadata.

If the stage already has fallback prim type metadata, the fallback types from the schema registry will be added to the existing metadata, only for types that are already present in the dictionary, i.e. this won’t overwrite existing fallback entries.

The current edit target determines whether the metadata is written to the root layer or the session layer. If the edit target specifies another layer besides these, this will produce an error.

This function can be used at any point before calling Save or Export on a stage to record the fallback types for the current schemas. This allows another version of Usd to open this stage and treat prim types it doesn’t recognize as a type it does recognize defined for it in this metadata.

Fallback Prim Types UsdSchemaRegistry::GetFallbackPrimTypes

LoadAll = Usd.Stage.LoadAll

LoadNone = Usd.Stage.LoadNone

property expired: True if this object has expired, False otherwise.

class pxr.Usd.StageCache

A strongly concurrency safe collection of UsdStageRefPtr s, enabling sharing across multiple clients and threads. See UsdStageCacheContext for typical use cases finding UsdStage s in a cache and publishing UsdStage s to a cache.

UsdStageCache is strongly thread safe: all operations other than construction and destruction may be performed concurrently.

Clients typically populate and fetch UsdStage s in caches by binding a UsdStageCacheContext object to a cache, then using the UsdStage::Open() API. See UsdStageCacheContext for more details. Clients may also populate and fetch directly via UsdStageCache::Insert() , UsdStageCache::Find() , UsdStageCache::FindOneMatching() , and UsdStageCache::FindAllMatching() API.

Caches provide a mechanism that associates a lightweight key, UsdStageCache::Id, with a cached stage. A UsdStageCache::Id can be converted to and from long int and string. This can be useful for communicating within a third party application that cannot transmit arbitrary C++ objects. See UsdStageCache::GetId() .

Clients may iterate all cache elements using UsdStageCache::GetAllStages() and remove elements with UsdStageCache::Erase() , UsdStageCache::EraseAll() , and UsdStageCache::Clear() .

Note that this class is a regular type: it can be copied and assigned at will. It is not a singleton. Also, since it holds a collection of UsdStageRefPtr objects, copying it does not create new UsdStage instances, it merely copies the RefPtrs.

Enabling the USD_STAGE_CACHE TF_DEBUG code will issue debug output for UsdStageCache Find/Insert/Erase/Clear operations. Also see UsdStageCache::SetDebugName() and UsdStageCache::GetDebugName() .

Classes:

Id

Methods:

`Clear`()	Remove all entries from this cache, leaving it empty and equivalent to a default-constructed cache.
`Contains`(stage)	Return true if `stage` is present in this cache, false otherwise.
`Erase`(id)	Erase the stage identified by `id` from this cache and return true.
`EraseAll`(rootLayer)	Erase all stages present in the cache with `rootLayer` and return the number erased.
`Find`(id)	Find the stage in this cache corresponding to `id` in this cache.
`FindAllMatching`(rootLayer)	Find all stages in this cache with `rootLayer` .
`FindOneMatching`(rootLayer)	Find a stage in this cache with `rootLayer` .
`GetAllStages`()	Return a vector containing the stages present in this cache.
`GetDebugName`()	Retrieve this cache's debug name, set with SetDebugName() .
`GetId`(stage)	Return the Id associated with `stage` in this cache.
`Insert`(stage)	Insert `stage` into this cache and return its associated Id.
`IsEmpty`()	Return true if this cache holds no stages, false otherwise.
`SetDebugName`(debugName)	Assign a debug name to this cache.
`Size`()	Return the number of stages present in this cache.
`swap`(other)	Swap the contents of this cache with `other` .

class Id

Methods:

`FromLongInt`
`FromString`
`IsValid`
`ToLongInt`
`ToString`

static FromLongInt()

static FromString()

IsValid()

ToLongInt()

ToString()

Clear() → None

Remove all entries from this cache, leaving it empty and equivalent to a default-constructed cache.

Since the cache contains UsdStageRefPtr, erasing a stage from the cache will only destroy the stage if no other UsdStageRefPtrs exist referring to it.

Contains(stage) → bool

Return true if stage is present in this cache, false otherwise.

Parameters: stage (Stage) –

Contains(id) -> bool

Return true if id is present in this cache, false otherwise.

Parameters: id (Id) –

Erase(id) → bool

Erase the stage identified by id from this cache and return true.

If id is invalid or there is no associated stage in this cache, do nothing and return false. Since the cache contains UsdStageRefPtr, erasing a stage from the cache will only destroy the stage if no other UsdStageRefPtrs exist referring to it.

Parameters: id (Id) –

Erase(stage) -> bool

Erase stage from this cache and return true.

If stage is not present in this cache, do nothing and return false. Since the cache contains UsdStageRefPtr, erasing a stage from the cache will only destroy the stage if no other UsdStageRefPtrs exist referring to it.

Parameters: stage (Stage) –

EraseAll(rootLayer) → int

Erase all stages present in the cache with rootLayer and return the number erased.

Since the cache contains UsdStageRefPtr, erasing a stage from the cache will only destroy the stage if no other UsdStageRefPtrs exist referring to it.

Parameters: rootLayer (Layer) –

EraseAll(rootLayer, sessionLayer) -> int

Erase all stages present in the cache with rootLayer and sessionLayer and return the number erased.

Since the cache contains UsdStageRefPtr, erasing a stage from the cache will only destroy the stage if no other UsdStageRefPtrs exist referring to it.

Parameters

rootLayer (Layer) –
sessionLayer (Layer) –

EraseAll(rootLayer, sessionLayer, pathResolverContext) -> int

Erase all stages present in the cache with rootLayer , sessionLayer , and pathResolverContext and return the number erased.

Since the cache contains UsdStageRefPtr, erasing a stage from the cache will only destroy the stage if no other UsdStageRefPtrs exist referring to it.

Parameters

rootLayer (Layer) –
sessionLayer (Layer) –
pathResolverContext (ResolverContext) –

Find(id) → Stage

Find the stage in this cache corresponding to id in this cache.

If id is not valid (see Id::IsValid() ) or if this cache does not have a stage corresponding to id , return null.

Parameters: id (Id) –

FindAllMatching(rootLayer) → list[Stage]

Find all stages in this cache with rootLayer .

If there is no matching stage in this cache, return an empty vector.

Parameters: rootLayer (Layer) –

FindAllMatching(rootLayer, sessionLayer) -> list[Stage]

Find all stages in this cache with rootLayer and sessionLayer .

If there is no matching stage in this cache, return an empty vector.

Parameters

rootLayer (Layer) –
sessionLayer (Layer) –

FindAllMatching(rootLayer, pathResolverContext) -> list[Stage]

Find all stages in this cache with rootLayer and pathResolverContext .

If there is no matching stage in this cache, return an empty vector.

Parameters

rootLayer (Layer) –
pathResolverContext (ResolverContext) –

FindAllMatching(rootLayer, sessionLayer, pathResolverContext) -> list[Stage]

Find all stages in this cache with rootLayer , sessionLayer , and pathResolverContext .

If there is no matching stage in this cache, return an empty vector. If there is more than one matching stage in this cache, return an arbitrary matching one.

Parameters

rootLayer (Layer) –
sessionLayer (Layer) –
pathResolverContext (ResolverContext) –

FindOneMatching(rootLayer) → Stage

Find a stage in this cache with rootLayer .

If there is no matching stage in this cache, return null. If there is more than one matching stage in this cache, return an arbitrary matching one. See also FindAllMatching() .

Parameters: rootLayer (Layer) –

FindOneMatching(rootLayer, sessionLayer) -> Stage

Find a stage in this cache with rootLayer and sessionLayer .

If there is no matching stage in this cache, return null. If there is more than one matching stage in this cache, return an arbitrary matching one. See also FindAllMatching() .

Parameters

rootLayer (Layer) –
sessionLayer (Layer) –

FindOneMatching(rootLayer, pathResolverContext) -> Stage

Find a stage in this cache with rootLayer and pathResolverContext .

If there is no matching stage in this cache, return null. If there is more than one matching stage in this cache, return an arbitrary matching one.

FindAllMatching()

Parameters

rootLayer (Layer) –
pathResolverContext (ResolverContext) –

FindOneMatching(rootLayer, sessionLayer, pathResolverContext) -> Stage

Find a stage in this cache with rootLayer , sessionLayer , and pathResolverContext .

If there is no matching stage in this cache, return null. If there is more than one matching stage in this cache, return an arbitrary matching one.

FindAllMatching()

Parameters

rootLayer (Layer) –
sessionLayer (Layer) –
pathResolverContext (ResolverContext) –

GetAllStages() → list[Stage]: Return a vector containing the stages present in this cache.

GetDebugName() → str

Retrieve this cache’s debug name, set with SetDebugName() .

If no debug name has been assigned, return the empty string.

GetId(stage) → Id

Return the Id associated with stage in this cache.

If stage is not present in this cache, return an invalid Id.

Parameters: stage (Stage) –

Insert(stage) → Id

Insert stage into this cache and return its associated Id.

If the given stage is already present in this cache, simply return its associated Id.

Parameters: stage (Stage) –

IsEmpty() → bool: Return true if this cache holds no stages, false otherwise.

SetDebugName(debugName) → None

Assign a debug name to this cache.

This will be emitted in debug output messages when the USD_STAGE_CACHES debug flag is enabled. If set to the empty string, the cache’s address will be used instead.

Parameters: debugName (str) –

Size() → int: Return the number of stages present in this cache.

swap(other) → None

Swap the contents of this cache with other .

Parameters: other (StageCache) –

class pxr.Usd.StageCacheContext

A context object that lets the UsdStage::Open() API read from or read from and write to a UsdStageCache instance during a scope of execution.

Code examples illustrate typical use:

{
    // A stage cache to work with.
    UsdStageCache stageCache;

    // Bind this cache.  UsdStage::Open() will attempt to find a matching
    // stage in the cache.  If none is found, it will open a new stage and
    // insert it into the cache.
    UsdStageCacheContext context(stageCache);

    // Since the cache is currently empty, this Open call will not find an
    // existing stage in the cache, but will insert the newly opened stage
    // in it.
    auto stage = UsdStage::Open(<args>);

    assert(stageCache.Contains(stage));

    // A subsequent Open() call with the same arguments will retrieve the
    // stage from cache.
    auto stage2 = UsdStage::Open(<args>);
    assert(stage2 == stage);
}

The UsdStage::Open() API examines caches in UsdStageCacheContexts that exist on the stack in the current thread in order starting with the most recently created (deepest in the stack) to the least recently created.

The UsdUseButDoNotPopulateCache() function makes a cache available for UsdStage::Open() to find stages in, but newly opened stages will not be published to it. This can be useful if you want to make use of a cache but cannot or do not wish to mutate that cache.

Passing UsdBlockStageCaches disables cache use entirely (as if no UsdStageCacheContexts exist on the stack), while UsdBlockStageCachePopulation disables writing to all bound caches (as if they were all established with UsdUseButDoNotPopulateCache()).

Threading note: Different threads have different call stacks, so UsdStageCacheContext objects that exist in one thread’s stack do not influence calls to UsdStage::Open() from a different thread.

class pxr.Usd.StageCacheContextBlockType

Methods:

GetValueFromName

Attributes:

allValues

static GetValueFromName()

allValues = (Usd.BlockStageCaches, Usd.BlockStageCachePopulation, Usd._NoBlock)

class pxr.Usd.StageLoadRules

This class represents rules that govern payload inclusion on UsdStages.

Rules are represented as pairs of SdfPath and a Rule enum value, one of AllRule, OnlyRule, and NoneRule. To understand how rules apply to particular paths, see UsdStageLoadRules::GetEffectiveRuleForPath() .

Convenience methods for manipulating rules by typical’Load’and’Unload’operations are provided in UsdStageLoadRules::LoadWithoutDescendants() , UsdStageLoadRules::LoadWithDescendants() , UsdStageLoadRules::Unload() .

For finer-grained rule crafting, see AddRule() .

Remove redundant rules that do not change the effective load state with UsdStageLoadRules::Minimize() .

Classes:

Rule

These values are paired with paths to govern payload inclusion on UsdStages.

Methods:

`AddRule`(path, rule)	Add a literal rule.
`GetEffectiveRuleForPath`(path)	Return the"effective"rule for the given `path` .
`GetRules`()	Return all the rules as a vector.
`IsLoaded`(path)	Return true if the given `path` is considered loaded by these rules, or false if it is considered unloaded.
`IsLoadedWithAllDescendants`(path)	Return true if the given `path` and all descendants are considered loaded by these rules; false otherwise.
`IsLoadedWithNoDescendants`(path)	Return true if the given `path` and is considered loaded, but none of its descendants are considered loaded by these rules; false otherwise.
`LoadAll`	classmethod LoadAll() -> StageLoadRules
`LoadAndUnload`(loadSet, unloadSet, policy)	Add rules as if Unload() was called for each element of `unloadSet` followed by calls to either LoadWithDescendants() (if `policy` is UsdLoadPolicy::LoadWithDescendants) or LoadWithoutDescendants() (if `policy` is UsdLoadPolicy::LoadWithoutDescendants) for each element of `loadSet` .
`LoadNone`	classmethod LoadNone() -> StageLoadRules
`LoadWithDescendants`(path)	Add a rule indicating that `path` , all its ancestors, and all its descendants shall be loaded.
`LoadWithoutDescendants`(path)	Add a rule indicating that `path` and all its ancestors but none of its descendants shall be loaded.
`Minimize`()	Remove any redundant rules to make the set of rules as small as possible without changing behavior.
`SetRules`(rules)	Set literal rules, must be sorted by SdfPath::operator< .
`Unload`(path)	Add a rule indicating that `path` and all its descendants shall be unloaded.
`swap`(other)	Swap the contents of these rules with `other` .

Attributes:

`AllRule`
`NoneRule`
`OnlyRule`

class Rule

These values are paired with paths to govern payload inclusion on UsdStages.

Methods:

GetValueFromName

Attributes:

allValues

static GetValueFromName()

allValues = (Usd.StageLoadRules.AllRule, Usd.StageLoadRules.OnlyRule, Usd.StageLoadRules.NoneRule)

AddRule(path, rule) → None

Add a literal rule. If there’s already a rule for path , replace it.

Parameters

path (Path) –
rule (Rule) –

GetEffectiveRuleForPath(path) → Rule

Return the”effective”rule for the given path .

For example, if the closest ancestral rule of path is an AllRule , return AllRule . If the closest ancestral rule of path is for path itself and it is an OnlyRule , return OnlyRule . Otherwise if there is a closest descendant rule to path this is an OnlyRule or an AllRule , return OnlyRule . Otherwise return NoneRule .

Parameters: path (Path) –

GetRules() → list[tuple[Path, Rule]]: Return all the rules as a vector.

IsLoaded(path) → bool

Return true if the given path is considered loaded by these rules, or false if it is considered unloaded.

This is equivalent to GetEffectiveRuleForPath(path) != NoneRule.

Parameters: path (Path) –

IsLoadedWithAllDescendants(path) → bool

Return true if the given path and all descendants are considered loaded by these rules; false otherwise.

Parameters: path (Path) –

IsLoadedWithNoDescendants(path) → bool

Return true if the given path and is considered loaded, but none of its descendants are considered loaded by these rules; false otherwise.

Parameters: path (Path) –

static LoadAll()

classmethod LoadAll() -> StageLoadRules

Return rules that load all payloads.

This is equivalent to default-constructed UsdStageLoadRules.

LoadAndUnload(loadSet, unloadSet, policy) → None

Add rules as if Unload() was called for each element of unloadSet followed by calls to either LoadWithDescendants() (if policy is UsdLoadPolicy::LoadWithDescendants) or LoadWithoutDescendants() (if policy is UsdLoadPolicy::LoadWithoutDescendants) for each element of loadSet .

Parameters

loadSet (SdfPathSet) –
unloadSet (SdfPathSet) –
policy (LoadPolicy) –

static LoadNone()

classmethod LoadNone() -> StageLoadRules

Return rules that load no payloads.

LoadWithDescendants(path) → None

Add a rule indicating that path , all its ancestors, and all its descendants shall be loaded.

Any previous rules created by calling LoadWithoutDescendants() or Unload() on this path or descendant paths are replaced by this rule. For example, calling LoadWithoutDescendants(‘/World/sets/kitchen’) followed by LoadWithDescendants(‘/World/sets’) will effectively remove the rule created in the first call. See AddRule() for more direct manipulation.

Parameters: path (Path) –

LoadWithoutDescendants(path) → None

Add a rule indicating that path and all its ancestors but none of its descendants shall be loaded.

Any previous rules created by calling LoadWithDescendants() or Unload() on this path or descendant paths are replaced or restricted by this rule. For example, calling LoadWithDescendants(‘/World/sets’) followed by LoadWithoutDescendants(‘/World/sets/kitchen’) will cause everything under’/World/sets’to load except for those things under’/World/sets/kitchen’. See AddRule() for more direct manipulation.

Parameters: path (Path) –

Minimize() → None: Remove any redundant rules to make the set of rules as small as possible without changing behavior.

SetRules(rules) → None

Set literal rules, must be sorted by SdfPath::operator< .

Parameters: rules (list[tuple[Path, Rule]]) –

SetRules(rules) -> None

Set literal rules, must be sorted by SdfPath::operator< .

Parameters: rules (list[tuple[Path, Rule]]) –

Unload(path) → None

Add a rule indicating that path and all its descendants shall be unloaded.

Any previous rules created by calling LoadWithDescendants() or LoadWithoutDescendants() on this path or descendant paths are replaced or restricted by this rule. For example, calling LoadWithDescendants(‘/World/sets’) followed by Unload(‘/World/sets/kitchen’) will cause everything under’/World/sets’to load, except for’/World/sets/kitchen’and everything under it.

Parameters: path (Path) –

swap(other) → None

Swap the contents of these rules with other .

Parameters: other (StageLoadRules) –

AllRule = Usd.StageLoadRules.AllRule

NoneRule = Usd.StageLoadRules.NoneRule

OnlyRule = Usd.StageLoadRules.OnlyRule

class pxr.Usd.StagePopulationMask

This class represents a mask that may be applied to a UsdStage to limit the set of UsdPrim s it populates. This is useful in cases where clients have a large scene but only wish to view or query a single or a handful of objects. For example, suppose we have a city block with buildings, cars, crowds of people, and a couple of main characters. Some tasks might only require looking at a single main character and perhaps a few props. We can create a population mask with the paths to the character and props of interest and open a UsdStage with that mask. Usd will avoid populating the other objects in the scene, saving time and memory. See UsdStage::OpenMasked() for more.

A mask is defined by a set of SdfPath s with the following qualities: they are absolute prim paths (or the absolute root path), and no path in the set is an ancestor path of any other path in the set other than itself. For example, the set of paths [‘/a/b’,’/a/c’,’/x/y’] is a valid mask, but the set of paths [‘/a/b’,’/a/b/c’,’/x/y’] is redundant, since’/a/b’is an ancestor of’/a/b/c’. The path’/a/b/c’may be removed. The GetUnion() and Add() methods ensure that no redundant paths are added.

Default-constructed UsdStagePopulationMask s are considered empty ( IsEmpty() ) and include no paths. A population mask containing SdfPath::AbsoluteRootPath() includes all paths.

Methods:

`Add`(other)	Assign this mask to be its union with `other` and return a reference to this mask.
`All`	classmethod All() -> StagePopulationMask
`GetIncludedChildNames`(path, childNames)	Return true if this mask includes any child prims beneath `path` , false otherwise.
`GetIntersection`(other)	Return a mask that is the intersection of this and `other` .
`GetPaths`()	Return the set of paths that define this mask.
`GetUnion`(other)	Return a mask that is the union of this and `other` .
`Includes`(other)	Return true if this mask is a superset of `other` .
`IncludesSubtree`(path)	Return true if this mask includes `path` and all paths descendant to `path` .
`Intersection`	classmethod Intersection(l, r) -> StagePopulationMask
`IsEmpty`()	Return true if this mask contains no paths.
`Union`	classmethod Union(l, r) -> StagePopulationMask

Add(other) → StagePopulationMask

Assign this mask to be its union with other and return a reference to this mask.

Parameters: other (StagePopulationMask) –

Add(path) -> StagePopulationMask

Assign this mask to be its union with path and return a reference to this mask.

Parameters: path (Path) –

static All()

classmethod All() -> StagePopulationMask

Return a mask that includes all paths.

This is the mask that contains the absolute root path.

GetIncludedChildNames(path, childNames) → bool

Return true if this mask includes any child prims beneath path , false otherwise.

If only specific child prims beneath path are included, the names of those children will be returned in childNames . If all child prims beneath path are included, childNames will be empty.

Parameters

path (Path) –
childNames (list[str]) –

GetIntersection(other) → StagePopulationMask

Return a mask that is the intersection of this and other .

Parameters: other (StagePopulationMask) –

GetPaths() → list[Path]: Return the set of paths that define this mask.

GetUnion(other) → StagePopulationMask

Return a mask that is the union of this and other .

Parameters: other (StagePopulationMask) –

GetUnion(path) -> StagePopulationMask

Return a mask that is the union of this and a mask containing the single path .

Parameters: path (Path) –

Includes(other) → bool

Return true if this mask is a superset of other .

That is, if this mask includes at least every path that other includes.

Parameters: other (StagePopulationMask) –

Includes(path) -> bool

Return true if this mask includes path .

This is true if path is one of the paths in this mask, or if it is either a descendant or an ancestor of one of the paths in this mask.

Parameters: path (Path) –

IncludesSubtree(path) → bool

Return true if this mask includes path and all paths descendant to path .

For example, consider a mask containing the path’/a/b’. Then the following holds:

mask.Includes('/a') -> true
mask.Includes('/a/b') -> true
mask.IncludesSubtree('/a') -> false
mask.IncludesSubtree('/a/b') -> true

Parameters: path (Path) –

static Intersection()

classmethod Intersection(l, r) -> StagePopulationMask

Return a mask that is the intersection of l and r .

Parameters

l (StagePopulationMask) –
r (StagePopulationMask) –

IsEmpty() → bool

Return true if this mask contains no paths.

Empty masks include no paths.

static Union()

classmethod Union(l, r) -> StagePopulationMask

Return a mask that is the union of l and r .

Parameters

l (StagePopulationMask) –
r (StagePopulationMask) –

class pxr.Usd.TimeCode

Represent a time value, which may be either numeric, holding a double value, or a sentinel value UsdTimeCode::Default() .

A UsdTimeCode does not represent an SMPTE timecode, although we may, in future, support conversion functions between the two. Instead, UsdTimeCode is an abstraction that acknowledges that in the principal domains of use for USD, there are many different ways of encoding time, and USD must be able to capture and translate between all of them for interchange, retaining as much intent of the authoring application as possible.

A UsdTimeCode is therefore a unitless, generic time measurement that serves as the ordinate for time-sampled data in USD files. A client of USD relies on the UsdStage (which in turn consults metadata authored in its root layer) to define the mapping of TimeCodes to units like seconds and frames.

UsdStage::GetStartTimeCode()

UsdStage::GetEndTimeCode()

UsdStage::GetTimeCodesPerSecond()

UsdStage::GetFramesPerSecond() As described in TimeSamples, Defaults, and Value Resolution, USD optionally provides an unvarying,’default’value for every attribute. UsdTimeCode embodies a time value that can either be a floating-point sample time, or the default.

All UsdAttribute and derived API that requires a time parameter defaults to UsdTimeCode::Default() if the parameter is left unspecified, and auto-constructs from a floating-point argument.

UsdTimeCode::EarliestTime() is provided to aid clients who wish to retrieve the first authored timesample for any attribute.

Classes:

Tokens

Methods:

`Default`	classmethod Default() -> TimeCode
`EarliestTime`	classmethod EarliestTime() -> TimeCode
`GetValue`()	Return the numeric value for this time.
`IsDefault`()	Return true if this time represents the'default'sentinel value, false otherwise.
`IsEarliestTime`()	Return true if this time represents the lowest/earliest possible timeCode, false otherwise.
`IsNumeric`()	Return true if this time represents a numeric value, false otherwise.
`SafeStep`	classmethod SafeStep(maxValue, maxCompression) -> float

class Tokens

Attributes:

`DEFAULT`
`EARLIEST`

DEFAULT = 'DEFAULT'

EARLIEST = 'EARLIEST'

static Default()

classmethod Default() -> TimeCode

Produce a UsdTimeCode representing the sentinel value for’default’.

In inequality comparisons, Default() is considered less than any numeric TimeCode, including EarliestTime() , indicative of the fact that in UsdAttribute value resolution, the sample at Default() (if any) is always weaker than any numeric timeSample in the same layer. For more information, see TimeSamples, Defaults, and Value Resolution

static EarliestTime()

classmethod EarliestTime() -> TimeCode

Produce a UsdTimeCode representing the lowest/earliest possible timeCode.

Thus, for any given timeSample s, its time ordinate t will obey: t>= UsdTimeCode::EarliestTime()

This is useful for clients that wish to retrieve the first authored timeSample for an attribute, as they can use UsdTimeCode::EarliestTime() as the time argument to UsdAttribute::Get() and UsdAttribute::GetBracketingTimeSamples()

GetValue() → float

Return the numeric value for this time.

If this time IsDefault(), return a quiet NaN value.

IsDefault() → bool

Return true if this time represents the’default’sentinel value, false otherwise.

This is equivalent to !IsNumeric().

IsEarliestTime() → bool: Return true if this time represents the lowest/earliest possible timeCode, false otherwise.

IsNumeric() → bool

Return true if this time represents a numeric value, false otherwise.

This is equivalent to !IsDefault().

static SafeStep()

classmethod SafeStep(maxValue, maxCompression) -> float

Produce a safe step value such that for any numeric UsdTimeCode t in [-maxValue, maxValue], t +/- (step / maxCompression) != t with a safety factor of 2.

This is shorthand for std::numeric_limits<double>::epsilon() * maxValue * maxCompression * 2.0. Such a step value is recommended for simulating jump discontinuities in time samples. For example, author value x at time t, and value y at time t + SafeStep() . This ensures that as the sample times are shifted and scaled, t and t + SafeStep() remain distinct so long as they adhere to the maxValue and maxCompression limits.

Parameters

maxValue (float) –
maxCompression (float) –

class pxr.Usd.Tokens

Attributes:

`apiSchemas`
`clipSets`
`clips`
`collection`
`collection_MultipleApplyTemplate_Excludes`
`collection_MultipleApplyTemplate_ExpansionRule`
`collection_MultipleApplyTemplate_IncludeRoot`
`collection_MultipleApplyTemplate_Includes`
`exclude`
`expandPrims`
`expandPrimsAndProperties`
`explicitOnly`
`fallbackPrimTypes`

apiSchemas = 'apiSchemas'

clipSets = 'clipSets'

clips = 'clips'

collection = 'collection'

collection_MultipleApplyTemplate_Excludes = 'collection:__INSTANCE_NAME__:excludes'

collection_MultipleApplyTemplate_ExpansionRule = 'collection:__INSTANCE_NAME__:expansionRule'

collection_MultipleApplyTemplate_IncludeRoot = 'collection:__INSTANCE_NAME__:includeRoot'

collection_MultipleApplyTemplate_Includes = 'collection:__INSTANCE_NAME__:includes'

exclude = 'exclude'

expandPrims = 'expandPrims'

expandPrimsAndProperties = 'expandPrimsAndProperties'

explicitOnly = 'explicitOnly'

fallbackPrimTypes = 'fallbackPrimTypes'

class pxr.Usd.Typed

The base class for all typed schemas (those that can impart a typeName to a UsdPrim), and therefore the base class for all instantiable and”IsA”schemas.

UsdTyped implements a typeName-based query for its override of UsdSchemaBase::_IsCompatible() . It provides no other behavior.

Methods:

GetSchemaAttributeNames

classmethod GetSchemaAttributeNames(includeInherited) -> list[str]

static GetSchemaAttributeNames()

classmethod GetSchemaAttributeNames(includeInherited) -> list[str]

Return a vector of names of all pre-declared attributes for this schema class and all its ancestor classes.

Does not include attributes that may be authored by custom/extended methods of the schemas involved.

Parameters: includeInherited (bool) –

class pxr.Usd.UsdCollectionMembershipQuery

Represents a flattened view of a collection. For more information about collections, please see UsdCollectionAPI as a way to encode and retrieve a collection from scene description. A UsdCollectionMembershipQuery object can be used to answer queries about membership of paths in the collection efficiently.

Methods:

`GetAsPathExpansionRuleMap`()	Returns a raw map of the paths included or excluded in the collection along with the expansion rules for the included paths.
`GetIncludedCollections`()	Returns a set of paths for all collections that were included in the collection from which this UsdCollectionMembershipQuery object was computed.
`HasExcludes`()	Returns true if the collection excludes one or more paths below an included path.
`IsPathIncluded`(path, expansionRule)	This is an overloaded member function, provided for convenience.

GetAsPathExpansionRuleMap() → PathExpansionRuleMap: Returns a raw map of the paths included or excluded in the collection along with the expansion rules for the included paths.

GetIncludedCollections() → SdfPathSet

Returns a set of paths for all collections that were included in the collection from which this UsdCollectionMembershipQuery object was computed.

This set is recursive, so collections that were included by other collections will be part of this set. The collection from which this UsdCollectionMembershipQuery object was computed is not part of this set.

HasExcludes() → bool: Returns true if the collection excludes one or more paths below an included path.

IsPathIncluded(path, expansionRule) → bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Returns whether the given path is included in the collection from which this UsdCollectionMembershipQuery object was computed.

This is the API that clients should use for determining if a given object is a member of the collection. To enumerate all the members of a collection, use UsdComputeIncludedObjectsFromCollection or UsdComputeIncludedPathsFromCollection.

If expansionRule is not nullptr, it is set to the expansion- rule value that caused the path to be included in or excluded from the collection. If path is not included in the collection, expansionRule is set to UsdTokens->exclude.

It is useful to specify this parameter and use this overload of IsPathIncluded() , when you’re interested in traversing a subtree and want to know whether the root of the subtree is included in a collection. For evaluating membership of descendants of the root, please use the other overload of IsPathIncluded() , that takes both a path and the parent expansionRule.

The python version of this method only returns the boolean result. It does not return expansionRule .

Parameters

path (Path) –
expansionRule (str) –

IsPathIncluded(path, parentExpansionRule, expansionRule) -> bool

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Returns whether the given path, path is included in the collection from which this UsdCollectionMembershipQuery object was computed, given the parent-path’s inherited expansion rule, parentExpansionRule .

If expansionRule is not nullptr, it is set to the expansion- rule value that caused the path to be included in or excluded from the collection. If path is not included in the collection, expansionRule is set to UsdTokens->exclude.

The python version of this method only returns the boolean result. It does not return expansionRule .

Parameters

path (Path) –
parentExpansionRule (str) –
expansionRule (str) –

class pxr.Usd.UsdFileFormat

File format for USD files.

When creating a file through the SdfLayer::CreateNew() interface, the meaningful SdfFileFormat::FileFormatArguments are as follows:

UsdUsdFileFormatTokens->FormatArg, which must be a supported format’s’Id’. The possible values are UsdUsdaFileFormatTokens->Id or UsdUsdcFileFormatTokens->Id. If no UsdUsdFileFormatTokens->FormatArg is supplied, the default is UsdUsdcFileFormatTokens->Id.

Methods:

GetUnderlyingFormatForLayer

classmethod GetUnderlyingFormatForLayer(layer) -> str

static GetUnderlyingFormatForLayer()

classmethod GetUnderlyingFormatForLayer(layer) -> str

Returns the value of the”format”argument to be used in the FileFormatArguments when exporting or saving the given layer.

Returns an empty token if the given layer does not have this file format.

Parameters: layer (Layer) –

class pxr.Usd.VariantSet

A UsdVariantSet represents a single VariantSet in USD (e.g. modelingVariant or shadingVariant), which can have multiple variations that express different sets of opinions about the scene description rooted at the prim that defines the VariantSet.

(More detailed description of variants to follow)

Methods:

`AddVariant`(variantName, position)	Author a variant spec for variantName in this VariantSet at the stage's current EditTarget, in the position specified by `position` .
`BlockVariantSelection`()	Block any weaker selections for this VariantSet by authoring an empty string at the stage's current EditTarget.
`ClearVariantSelection`()	Clear any selection for this VariantSet from the current EditTarget.
`GetName`()	Return this VariantSet's name.
`GetPrim`()	Return this VariantSet's held prim.
`GetVariantEditContext`(layer)	Helper function for configuring a UsdStage 's EditTarget to author into the currently selected variant.
`GetVariantEditTarget`(layer)	Return a UsdEditTarget that edits the currently selected variant in this VariantSet in layer.
`GetVariantNames`()	Return the composed variant names for this VariantSet, ordered lexicographically.
`GetVariantSelection`()	Return the variant selection for this VariantSet.
`HasAuthoredVariant`(variantName)	Returns true if this VariantSet already possesses a variant.
`HasAuthoredVariantSelection`(value)	Returns true if there is a selection authored for this VariantSet in any layer.
`IsValid`()	Is this UsdVariantSet object usable? If not, calling any of its other methods is likely to crash.
`SetVariantSelection`(variantName)	Author a variant selection for this VariantSet, setting it to variantName in the stage's current EditTarget.

AddVariant(variantName, position) → bool

Author a variant spec for variantName in this VariantSet at the stage’s current EditTarget, in the position specified by position .

Return true if the spec was successfully authored, false otherwise.

This will create the VariantSet itself, if necessary, so as long as UsdPrim “prim”is valid, the following should always work:

UsdVariantSet vs = prim.GetVariantSet("myVariantSet");
vs.AddVariant("myFirstVariation");
vs.SetVariantSelection("myFirstVariation");
{
    UsdEditContext ctx(vs.GetVariantEditContext());
    // Now all of our subsequent edits will go "inside" the
    // 'myFirstVariation' variant of 'myVariantSet'
}

Parameters

variantName (str) –
position (ListPosition) –

BlockVariantSelection() → bool

Block any weaker selections for this VariantSet by authoring an empty string at the stage’s current EditTarget.

Return true on success, false otherwise.

ClearVariantSelection() → bool

Clear any selection for this VariantSet from the current EditTarget.

Return true on success, false otherwise.

GetName() → str: Return this VariantSet’s name.

GetPrim() → Prim: Return this VariantSet’s held prim.

GetVariantEditContext(layer) → tuple[Stage, EditTarget]

Helper function for configuring a UsdStage ‘s EditTarget to author into the currently selected variant.

Returns configuration for a UsdEditContext

To begin editing into VariantSet varSet’s currently selected variant:

In C++, we would use the following pattern:

{
    UsdEditContext ctxt(varSet.GetVariantEditContext());

    // All Usd mutation of the UsdStage on which varSet sits will
    // now go "inside" the currently selected variant of varSet
}

In python, the pattern is:

with varSet.GetVariantEditContext():
    # Now sending mutations to current variant

See GetVariantEditTarget() for discussion of layer parameter

Parameters: layer (Layer) –

GetVariantEditTarget(layer) → EditTarget

Return a UsdEditTarget that edits the currently selected variant in this VariantSet in layer.

If there is no currently selected variant in this VariantSet, return an invalid EditTarget.

If layer is unspecified, then we will use the layer of our prim’s stage’s current UsdEditTarget.

Currently, we require layer to be in the stage’s local LayerStack (see UsdStage::HasLocalLayer() ), and will issue an error and return an invalid EditTarget if layer is not. We may relax this restriction in the future, if need arises, but it introduces several complications in specification and behavior.

Parameters: layer (Layer) –

GetVariantNames() → list[str]: Return the composed variant names for this VariantSet, ordered lexicographically.

GetVariantSelection() → str

Return the variant selection for this VariantSet.

If there is no selection, return the empty string.

HasAuthoredVariant(variantName) → bool

Returns true if this VariantSet already possesses a variant.

Parameters: variantName (str) –

HasAuthoredVariantSelection(value) → bool

Returns true if there is a selection authored for this VariantSet in any layer.

If requested, the variant selection (if any) will be returned in value .

Parameters: value (str) –

IsValid() → bool: Is this UsdVariantSet object usable? If not, calling any of its other methods is likely to crash.

SetVariantSelection(variantName) → bool

Author a variant selection for this VariantSet, setting it to variantName in the stage’s current EditTarget.

If variantName is empty, clear the variant selection (see ClearVariantSelection). Call BlockVariantSelection to explicitly set an empty variant selection.

Return true if the selection was successfully authored or cleared, false otherwise.

Parameters: variantName (str) –

class pxr.Usd.VariantSets

UsdVariantSets represents the collection of VariantSets that are present on a UsdPrim.

A UsdVariantSets object, retrieved from a prim via UsdPrim::GetVariantSets() , provides the API for interrogating and modifying the composed list of VariantSets active defined on the prim, and also the facility for authoring a VariantSet selection for any of those VariantSets.

Methods:

`AddVariantSet`(variantSetName, position)	Find an existing, or create a new VariantSet on the originating UsdPrim, named `variantSetName` .
`GetAllVariantSelections`()	Returns the composed map of all variant selections authored on the the originating UsdPrim, regardless of whether a corresponding variant set exists.
`GetNames`(names)	Compute the list of all VariantSets authored on the originating UsdPrim.
`GetVariantSelection`(variantSetName)	Return the composed variant selection for the VariantSet named variantSetName.
`GetVariantSet`(variantSetName)	Return a UsdVariantSet object for `variantSetName` .
`HasVariantSet`(variantSetName)	Returns true if a VariantSet named `variantSetName` exists on the originating prim.
`SetSelection`(variantSetName, variantName)	param variantSetName

AddVariantSet(variantSetName, position) → VariantSet

Find an existing, or create a new VariantSet on the originating UsdPrim, named variantSetName .

This step is not always necessary, because if this UsdVariantSets object is valid, then

 varSetsObj.GetVariantSet(variantSetName).AddVariant(variantName);

will always succeed, creating the VariantSet first, if necessary.

This method exists for situations in which you want to create a VariantSet without necessarily populating it with variants.

Parameters

variantSetName (str) –
position (ListPosition) –

GetAllVariantSelections() → SdfVariantSelectionMap: Returns the composed map of all variant selections authored on the the originating UsdPrim, regardless of whether a corresponding variant set exists.

GetNames(names) → bool

Compute the list of all VariantSets authored on the originating UsdPrim.

Always return true. Clear the contents of names and store the result there.

Parameters: names (list[str]) –

GetNames() -> list[str]

Return a list of all VariantSets authored on the originating UsdPrim.

GetVariantSelection(variantSetName) → str

Return the composed variant selection for the VariantSet named variantSetName.

If there is no selection, (or variantSetName does not exist) return the empty string.

Parameters: variantSetName (str) –

GetVariantSet(variantSetName) → VariantSet

Return a UsdVariantSet object for variantSetName .

This always succeeds, although the returned VariantSet will be invalid if the originating prim is invalid

Parameters: variantSetName (str) –

HasVariantSet(variantSetName) → bool

Returns true if a VariantSet named variantSetName exists on the originating prim.

Parameters: variantSetName (str) –

SetSelection(variantSetName, variantName) → bool

Parameters

variantSetName (str) –
variantName (str) –

class pxr.Usd.ZipFile

Class for reading a zip file. This class is primarily intended to support the .usdz file format. It is not a general-purpose zip reader, as it does not implement the full zip file specification. In particular:

This class does not natively support decompressing data from a zip archive. Clients may access the data exactly as stored in the file and perform their own decompression if desired.

This class does not rely on the central directory in order to read the contents of the file. This allows it to operate on partial zip archives. However, this also means it may handle certain zip files incorrectly. For example, if a file was deleted from a zip archive by just removing its central directory header, that file will still be found by this class.

Classes:

FileInfo

Methods:

`DumpContents`()	Print out listing of contents of this zip archive to stdout.
`GetFile`
`GetFileInfo`
`GetFileNames`
`Open`	classmethod Open(filePath) -> ZipFile

class FileInfo

Attributes:

`compressionMethod`
`dataOffset`
`encrypted`
`size`
`uncompressedSize`

property compressionMethod

property dataOffset

property encrypted

property size

property uncompressedSize

DumpContents() → None

Print out listing of contents of this zip archive to stdout.

For diagnostic purposes only.

GetFile()

GetFileInfo()

GetFileNames()

static Open()

classmethod Open(filePath) -> ZipFile

Opens the zip archive at filePath .

Returns invalid object on error.

Parameters: filePath (str) –

Open(asset) -> ZipFile

Opens the zip archive asset .

Returns invalid object on error.

Parameters: asset (ArAsset) –

class pxr.Usd.ZipFileWriter

Class for writing a zip file. This class is primarily intended to support the .usdz file format. It is not a general-purpose zip writer, as it does not implement the full zip file specification. However, all files written by this class should be valid zip files and readable by external zip modules and utilities.

Methods:

`AddFile`(filePath, filePathInArchive)	Adds the file at `filePath` to the zip archive with no compression applied.
`CreateNew`	classmethod CreateNew(filePath) -> ZipFileWriter
`Discard`()	Discards the zip archive so that it is not saved to the destination file path.
`Save`()	Finalizes the zip archive and saves it to the destination file path.

AddFile(filePath, filePathInArchive) → str

Adds the file at filePath to the zip archive with no compression applied.

If filePathInArchive is non-empty, the file will be added at that path in the archive. Otherwise, it will be added at filePath .

Returns the file path used to identify the file in the zip archive on success. This path conforms to the zip file specification and may not be the same as filePath or filePathInArchive . Returns an empty string on failure.

Parameters

filePath (str) –
filePathInArchive (str) –

static CreateNew()

classmethod CreateNew(filePath) -> ZipFileWriter

Create a new file writer with filePath as the destination file path where the zip archive will be written.

The zip file will not be written to filePath until the writer is destroyed or Save() is called.

Returns an invalid object on error.

Parameters: filePath (str) –

Discard() → None

Discards the zip archive so that it is not saved to the destination file path.

Once discarded, the file writer is invalid and may not be reused.

Save() → bool

Finalizes the zip archive and saves it to the destination file path.

Once saved, the file writer is invalid and may not be reused. Returns true on success, false otherwise.