UsdRenderVar

Fully qualified name: usdrt::UsdRenderVar

class UsdRenderVar : public usdrt::UsdTyped

A UsdRenderVar describes a custom data variable for a render to produce. The prim describes the source of the data, which can be a shader output or an LPE (Light Path Expression), and also allows encoding of (generally renderer-specific) parameters that configure the renderer for computing the variable.

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

Note

The name of the RenderVar prim drives the name of the data variable that the renderer will produce.

Note

In the future, UsdRender may standardize RenderVar representation for well-known variables under the sourceType intrinsic, such as r, g, b, a, z, or id.

Public Functions

inline explicit UsdRenderVar(const UsdPrim &prim = UsdPrim())

Construct a UsdRenderVar on UsdPrim prim. Equivalent to UsdRenderVar::Get(prim.GetStage(), prim.GetPath()) for a valid prim , but will not immediately throw an error for an invalid prim.

inline explicit UsdRenderVar(const UsdSchemaBase &schemaObj)

Construct a UsdRenderVar on the prim held by schemaObj . Should be preferred over UsdRenderVar(schemaObj.GetPrim()), as it preserves SchemaBase state.

inline virtual ~UsdRenderVar()

Destructor.

inline UsdAttribute GetDataTypeAttr() const

The type of this channel, as a USD attribute type.

Declaration	uniform token dataType = "color3f"
C++ Type	TfToken
Usd Type	SdfValueTypeNames->Token
Variability	SdfVariabilityUniform

inline UsdAttribute CreateDataTypeAttr() const

See GetDataTypeAttr(), 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.

inline UsdAttribute GetSourceNameAttr() const

The renderer should look for an output of this name as the computed value for the RenderVar.

Declaration	uniform string sourceName = ""
C++ Type	std::string
Usd Type	SdfValueTypeNames->String
Variability	SdfVariabilityUniform

inline UsdAttribute CreateSourceNameAttr() const

See GetSourceNameAttr(), 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.

inline UsdAttribute GetSourceTypeAttr() const

Indicates the type of the source.

• “raw”: The name should be passed directly to the renderer. This is the default behavior.

• ”primvar”: This source represents the name of a primvar. Some renderers may use this to ensure that the primvar is provided; other renderers may require that a suitable material network be provided, in which case this is simply an advisory setting.

• ”lpe”: Specifies a Light Path Expression in the OSL Light Path Expressions language as the source for this RenderVar. Some renderers may use extensions to that syntax, which will necessarily be non-portable.

• ”intrinsic”: This setting is currently unimplemented, but represents a future namespace for UsdRender to provide portable baseline RenderVars, such as camera depth, that may have varying implementations for each renderer.

Declaration	uniform token sourceType = "raw"
C++ Type	TfToken
Usd Type	SdfValueTypeNames->Token
Variability	SdfVariabilityUniform
Allowed Values	raw, primvar, lpe, intrinsic

inline UsdAttribute CreateSourceTypeAttr() const

See GetSourceTypeAttr(), 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.

UsdPrim GetPrim() const

Return this schema object’s held prim.

SdfPath GetPath() const

Return the SdfPath to this schema object’s held prim.

inline explicit operator bool() const

Check if this schema object is compatible with it’s held prim and that the prim is valid.

A typed schema object is compatible if the held prim’s type is or is a subtype of the schema’s type. Based on prim.IsA().

An API schema object is compatible if the API is of type SingleApplyAPI or UsdSchemaType::MultipleApplyAPI, and the schema has been applied to the prim. Based on prim.HasAPI.

This method invokes polymorphic behaviour.

See also

UsdSchemaBase::_IsCompatible()

Returns:

True if the help prim is valid, and the schema object is compatible with its held prim.

Public Static Functions

static inline UsdRenderVar Define(

const UsdStageRefPtr &stage,

const SdfPath &path,

)

Attempt to ensure a UsdPrim adhering to this schema at path is defined (according to UsdPrim::IsDefined()) on this stage.

Public Static Attributes

static const UsdSchemaType schemaType = UsdSchemaType::ConcreteTyped

Compile time constant representing what kind of schema this class is.

See also

UsdSchemaType

Protected Functions

inline virtual bool _IsCompatible() const

Helper for subclasses to do specific compatibility checking with the given prim. Subclassess may override _isCompatible to for example check type compatibility or value compatibility on the prim.

Overrides exist for UsdTyped and UsdAPISchemaBase.

This check is called when clients invoke the bool operator.

Returns:

True if the schema object is compatible with its held prim.

inline const TfToken _GetType() const

Helper for subclasses to get this schema’s type token.

Note

This diverges from Usd and returns a TfToken, since we don’t implements TfType.

Returns:

The token representing the schema’s TfType.