usdrt::UsdGeomCurves

Defined in usdrt/scenegraph/usd/usdGeom/curves.h

Functions

usdrt::PhysxSchemaPlane::CreateAccelerationsAttr: See GetAccelerationsAttr() , 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 .
usdrt::UsdGeomBasisCurves::CreateCurveVertexCountsAttr: See GetCurveVertexCountsAttr() , 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 .
usdrt::PhysxSchemaPhysxParticleSystem::CreateDisplayColorAttr: See GetDisplayColorAttr() , 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 .
usdrt::PhysxSchemaPhysxParticleSystem::CreateDisplayOpacityAttr: See GetDisplayOpacityAttr() , 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 .
usdrt::PhysxSchemaPhysxParticleSystem::CreateDoubleSidedAttr: See GetDoubleSidedAttr() , 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 .
usdrt::PhysxSchemaPhysxParticleSystem::CreateExtentAttr: See GetExtentAttr() , 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 .
usdrt::PhysxSchemaPlane::CreateNormalsAttr: See GetNormalsAttr() , 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 .
usdrt::PhysxSchemaPhysxParticleSystem::CreateOrientationAttr: See GetOrientationAttr() , 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 .
usdrt::PhysxSchemaPlane::CreatePointsAttr: See GetPointsAttr() , 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 .
usdrt::PhysxSchemaPhysxParticleSystem::CreateProxyPrimRel: See GetProxyPrimRel() , and also Create vs Get Property Methods for when to use Get vs Create.
usdrt::PhysxSchemaPhysxParticleSystem::CreatePurposeAttr: See GetPurposeAttr() , 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 .
usdrt::PhysxSchemaPlane::CreateVelocitiesAttr: See GetVelocitiesAttr() , 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 .
usdrt::PhysxSchemaPhysxParticleSystem::CreateVisibilityAttr: See GetVisibilityAttr() , 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 .
usdrt::UsdGeomBasisCurves::CreateWidthsAttr: See GetWidthsAttr() , 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 .
usdrt::PhysxSchemaPhysxParticleSystem::CreateXformOpOrderAttr: See GetXformOpOrderAttr() , 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 .
usdrt::PhysxSchemaPlane::GetAccelerationsAttr: If provided, 'accelerations' should be used with velocities to compute positions between samples for the 'points' attribute rather than interpolating between neighboring 'points' samples. Acceleration is measured in position units per second-squared. To convert to position units per squared UsdTimeCode, divide by the square of UsdStage::GetTimeCodesPerSecond().
usdrt::UsdGeomBasisCurves::GetCurveVertexCountsAttr: Curves-derived primitives can represent multiple distinct, potentially disconnected curves. The length of 'curveVertexCounts' gives the number of such curves, and each element describes the number of vertices in the corresponding curve.
usdrt::PhysxSchemaPhysxParticleSystem::GetDisplayColorAttr: It is useful to have an "official" colorSet that can be used as a display or modeling color, even in the absence of any specified shader for a gprim. DisplayColor serves this role; because it is a UsdGeomPrimvar, it can also be used as a gprim override for any shader that consumes a displayColor parameter.
usdrt::PhysxSchemaPhysxParticleSystem::GetDisplayOpacityAttr: Companion to displayColor that specifies opacity, broken out as an independent attribute rather than an rgba color, both so that each can be independently overridden, and because shaders rarely consume rgba parameters.
usdrt::PhysxSchemaPhysxParticleSystem::GetDoubleSidedAttr: Although some renderers treat all parametric or polygonal surfaces as if they were effectively laminae with outward-facing normals on both sides, some renderers derive significant optimizations by considering these surfaces to have only a single outward side, typically determined by control-point winding order and/or orientation . By doing so they can perform "backface culling" to avoid drawing the many polygons of most closed surfaces that face away from the viewer.
usdrt::PhysxSchemaPhysxParticleSystem::GetExtentAttr: Extent is a three dimensional range measuring the geometric extent of the authored gprim in its own local space (i.e. its own transform not applied), without accounting for any shader-induced displacement. If any extent value has been authored for a given Boundable, then it should be authored at every timeSample at which geometry-affecting properties are authored, to ensure correct evaluation via ComputeExtent(). If no extent value has been authored, then ComputeExtent() will call the Boundable's registered ComputeExtentFunction(), which may be expensive, which is why we strongly encourage proper authoring of extent.
usdrt::PhysxSchemaPlane::GetNormalsAttr: Provide an object-space orientation for individual points, which, depending on subclass, may define a surface, curve, or free points. Note that 'normals' should not be authored on any Mesh that is subdivided, since the subdivision algorithm will define its own normals. 'normals' is not a generic primvar, but the number of elements in this attribute will be determined by its 'interpolation'. See SetNormalsInterpolation() . If 'normals' and 'primvars:normals' are both specified, the latter has precedence.
usdrt::PhysxSchemaPhysxParticleSystem::GetOrientationAttr: Orientation specifies whether the gprim's surface normal should be computed using the right hand rule, or the left hand rule. Please see UsdGeom_WindingOrder for a deeper explanation and generalization of orientation to composed scenes with transformation hierarchies.
usdrt::DestructionSchemaDestructibleBaseAPI::GetPath: Return the SdfPath to this schema object's held prim.
usdrt::PhysxSchemaPlane::GetPointsAttr: The primary geometry attribute for all PointBased primitives, describes points in (local) space.
usdrt::DestructionSchemaDestructibleBaseAPI::GetPrim: Return this schema object's held prim.
usdrt::PhysxSchemaPhysxParticleSystem::GetProxyPrimRel: The proxyPrim relationship allows us to link a prim whose purpose is "render" to its (single target) purpose="proxy" prim. This is entirely optional, but can be useful in several scenarios:
usdrt::PhysxSchemaPhysxParticleSystem::GetPurposeAttr: Purpose is a classification of geometry into categories that can each be independently included or excluded from traversals of prims on a stage, such as rendering or bounding-box computation traversals.
usdrt::PhysxSchemaPlane::GetVelocitiesAttr: If provided, 'velocities' should be used by renderers to.
usdrt::PhysxSchemaPhysxParticleSystem::GetVisibilityAttr: Visibility is meant to be the simplest form of "pruning" visibility that is supported by most DCC apps. Visibility is animatable, allowing a sub-tree of geometry to be present for some segment of a shot, and absent from others; unlike the action of deactivating geometry prims, invisible geometry is still available for inspection, for positioning, for defining volumes, etc.
usdrt::UsdGeomBasisCurves::GetWidthsAttr: Provides width specification for the curves, whose application will depend on whether the curve is oriented (normals are defined for it), in which case widths are "ribbon width", or unoriented, in which case widths are cylinder width. 'widths' is not a generic Primvar, but the number of elements in this attribute will be determined by its 'interpolation'. See SetWidthsInterpolation() . If 'widths' and 'primvars:widths' are both specified, the latter has precedence.
usdrt::PhysxSchemaPhysxParticleSystem::GetXformOpOrderAttr: Encodes the sequence of transformation operations in the order in which they should be pushed onto a transform stack while visiting a UsdStage 's prims in a graph traversal that will effect the desired positioning for this prim and its descendant prims.
usdrt::UsdGeomCurves::UsdGeomCurves: Construct a UsdGeomCurves on the prim held by schemaObj . Should be preferred over UsdGeomCurves (schemaObj.GetPrim()), as it preserves SchemaBase state.
usdrt::UsdGeomCurves::UsdGeomCurves: Construct a UsdGeomCurves on UsdPrim prim . Equivalent to UsdGeomCurves::Get(prim.GetStage(), prim.GetPath()) for a valid prim , but will not immediately throw an error for an invalid prim .
usdrt::UsdGeomCurves::operator bool: Boolean operator.
usdrt::UsdGeomCurves::~UsdGeomCurves: Destructor.

Variables

usdrt::UsdGeomCurves::schemaType: Compile time constant representing what kind of schema this class is.

class UsdGeomCurves : public usdrt::UsdGeomPointBased 

Base class for UsdGeomBasisCurves, UsdGeomNurbsCurves, and UsdGeomHermiteCurves. The BasisCurves schema is designed to be analagous to offline renderers’ notion of batched curves (such as the classical RIB definition via Basis and Curves statements), while the NurbsCurve schema is designed to be analgous to the NURBS curves found in packages like Maya and Houdini while retaining their consistency with the RenderMan specification for NURBS Patches. HermiteCurves are useful for the interchange of animation guides and paths.

It is safe to use the length of the curve vertex count to derive the number of curves and the number and layout of curve vertices, but this schema should NOT be used to derive the number of curve points. While vertex indices are implicit in all shipped descendent types of this schema, one should not assume that all internal or future shipped schemas will follow this pattern. Be sure to key any indexing behavior off the concrete type, not this abstract type.

Subclassed by usdrt::UsdGeomBasisCurves, usdrt::UsdGeomHermiteCurves, usdrt::UsdGeomNurbsCurves

Public Functions

inline explicit UsdGeomCurves(const UsdPrim &prim = UsdPrim()): Construct a UsdGeomCurves on UsdPrim prim. Equivalent to UsdGeomCurves::Get(prim.GetStage(), prim.GetPath()) for a valid prim , but will not immediately throw an error for an invalid prim.

inline explicit UsdGeomCurves(const UsdSchemaBase &schemaObj): Construct a UsdGeomCurves on the prim held by schemaObj . Should be preferred over UsdGeomCurves(schemaObj.GetPrim()), as it preserves SchemaBase state.

inline virtual ~UsdGeomCurves(): Destructor.

inline operator bool() const

Boolean operator.

Returns: Return true if the contained prim is an instance of this schema using IsA, and false otherwise.

inline UsdAttribute GetCurveVertexCountsAttr() const

Curves-derived primitives can represent multiple distinct, potentially disconnected curves. The length of ‘curveVertexCounts’ gives the number of such curves, and each element describes the number of vertices in the corresponding curve.


Declaration	`int[] curveVertexCounts`
C++ Type	VtArray<int>
Usd Type	SdfValueTypeNames->IntArray

inline UsdAttribute CreateCurveVertexCountsAttr() const: See GetCurveVertexCountsAttr(), 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 GetWidthsAttr() const

Provides width specification for the curves, whose application will depend on whether the curve is oriented (normals are defined for it), in which case widths are “ribbon width”, or unoriented, in which case widths are cylinder width. ‘widths’ is not a generic Primvar, but the number of elements in this attribute will be determined by its ‘interpolation’. See SetWidthsInterpolation() . If ‘widths’ and ‘primvars:widths’ are both specified, the latter has precedence.


Declaration	`float[] widths`
C++ Type	VtArray<float>
Usd Type	SdfValueTypeNames->FloatArray

inline UsdAttribute CreateWidthsAttr() const: See GetWidthsAttr(), 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 GetPointsAttr() const

The primary geometry attribute for all PointBased primitives, describes points in (local) space.


Declaration	`point3f[] points`
C++ Type	VtArray<GfVec3f>
Usd Type	SdfValueTypeNames->Point3fArray

inline UsdAttribute CreatePointsAttr() const: See GetPointsAttr(), 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 GetVelocitiesAttr() const

If provided, ‘velocities’ should be used by renderers to.

compute positions between samples for the ‘points’ attribute, rather than interpolating between neighboring ‘points’ samples. This is the only reasonable means of computing motion blur for topologically varying PointBased primitives. It follows that the length of each ‘velocities’ sample must match the length of the corresponding ‘points’ sample. Velocity is measured in position units per second, as per most simulation software. To convert to position units per UsdTimeCode, divide by UsdStage::GetTimeCodesPerSecond().

See also UsdGeom_VelocityInterpolation .


Declaration	`vector3f[] velocities`
C++ Type	VtArray<GfVec3f>
Usd Type	SdfValueTypeNames->Vector3fArray

inline UsdAttribute CreateVelocitiesAttr() const: See GetVelocitiesAttr(), 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 GetAccelerationsAttr() const

If provided, ‘accelerations’ should be used with velocities to compute positions between samples for the ‘points’ attribute rather than interpolating between neighboring ‘points’ samples. Acceleration is measured in position units per second-squared. To convert to position units per squared UsdTimeCode, divide by the square of UsdStage::GetTimeCodesPerSecond().


Declaration	`vector3f[] accelerations`
C++ Type	VtArray<GfVec3f>
Usd Type	SdfValueTypeNames->Vector3fArray

inline UsdAttribute CreateAccelerationsAttr() const: See GetAccelerationsAttr(), 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 GetNormalsAttr() const

Provide an object-space orientation for individual points, which, depending on subclass, may define a surface, curve, or free points. Note that ‘normals’ should not be authored on any Mesh that is subdivided, since the subdivision algorithm will define its own normals. ‘normals’ is not a generic primvar, but the number of elements in this attribute will be determined by its ‘interpolation’. See SetNormalsInterpolation() . If ‘normals’ and ‘primvars:normals’ are both specified, the latter has precedence.


Declaration	`normal3f[] normals`
C++ Type	VtArray<GfVec3f>
Usd Type	SdfValueTypeNames->Normal3fArray

inline UsdAttribute CreateNormalsAttr() const: See GetNormalsAttr(), 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 GetDisplayColorAttr() const

It is useful to have an “official” colorSet that can be used as a display or modeling color, even in the absence of any specified shader for a gprim. DisplayColor serves this role; because it is a UsdGeomPrimvar, it can also be used as a gprim override for any shader that consumes a displayColor parameter.


Declaration	`color3f[] primvars:displayColor`
C++ Type	VtArray<GfVec3f>
Usd Type	SdfValueTypeNames->Color3fArray

inline UsdAttribute CreateDisplayColorAttr() const: See GetDisplayColorAttr(), 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 GetDisplayOpacityAttr() const

Companion to displayColor that specifies opacity, broken out as an independent attribute rather than an rgba color, both so that each can be independently overridden, and because shaders rarely consume rgba parameters.


Declaration	`float[] primvars:displayOpacity`
C++ Type	VtArray<float>
Usd Type	SdfValueTypeNames->FloatArray

inline UsdAttribute CreateDisplayOpacityAttr() const: See GetDisplayOpacityAttr(), 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 GetDoubleSidedAttr() const

Although some renderers treat all parametric or polygonal surfaces as if they were effectively laminae with outward-facing normals on both sides, some renderers derive significant optimizations by considering these surfaces to have only a single outward side, typically determined by control-point winding order and/or orientation. By doing so they can perform “backface culling” to avoid drawing the many polygons of most closed surfaces that face away from the viewer.

However, it is often advantageous to model thin objects such as paper and cloth as single, open surfaces that must be viewable from both sides, always. Setting a gprim’s doubleSided attribute to true instructs all renderers to disable optimizations such as backface culling for the gprim, and attempt (not all renderers are able to do so, but the USD reference GL renderer always will) to provide forward-facing normals on each side of the surface for lighting calculations.


Declaration	`uniform bool doubleSided = 0`
C++ Type	bool
Usd Type	SdfValueTypeNames->Bool
Variability	SdfVariabilityUniform

inline UsdAttribute CreateDoubleSidedAttr() const: See GetDoubleSidedAttr(), 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 GetOrientationAttr() const

Orientation specifies whether the gprim’s surface normal should be computed using the right hand rule, or the left hand rule. Please see UsdGeom_WindingOrder for a deeper explanation and generalization of orientation to composed scenes with transformation hierarchies.


Declaration	`uniform token orientation = "rightHanded"`
C++ Type	TfToken
Usd Type	SdfValueTypeNames->Token
Variability	SdfVariabilityUniform
Allowed Values	rightHanded, leftHanded

inline UsdAttribute CreateOrientationAttr() const: See GetOrientationAttr(), 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 GetExtentAttr() const

Extent is a three dimensional range measuring the geometric extent of the authored gprim in its own local space (i.e. its own transform not applied), without accounting for any shader-induced displacement. If any extent value has been authored for a given Boundable, then it should be authored at every timeSample at which geometry-affecting properties are authored, to ensure correct evaluation via ComputeExtent(). If no extent value has been authored, then ComputeExtent() will call the Boundable’s registered ComputeExtentFunction(), which may be expensive, which is why we strongly encourage proper authoring of extent.

An authored extent on a prim which has children is expected to include the extent of all children, as they will be pruned from BBox computation during traversal.