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UsdGeomMotionAPI Class Reference

#include <motionAPI.h>

+ Inheritance diagram for UsdGeomMotionAPI:

Public Member Functions

 UsdGeomMotionAPI (const UsdPrim &prim=UsdPrim())
 UsdGeomMotionAPI (const UsdSchemaBase &schemaObj)
virtual USDGEOM_API ~UsdGeomMotionAPI ()
 Destructor. More...
USDGEOM_API UsdAttribute GetVelocityScaleAttr () const
USDGEOM_API UsdAttribute CreateVelocityScaleAttr (VtValue const &defaultValue=VtValue(), bool writeSparsely=false) const
USDGEOM_API float ComputeVelocityScale (UsdTimeCode time=UsdTimeCode::Default()) const
- Public Member Functions inherited from UsdAPISchemaBase
 UsdAPISchemaBase (const UsdPrim &prim=UsdPrim())
 UsdAPISchemaBase (const UsdSchemaBase &schemaObj)
virtual USD_API ~UsdAPISchemaBase ()=0
 Destructor. More...
- Public Member Functions inherited from UsdSchemaBase
bool IsConcrete () const
bool IsTyped () const
bool IsAPISchema () const
 Returns whether this is an API schema or not. More...
bool IsAppliedAPISchema () const
bool IsMultipleApplyAPISchema () const
UsdSchemaType GetSchemaType () const
USD_API UsdSchemaBase (const UsdPrim &prim=UsdPrim())
 Construct and store prim as the held prim. More...
USD_API UsdSchemaBase (const UsdSchemaBase &otherSchema)
 Construct and store for the same prim held by otherSchema. More...
virtual USD_API ~UsdSchemaBase ()
 Destructor. More...
USD_API operator bool () const
UsdPrim GetPrim () const
 Return this schema object's held prim. More...
SdfPath GetPath () const
 Shorthand for GetPrim()->GetPath(). More...
USD_API const UsdPrimDefinitionGetSchemaClassPrimDefinition () const

Static Public Member Functions

static USDGEOM_API const
GetSchemaAttributeNames (bool includeInherited=true)
static USDGEOM_API UsdGeomMotionAPI Get (const UsdStagePtr &stage, const SdfPath &path)
static USDGEOM_API UsdGeomMotionAPI Apply (const UsdPrim &prim)
- Static Public Member Functions inherited from UsdAPISchemaBase
static USD_API const
GetSchemaAttributeNames (bool includeInherited=true)
- Static Public Member Functions inherited from UsdSchemaBase
static const TfTokenVectorGetSchemaAttributeNames (bool includeInherited=true)

Static Public Attributes

static const UsdSchemaType schemaType = UsdSchemaType::SingleApplyAPI
- Static Public Attributes inherited from UsdAPISchemaBase
static const UsdSchemaType schemaType = UsdSchemaType::AbstractBase
- Static Public Attributes inherited from UsdSchemaBase
static const UsdSchemaType schemaType = UsdSchemaType::AbstractBase

Protected Member Functions

USDGEOM_API UsdSchemaType _GetSchemaType () const override
- Protected Member Functions inherited from UsdAPISchemaBase
 UsdAPISchemaBase (const UsdPrim &prim, const TfToken &instanceName)
 UsdAPISchemaBase (const UsdSchemaBase &schemaObj, const TfToken &instanceName)
const TfToken_GetInstanceName () const
USD_API bool _IsCompatible () const override
- Protected Member Functions inherited from UsdSchemaBase
const TfType_GetType () const
USD_API UsdAttribute _CreateAttr (TfToken const &attrName, SdfValueTypeName const &typeName, bool custom, SdfVariability variability, VtValue const &defaultValue, bool writeSparsely) const


class UsdSchemaRegistry

Additional Inherited Members

- Static Protected Member Functions inherited from UsdAPISchemaBase
template<typename APISchemaType >
static APISchemaType _ApplyAPISchema (const UsdPrim &prim, const TfToken &apiSchemaName)
template<typename APISchemaType >
static APISchemaType _MultipleApplyAPISchema (const UsdPrim &prim, const TfToken &apiSchemaName, const TfToken &instanceName)

Detailed Description

UsdGeomMotionAPI encodes data that can live on any prim that may affect computations involving:

  • computed motion for motion blur
  • sampling for motion blur

For example, UsdGeomMotionAPI provides velocityScale (GetVelocityScaleAttr()) for controlling how motion-blur samples should be computed by velocity-consuming schemas.

Definition at line 64 of file motionAPI.h.

Constructor & Destructor Documentation

UsdGeomMotionAPI::UsdGeomMotionAPI ( const UsdPrim prim = UsdPrim())

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

Definition at line 76 of file motionAPI.h.

UsdGeomMotionAPI::UsdGeomMotionAPI ( const UsdSchemaBase schemaObj)

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

Definition at line 84 of file motionAPI.h.

virtual USDGEOM_API UsdGeomMotionAPI::~UsdGeomMotionAPI ( )


Member Function Documentation

USDGEOM_API UsdSchemaType UsdGeomMotionAPI::_GetSchemaType ( ) const

Returns the type of schema this class belongs to.

See Also

Reimplemented from UsdAPISchemaBase.

static USDGEOM_API UsdGeomMotionAPI UsdGeomMotionAPI::Apply ( const UsdPrim prim)

Applies this single-apply API schema to the given prim. This information is stored by adding "MotionAPI" to the token-valued, listOp metadata apiSchemas on the prim.

A valid UsdGeomMotionAPI object is returned upon success. An invalid (or empty) UsdGeomMotionAPI object is returned upon failure. See UsdPrim::ApplyAPI() for conditions resulting in failure.
See Also
USDGEOM_API float UsdGeomMotionAPI::ComputeVelocityScale ( UsdTimeCode  time = UsdTimeCode::Default()) const

Compute the inherited value of velocityScale at time, i.e. the authored value on the prim closest to this prim in namespace, resolved upwards through its ancestors in namespace.

the inherited value, or 1.0 if neither the prim nor any of its ancestors possesses an authored value.
this is a reference implementation that is not particularly efficient if evaluating over many prims, because it does not share inherited results.
USDGEOM_API UsdAttribute UsdGeomMotionAPI::CreateVelocityScaleAttr ( VtValue const defaultValue = VtValue(),
bool  writeSparsely = false 
) const

See GetVelocityScaleAttr(), and also Usd_Create_Or_Get_Property 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.

static USDGEOM_API UsdGeomMotionAPI UsdGeomMotionAPI::Get ( const UsdStagePtr &  stage,
const SdfPath path 

Return a UsdGeomMotionAPI 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:

static USDGEOM_API const TfTokenVector& UsdGeomMotionAPI::GetSchemaAttributeNames ( bool  includeInherited = true)

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.

USDGEOM_API UsdAttribute UsdGeomMotionAPI::GetVelocityScaleAttr ( ) const

VelocityScale is an inherited float attribute that velocity-based schemas (e.g. PointBased, PointInstancer) can consume to compute interpolated positions and orientations by applying velocity and angularVelocity, which is required for interpolating between samples when topology is varying over time. Although these quantities are generally physically computed by a simulator, sometimes we require more or less motion-blur to achieve the desired look. VelocityScale allows artists to dial-in, as a post-sim correction, a scale factor to be applied to the velocity prior to computing interpolated positions from it.

See also ComputeVelocityScale()

Declaration float motion:velocityScale = 1
C++ Type float
Usd Type SdfValueTypeNames->Float

Friends And Related Function Documentation

friend class UsdSchemaRegistry

Definition at line 141 of file motionAPI.h.

Member Data Documentation

const UsdSchemaType UsdGeomMotionAPI::schemaType = UsdSchemaType::SingleApplyAPI

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

See Also

Definition at line 70 of file motionAPI.h.

The documentation for this class was generated from the following file: