bindingAPI.h

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//
// Copyright 2016 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef USDSKEL_GENERATED_BINDINGAPI_H
#define USDSKEL_GENERATED_BINDINGAPI_H

/// \file usdSkel/bindingAPI.h

#include "pxr/pxr.h"
#include "pxr/usd/usdSkel/api.h"
#include "pxr/usd/usd/apiSchemaBase.h"
#include "pxr/usd/usd/prim.h"
#include "pxr/usd/usd/stage.h"
#include "pxr/usd/usdSkel/tokens.h"

#include "pxr/base/tf/span.h"
#include "pxr/usd/usdGeom/primvar.h"
#include "pxr/usd/usdSkel/skeleton.h" 

#include "pxr/base/vt/value.h"

#include "pxr/base/gf/vec3d.h"
#include "pxr/base/gf/vec3f.h"
#include "pxr/base/gf/matrix4d.h"

#include "pxr/base/tf/token.h"
#include "pxr/base/tf/type.h"

PXR_NAMESPACE_OPEN_SCOPE

class SdfAssetPath;

// -------------------------------------------------------------------------- //
// SKELBINDINGAPI                                                             //
// -------------------------------------------------------------------------- //

/// \class UsdSkelBindingAPI
///
/// Provides API for authoring and extracting all the skinning-related
/// data that lives in the "geometry hierarchy" of prims and models that want
/// to be skeletally deformed.
/// 
/// See the extended \ref UsdSkel_BindingAPI "UsdSkelBindingAPI schema"
/// documentation for more about bindings and how they apply in a scene graph.
/// 
///
/// For any described attribute \em Fallback \em Value or \em Allowed \em Values below
/// that are text/tokens, the actual token is published and defined in \ref UsdSkelTokens.
/// So to set an attribute to the value "rightHanded", use UsdSkelTokens->rightHanded
/// as the value.
///
class UsdSkelBindingAPI : public UsdAPISchemaBase
{
public:
    /// Compile time constant representing what kind of schema this class is.
    ///
    /// \sa UsdSchemaKind
    static const UsdSchemaKind schemaKind = UsdSchemaKind::SingleApplyAPI;

    /// Construct a UsdSkelBindingAPI on UsdPrim \p prim .
    /// Equivalent to UsdSkelBindingAPI::Get(prim.GetStage(), prim.GetPath())
    /// for a \em valid \p prim, but will not immediately throw an error for
    /// an invalid \p prim
    explicit UsdSkelBindingAPI(const UsdPrim& prim=UsdPrim())
        : UsdAPISchemaBase(prim)
    {
    }

    /// Construct a UsdSkelBindingAPI on the prim held by \p schemaObj .
    /// Should be preferred over UsdSkelBindingAPI(schemaObj.GetPrim()),
    /// as it preserves SchemaBase state.
    explicit UsdSkelBindingAPI(const UsdSchemaBase& schemaObj)
        : UsdAPISchemaBase(schemaObj)
    {
    }

    /// Destructor.
    USDSKEL_API
    virtual ~UsdSkelBindingAPI();

    /// 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.
    USDSKEL_API
    static const TfTokenVector &
    GetSchemaAttributeNames(bool includeInherited=true);

    /// Return a UsdSkelBindingAPI holding the prim adhering to this
    /// schema at \p path on \p stage.  If no prim exists at \p path on
    /// \p 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:
    ///
    /// \code
    /// UsdSkelBindingAPI(stage->GetPrimAtPath(path));
    /// \endcode
    ///
    USDSKEL_API
    static UsdSkelBindingAPI
    Get(const UsdStagePtr &stage, const SdfPath &path);


    /// Returns true if this <b>single-apply</b> API schema can be applied to 
    /// the given \p prim. If this schema can not be a applied to the prim, 
    /// this returns false and, if provided, populates \p 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.
    /// 
    /// \sa UsdPrim::GetAppliedSchemas()
    /// \sa UsdPrim::HasAPI()
    /// \sa UsdPrim::CanApplyAPI()
    /// \sa UsdPrim::ApplyAPI()
    /// \sa UsdPrim::RemoveAPI()
    ///
    USDSKEL_API
    static bool 
    CanApply(const UsdPrim &prim, std::string *whyNot=nullptr);

    /// Applies this <b>single-apply</b> API schema to the given \p prim.
    /// This information is stored by adding "SkelBindingAPI" to the 
    /// token-valued, listOp metadata \em apiSchemas on the prim.
    /// 
    /// \return A valid UsdSkelBindingAPI object is returned upon success. 
    /// An invalid (or empty) UsdSkelBindingAPI object is returned upon 
    /// failure. See \ref UsdPrim::ApplyAPI() for conditions 
    /// resulting in failure. 
    /// 
    /// \sa UsdPrim::GetAppliedSchemas()
    /// \sa UsdPrim::HasAPI()
    /// \sa UsdPrim::CanApplyAPI()
    /// \sa UsdPrim::ApplyAPI()
    /// \sa UsdPrim::RemoveAPI()
    ///
    USDSKEL_API
    static UsdSkelBindingAPI 
    Apply(const UsdPrim &prim);

protected:
    /// Returns the kind of schema this class belongs to.
    ///
    /// \sa UsdSchemaKind
    USDSKEL_API
    UsdSchemaKind _GetSchemaKind() const override;

private:
    // needs to invoke _GetStaticTfType.
    friend class UsdSchemaRegistry;
    USDSKEL_API
    static const TfType &_GetStaticTfType();

    static bool _IsTypedSchema();

    // override SchemaBase virtuals.
    USDSKEL_API
    const TfType &_GetTfType() const override;

public:
    // --------------------------------------------------------------------- //
    // SKINNINGMETHOD 
    // --------------------------------------------------------------------- //
    /// The skinningMethod specifies the skinning method for the prim.
    ///
    /// | ||
    /// | -- | -- |
    /// | Declaration | `uniform token primvars:skel:skinningMethod = "classicLinear"` |
    /// | C++ Type | TfToken |
    /// | \ref Usd_Datatypes "Usd Type" | SdfValueTypeNames->Token |
    /// | \ref SdfVariability "Variability" | SdfVariabilityUniform |
    /// | \ref UsdSkelTokens "Allowed Values" | classicLinear, dualQuaternion |
    USDSKEL_API
    UsdAttribute GetSkinningMethodAttr() const;

    /// See GetSkinningMethodAttr(), and also 
    /// \ref Usd_Create_Or_Get_Property for when to use Get vs Create.
    /// If specified, author \p defaultValue as the attribute's default,
    /// sparsely (when it makes sense to do so) if \p writeSparsely is \c true -
    /// the default for \p writeSparsely is \c false.
    USDSKEL_API
    UsdAttribute CreateSkinningMethodAttr(VtValue const &defaultValue = VtValue(), bool writeSparsely=false) const;

public:
    // --------------------------------------------------------------------- //
    // GEOMBINDTRANSFORM 
    // --------------------------------------------------------------------- //
    /// Encodes the bind-time world space transforms of the prim.
    /// If the transform is identical for a group of gprims that share a common
    /// ancestor, the transform may be authored on the ancestor, to "inherit"
    /// down to all the leaf gprims. If this transform is unset, an identity
    /// transform is used instead.
    ///
    /// | ||
    /// | -- | -- |
    /// | Declaration | `matrix4d primvars:skel:geomBindTransform` |
    /// | C++ Type | GfMatrix4d |
    /// | \ref Usd_Datatypes "Usd Type" | SdfValueTypeNames->Matrix4d |
    USDSKEL_API
    UsdAttribute GetGeomBindTransformAttr() const;

    /// See GetGeomBindTransformAttr(), and also 
    /// \ref Usd_Create_Or_Get_Property for when to use Get vs Create.
    /// If specified, author \p defaultValue as the attribute's default,
    /// sparsely (when it makes sense to do so) if \p writeSparsely is \c true -
    /// the default for \p writeSparsely is \c false.
    USDSKEL_API
    UsdAttribute CreateGeomBindTransformAttr(VtValue const &defaultValue = VtValue(), bool writeSparsely=false) const;

public:
    // --------------------------------------------------------------------- //
    // JOINTS 
    // --------------------------------------------------------------------- //
    /// An (optional) array of tokens defining the list of
    /// joints to which jointIndices apply. If not defined, jointIndices applies
    /// to the ordered list of joints defined in the bound Skeleton's *joints*
    /// attribute. If undefined on a primitive, the primitive inherits the 
    /// value of the nearest ancestor prim, if any.
    ///
    /// | ||
    /// | -- | -- |
    /// | Declaration | `uniform token[] skel:joints` |
    /// | C++ Type | VtArray<TfToken> |
    /// | \ref Usd_Datatypes "Usd Type" | SdfValueTypeNames->TokenArray |
    /// | \ref SdfVariability "Variability" | SdfVariabilityUniform |
    USDSKEL_API
    UsdAttribute GetJointsAttr() const;

    /// See GetJointsAttr(), and also 
    /// \ref Usd_Create_Or_Get_Property for when to use Get vs Create.
    /// If specified, author \p defaultValue as the attribute's default,
    /// sparsely (when it makes sense to do so) if \p writeSparsely is \c true -
    /// the default for \p writeSparsely is \c false.
    USDSKEL_API
    UsdAttribute CreateJointsAttr(VtValue const &defaultValue = VtValue(), bool writeSparsely=false) const;

public:
    // --------------------------------------------------------------------- //
    // JOINTINDICES 
    // --------------------------------------------------------------------- //
    /// Indices into the *joints* attribute of the closest
    /// (in namespace) bound Skeleton that affect each point of a PointBased
    /// gprim. The primvar can have either *constant* or *vertex* interpolation.
    /// This primvar's *elementSize* will determine how many joint influences
    /// apply to each point. Indices must point be valid. Null influences should
    /// be defined by setting values in jointWeights to zero.
    /// See UsdGeomPrimvar for more information on interpolation and
    /// elementSize.
    ///
    /// | ||
    /// | -- | -- |
    /// | Declaration | `int[] primvars:skel:jointIndices` |
    /// | C++ Type | VtArray<int> |
    /// | \ref Usd_Datatypes "Usd Type" | SdfValueTypeNames->IntArray |
    USDSKEL_API
    UsdAttribute GetJointIndicesAttr() const;

    /// See GetJointIndicesAttr(), and also 
    /// \ref Usd_Create_Or_Get_Property for when to use Get vs Create.
    /// If specified, author \p defaultValue as the attribute's default,
    /// sparsely (when it makes sense to do so) if \p writeSparsely is \c true -
    /// the default for \p writeSparsely is \c false.
    USDSKEL_API
    UsdAttribute CreateJointIndicesAttr(VtValue const &defaultValue = VtValue(), bool writeSparsely=false) const;

public:
    // --------------------------------------------------------------------- //
    // JOINTWEIGHTS 
    // --------------------------------------------------------------------- //
    /// Weights for the joints that affect each point of a PointBased
    /// gprim. The primvar can have either *constant* or *vertex* interpolation.
    /// This primvar's *elementSize* will determine how many joints influences
    /// apply to each point. The length, interpolation, and elementSize of
    /// *jointWeights* must match that of *jointIndices*. See UsdGeomPrimvar
    /// for more information on interpolation and elementSize.
    ///
    /// | ||
    /// | -- | -- |
    /// | Declaration | `float[] primvars:skel:jointWeights` |
    /// | C++ Type | VtArray<float> |
    /// | \ref Usd_Datatypes "Usd Type" | SdfValueTypeNames->FloatArray |
    USDSKEL_API
    UsdAttribute GetJointWeightsAttr() const;

    /// See GetJointWeightsAttr(), and also 
    /// \ref Usd_Create_Or_Get_Property for when to use Get vs Create.
    /// If specified, author \p defaultValue as the attribute's default,
    /// sparsely (when it makes sense to do so) if \p writeSparsely is \c true -
    /// the default for \p writeSparsely is \c false.
    USDSKEL_API
    UsdAttribute CreateJointWeightsAttr(VtValue const &defaultValue = VtValue(), bool writeSparsely=false) const;

public:
    // --------------------------------------------------------------------- //
    // BLENDSHAPES 
    // --------------------------------------------------------------------- //
    /// An array of tokens defining the order onto which blend shape
    /// weights from an animation source map onto the *skel:blendShapeTargets*
    /// rel of a binding site. If authored, the number of elements must be equal
    /// to the number of targets in the _blendShapeTargets_ rel. This property
    /// is not inherited hierarchically, and is expected to be authored directly
    /// on the skinnable primitive to which the blend shapes apply.
    ///
    /// | ||
    /// | -- | -- |
    /// | Declaration | `uniform token[] skel:blendShapes` |
    /// | C++ Type | VtArray<TfToken> |
    /// | \ref Usd_Datatypes "Usd Type" | SdfValueTypeNames->TokenArray |
    /// | \ref SdfVariability "Variability" | SdfVariabilityUniform |
    USDSKEL_API
    UsdAttribute GetBlendShapesAttr() const;

    /// See GetBlendShapesAttr(), and also 
    /// \ref Usd_Create_Or_Get_Property for when to use Get vs Create.
    /// If specified, author \p defaultValue as the attribute's default,
    /// sparsely (when it makes sense to do so) if \p writeSparsely is \c true -
    /// the default for \p writeSparsely is \c false.
    USDSKEL_API
    UsdAttribute CreateBlendShapesAttr(VtValue const &defaultValue = VtValue(), bool writeSparsely=false) const;

public:
    // --------------------------------------------------------------------- //
    // ANIMATIONSOURCE 
    // --------------------------------------------------------------------- //
    /// Animation source to be bound to Skeleton primitives at or
    /// beneath the location at which this property is defined.
    /// 
    ///
    USDSKEL_API
    UsdRelationship GetAnimationSourceRel() const;

    /// See GetAnimationSourceRel(), and also 
    /// \ref Usd_Create_Or_Get_Property for when to use Get vs Create
    USDSKEL_API
    UsdRelationship CreateAnimationSourceRel() const;

public:
    // --------------------------------------------------------------------- //
    // SKELETON 
    // --------------------------------------------------------------------- //
    /// Skeleton to be bound to this prim and its descendents that
    /// possess a mapping and weighting to the joints of the identified
    /// Skeleton.
    ///
    USDSKEL_API
    UsdRelationship GetSkeletonRel() const;

    /// See GetSkeletonRel(), and also 
    /// \ref Usd_Create_Or_Get_Property for when to use Get vs Create
    USDSKEL_API
    UsdRelationship CreateSkeletonRel() const;

public:
    // --------------------------------------------------------------------- //
    // BLENDSHAPETARGETS 
    // --------------------------------------------------------------------- //
    /// Ordered list of all target blend shapes. This property is not
    /// inherited hierarchically, and is expected to be authored directly on
    /// the skinnable primitive to which the the blend shapes apply.
    ///
    USDSKEL_API
    UsdRelationship GetBlendShapeTargetsRel() const;

    /// See GetBlendShapeTargetsRel(), and also 
    /// \ref Usd_Create_Or_Get_Property for when to use Get vs Create
    USDSKEL_API
    UsdRelationship CreateBlendShapeTargetsRel() const;

public:
    // ===================================================================== //
    // Feel free to add custom code below this line, it will be preserved by 
    // the code generator. 
    //
    // Just remember to: 
    //  - Close the class declaration with }; 
    //  - Close the namespace with PXR_NAMESPACE_CLOSE_SCOPE
    //  - Close the include guard with #endif
    // ===================================================================== //
    // --(BEGIN CUSTOM CODE)--

    /// Convenience function to get the jointIndices attribute as a primvar.
    ///
    /// \sa GetJointIndicesAttr, GetInheritedJointWeightsPrimvar
    USDSKEL_API
    UsdGeomPrimvar GetJointIndicesPrimvar() const;

    /// Convenience function to create the jointIndices primvar, optionally
    /// specifying elementSize.
    /// If \p constant is true, the resulting primvar is configured 
    /// with 'constant' interpolation, and describes a rigid deformation.
    /// Otherwise, the primvar is configured with 'vertex' interpolation,
    /// and describes joint influences that vary per point.
    ///
    /// \sa CreateJointIndicesAttr(), GetJointIndicesPrimvar()
    USDSKEL_API
    UsdGeomPrimvar CreateJointIndicesPrimvar(bool constant,
                                             int elementSize=-1) const;

    /// Convenience function to get the jointWeights attribute as a primvar.
    ///
    /// \sa GetJointWeightsAttr, GetInheritedJointWeightsPrimvar
    USDSKEL_API
    UsdGeomPrimvar GetJointWeightsPrimvar() const;

    /// Convenience function to create the jointWeights primvar, optionally
    /// specifying elementSize.
    /// If \p constant is true, the resulting primvar is configured 
    /// with 'constant' interpolation, and describes a rigid deformation.
    /// Otherwise, the primvar is configured with 'vertex' interpolation,
    /// and describes joint influences that vary per point.
    ///
    /// \sa CreateJointWeightsAttr(), GetJointWeightsPrimvar()
    USDSKEL_API
    UsdGeomPrimvar CreateJointWeightsPrimvar(bool constant,
                                             int elementSize=-1) const;

    /// Convenience method for defining joints influences that
    /// make a primitive rigidly deformed by a single joint.
    USDSKEL_API
    bool SetRigidJointInfluence(int jointIndex, float weight=1) const;

    /// Convenience method to query the Skeleton bound on this prim.
    /// Returns true if a Skeleton binding is defined, and sets \p skel to
    /// the target skel. The resulting Skeleton may still be invalid,
    /// if the Skeleton has been explicitly *unbound*.
    ///
    /// This does not resolved inherited skeleton bindings.
    USDSKEL_API
    bool GetSkeleton(UsdSkelSkeleton* skel) const;

    /// Convenience method to query the animation source bound on this prim.
    /// Returns true if an animation source binding is defined, and sets
    /// \p prim to the target prim. The resulting primitive may still be
    /// invalid, if the prim has been explicitly *unbound*.
    ///
    /// This does not resolved inherited animation source bindings.
    USDSKEL_API
    bool GetAnimationSource(UsdPrim* prim) const;

    /// Returns the skeleton bound at this prim, or one of its ancestors.
    USDSKEL_API
    UsdSkelSkeleton GetInheritedSkeleton() const;

    /// Returns the animation source bound at this prim, or one of
    /// its ancestors.
    USDSKEL_API
    UsdPrim GetInheritedAnimationSource() const;

    /// Validate an array  of joint indices.
    /// This ensures that all indices are the in the range [0, numJoints).
    /// Returns true if the indices are valid, or false otherwise.
    /// If invalid and \p reason is non-null, an error message describing
    /// the first validation error will be set.
    USDSKEL_API
    static bool ValidateJointIndices(TfSpan<const int> indices,
                                     size_t numJoints,
                                     std::string* reason=nullptr);
};

PXR_NAMESPACE_CLOSE_SCOPE

#endif