Include a UsdSkelAnimMapper for blend shapes in UsdSkelSkinningQuery.

This makes the data model more consistent between joint anim and blend shapes
Fixing bug in UsdSkelBakeSkinning with skinning transforms being computed
on prims that have no joint influences.
Adding UsdSkelAnimQuery::GetBlendShapeAttributes() method,
matching the interface of UsdSkelAnimQuery::GetJointTransformAttributes().
GetBlendShapeAttributes() is needed for motion sampling in Katana.
Adding UsdSkelBlendShapeQuery::GetBlendShapeIndex, for determining which blendshape
goes with each sub-shape.

(Internal change: 1973864)

pxr/usd/lib/usdSkel/animQuery.cpp

@@ -160,6 +160,17 @@ UsdSkelAnimQuery::GetBlendShapeWeightTimeSamples(
 }
 
 
+bool 
+UsdSkelAnimQuery::GetBlendShapeWeightAttributes(
+    std::vector<UsdAttribute>* attrs) const
+{
+    if(TF_VERIFY(IsValid(), "invalid anim query.")) {
+        return _impl->GetBlendShapeWeightAttributes(attrs);
+    }
+    return false;
+}
+
+
 bool
 UsdSkelAnimQuery::GetBlendShapeWeightTimeSamplesInInterval(
     const GfInterval& interval,

pxr/usd/lib/usdSkel/animQuery.h

@@ -156,6 +156,10 @@ class UsdSkelAnimQuery
     bool GetBlendShapeWeightTimeSamplesInInterval(const GfInterval& interval,
                                                   std::vector<double>* times) const;
 
+    /// Get the attributes contributing to blendshape weight computations.
+    USDSKEL_API
+    bool GetBlendShapeWeightAttributes(std::vector<UsdAttribute>* attrs) const;
+
     /// Return true if it possible, but not certain, that the blend shape
     /// weights computed through this animation query change over time,
     /// false otherwise.

pxr/usd/lib/usdSkel/animQueryImpl.cpp

@@ -84,6 +84,9 @@ class UsdSkel_SkelAnimationQueryImpl : public UsdSkel_AnimQueryImpl
              const GfInterval& interval,
              std::vector<double>* times) const override;
 
+    bool GetBlendShapeWeightAttributes(
+             std::vector<UsdAttribute>* attrs) const override;
+
     bool BlendShapeWeightsMightBeTimeVarying() const override;
 
 private:
@@ -229,6 +232,14 @@ UsdSkel_SkelAnimationQueryImpl::GetBlendShapeWeightTimeSamples(
 }
 
 
+bool
+UsdSkel_SkelAnimationQueryImpl::GetBlendShapeWeightAttributes(
+    std::vector<UsdAttribute>* attrs) const
+{
+    attrs->push_back(_blendShapeWeights.GetAttribute());
+    return true;
+}
+
 bool
 UsdSkel_SkelAnimationQueryImpl::BlendShapeWeightsMightBeTimeVarying() const
 {

pxr/usd/lib/usdSkel/animQueryImpl.h

@@ -91,6 +91,9 @@ class UsdSkel_AnimQueryImpl : public TfRefBase
     GetBlendShapeWeightTimeSamples(const GfInterval& interval,
                                    std::vector<double>* times) const = 0;
 
+    virtual bool
+    GetBlendShapeWeightAttributes(std::vector<UsdAttribute>* attrs) const = 0;
+
     virtual bool
     BlendShapeWeightsMightBeTimeVarying() const = 0;
 

pxr/usd/lib/usdSkel/blendShapeQuery.cpp

@@ -138,6 +138,17 @@ UsdSkelBlendShapeQuery::GetInbetween(size_t subShapeIndex) const
 }
 
 
+size_t
+UsdSkelBlendShapeQuery::GetBlendShapeIndex(size_t subShapeIndex) const
+{
+    if (subShapeIndex < _subShapes.size()) {
+        return _subShapes[subShapeIndex].GetBlendShapeIndex();
+    }
+    return 0;
+}
+
+
+
 std::vector<VtUIntArray>
 UsdSkelBlendShapeQuery::ComputeBlendShapePointIndices() const
 {

pxr/usd/lib/usdSkel/blendShapeQuery.h

@@ -69,6 +69,9 @@ class UsdSkelBlendShapeQuery
     /// Returns the inbetween shape corresponding to sub-shape \p i, if any.
     USDSKEL_API UsdSkelInbetweenShape GetInbetween(size_t subShapeIndex) const;
 
+    /// Returns the blend shape index corresponding to the \p i'th sub-shape.
+    USDSKEL_API size_t GetBlendShapeIndex(size_t subShapeIndex) const;
+
     size_t GetNumBlendShapes() const { return _blendShapes.size(); }
 
     size_t GetNumSubShapes() const { return _subShapes.size(); }

pxr/usd/lib/usdSkel/cacheImpl.cpp

@@ -170,11 +170,13 @@ UsdSkel_CacheImpl::ReadScope::_FindOrCreateSkinningQuery(
     const SkinningQueryKey& key)
 {
     UsdSkelSkeletonQuery skelQuery = FindOrCreateSkelQuery(key.skel);
+    const UsdSkelAnimQuery& animQuery = skelQuery.GetAnimQuery();
 
     // TODO: Consider some form of deduplication.
     return UsdSkelSkinningQuery(
         skinnedPrim,
         skelQuery ? skelQuery.GetJointOrder() : VtTokenArray(),
+        animQuery ? animQuery.GetBlendShapeOrder() : VtTokenArray(),
         key.jointIndicesAttr, key.jointWeightsAttr,
         key.geomBindTransformAttr, key.jointsAttr,
         key.blendShapesAttr, key.blendShapeTargetsRel);

pxr/usd/lib/usdSkel/skinningQuery.cpp

@@ -58,6 +58,7 @@ UsdSkelSkinningQuery::UsdSkelSkinningQuery()
 UsdSkelSkinningQuery::UsdSkelSkinningQuery(
     const UsdPrim& prim,
     const VtTokenArray& skelJointOrder,
+    const VtTokenArray& animBlendShapeOrder,
     const UsdAttribute& jointIndices,
     const UsdAttribute& jointWeights,
     const UsdAttribute& geomBindTransform,
@@ -72,11 +73,16 @@ UsdSkelSkinningQuery::UsdSkelSkinningQuery(
       _blendShapes(blendShapes),
       _blendShapeTargets(blendShapeTargets)
 {
-    VtTokenArray jointOrder;
-    if (joints && joints.Get(&jointOrder)) {
-        _jointOrder = jointOrder;
-        _mapper =
-            std::make_shared<UsdSkelAnimMapper>(skelJointOrder, jointOrder);
+    VtTokenArray order;
+    if (joints && joints.Get(&order)) {
+        _jointOrder = order;
+        _jointMapper =
+            std::make_shared<UsdSkelAnimMapper>(skelJointOrder, order);
+    }
+    if (blendShapes && blendShapes.Get(&order)) {
+        _blendShapeOrder = order;
+        _blendShapeMapper =
+            std::make_shared<UsdSkelAnimMapper>(animBlendShapeOrder, order);
     }
 
     _InitializeJointInfluenceBindings(jointIndices, jointWeights);
@@ -146,7 +152,7 @@ UsdSkelSkinningQuery::_InitializeBlendShapeBindings(
     const UsdAttribute& blendShapes,
     const UsdRelationship& blendShapeTargets)
 {
-    if (blendShapes && blendShapeTargets) {
+    if (blendShapes && blendShapeTargets && _blendShapeMapper) {
         _flags |= UsdSkel_HasBlendShapes;
     }
 }
@@ -188,6 +194,21 @@ UsdSkelSkinningQuery::GetJointOrder(VtTokenArray* jointOrder) const
 }
 
 
+bool
+UsdSkelSkinningQuery::GetBlendShapeOrder(VtTokenArray* blendShapeOrder) const
+{
+    if (blendShapeOrder) {
+        if (_blendShapeOrder) {
+            *blendShapeOrder = *_blendShapeOrder;
+            return true;
+        }
+    } else {
+        TF_CODING_ERROR("'blendShapeOrder' pointer is null.");
+    }
+    return false;
+}
+
+
 bool
 UsdSkelSkinningQuery::GetTimeSamples(std::vector<double>* times) const
 {
@@ -324,8 +345,8 @@ UsdSkelSkinningQuery::ComputeSkinnedPoints(const VtArray<Matrix4>& xforms,
         // a mapper that should be used to reorder transforms
         // (skel order -> binding order)
         VtArray<Matrix4> orderedXforms(xforms);
-        if (_mapper) {
-            if (!_mapper->RemapTransforms(xforms, &orderedXforms)) {
+        if (_jointMapper) {
+            if (!_jointMapper->RemapTransforms(xforms, &orderedXforms)) {
                 return false;
             }
         }
@@ -376,8 +397,8 @@ UsdSkelSkinningQuery::ComputeSkinnedTransform(const VtArray<Matrix4>& xforms,
         // a mapper that should be used to reorder transforms
         // (skel order -> binding order)
         VtArray<Matrix4> orderedXforms(xforms);
-        if (_mapper) {
-            if (!_mapper->Remap(xforms, &orderedXforms)) {
+        if (_jointMapper) {
+            if (!_jointMapper->Remap(xforms, &orderedXforms)) {
                 return false;
             }
         }

pxr/usd/lib/usdSkel/skinningQuery.h

@@ -60,6 +60,7 @@ class UsdSkelSkinningQuery
     USDSKEL_API
     UsdSkelSkinningQuery(const UsdPrim& prim,
                          const VtTokenArray& skelJointOrder,
+                         const VtTokenArray& blendShapeOrder,
                          const UsdAttribute& jointIndices,
                          const UsdAttribute& jointWeights,
                          const UsdAttribute& geomBindTransform,
@@ -119,16 +120,38 @@ class UsdSkelSkinningQuery
         return _blendShapeTargets;
     }
 
-    /// Return the mapper for this target, if any.
-    /// This corresponds to the mapping of the joint order from
-    /// the ordering on the skeleton to the order of a custom
-    /// \em skel:joints relationships, set inside the hierarchy.
-    const UsdSkelAnimMapperRefPtr& GetMapper() const { return _mapper; }
+    /// Return a mapper for remapping from the joint order of the skeleton
+    /// to the local joint order of this prim, if any. Returns a null
+    /// pointer if the prim has no custom joint orer.
+    /// The mapper maps data from the order given by the \em joints order
+    /// on the Skeleton to the order given by the \em skel:joints property,
+    /// as optionally set through the UsdSkelBindingAPI.
+    const UsdSkelAnimMapperRefPtr& GetJointMapper() const {
+        return _jointMapper;
+    }
+
+    /// \deprecated Use GetJointMapper.
+    const UsdSkelAnimMapperRefPtr& GetMapper() const { return _jointMapper; }
+
+
+    /// Return the mapper for remapping blend shapes from the order of the
+    /// bound SkelAnimation to the local blend shape order of this prim.
+    /// Returns a null reference if the underlying prim has no blend shapes.
+    /// The mapper maps data from the order given by the \em blendShapes order
+    /// on the SkelAnimation to the order given by the \em skel:blendShapes
+    /// property, as set through the UsdSkelBindingAPI.
+    const UsdSkelAnimMapperRefPtr& GetBlendShapeMapper() const {
+        return _blendShapeMapper;
+    }
 
     /// Get the custom joint order for this skinning site, if any.
     USDSKEL_API
     bool GetJointOrder(VtTokenArray* jointOrder) const;
 
+    /// Get the blend shapes for this skinning site, if any.
+    USDSKEL_API
+    bool GetBlendShapeOrder(VtTokenArray* blendShapes) const;
+
     /// Populate \p times with the union of time samples for all properties
     /// that affect skinning, independent of joint transforms and any
     /// other prim-specific properties (such as points).
@@ -233,8 +256,10 @@ class UsdSkelSkinningQuery
     UsdAttribute _geomBindTransformAttr;
     UsdAttribute _blendShapes;
     UsdRelationship _blendShapeTargets;
-    UsdSkelAnimMapperRefPtr _mapper;
+    UsdSkelAnimMapperRefPtr _jointMapper;
+    UsdSkelAnimMapperRefPtr _blendShapeMapper;
     boost::optional<VtTokenArray> _jointOrder;
+    boost::optional<VtTokenArray> _blendShapeOrder;
 };
 
 PXR_NAMESPACE_CLOSE_SCOPE

pxr/usd/lib/usdSkel/testenv/testUsdSkelCache.py

@@ -220,26 +220,26 @@ def _GetSkinningQuery(path):
         query = _GetSkinningQuery(rootPath+"/Model1/NonRigidScope1/A")
         assert query
         assert query.IsRigidlyDeformed()
-        assert query.GetMapper()
+        assert query.GetJointMapper()
         self.assertEquals(query.GetJointOrder(),
                           Vt.TokenArray(["A", "B", "C"]))
 
         query = _GetSkinningQuery(rootPath+"/Model1/NonRigidScope1/B")
         assert query
         assert not query.IsRigidlyDeformed()
-        assert not query.GetMapper()
+        assert not query.GetJointMapper()
 
         query = _GetSkinningQuery(rootPath+"/Model1/NonRigidScope2/A")
         assert query
         assert query.IsRigidlyDeformed()
-        assert query.GetMapper()
+        assert query.GetJointMapper()
         self.assertEquals(query.GetJointOrder(),
                           Vt.TokenArray(["A", "B", "C"]))
 
         query = _GetSkinningQuery(rootPath+"/Model1/NonRigidScope2/B")
         assert query
         assert query.IsRigidlyDeformed()
-        assert not query.GetMapper()
+        assert not query.GetJointMapper()
 
         # TODO: When adding support for rigid deformation of intermediate
         # xformables, Model1/RigidScopeParent/RigidScope should be treated

pxr/usd/lib/usdSkel/utils.cpp

@@ -1956,25 +1956,6 @@ _BakeSkinnedPoints(const UsdPrim& prim,
     const std::vector<VtVec3fArray> subShapePointOffsets =
         blendShapeQuery.ComputeSubShapePointOffsets();
 
-    // Compute mapper for remapping blend shape weights.
-    UsdSkelAnimMapper blendShapeMapper;
-    bool haveBlendShapes = false;
-
-    if (skinningQuery.HasBlendShapes()) {
-
-        // We have bindings for blend shapes, but these only mean
-        // something if we have an animation source to provide weight values.
-        if (const auto& animQuery = skelQuery.GetAnimQuery()) {
-            VtTokenArray blendShapeOrder;
-            if (skinningQuery.GetBlendShapesAttr().Get(&blendShapeOrder)) {
-                blendShapeMapper =
-                    UsdSkelAnimMapper(animQuery.GetBlendShapeOrder(),
-                                      blendShapeOrder);
-                haveBlendShapes = true;
-            }
-        }
-    }
-
     for (size_t i = 0; i < times.size(); ++i) {
         const VtValue& points = pointsValues[i];
         if (!points.IsHolding<VtVec3fArray>()) {
@@ -1989,25 +1970,10 @@ _BakeSkinnedPoints(const UsdPrim& prim,
             "(sample %zu of %zu)\n",
             TfStringify(time).c_str(), i, times.size());
 
-        // XXX: More complete and sophisticated skinning code would compute
-        // skinning transforms and blend shape weights once for all prims
-        // deformed by a single skeleton, instead of recomputing them for each
-        // individual prim skinned.
-        // However, since this method is intended only for testing, simplicity
-        // and correctness are greater priorities than performance.
-
-        VtMatrix4dArray xforms;
-        if (!skelQuery.ComputeSkinningTransforms(&xforms, time)) {
-            TF_DEBUG(USDSKEL_BAKESKINNING).Msg(
-                "[UsdSkelBakeSkinning]   Failed computing "
-                "skinning transforms\n");
-            return false;
-        }
-
         VtVec3fArray skinnedPoints(points.UncheckedGet<VtVec3fArray>());
 
         // Apply blend shapes before skinning.
-        if (haveBlendShapes) {
+        if (skinningQuery.HasBlendShapes()) {
 
             TF_DEBUG(USDSKEL_BAKESKINNING).Msg(
                 "[UsdSkelBakeSkinning]    Applying blend shapes\n");
@@ -2024,7 +1990,8 @@ _BakeSkinnedPoints(const UsdPrim& prim,
             // Remap the weights from the order on the animation source
             // to the order of the shapes bound to this skinnable prim.
             VtFloatArray weightsForPrim;
-            if (!blendShapeMapper.Remap(weights, &weightsForPrim)) {
+            if (!skinningQuery.GetBlendShapeMapper()->Remap(
+                    weights, &weightsForPrim)) {
                 return false;
             }
 
@@ -2049,6 +2016,21 @@ _BakeSkinnedPoints(const UsdPrim& prim,
             TF_DEBUG(USDSKEL_BAKESKINNING).Msg(
                 "[UsdSkelBakeSkinning]    Applying linear blend skinning\n");
 
+            // XXX: More complete and sophisticated skinning code would compute
+            // skinning transforms and blend shape weights once for all prims
+            // deformed by a single skeleton, instead of recomputing them for each
+            // individual prim skinned.
+            // However, since this method is intended only for testing, simplicity
+            // and correctness are greater priorities than performance.
+
+            VtMatrix4dArray xforms;
+            if (!skelQuery.ComputeSkinningTransforms(&xforms, time)) {
+                TF_DEBUG(USDSKEL_BAKESKINNING).Msg(
+                    "[UsdSkelBakeSkinning]   Failed computing "
+                    "skinning transforms\n");
+                return false;
+            }
+
             if (!skinningQuery.ComputeSkinnedPoints(
                     xforms, &skinnedPoints, time)) {
                 TF_DEBUG(USDSKEL_BAKESKINNING).Msg(

pxr/usd/lib/usdSkel/wrapBlendShapeQuery.cpp

@@ -94,6 +94,7 @@ void wrapUsdSkelBlendShapeQuery()
 
         .def("GetBlendShape", &This::GetBlendShape)
         .def("GetInbetween", &This::GetInbetween)
+        .def("GetBlendShapeIndex", &This::GetBlendShapeIndex)
 
         .def("GetNumBlendShapes", &This::GetNumBlendShapes)
         .def("GetNumSubShapes", &This::GetNumSubShapes)

pxr/usd/lib/usdSkel/wrapSkinningQuery.cpp

@@ -163,9 +163,16 @@ void wrapUsdSkelSkinningQuery()
         .def("GetJointWeightsPrimvar", &This::GetJointWeightsPrimvar,
              return_value_policy<return_by_value>())
 
+        // deprecated
         .def("GetMapper", &This::GetMapper,
              return_value_policy<return_by_value>())
 
+        .def("GetJointMapper", &This::GetJointMapper,
+             return_value_policy<return_by_value>())
+
+        .def("GetBlendShapeMapper", &This::GetBlendShapeMapper,
+             return_value_policy<return_by_value>())
+
         .def("GetJointOrder", &_GetJointOrder)
 
         .def("GetTimeSamples", &_GetTimeSamples)