MAYA-106486 Import UV set mappings

lib/mayaUsd/fileio/shading/shadingModeExporterContext.cpp

@@ -537,7 +537,7 @@ class _UVMappingManager
             = _material.GetPrim().GetPath().GetParentPath().AppendChild(TfToken(newName.c_str()));
         UsdShadeMaterial newMaterial
             = UsdShadeMaterial::Define(_material.GetPrim().GetStage(), newPath);
-        newMaterial.GetPrim().GetSpecializes().AddSpecialize(_material.GetPrim().GetPath());
+        newMaterial.SetBaseMaterial(_material);
 
         TfTokenVector::const_iterator itNode = _nodesWithUVInput.cbegin();
         TfTokenVector::const_iterator itName = uvNames.cbegin();

lib/mayaUsd/fileio/translators/translatorMaterial.cpp

@@ -28,7 +28,9 @@
 #include <pxr/base/tf/token.h>
 #include <pxr/base/vt/types.h>
 #include <pxr/usd/sdf/assetPath.h>
+#include <pxr/usd/sdf/layer.h>
 #include <pxr/usd/sdf/path.h>
+#include <pxr/usd/usd/primCompositionQuery.h>
 #include <pxr/usd/usd/stage.h>
 #include <pxr/usd/usdGeom/gprim.h>
 #include <pxr/usd/usdGeom/mesh.h>
@@ -38,8 +40,10 @@
 
 #include <maya/MDagPath.h>
 #include <maya/MFnDagNode.h>
+#include <maya/MFnDependencyNode.h>
 #include <maya/MFnSet.h>
 #include <maya/MFnSingleIndexedComponent.h>
+#include <maya/MGlobal.h>
 #include <maya/MIntArray.h>
 #include <maya/MObject.h>
 #include <maya/MSelectionList.h>
@@ -51,6 +55,66 @@
 
 PXR_NAMESPACE_OPEN_SCOPE
 
+// clang-format off
+TF_DEFINE_PRIVATE_TOKENS(
+    _tokens,
+
+    (inputs)
+    (varname)
+);
+// clang-format on
+
+namespace {
+// We want to know if this material is a specialization that was created to handle UV mappings on
+// export. For details, see the _UVMappingManager class in ..\shading\shadingModeExporterContext.cpp
+//
+bool _IsMergeableMaterial(const UsdShadeMaterial& shadeMaterial)
+{
+    if (!shadeMaterial || !shadeMaterial.HasBaseMaterial()) {
+        return false;
+    }
+
+    // Check for materials created by _UVMappingManager::getMaterial(). This code could probably be
+    // expanded to be more generic and handle more complex composition arcs at a later stage.
+
+    UsdPrimCompositionQuery query(shadeMaterial.GetPrim());
+    if (query.GetCompositionArcs().size() != 2) {
+        // Materials created by the _UVMappingManager have only 2 arcs:
+        return false;
+    }
+
+    // This is a little more robust than grabbing a specific arc index.
+    UsdPrimCompositionQuery::Filter filter;
+    filter.arcTypeFilter = UsdPrimCompositionQuery::ArcTypeFilter::Specialize;
+    query.SetFilter(filter);
+    std::vector<UsdPrimCompositionQueryArc> arcs = query.GetCompositionArcs();
+    const UsdPrimCompositionQueryArc        specializationArc = arcs.front();
+
+    const SdfLayerHandle    layer = specializationArc.GetIntroducingLayer();
+    const SdfPrimSpecHandle primSpec = layer->GetPrimAtPath(shadeMaterial.GetPath());
+
+    // If the primSpec that specializes the base material introduces other
+    // namespace children, it can't be merged.
+    if (!primSpec->GetNameChildren().empty()) {
+        return false;
+    }
+
+    // Check that the only properties authored are varname inputs.
+    for (const SdfPropertySpecHandle& propSpec : primSpec->GetProperties()) {
+        const SdfPath propPath = propSpec->GetPath();
+
+        const std::vector<std::string> splitName = SdfPath::TokenizeIdentifier(propPath.GetName());
+        // We allow only ["inputs", "<texture_name>", "varname"]
+        if (splitName.size() != 3u || splitName[0u] != _tokens->inputs.GetString()
+            || splitName[2u] != _tokens->varname.GetString()) {
+            return false;
+        }
+    }
+
+    return true;
+}
+} // namespace
+
 /* static */
 MObject UsdMayaTranslatorMaterial::Read(
     const UsdMayaJobImportArgs& jobArguments,
@@ -70,6 +134,11 @@ MObject UsdMayaTranslatorMaterial::Read(
         return shadingEngine;
     }
 
+    if (_IsMergeableMaterial(shadeMaterial)) {
+        // Use the base material instead
+        return Read(jobArguments, shadeMaterial.GetBaseMaterial(), boundPrim, context);
+    }
+
     UsdMayaJobImportArgs localArguments = jobArguments;
     for (const auto& shadingMode : jobArguments.shadingModes) {
         if (shadingMode.mode == UsdMayaShadingModeTokens->none) {
@@ -89,10 +158,87 @@ MObject UsdMayaTranslatorMaterial::Read(
     return shadingEngine;
 }
 
+namespace {
+using _UVBindings = std::map<TfToken, TfToken>;
+
+static _UVBindings
+_GetUVBindingsFromMaterial(const UsdShadeMaterial& material, UsdMayaPrimReaderContext* context)
+{
+    _UVBindings retVal;
+
+    if (!material || !context) {
+        return retVal;
+    }
+    const bool isMergeable = _IsMergeableMaterial(material);
+    // Find out the nodes requiring mapping. This code has deep knowledge of how the mappings are
+    // exported. See the _UVMappingManager class in ..\shading\shadingModeExporterContext.cpp for
+    // details.
+    for (const UsdShadeInput& input : material.GetInputs()) {
+        const UsdAttribute&      usdAttr = input.GetAttr();
+        std::vector<std::string> splitName = usdAttr.SplitName();
+        if (splitName.size() != 3 || splitName[2] != _tokens->varname.GetString()) {
+            continue;
+        }
+        VtValue val;
+        usdAttr.Get(&val);
+        if (!val.IsHolding<TfToken>()) {
+            continue;
+        }
+        SdfPath nodePath = isMergeable
+            ? material.GetBaseMaterial().GetPath().AppendChild(TfToken(splitName[1]))
+            : material.GetPath().AppendChild(TfToken(splitName[1]));
+        MObject           mayaNode = context->GetMayaNode(nodePath, false);
+        MStatus           status;
+        MFnDependencyNode depFn(mayaNode, &status);
+        if (!status) {
+            continue;
+        }
+        retVal[val.UncheckedGet<TfToken>()] = TfToken(depFn.name().asChar());
+    }
+
+    return retVal;
+}
+
+static void _BindUVs(const MDagPath& shapeDagPath, const _UVBindings& uvBindings)
+{
+    if (uvBindings.empty()) {
+        return;
+    }
+
+    MStatus status;
+    MFnMesh meshFn(shapeDagPath, &status);
+    if (!status) {
+        return;
+    }
+
+    MStringArray uvSets;
+    meshFn.getUVSetNames(uvSets);
+
+    // We explicitly skip uvSet[0] since it is the default in Maya and does not require explicit
+    // linking:
+    for (unsigned int uvSetIndex = 1; uvSetIndex < uvSets.length(); uvSetIndex++) {
+        TfToken                     uvSetName(uvSets[uvSetIndex].asChar());
+        _UVBindings::const_iterator iter = uvBindings.find(uvSetName);
+        if (iter == uvBindings.cend()) {
+            continue;
+        }
+        MString uvLinkCommand("uvLink -make -uvs \"");
+        uvLinkCommand += shapeDagPath.fullPathName();
+        uvLinkCommand += ".uvSet[";
+        uvLinkCommand += uvSetIndex;
+        uvLinkCommand += "].uvSetName\" -t \"";
+        uvLinkCommand += iter->second.GetText(); // texture name
+        uvLinkCommand += "\";";
+        status = MGlobal::executeCommand(uvLinkCommand);
+    }
+}
+} // namespace
+
 static bool _AssignMaterialFaceSet(
-    const MObject&    shadingEngine,
-    const MDagPath&   shapeDagPath,
-    const VtIntArray& faceIndices)
+    const MObject&     shadingEngine,
+    const MDagPath&    shapeDagPath,
+    const VtIntArray&  faceIndices,
+    const _UVBindings& faceUVBindings)
 {
     MStatus status;
 
@@ -117,6 +263,7 @@ static bool _AssignMaterialFaceSet(
                 "Could not add component to shadingEngine %s.", seFnSet.name().asChar());
             return false;
         }
+        _BindUVs(shapeDagPath, faceUVBindings);
     }
 
     return true;
@@ -141,14 +288,18 @@ bool UsdMayaTranslatorMaterial::AssignMaterial(
 
     MStatus                          status;
     const UsdShadeMaterialBindingAPI bindingAPI(primSchema.GetPrim());
-    MObject                          shadingEngine = UsdMayaTranslatorMaterial::Read(
-        jobArguments, bindingAPI.ComputeBoundMaterial(), primSchema, context);
+    UsdShadeMaterial                 meshMaterial = bindingAPI.ComputeBoundMaterial();
+    _UVBindings                      uvBindings;
+    MObject                          shadingEngine
+        = UsdMayaTranslatorMaterial::Read(jobArguments, meshMaterial, primSchema, context);
 
     if (shadingEngine.isNull()) {
         status = UsdMayaUtil::GetMObjectByName("initialShadingGroup", shadingEngine);
         if (status != MS::kSuccess) {
             return false;
         }
+    } else {
+        uvBindings = _GetUVBindingsFromMaterial(meshMaterial, context);
     }
 
     // If the gprim does not have a material faceSet which represents per-face
@@ -164,6 +315,7 @@ bool UsdMayaTranslatorMaterial::AssignMaterial(
                 TF_RUNTIME_ERROR(
                     "Could not add shadingEngine for '%s'.", shapeDagPath.fullPathName().asChar());
             }
+            _BindUVs(shapeDagPath, uvBindings);
         }
 
         return true;
@@ -197,7 +349,8 @@ bool UsdMayaTranslatorMaterial::AssignMaterial(
 
             VtIntArray unassignedIndices
                 = UsdGeomSubset::GetUnassignedIndices(faceSubsets, faceCount);
-            if (!_AssignMaterialFaceSet(shadingEngine, shapeDagPath, unassignedIndices)) {
+            if (!_AssignMaterialFaceSet(
+                    shadingEngine, shapeDagPath, unassignedIndices, uvBindings)) {
                 return false;
             }
         }
@@ -208,20 +361,25 @@ bool UsdMayaTranslatorMaterial::AssignMaterial(
             if (boundMaterial) {
                 MObject faceSubsetShadingEngine = UsdMayaTranslatorMaterial::Read(
                     jobArguments, boundMaterial, UsdGeomGprim(), context);
+
+                _UVBindings faceUVBindings;
                 if (faceSubsetShadingEngine.isNull()) {
                     status = UsdMayaUtil::GetMObjectByName(
                         "initialShadingGroup", faceSubsetShadingEngine);
                     if (status != MS::kSuccess) {
                         return false;
                     }
+                } else {
+                    faceUVBindings = _GetUVBindingsFromMaterial(boundMaterial, context);
                 }
 
                 // Only transfer the first timeSample or default indices, if
                 // there are no time-samples.
                 VtIntArray indices;
                 subset.GetIndicesAttr().Get(&indices, UsdTimeCode::EarliestTime());
 
-                if (!_AssignMaterialFaceSet(faceSubsetShadingEngine, shapeDagPath, indices)) {
+                if (!_AssignMaterialFaceSet(
+                        faceSubsetShadingEngine, shapeDagPath, indices, faceUVBindings)) {
                     return false;
                 }
             }

lib/usd/translators/meshReader.cpp

@@ -127,15 +127,16 @@ bool MayaUsdPrimReaderMesh::Read(UsdMayaPrimReaderContext* context)
         }
     }
 
-    // assign material
-    assignMaterial(mesh, _GetArgs(), meshRead.meshObject(), context);
-
     // assign primvars to mesh
     UsdMayaMeshReadUtils::assignPrimvarsToMesh(
         mesh, meshRead.meshObject(), _GetArgs().GetExcludePrimvarNames());
+
     // assign invisible faces
     UsdMayaMeshReadUtils::assignInvisibleFaces(mesh, meshRead.meshObject());
 
+    // assign material
+    assignMaterial(mesh, _GetArgs(), meshRead.meshObject(), context);
+
     return true;
 }
 

lib/usd/translators/shading/usdUVTextureReader.cpp

@@ -98,6 +98,12 @@ TF_DEFINE_PRIVATE_TOKENS(
     (wrapS)
     (wrapT)
 
+    // uv connections:
+    (outUvFilterSize)
+    (uvFilterSize)
+    (outUV)
+    (uvCoord)
+
     // Values for wrapS and wrapT
     (black)
     (repeat)
@@ -175,6 +181,16 @@ bool PxrMayaUsdUVTexture_Reader::Read(UsdMayaPrimReaderContext* context)
     }
 
     // Connect manually (fileTexturePlacementConnect is not available in batch):
+    {
+        MPlug uvPlug = uvDepFn.findPlug(_tokens->outUV.GetText(), true, &status);
+        MPlug filePlug = depFn.findPlug(_tokens->uvCoord.GetText(), true, &status);
+        UsdMayaUtil::Connect(uvPlug, filePlug, false);
+    }
+    {
+        MPlug uvPlug = uvDepFn.findPlug(_tokens->outUvFilterSize.GetText(), true, &status);
+        MPlug filePlug = depFn.findPlug(_tokens->uvFilterSize.GetText(), true, &status);
+        UsdMayaUtil::Connect(uvPlug, filePlug, false);
+    }
     MString connectCmd;
     for (const TfToken& uvName : _Place2dTextureConnections) {
         MPlug uvPlug = uvDepFn.findPlug(uvName.GetText(), true, &status);

test/lib/usd/translators/CMakeLists.txt

@@ -56,6 +56,7 @@ set(TEST_SCRIPT_FILES
     testUsdImportSessionLayer.py
     testUsdImportShadingModeDisplayColor.py
     testUsdImportShadingModePxrRis.py
+    testUsdImportUVSetMappings.py
     testUsdExportImportRoundtripPreviewSurface.py
     testUsdExportImportUDIM.py
     testUsdImportSkeleton.py