Added PrimvarReader_float3 translation for displayColor

lib/usd/translators/shading/CMakeLists.txt

@@ -17,6 +17,7 @@ target_sources(${TARGET_NAME}
         usdPhongEWriter.cpp
         usdReflectWriter.cpp
         usdUVTextureReader.cpp
+        usdPrimvarReaderFloat3Reader.cpp
 )
 
 if (BUILD_RFM_TRANSLATORS)

lib/usd/translators/shading/shadingTokens.cpp

@@ -21,7 +21,7 @@ TF_DEFINE_PUBLIC_TOKENS(TrUsdTokens, TR_USD_COMMON TR_USD_TEXTURE TR_USD_PRIMVAR
 
 TF_DEFINE_PUBLIC_TOKENS(
     TrMayaTokens,
-    TR_MAYA_MATERIALS TR_MAYA_STANDARD_SURFACE TR_MAYA_FILE TR_MAYA_UV);
+    TR_MAYA_MATERIALS TR_MAYA_STANDARD_SURFACE TR_MAYA_FILE TR_MAYA_UV TR_MAYA_PRIMVAR);
 
 #ifdef WANT_MATERIALX_TRANSLATORS
 TF_DEFINE_PUBLIC_TOKENS(

lib/usd/translators/shading/shadingTokens.h

@@ -52,6 +52,7 @@ PXR_NAMESPACE_OPEN_SCOPE
 
 #define TR_USD_PRIMVAR \
     (UsdPrimvarReader_float2) \
+    (displayColor) \
     (result)
 
 #define TR_USD_XFORM \
@@ -173,12 +174,15 @@ TF_DECLARE_PUBLIC_TOKENS(TrUsdTokens, , TR_USD_COMMON TR_USD_TEXTURE TR_USD_PRIM
     (outUV) \
     (uvCoord)
 
+#define TR_MAYA_PRIMVAR \
+    (cpvColor)
+
 // clang-format on
 
 TF_DECLARE_PUBLIC_TOKENS(
     TrMayaTokens,
     ,
-    TR_MAYA_MATERIALS TR_MAYA_STANDARD_SURFACE TR_MAYA_FILE TR_MAYA_UV);
+    TR_MAYA_MATERIALS TR_MAYA_STANDARD_SURFACE TR_MAYA_FILE TR_MAYA_UV TR_MAYA_PRIMVAR);
 
 #ifdef WANT_MATERIALX_TRANSLATORS
 

lib/usd/translators/shading/usdPrimvarReaderFloat3Reader.cpp

@@ -0,0 +1,97 @@
+//
+// Copyright 2021 Animal Logic
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include "shadingTokens.h"
+
+#include <mayaUsd/fileio/shaderReader.h>
+#include <mayaUsd/fileio/shaderReaderRegistry.h>
+
+#include <pxr/usd/usdShade/shader.h>
+
+#include <maya/MFnDependencyNode.h>
+
+PXR_NAMESPACE_OPEN_SCOPE
+
+class PxrMayaUsdPrimvarReader_float3_Reader : public UsdMayaShaderReader
+{
+public:
+    PxrMayaUsdPrimvarReader_float3_Reader(const UsdMayaPrimReaderArgs& readArgs);
+
+    bool Read(UsdMayaPrimReaderContext& context) override;
+
+    TfToken GetMayaNameForUsdAttrName(const TfToken& usdAttrName) const override;
+};
+
+PXRUSDMAYA_REGISTER_SHADER_READER(UsdPrimvarReader_float3, PxrMayaUsdPrimvarReader_float3_Reader)
+
+PxrMayaUsdPrimvarReader_float3_Reader::PxrMayaUsdPrimvarReader_float3_Reader(
+    const UsdMayaPrimReaderArgs& readArgs)
+    : UsdMayaShaderReader(readArgs)
+{
+}
+
+/* virtual */
+bool PxrMayaUsdPrimvarReader_float3_Reader::Read(UsdMayaPrimReaderContext& context)
+{
+    const UsdPrim& prim = _GetArgs().GetUsdPrim();
+    UsdShadeShader shaderSchema = UsdShadeShader(prim);
+    if (!shaderSchema) {
+        return false;
+    }
+
+    MObject       obj;
+    VtValue       val;
+    UsdShadeInput usdInput = shaderSchema.GetInput(TrUsdTokens->varname);
+    if (usdInput && usdInput.Get(&val) && val.IsHolding<std::string>()
+        && val.UncheckedGet<std::string>() == TrUsdTokens->displayColor.GetString()) {
+        // Create a CPV color node in place of USD's displayColor primvar reader
+        MStatus           status;
+        MFnDependencyNode depFn;
+        obj = depFn.create(TrMayaTokens->cpvColor.GetText(), &status);
+        if (status != MS::kSuccess) {
+            TF_RUNTIME_ERROR(
+                "Could not create node of type %s for prim '%s'. ",
+                TrMayaTokens->cpvColor.GetText(),
+                prim.GetPath().GetText());
+            return false;
+        }
+    }
+
+    if (obj.isNull()) {
+        return false;
+    }
+
+    context.RegisterNewMayaNode(prim.GetPath().GetString(), obj);
+    return true;
+}
+
+/* virtual */
+TfToken
+PxrMayaUsdPrimvarReader_float3_Reader::GetMayaNameForUsdAttrName(const TfToken& usdAttrName) const
+{
+    TfToken               baseName;
+    UsdShadeAttributeType attrType;
+    std::tie(baseName, attrType) = UsdShadeUtils::GetBaseNameAndType(usdAttrName);
+
+    if (attrType == UsdShadeAttributeType::Output) {
+        if (baseName == TrUsdTokens->result) {
+            return TrMayaTokens->outColor;
+        }
+    }
+    return TfToken();
+}
+
+PXR_NAMESPACE_CLOSE_SCOPE