Added vertex colour utility node and translation for USD preview surface

lib/usd/pxrUsdPreviewSurface/CMakeLists.txt

@@ -30,6 +30,7 @@ add_library(${TARGET_NAME} SHARED)
 # -----------------------------------------------------------------------------
 target_sources(${TARGET_NAME} 
     PRIVATE
+        cpvColor.cpp
         usdPreviewSurface.cpp
         usdPreviewSurfacePlugin.cpp
         usdPreviewSurfaceReader.cpp

lib/usd/pxrUsdPreviewSurface/cpvColor.cpp

@@ -0,0 +1,111 @@
+//
+// 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 "cpvColor.h"
+
+#include <maya/MFnNumericAttribute.h>
+
+PXR_NAMESPACE_OPEN_SCOPE
+
+static const MString cpvInputFragmentName("mayaCPVInput");
+
+const MString CPVColor::name("cpvColor");
+const MString CPVColor::userClassification("utility/color:");
+const MString CPVColor::drawClassification("drawdb/shader/utility/color/");
+
+const MTypeId CPVColor::id(0x58000098);
+MObject       CPVColor::aOutColor;
+MObject       CPVColor::aOutAlpha;
+MObject       CPVColor::aOutOpacity;
+
+void* CPVColor::creator() { return new CPVColor(); }
+
+CPVColor::CPVColor() { }
+
+CPVColor::~CPVColor() { }
+
+MStatus CPVColor::initialize()
+{
+    // Define implicit shading network attributes
+    MFnNumericAttribute nAttr;
+    aOutColor = nAttr.createColor("outColor", "oc");
+    CHECK_MSTATUS(nAttr.setKeyable(false));
+    CHECK_MSTATUS(nAttr.setStorable(false));
+    CHECK_MSTATUS(nAttr.setReadable(true));
+    CHECK_MSTATUS(nAttr.setWritable(false));
+    aOutAlpha = nAttr.create("outAlpha", "oa", MFnNumericData::kFloat);
+    CHECK_MSTATUS(nAttr.setKeyable(false));
+    CHECK_MSTATUS(nAttr.setStorable(false));
+    CHECK_MSTATUS(nAttr.setReadable(true));
+    CHECK_MSTATUS(nAttr.setWritable(false));
+    CHECK_MSTATUS(nAttr.setHidden(true));
+    aOutOpacity = nAttr.create("outOpacity", "oo", MFnNumericData::kFloat);
+    CHECK_MSTATUS(nAttr.setKeyable(false));
+    CHECK_MSTATUS(nAttr.setStorable(false));
+    CHECK_MSTATUS(nAttr.setReadable(true));
+    CHECK_MSTATUS(nAttr.setWritable(false));
+
+    // Add attributes
+    CHECK_MSTATUS(addAttribute(aOutColor));
+    CHECK_MSTATUS(addAttribute(aOutAlpha));
+    CHECK_MSTATUS(addAttribute(aOutOpacity));
+
+    return MS::kSuccess;
+}
+
+MPxNode::SchedulingType CPVColor::schedulingType() const { return SchedulingType::kParallel; }
+
+MStatus CPVColor::compute(const MPlug& plug, MDataBlock& block)
+{
+    if ((plug != aOutColor) && (plug.parent() != aOutColor) && (plug != aOutAlpha)
+        && (plug != aOutOpacity))
+        return MS::kUnknownParameter;
+
+    // Complement alpha for opacity attribute
+    MDataHandle outAlphaHandle = block.outputValue(aOutAlpha);
+    MDataHandle outOpacityHandle = block.outputValue(aOutOpacity);
+    float&      outOpacity = outOpacityHandle.asFloat();
+    outOpacity = 1 - outAlphaHandle.asFloat();
+    outOpacityHandle.setClean();
+    outAlphaHandle.setClean();
+
+    return MS::kSuccess;
+}
+
+MHWRender::MPxShadingNodeOverride* CPVColorShadingNodeOverride::creator(const MObject& obj)
+{
+    return new CPVColorShadingNodeOverride(obj);
+}
+
+CPVColorShadingNodeOverride::CPVColorShadingNodeOverride(const MObject& obj)
+    : MPxShadingNodeOverride(obj)
+{
+}
+
+CPVColorShadingNodeOverride::~CPVColorShadingNodeOverride() { }
+
+MHWRender::DrawAPI CPVColorShadingNodeOverride::supportedDrawAPIs() const
+{
+    return MHWRender::kOpenGL | MHWRender::kDirectX11 | MHWRender::kOpenGLCoreProfile;
+}
+
+MString CPVColorShadingNodeOverride::fragmentName() const
+{
+    // Delegate the maya standard CPV input fragment to drive output
+    return cpvInputFragmentName;
+}
+
+PXR_NAMESPACE_CLOSE_SCOPE

lib/usd/pxrUsdPreviewSurface/cpvColor.h

@@ -0,0 +1,91 @@
+//
+// 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.
+//
+
+#ifndef PXRUSDPREVIEWSURFACE_CPVCOLOR_H
+#define PXRUSDPREVIEWSURFACE_CPVCOLOR_H
+
+#include "api.h"
+
+#include <pxr/pxr.h>
+
+#include <maya/MPxNode.h>
+#include <maya/MPxShadingNodeOverride.h>
+
+PXR_NAMESPACE_OPEN_SCOPE
+
+class CPVColor : public MPxNode
+{
+public:
+    PXRUSDPREVIEWSURFACE_API
+    static const MString name;
+
+    PXRUSDPREVIEWSURFACE_API
+    static const MString userClassification;
+
+    PXRUSDPREVIEWSURFACE_API
+    static const MString drawClassification;
+
+    PXRUSDPREVIEWSURFACE_API
+    static void* creator();
+
+    PXRUSDPREVIEWSURFACE_API
+    CPVColor();
+
+    PXRUSDPREVIEWSURFACE_API
+    ~CPVColor() override;
+
+    PXRUSDPREVIEWSURFACE_API
+    static MStatus initialize();
+
+    PXRUSDPREVIEWSURFACE_API
+    SchedulingType schedulingType() const override;
+
+    PXRUSDPREVIEWSURFACE_API
+    MStatus compute(const MPlug& plug, MDataBlock& block) override;
+
+    PXRUSDPREVIEWSURFACE_API
+    static const MTypeId id;
+
+private:
+    static MObject aOutColor;
+
+    static MObject aOutAlpha;
+
+    static MObject aOutOpacity;
+};
+
+class CPVColorShadingNodeOverride : public MHWRender::MPxShadingNodeOverride
+{
+public:
+    PXRUSDPREVIEWSURFACE_API
+    static MHWRender::MPxShadingNodeOverride* creator(const MObject& obj);
+
+    PXRUSDPREVIEWSURFACE_API
+    ~CPVColorShadingNodeOverride() override;
+
+    PXRUSDPREVIEWSURFACE_API
+    MHWRender::DrawAPI supportedDrawAPIs() const override;
+
+    PXRUSDPREVIEWSURFACE_API
+    MString fragmentName() const override;
+
+private:
+    CPVColorShadingNodeOverride(const MObject& obj);
+};
+
+PXR_NAMESPACE_CLOSE_SCOPE
+
+#endif

lib/usd/pxrUsdPreviewSurface/usdPreviewSurfacePlugin.cpp

@@ -15,6 +15,7 @@
 //
 #include "usdPreviewSurfacePlugin.h"
 
+#include "cpvColor.h"
 #include "usdPreviewSurface.h"
 #include "usdPreviewSurfaceReader.h"
 #include "usdPreviewSurfaceShadingNodeOverride.h"
@@ -37,7 +38,7 @@ PXR_NAMESPACE_OPEN_SCOPE
 
 namespace {
 TfToken::Set _registeredTypeNames;
-}
+} // namespace
 /* static */
 MStatus PxrMayaUsdPreviewSurfacePlugin::initialize(
     MFnPlugin&     plugin,
@@ -71,6 +72,24 @@ MStatus PxrMayaUsdPreviewSurfacePlugin::initialize(
         drawDbClassification, registrantId, PxrMayaUsdPreviewSurfaceShadingNodeOverride::creator);
     CHECK_MSTATUS(status);
 
+    // Register CPV shader node
+    const MString cpvDrawClassify(CPVColor::drawClassification + CPVColor::name);
+    MString       cpvUserClassify(CPVColor::userClassification);
+    cpvUserClassify += cpvDrawClassify;
+
+    status = plugin.registerNode(
+        CPVColor::name,
+        CPVColor::id,
+        CPVColor::creator,
+        CPVColor::initialize,
+        MPxNode::kDependNode,
+        &cpvUserClassify);
+    CHECK_MSTATUS(status);
+
+    status = MHWRender::MDrawRegistry::registerShadingNodeOverrideCreator(
+        cpvDrawClassify, registrantId, CPVColorShadingNodeOverride::creator);
+    CHECK_MSTATUS(status);
+
     return status;
 }
 
@@ -93,7 +112,13 @@ MStatus PxrMayaUsdPreviewSurfacePlugin::finalize(
 
     deregisterFragments();
 
-    MStatus status = MHWRender::MDrawRegistry::deregisterSurfaceShadingNodeOverrideCreator(
+    MStatus status = plugin.deregisterNode(CPVColor::id);
+    CHECK_MSTATUS(status);
+    status = MHWRender::MDrawRegistry::deregisterShadingNodeOverrideCreator(
+        CPVColor::drawClassification + CPVColor::name, registrantId);
+    CHECK_MSTATUS(status);
+
+    status = MHWRender::MDrawRegistry::deregisterSurfaceShadingNodeOverrideCreator(
         drawDbClassification, registrantId);
     CHECK_MSTATUS(status);
 

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