extract RenderMan for Maya shading export from "pxrRis" shadingMode for use with "useRegistry"

CMakeLists.txt

@@ -25,6 +25,7 @@ option(BUILD_ADSK_PLUGIN "Build Autodesk USD plugin." ON)
 option(BUILD_PXR_PLUGIN "Build the Pixar USD plugin and libraries." ON)
 option(BUILD_AL_PLUGIN "Build the Animal Logic USD plugin and libraries." ON)
 option(BUILD_HDMAYA "Build the Maya-To-Hydra plugin and scene delegate." ON)
+option(BUILD_RFM_TRANSLATORS "Build translators for RenderMan for Maya shaders." ON)
 option(BUILD_TESTS "Build tests." ON)
 option(BUILD_STRICT_MODE "Enforce all warnings as errors." ON)
 option(BUILD_SHARED_LIBS "Build libraries as shared or static." ON)

doc/build.md

@@ -107,6 +107,7 @@ BUILD_ADSK_PLUGIN           | builds Autodesk USD plugin.
 BUILD_PXR_PLUGIN            | builds the Pixar USD plugin and libraries.                 | ON
 BUILD_AL_PLUGIN             | builds the Animal Logic USD plugin and libraries.          | ON
 BUILD_HDMAYA                | builds the Maya-To-Hydra plugin and scene delegate.        | ON
+BUILD_RFM_TRANSLATORS       | builds translators for RenderMan for Maya shaders.         | ON
 BUILD_TESTS                 | builds all unit tests.                                     | ON
 BUILD_STRICT_MODE           | enforces all warnings as errors.                           | ON
 BUILD_WITH_PYTHON_3			| build with python 3.										 | OFF

lib/mayaUsd/fileio/shading/CMakeLists.txt

@@ -13,6 +13,7 @@ target_sources(${PROJECT_NAME}
 )
 
 set(HEADERS
+    rfmShaderMap.h
     shadingModeExporter.h
     shadingModeExporterContext.h
     shadingModeImporter.h

lib/mayaUsd/fileio/shading/shadingModeExporterContext.cpp

@@ -511,29 +511,5 @@ UsdMayaShadingModeExportContext::MakeStandardMaterialPrim(
     return UsdPrim();
 }
 
-std::string
-UsdMayaShadingModeExportContext::GetStandardAttrName(
-        const MPlug& plug,
-        const bool allowMultiElementArrays) const
-{
-    if (plug.isElement()) {
-        MString mayaPlgName = plug.array().partialName(false, false, false, false, false, true);
-        unsigned int logicalIdx = plug.logicalIndex();
-        if (allowMultiElementArrays) {
-            return TfStringPrintf("%s_%d", mayaPlgName.asChar(), logicalIdx);
-        }
-        else if (logicalIdx == 0) {
-            return mayaPlgName.asChar();
-        }
-        else {
-            return TfToken();
-        }
-    }
-    else {
-        MString mayaPlgName = plug.partialName(false, false, false, false, false, true);
-        return mayaPlgName.asChar();
-    }
-}
-
 
 PXR_NAMESPACE_CLOSE_SCOPE

lib/mayaUsd/fileio/shading/shadingModeExporterContext.h

@@ -117,20 +117,6 @@ class UsdMayaShadingModeExportContext
             const std::string& name=std::string(),
             SdfPathSet* const boundPrimPaths=nullptr) const;
 
-    /// Use this function to get a "standard" usd attr name for \p attrPlug.
-    /// The definition of "standard" may depend on arguments passed to the
-    /// script (i.e. stripping namespaces, etc.).
-    ///
-    /// If attrPlug is an element in an array and if \p allowMultiElementArrays
-    /// is true, this will <attrName>_<idx>.
-    ///
-    /// If it's false, this will return <attrName> if it's the 0-th logical
-    /// element and an empty token otherwise.
-    MAYAUSD_CORE_PUBLIC
-    std::string GetStandardAttrName(
-            const MPlug& attrPlug,
-            const bool allowMultiElementArrays) const;
-
     MAYAUSD_CORE_PUBLIC
     UsdMayaShadingModeExportContext(
             const MObject& shadingEngine,

lib/mayaUsd/fileio/shading/shadingModePxrRis.cpp

@@ -14,15 +14,14 @@
 // limitations under the License.
 //
 
-// Defines the RenderMan for Maya mapping between Pxr objects and Maya internal nodes
-#include "shadingModePxrRis_rfm_map.h"
-
+#include <mayaUsd/fileio/shading/rfmShaderMap.h>
 #include <mayaUsd/fileio/shading/shadingModeExporter.h>
 #include <mayaUsd/fileio/shading/shadingModeExporterContext.h>
 #include <mayaUsd/fileio/shading/shadingModeImporter.h>
 #include <mayaUsd/fileio/shading/shadingModeRegistry.h>
 #include <mayaUsd/fileio/translators/translatorUtil.h>
 #include <mayaUsd/fileio/utils/roundTripUtil.h>
+#include <mayaUsd/fileio/utils/shadingUtil.h>
 #include <mayaUsd/fileio/utils/writeUtil.h>
 #include <mayaUsd/utils/converter.h>
 #include <mayaUsd/utils/util.h>
@@ -125,7 +124,7 @@ class PxrRisShadingModeExporter : public UsdMayaShadingModeExporter {
 
         // Now look into the RIS TABLE if the typeName doesn't starts with Pxr.
         if (!TfStringStartsWith(mayaTypeName, _tokens->PxrShaderPrefix)) {
-            for (const auto& i : _RFM_RISNODE_TABLE) {
+            for (const auto& i : RfmNodesToShaderIds) {
                 if (i.first == mayaTypeName) {
                     return i.second;
                 }
@@ -225,7 +224,7 @@ class PxrRisShadingModeExporter : public UsdMayaShadingModeExporter {
             // maybe that's OK?  nothing downstream cares about it.
 
             const TfToken attrName = TfToken(
-                context.GetStandardAttrName(attrPlug, false));
+                UsdMayaShadingUtil::GetStandardAttrName(attrPlug, false));
             if (attrName.IsEmpty()) {
                 continue;
             }
@@ -270,7 +269,7 @@ class PxrRisShadingModeExporter : public UsdMayaShadingModeExporter {
                 UsdShadeConnectableAPI::ConnectToSource(
                     input,
                     UsdShadeShader(cPrim),
-                    TfToken(context.GetStandardAttrName(connectedPlug, false)));
+                    TfToken(UsdMayaShadingUtil::GetStandardAttrName(connectedPlug, false)));
             }
         }
 
@@ -455,7 +454,7 @@ _GetMayaTypeNameForShaderId(
         const TfToken& shaderId)
 {
     // Remap the mayaTypeName if found in the RIS table.
-    for (const auto & i : _RFM_RISNODE_TABLE) {
+    for (const auto & i : RfmNodesToShaderIds) {
         if (i.second == shaderId) {
             return i.first;
         }

lib/mayaUsd/fileio/shading/shadingModeUseRegistry.cpp

@@ -89,12 +89,6 @@ class UseRegistryShadingModeExporter : public UsdMayaShadingModeExporter
                 return nullptr;
             }
 
-            if (depNode.hasFn(MFn::kDagNode)) {
-                // XXX: Skip DAG nodes for now, but we may eventually want/need
-                // to consider them.
-                return nullptr;
-            }
-
             if (!UsdMayaUtil::isWritable(depNode)) {
                 return nullptr;
             }
@@ -266,14 +260,14 @@ class UseRegistryShadingModeExporter : public UsdMayaShadingModeExporter
                     // Maya plugs represent so that we can author the
                     // connection in USD.
 
-                    const TfToken srcPlugName =
-                        TfToken(context.GetStandardAttrName(srcPlug, false));
+                    const TfToken srcPlugName = TfToken(
+                        UsdMayaShadingUtil::GetStandardAttrName(srcPlug, false));
                     UsdAttribute srcAttribute =
                         srcShaderInfo->GetShadingAttributeForMayaAttrName(
                             srcPlugName);
 
-                    const TfToken dstPlugName =
-                        TfToken(context.GetStandardAttrName(dstPlug, false));
+                    const TfToken dstPlugName = TfToken(
+                        UsdMayaShadingUtil::GetStandardAttrName(dstPlug, false));
                     UsdAttribute dstAttribute =
                         dstShaderInfo->GetShadingAttributeForMayaAttrName(
                             dstPlugName);

lib/mayaUsd/fileio/utils/shadingUtil.cpp

@@ -16,15 +16,47 @@
 #include "shadingUtil.h"
 
 #include <pxr/pxr.h>
+#include <pxr/base/tf/stringUtils.h>
 #include <pxr/base/tf/token.h>
 #include <pxr/usd/sdf/valueTypeName.h>
 #include <pxr/usd/usdShade/input.h>
 #include <pxr/usd/usdShade/material.h>
 #include <pxr/usd/usdShade/output.h>
 #include <pxr/usd/usdShade/shader.h>
 
+#include <maya/MPlug.h>
+#include <maya/MString.h>
+
+#include <string>
+
+
 PXR_NAMESPACE_USING_DIRECTIVE
 
+
+std::string
+UsdMayaShadingUtil::GetStandardAttrName(
+        const MPlug& attrPlug,
+        bool allowMultiElementArrays)
+{
+    if (!attrPlug.isElement()) {
+        const MString mayaPlugName =
+            attrPlug.partialName(false, false, false, false, false, true);
+        return mayaPlugName.asChar();
+    }
+
+    const MString mayaPlugName =
+        attrPlug.array().partialName(false, false, false, false, false, true);
+    const unsigned int logicalIndex = attrPlug.logicalIndex();
+
+    if (allowMultiElementArrays) {
+        return TfStringPrintf("%s_%d", mayaPlugName.asChar(), logicalIndex);
+    } else if (logicalIndex == 0) {
+        return mayaPlugName.asChar();
+    }
+
+    return std::string();
+}
+
 UsdShadeInput
 UsdMayaShadingUtil::CreateMaterialInputAndConnectShader(
         UsdShadeMaterial& material,

lib/mayaUsd/fileio/utils/shadingUtil.h

@@ -16,6 +16,10 @@
 #ifndef PXRUSDMAYA_SHADING_UTIL_H
 #define PXRUSDMAYA_SHADING_UTIL_H
 
+/// \file
+
+#include <mayaUsd/base/api.h>
+
 #include <pxr/pxr.h>
 #include <pxr/base/tf/token.h>
 #include <pxr/usd/sdf/valueTypeName.h>
@@ -24,12 +28,30 @@
 #include <pxr/usd/usdShade/output.h>
 #include <pxr/usd/usdShade/shader.h>
 
-#include <mayaUsd/base/api.h>
+#include <maya/MPlug.h>
+
+#include <string>
+
 
 PXR_NAMESPACE_OPEN_SCOPE
 
+
 namespace UsdMayaShadingUtil
 {
+/// Get a "standard" USD attribute name for \p attrPlug.
+///
+/// If \p attrPlug is not an element in a Maya array attribute, then its name
+/// is simply returned.
+///
+/// If \p attrPlug is an element in an array and if \p allowMultiElementArrays
+/// is true, this will return a name of the form "<attrName>_<index>". If
+/// \p allowMultiElementArrays is false, this will return <attrName> if it's
+/// the 0-th logical element. Otherwise it will return an empty string.
+MAYAUSD_CORE_PUBLIC
+std::string GetStandardAttrName(
+        const MPlug& attrPlug,
+        bool allowMultiElementArrays);
+
 /// Create an input on the given material and shader and create a connection
 /// between them.
 ///

lib/usd/translators/shading/CMakeLists.txt

@@ -1,8 +1,9 @@
 # -----------------------------------------------------------------------------
 # sources
 # -----------------------------------------------------------------------------
-target_sources(${TARGET_NAME} 
+target_sources(${TARGET_NAME}
     PRIVATE
+        symmetricShaderWriter.cpp
         usdBlinnReader.cpp
         usdBlinnWriter.cpp
         usdFileTextureWriter.cpp
@@ -18,8 +19,15 @@ target_sources(${TARGET_NAME}
         usdUVTextureReader.cpp
 )
 
+if (BUILD_RFM_TRANSLATORS)
+    target_sources(${TARGET_NAME}
+        PRIVATE
+            rfmShaderTranslation.cpp
+    )
+endif()
+
 if (MAYA_APP_VERSION VERSION_GREATER_EQUAL 2020)
-    target_sources(${TARGET_NAME} 
+    target_sources(${TARGET_NAME}
         PRIVATE
             usdStandardSurfaceReader.cpp
             usdStandardSurfaceWriter.cpp