[usdMtlx, hdMtlx, hdSt] Add Texture support for MaterialX custom node…

…s defined in libraries

Custom nodes defined in a separate library indicated with the
PXR_MTLX_PLUGIN_SEARCH_PATHS envar that use textures need
to have the 'textureuser' group so that UsdMtlx and hdMtlx know
they use textures and can properly initialize texture coordinates.
Similarly custom nodes that use texcoords need the
'texcoorduser' group. These custom nodes now work in both
Storm and HdPrman.
Changes in hdSt are since custom nodes can name the input for
the file anything instead of 'file' which the stdlib texture nodes use.

Note:
- users need to add 'textureuser' or 'texcoorduser' as the custom node's nodegroup
- need to use the fallback texture coordinates
- cannot use mutliple textures inside one custom node

Fixes #1636
Fixes #1786

(Internal change: 2242208)

pxr/imaging/hdMtlx/hdMtlx.cpp

@@ -194,26 +194,27 @@ _AddMaterialXNode(
     // Get the mxNode information
     TfToken hdNodeType = netInterface->GetNodeType(hdNodeName);
     mx::NodeDefPtr mxNodeDef = mxDoc->getNodeDef(hdNodeType.GetString());
-    if (!mxNodeDef){
+    if (!mxNodeDef) {
         TF_WARN("NodeDef not found for Node '%s'", hdNodeType.GetText());
         return mx::NodePtr();
     }
     const SdfPath hdNodePath(hdNodeName.GetString());
-    const std::string & mxNodeCategory = mxNodeDef->getNodeString();
-    const std::string & mxNodeType = mxNodeDef->getType();
-    const std::string & mxNodeName = hdNodePath.GetName();
+    const std::string &mxNodeCategory = mxNodeDef->getNodeString();
+    const std::string &mxNodeType = mxNodeDef->getType();
+    const std::string &mxNodeGroup = mxNodeDef->getNodeGroup();
+    const std::string &mxNodeName = hdNodePath.GetName();
 
     // Add the mxNode to the mxNodeGraph
     mx::NodePtr mxNode =
         _AddNodeToNodeGraph(mxNodeName, mxNodeCategory, 
                             mxNodeType, mxNodeGraph, addedNodeNames);
 
-    if(mxNode->getNodeDef()) {
+    if (mxNode->getNodeDef()) {
         // Sometimes mxNode->getNodeDef() starts failing.
         // It seems to happen when there are connections with mismatched types.
         // Explicitly setting the node def string appparently fixes the problem.
         // If we don't do this code gen may fail.
-        if(mxNode->getNodeDefString().empty()) {
+        if (mxNode->getNodeDefString().empty()) {
             mxNode->setNodeDefString(hdNodeType.GetText());
         }
     }
@@ -236,8 +237,9 @@ _AddMaterialXNode(
         mxNode->setInputValue(mxInputName, mxInputValue, mxInputType);
     }
 
-    // If this is a MaterialX Texture node
-    if (mxNodeCategory == "image" || mxNodeCategory == "tiledimage") {
+    // Stdlib MaterialX Texture node or a custom node that uses a texture
+    if (mxNodeCategory == "image" || mxNodeCategory == "tiledimage" ||
+        mxNodeGroup == "textureuser") {
         // Save the corresponding MaterialX and Hydra names for ShaderGen
         if (mxHdTextureMap) {
             (*mxHdTextureMap)[mxNodeName] = connectionName;
@@ -249,15 +251,16 @@ _AddMaterialXNode(
         }
     }
 
-    // If this is a MaterialX primvar node
+    // MaterialX primvar node
     if (mxNodeCategory == "geompropvalue") {
         // Save the path to have the primvarName declared in ShaderGen
         if (hdPrimvarNodes) {
             hdPrimvarNodes->insert(hdNodePath);
         }
     }
-    // If this is a MaterialX texture coordinate node
-    if (mxNodeCategory == "texcoord") {
+    // Stdlib MaterialX texture coordinate node or a custom node that 
+    // uses texture coordinates
+    if (mxNodeCategory == "texcoord" || mxNodeGroup == "texcoorduser") {
         if (hdPrimvarNodes) {
             // Make sure it has the index parameter set.
             if (std::find(hdNodeParamNames.begin(), hdNodeParamNames.end(), 

pxr/imaging/hdSt/materialXFilter.cpp

@@ -347,7 +347,6 @@ _GetTextureCoordinateName(
             // Save the default texture coordinate name for the glslfx header
             *defaultTexcoordName = primvarName;
         }
-
     }
 }
 
@@ -421,7 +420,22 @@ _UpdateTextureNodes(
         // HdStMaterialXShaderGen match up correctly
         std::string newConnName = texturePath.GetName() + "_" + 
                                 (*mxHdTextureMap)[texturePath.GetName()];
-        (*mxHdTextureMap)[texturePath.GetName()] = newConnName;
+
+        // Replace the texturePath.GetName() in the textureMap to the variable
+        // name used in the shader: textureName_fileInputName 
+        std::string fileInputName = "file";
+        const mx::NodeDefPtr mxNodeDef =
+            mxDoc->getNodeDef(hdTextureNode.nodeTypeId.GetString());
+        if (mxNodeDef) {
+            for (auto mxInput : mxNodeDef->getInputs()) {
+                if (mxInput->getType() == "filename") {
+                    fileInputName = mxInput->getName();
+                }
+            }
+        }
+        mxHdTextureMap->erase(texturePath.GetName());
+        mxHdTextureMap->insert(std::pair<std::string, std::string>(
+                texturePath.GetName() + "_" + fileInputName, newConnName));
 
         // Make and add a new connection to the terminal node
         HdMaterialConnection2 textureConn;

pxr/imaging/hdSt/materialXShaderGen.cpp

@@ -330,7 +330,7 @@ HdStMaterialXShaderGen::_EmitMxFunctions(
                 if (texturePair.first == "domeLightFallback") {
                     continue;
                 }
-                emitLine(TfStringPrintf("#define %s_file HdGetSampler_%s()",
+                emitLine(TfStringPrintf("#define %s HdGetSampler_%s()",
                                         texturePair.first.c_str(),
                                         texturePair.second.c_str()),
                         mxStage, false);
@@ -626,7 +626,7 @@ HdStMaterialXShaderGen::_EmitMxInitFunction(
             if (texturePair.first == "domeLightFallback") {
                 continue;
             }
-            emitLine(texturePair.first + "_file = "
+            emitLine(texturePair.first + " = "
                     "HdGetSampler_" + texturePair.second + "()", mxStage);
         }
         emitLineBreak(mxStage);

pxr/usd/usdMtlx/parser.cpp

@@ -262,8 +262,11 @@ ParseMetadata(
 {
     const auto& value = element->getAttribute(attribute);
     if (!value.empty()) {
-        // Change the MaterialX Texture node role from 'texture2d' to 'texture' 
-        if (key == SdrNodeMetadata->Role && value == "texture2d") {
+        // Change the 'texture2d' role for stdlib MaterialX Texture nodes,
+        // and the 'textureuser' role for custom MaterialX nodes that use  
+        // textures, to 'texture' for Sdr.
+        if (key == SdrNodeMetadata->Role && 
+            (value == "texture2d" || value == "textureuser")) {
             builder->metadata[key] = "texture";
         }
         else {
@@ -335,6 +338,13 @@ ParseElement(ShaderBuilder* builder, const mx::ConstNodeDefPtr& nodeDef)
     if (nodeDef->getName() == "ND_texcoord_vector2") {
         primvars.push_back(_GetPrimaryUvSetName());
     }
+    // Add the default texturecoord primvar for custom nodes that use 
+    // textures/texcoords
+    // XXX custom nodes must use the default texture coord name
+    if (nodeDef->getNodeGroup() == "textureuser" ||
+        nodeDef->getNodeGroup() == "texcoorduser") {
+        primvars.push_back(_GetPrimaryUvSetName());
+    }
 
     // Also check internalgeomprops.
     static const std::string internalgeompropsName("internalgeomprops");
@@ -380,8 +390,7 @@ class UsdMtlxParserPlugin : public NdrParserPlugin {
 };
 
 NdrNodeUniquePtr
-UsdMtlxParserPlugin::Parse(
-    const NdrNodeDiscoveryResult& discoveryResult)
+UsdMtlxParserPlugin::Parse(const NdrNodeDiscoveryResult& discoveryResult)
 {
     MaterialX::ConstDocumentPtr document = nullptr;
     // Get the MaterialX document.
@@ -393,8 +402,7 @@ UsdMtlxParserPlugin::Parse(
             return GetInvalidNode(discoveryResult);
         }
     } else if (!discoveryResult.sourceCode.empty()) {
-        document = UsdMtlxGetDocumentFromString(
-            discoveryResult.sourceCode);
+        document = UsdMtlxGetDocumentFromString(discoveryResult.sourceCode);
         if (!document) {
             TF_WARN("Invalid mtlx source code.");
             return GetInvalidNode(discoveryResult);

pxr/usd/usdMtlx/utils.cpp

@@ -371,6 +371,33 @@ UsdMtlxGetDocumentFromString(const std::string &mtlxXml)
     return document;
 }
 
+static void
+_ImportLibraries(mx::DocumentPtr *document, const NdrStringVec &searchPaths)
+{
+    for (auto&& fileResult : NdrFsHelpersDiscoverFiles(searchPaths,
+                                UsdMtlxStandardFileExtensions(), false)) {
+
+        // Read the file. If this fails due to an exception, a runtime
+        // error will be raised so we can just skip to the next file.
+        auto doc = UsdMtlxReadDocument(fileResult.resolvedUri);
+        if (!doc) {
+            continue;
+        }
+
+        try {
+            // Merge this document into the global library
+            // This properly sets the attributes on the destination 
+            // elements, like source URI and namespace
+            (*document)->importLibrary(doc);
+        }
+        catch (mx::Exception& x) {
+            TF_RUNTIME_ERROR("MaterialX error reading '%s': %s",
+                                fileResult.resolvedUri.c_str(),
+                                x.what());
+        }
+    }
+}
+
 mx::ConstDocumentPtr
 UsdMtlxGetDocument(const std::string& resolvedUri)
 {
@@ -387,32 +414,8 @@ UsdMtlxGetDocument(const std::string& resolvedUri)
     // Read the file or the standard library files.
     if (resolvedUri.empty()) {
         document = mx::createDocument();
-        for (auto&& fileResult:
-                NdrFsHelpersDiscoverFiles(
-                    UsdMtlxStandardLibraryPaths(),
-                    UsdMtlxStandardFileExtensions(),
-                    false)) {
-
-            // Read the file. If this fails due to an exception, a runtime
-            // error will be raised so we can just skip to the next file.
-            auto doc = UsdMtlxReadDocument(fileResult.resolvedUri);
-            if (!doc) {
-                continue;
-            }
-
-            try {
-
-                // Merge this document into the global library
-                // This properly sets the attributes on the destination 
-                // elements, like source URI and namespace
-                document->importLibrary(doc);
-            }
-            catch (mx::Exception& x) {
-                TF_RUNTIME_ERROR("MaterialX error reading '%s': %s",
-                                 fileResult.resolvedUri.c_str(),
-                                 x.what());
-            }
-        }
+        _ImportLibraries(&document, UsdMtlxStandardLibraryPaths());
+        _ImportLibraries(&document, UsdMtlxCustomSearchPaths());
     }
     else {
         document = UsdMtlxReadDocument(resolvedUri);

pxr/usdImaging/usdImagingGL/CMakeLists.txt

@@ -3376,6 +3376,25 @@ if (MaterialX_FOUND AND ${PXR_ENABLE_MATERIALX_SUPPORT})
         EXPECTED_RETURN_CODE 0
         TESTENV testUsdImagingGLMaterialX
     )
+
+    pxr_install_test_dir(
+        SRC testenv/testUsdImagingGLMaterialXCustomNodes
+        DEST testUsdImagingGLMaterialXCustomNodes
+    )
+
+    pxr_register_test(testUsdImagingGLMaterialXCustomNodes_customTexNode
+        COMMAND "${CMAKE_INSTALL_PREFIX}/tests/testUsdImagingGLBasicDrawing -lighting -sceneLights -shading smooth -complexity 1.3 -offscreen -camera /Camera -stage customTexNode.usda -write customTexNode.png"
+        IMAGE_DIFF_COMPARE
+            customTexNode.png
+        FAIL 0.5
+        FAIL_PERCENT 0.005
+        WARN 0.05
+        WARN_PERCENT 0.2
+        EXPECTED_RETURN_CODE 0
+        TESTENV testUsdImagingGLMaterialXCustomNodes
+        ENV
+            PXR_MTLX_PLUGIN_SEARCH_PATHS=./customNodeDefs
+    )
 endif()
 
 pxr_register_test(testUsdImagingGLInstancePrimvars

pxr/usdImaging/usdImagingGL/testenv/testUsdImagingGLMaterialXCustomNodes/customNodeDefs/nodeDef.mtlx

@@ -0,0 +1,58 @@
+<?xml version="1.0"?>
+<materialx version="1.38">
+
+  <!-- custom node using texture coordinates -->
+  <nodedef name="ND_checker_float" node="checker3" nodegroup="texcoorduser">
+    <input name="scale" type="vector2" value="8.0, 8.0" />
+    <output name="out" type="color3" />
+  </nodedef>
+  <nodegraph name="NG_checker_float" nodedef="ND_checker_float">
+    <texcoord name="texcoord1" type="vector2">
+      <input name="index" type="integer" value="0" />
+    </texcoord>
+    <multiply name="mult1" type="vector2">
+      <input name="in1" type="vector2" nodename="texcoord1" />
+      <input name="in2" type="vector2" interfacename="scale" />
+    </multiply>
+    <swizzle name="swizz_x" type="float">
+      <input name="in" type="vector2" nodename="mult1" />
+      <input name="channels" type="string" value="x" />
+    </swizzle>
+    <swizzle name="swizz_y" type="float">
+      <input name="in" type="vector2" nodename="mult1" />
+      <input name="channels" type="string" value="y" />
+    </swizzle>
+    <floor name="floor1" type="float">
+      <input name="in" type="float" nodename="swizz_x" />
+    </floor>
+    <floor name="floor2" type="float">
+      <input name="in" type="float" nodename="swizz_y" />
+    </floor>
+    <add name="add1" type="float">
+      <input name="in1" type="float" nodename="floor1" />
+      <input name="in2" type="float" nodename="floor2" />
+    </add>
+    <modulo name="mod1" type="float">
+      <input name="in1" type="float" nodename="add1" />
+      <input name="in2" type="float" value="2.0" />
+    </modulo>
+    <swizzle name="swizz_xxx" type="color3">
+      <input name="in" type="float" nodename="mod1" />
+      <input name="channels" type="string" value="xxx" />
+    </swizzle>
+    <output name="out" type="color3" nodename="swizz_xxx" />
+  </nodegraph>
+
+  <!-- custom node using textures -->
+  <nodedef name="custom_image_nodedef" node="custom_image_node" nodegroup="textureuser">
+    <input name="file_input" type="filename" />
+    <output name="out_color" type="color3" />
+  </nodedef>
+  <nodegraph name="custom_image_nodegraph" nodedef="custom_image_nodedef">
+    <image name="image_node" type="color3">
+      <input name="file" type="filename" colorspace="gamma22" interfacename="file_input" />
+    </image>
+    <output name="out_color" type="color3" nodename="image_node" />
+  </nodegraph>
+
+</materialx>

pxr/usdImaging/usdImagingGL/testenv/testUsdImagingGLMaterialXCustomNodes/customTexNode.usda

@@ -0,0 +1,61 @@
+#usda 1.0
+(
+    upAxis = "Z"
+)
+
+def "CustomNodeDef" (
+    references = @texturedSphere.usda@
+)
+{
+    rel material:binding = </MaterialX/Materials/test_material>
+    color3f[] primvars:displayColor = [(0.1, 0.5, 0.8)]
+    double radius = 9.0
+    matrix4d xformOp:transform = ( (1, 0, 0, 0),
+                                    (0, 1, 0, 0),
+                                    (0, 0, 1, 0),
+                                    (-10, 0, 0, 1) )
+    uniform token[] xformOpOrder = ["xformOp:transform"]
+}
+
+def "ImageCustomNodeDef" (
+    references = @texturedSphere.usda@
+)
+{
+    rel material:binding = </MaterialX/Materials/test_image_material>
+    color3f[] primvars:displayColor = [(0.1, 0.5, 0.8)]
+    matrix4d xformOp:transform = ( (1, 0, 0, 0),
+                                   (0, 1, 0, 0),
+                                   (0, 0, 1, 0),
+                                   (10, 0, 0, 1) )
+    uniform token[] xformOpOrder = ["xformOp:transform"]
+}
+
+def Scope "MaterialX"(
+    references = @./material.mtlx@</MaterialX>
+    )
+{
+}
+
+def Xform "lights" 
+{
+    def DomeLight "DomeLight"
+    {
+        asset inputs:texture:file = @./StinsonBeach.hdr@
+        float xformOp:rotateX:Zup = 90
+        uniform token[] xformOpOrder = ["xformOp:rotateX:Zup"]
+    }
+    def SphereLight "Light"
+    {
+        float inputs:radius = 20
+        float inputs:intensity = 5
+        Vec3f xformOp:translate = (0, -50, 0)
+        uniform token[] xformOpOrder = ["xformOp:translate"]
+    }
+}
+
+def Camera "Camera"
+{
+    double3 xformOp:translate = (0, 0, 125)
+    float xformOp:rotateX:Zup = 90
+    uniform token[] xformOpOrder = ["xformOp:rotateX:Zup","xformOp:translate"]
+}