Enable color and unit transforms on root nodes (#1757)

This changelist adds support for color and unit transforms on the root nodes that are passed into shader generation, where previously they were only supported on non-root nodes in the material graph. In MaterialX 1.38.9, a special-case pathway for root surface shader nodes was merged into the main logic, causing color transforms in some USD/MaterialX contexts to be omitted, and this changelist restores and generalizes the original approach to handle all root nodes.
AcademySoftwareFoundation · Apr 1, 2024 · 710f272 · 710f272
1 parent 281320c
commit 710f272
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Showing 2 changed files with 57 additions and 44 deletions.
diff --git a/source/MaterialXGenShader/ShaderGraph.cpp b/source/MaterialXGenShader/ShaderGraph.cpp
@@ -569,6 +569,7 @@ ShaderGraphPtr ShaderGraph::create(const ShaderGraph* parent, const string& name
                     }
                 }
 
+                input->setBindInput();
                 const string path = nodeInput->getNamePath();
                 if (!path.empty())
                 {
@@ -596,6 +597,9 @@ ShaderGraphPtr ShaderGraph::create(const ShaderGraph* parent, const string& name
             inputSocket->setMetadata(input->getMetadata());
         }
 
+        // Apply color and unit transforms to each input.
+        graph->applyInputTransforms(node, newNode, context);
+
         // Set root for upstream dependency traversal
         root = node;
     }
@@ -616,6 +620,54 @@ ShaderGraphPtr ShaderGraph::create(const ShaderGraph* parent, const string& name
     return graph;
 }
 
+void ShaderGraph::applyInputTransforms(ConstNodePtr node, ShaderNodePtr shaderNode, GenContext& context)
+{
+    ColorManagementSystemPtr colorManagementSystem = context.getShaderGenerator().getColorManagementSystem();
+    UnitSystemPtr unitSystem = context.getShaderGenerator().getUnitSystem();
+
+    const string& targetColorSpace = context.getOptions().targetColorSpaceOverride.empty() ?
+                                     _document->getActiveColorSpace() :
+                                     context.getOptions().targetColorSpaceOverride;
+    const string& targetDistanceUnit = context.getOptions().targetDistanceUnit;
+
+    for (InputPtr input : node->getInputs())
+    {
+        if (input->hasValue() || input->hasInterfaceName())
+        {
+            string sourceColorSpace = input->getActiveColorSpace();
+            if (input->getType() == FILENAME_TYPE_STRING && node->isColorType())
+            {
+                // Adjust the source color space for filename interface names.
+                if (input->hasInterfaceName())
+                {
+                    for (ConstNodePtr parentNode : context.getParentNodes())
+                    {
+                        if (!parentNode->isColorType())
+                        {
+                            InputPtr interfaceInput = parentNode->getInput(input->getInterfaceName());
+                            string interfaceColorSpace = interfaceInput ? interfaceInput->getActiveColorSpace() : EMPTY_STRING;
+                            if (!interfaceColorSpace.empty())
+                            {
+                                sourceColorSpace = interfaceColorSpace;
+                            }
+                        }
+                    }
+                }
+
+                ShaderOutput* shaderOutput = shaderNode->getOutput();
+                populateColorTransformMap(colorManagementSystem, shaderOutput, sourceColorSpace, targetColorSpace, false);
+                populateUnitTransformMap(unitSystem, shaderOutput, input, targetDistanceUnit, false);
+            }
+            else
+            {
+                ShaderInput* shaderInput = shaderNode->getInput(input->getName());
+                populateColorTransformMap(colorManagementSystem, shaderInput, sourceColorSpace, targetColorSpace, true);
+                populateUnitTransformMap(unitSystem, shaderInput, input, targetDistanceUnit, true);
+            }
+        }
+    }
+}
+
 ShaderNode* ShaderGraph::createNode(ConstNodePtr node, GenContext& context)
 {
     NodeDefPtr nodeDef = node->getNodeDef();
@@ -669,50 +721,8 @@ ShaderNode* ShaderGraph::createNode(ConstNodePtr node, GenContext& context)
         }
     }
 
-    // Handle colorspace and unit conversion if needed.
-    ColorManagementSystemPtr colorManagementSystem = context.getShaderGenerator().getColorManagementSystem();
-    UnitSystemPtr unitSystem = context.getShaderGenerator().getUnitSystem();
-    const string& targetColorSpace = context.getOptions().targetColorSpaceOverride.empty() ?
-                                     _document->getActiveColorSpace() :
-                                     context.getOptions().targetColorSpaceOverride;
-    const string& targetDistanceUnit = context.getOptions().targetDistanceUnit;
-
-    for (InputPtr input : node->getInputs())
-    {
-        if (input->hasValue() || input->hasInterfaceName())
-        {
-            string sourceColorSpace = input->getActiveColorSpace();
-            if (input->getType() == FILENAME_TYPE_STRING && node->isColorType())
-            {
-                // Adjust the source color space for filename interface names.
-                if (input->hasInterfaceName())
-                {
-                    for (ConstNodePtr parentNode : context.getParentNodes())
-                    {
-                        if (!parentNode->isColorType())
-                        {
-                            InputPtr interfaceInput = parentNode->getInput(input->getInterfaceName());
-                            string interfaceColorSpace = interfaceInput ? interfaceInput->getActiveColorSpace() : EMPTY_STRING;
-                            if (!interfaceColorSpace.empty())
-                            {
-                                sourceColorSpace = interfaceColorSpace;
-                            }
-                        }
-                    }
-                }
-
-                ShaderOutput* shaderOutput = newNode->getOutput();
-                populateColorTransformMap(colorManagementSystem, shaderOutput, sourceColorSpace, targetColorSpace, false);
-                populateUnitTransformMap(unitSystem, shaderOutput, input, targetDistanceUnit, false);
-            }
-            else
-            {
-                ShaderInput* shaderInput = newNode->getInput(input->getName());
-                populateColorTransformMap(colorManagementSystem, shaderInput, sourceColorSpace, targetColorSpace, true);
-                populateUnitTransformMap(unitSystem, shaderInput, input, targetDistanceUnit, true);
-            }
-        }
-    }
+    // Apply color and unit transforms to each input.
+    applyInputTransforms(node, newNode, context);
 
     return newNode.get();
 }

diff --git a/source/MaterialXGenShader/ShaderGraph.h b/source/MaterialXGenShader/ShaderGraph.h
@@ -92,6 +92,9 @@ class MX_GENSHADER_API ShaderGraph : public ShaderNode
     const vector<ShaderGraphInputSocket*>& getInputSockets() const { return _outputOrder; }
     const vector<ShaderGraphOutputSocket*>& getOutputSockets() const { return _inputOrder; }
 
+    /// Apply color and unit transforms to each input of a node.
+    void applyInputTransforms(ConstNodePtr node, ShaderNodePtr shaderNode, GenContext& context);
+
     /// Create a new node in the graph
     ShaderNode* createNode(ConstNodePtr node, GenContext& context);