From b23de80a5e8e3cdf4b2ed5a5e12ced765c8b0125 Mon Sep 17 00:00:00 2001
From: Bernard Kwok <kwokcb@gmail.com>
Date: Thu, 17 Aug 2023 22:29:08 -0400
Subject: [PATCH] Add support for top level inputs (#1453)

Fix so that top level inputs are parsed properly and values and path reflection data is correct (for uniform updates).
---
 .../stdlib/nodegraph_inputs/top_level_input.mtlx     | 10 ++++++++++
 source/MaterialXCore/Interface.cpp                   |  2 +-
 source/MaterialXGenShader/ShaderNode.cpp             | 12 +++++++++++-
 3 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 resources/Materials/TestSuite/stdlib/nodegraph_inputs/top_level_input.mtlx

diff --git a/resources/Materials/TestSuite/stdlib/nodegraph_inputs/top_level_input.mtlx b/resources/Materials/TestSuite/stdlib/nodegraph_inputs/top_level_input.mtlx
new file mode 100644
index 0000000000..d92eae7f19
--- /dev/null
+++ b/resources/Materials/TestSuite/stdlib/nodegraph_inputs/top_level_input.mtlx
@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+<materialx version="1.38" colorspace="lin_rec709">
+  <surfacematerial name="surfacematerial" type="material" xpos="17.246376" ypos="-15.689655">
+    <input name="surfaceshader" type="surfaceshader" nodename="surface_unlit" />
+  </surfacematerial>
+  <input name="input_color3" type="color3" value="0, 0, 1" xpos="10.905797" ypos="-15.982759" />
+  <surface_unlit name="surface_unlit" type="surfaceshader" xpos="14.231884" ypos="-16.241379">
+    <input name="emission_color" type="color3" interfacename="input_color3" />
+  </surface_unlit>
+</materialx>
diff --git a/source/MaterialXCore/Interface.cpp b/source/MaterialXCore/Interface.cpp
index 3a93a384c2..b733d3a4c7 100644
--- a/source/MaterialXCore/Interface.cpp
+++ b/source/MaterialXCore/Interface.cpp
@@ -305,7 +305,7 @@ InputPtr Input::getInterfaceInput() const
 {
     if (hasInterfaceName())
     {
-        ConstNodeGraphPtr graph = getAncestorOfType<NodeGraph>();
+        ConstGraphElementPtr graph = getAncestorOfType<GraphElement>();
         if (graph)
         {
             return graph->getInput(getInterfaceName());
diff --git a/source/MaterialXGenShader/ShaderNode.cpp b/source/MaterialXGenShader/ShaderNode.cpp
index c923e4be57..3eb750f1ff 100644
--- a/source/MaterialXGenShader/ShaderNode.cpp
+++ b/source/MaterialXGenShader/ShaderNode.cpp
@@ -381,7 +381,17 @@ void ShaderNode::initialize(const Node& node, const NodeDef& nodeDef, GenContext
         ShaderInput* input = getInput(nodeValue->getName());
         if (input)
         {
-            input->setPath(nodeValue->getNamePath());
+            string path = nodeValue->getNamePath();
+            InputPtr nodeInput = nodeValue->asA<Input>();
+            if (nodeInput)
+            {
+                InputPtr interfaceInput = nodeInput->getInterfaceInput();
+                if (interfaceInput)
+                {
+                    path = interfaceInput->getNamePath();
+                }
+            }
+            input->setPath(path);
         }
     }