Merge pull request #2528 from Autodesk/t_gamaj/update_to_materialx_1_…

…38_5

T gamaj/update to materialx 1 38 5

lib/mayaUsd/render/MaterialXGenOgsXml/GlslFragmentGenerator.cpp

@@ -171,14 +171,22 @@ ShaderPtr GlslFragmentGenerator::generate(
 
     const bool lighting = requiresLighting(graph);
 
-#if MATERIALX_MAJOR_VERSION == 1 && MATERIALX_MINOR_VERSION == 38 && MATERIALX_BUILD_VERSION == 3
+#if MX_COMBINED_VERSION == 13804
+    // 1.38.4 is the only version requiring "libraries" in the path
+    std::string libRoot = "libraries/";
+#else
+    // No libRoot for other versions:
     std::string libRoot;
+#endif
+
+#if MX_COMBINED_VERSION <= 13804
+#define MX_EMIT_INCLUDE emitInclude
 #else
-    std::string libRoot = "libraries/";
+#define MX_EMIT_INCLUDE emitLibraryInclude
 #endif
 
     // Emit common math functions
-    emitInclude(libRoot + "stdlib/genglsl/lib/mx_math.glsl", context, pixelStage);
+    MX_EMIT_INCLUDE(libRoot + "stdlib/genglsl/lib/mx_math.glsl", context, pixelStage);
     emitLineBreak(pixelStage);
 
     int specularMethod = context.getOptions().hwSpecularEnvironmentMethod;
@@ -202,18 +210,18 @@ ShaderPtr GlslFragmentGenerator::generate(
             emitLine("#define MX_NUM_FIS_SAMPLES 64", pixelStage, false);
         }
         emitLineBreak(pixelStage);
-        emitInclude(
+        MX_EMIT_INCLUDE(
             libRoot + "pbrlib/genglsl/ogsxml/mx_lighting_maya_v3.glsl", context, pixelStage);
     } else if (specularMethod == SPECULAR_ENVIRONMENT_PREFILTER) {
         if (OgsXmlGenerator::useLightAPI() < 2) {
-            emitInclude(
+            MX_EMIT_INCLUDE(
                 libRoot + "pbrlib/genglsl/ogsxml/mx_lighting_maya_v1.glsl", context, pixelStage);
         } else {
-            emitInclude(
+            MX_EMIT_INCLUDE(
                 libRoot + "pbrlib/genglsl/ogsxml/mx_lighting_maya_v2.glsl", context, pixelStage);
         }
     } else if (specularMethod == SPECULAR_ENVIRONMENT_NONE) {
-        emitInclude(
+        MX_EMIT_INCLUDE(
             libRoot + "pbrlib/genglsl/ogsxml/mx_lighting_maya_none.glsl", context, pixelStage);
     } else {
         throw ExceptionShaderGenError(
@@ -222,11 +230,22 @@ ShaderPtr GlslFragmentGenerator::generate(
     }
     emitLineBreak(pixelStage);
 
+#if MX_COMBINED_VERSION >= 13805
+    emitTransmissionRender(context, pixelStage);
+#endif
+
     // Set the include file to use for uv transformations,
     // depending on the vertical flip flag.
+#if MX_COMBINED_VERSION <= 13804
     _tokenSubstitutions[ShaderGenerator::T_FILE_TRANSFORM_UV] = string(libRoot + "stdlib/genglsl")
         + (context.getOptions().fileTextureVerticalFlip ? "/lib/mx_transform_uv_vflip.glsl"
                                                         : "/lib/mx_transform_uv.glsl");
+#else
+    _tokenSubstitutions[ShaderGenerator::T_FILE_TRANSFORM_UV]
+        = (context.getOptions().fileTextureVerticalFlip ? "mx_transform_uv_vflip.glsl"
+                                                        : "mx_transform_uv.glsl");
+    _tokenSubstitutions[HW::T_REFRACTION_ENV] = MX_REFRACTION_SUBSTITUTION;
+#endif
 
     // Add all functions for node implementations
     emitFunctionDefinitions(graph, context, pixelStage);

lib/mayaUsd/render/MaterialXGenOgsXml/GlslFragmentGenerator.h

@@ -15,6 +15,18 @@
 
 MATERIALX_NAMESPACE_BEGIN
 
+#if !defined(MATERIALX_NAMESPACE_BEGIN)
+// The above define was introduced in MaterialX 1.38.3. If it does not exist, we know we are on an
+// earlier 1.38 MaterialX version that can use the same code we use for 1.38.3
+#define MX_COMBINED_VERSION 13803
+#else
+#define MX_COMBINED_VERSION                                                  \
+    ((MATERIALX_MAJOR_VERSION * 100 * 100) + (MATERIALX_MINOR_VERSION * 100) \
+     + MATERIALX_BUILD_VERSION)
+#endif
+
+#define MX_REFRACTION_SUBSTITUTION "(mayaGetSpecularEnvironmentNumLOD() > 0)"
+
 namespace Stage {
 /// A special stage for private uniform definitions that are not included
 /// in the GLSL fragment but need to be known to the GLSL-to-HLSL

lib/mayaUsd/render/MaterialXGenOgsXml/OgsFragment.cpp

@@ -128,6 +128,14 @@ class GlslGeneratorWrapperBase
             }
         }
 
+#if MX_COMBINED_VERSION >= 13805
+        // MaterialX has a new implementation of transmission as refraction in version 1.38.5, but
+        // does not work out of the box in Maya (probably because we only output a color).
+        // We will deactivate until we have time to upgrade the MaterialX output to a Maya surface
+        // struct where we can expose transmission values.
+        genOptions.hwTransmissionRenderMethod = mx::TRANSMISSION_OPACITY;
+#endif
+
         // Set to use no direct lighting
         if (mx::OgsXmlGenerator::useLightAPI() >= 2) {
             genOptions.hwMaxActiveLightSources = 0;

lib/mayaUsd/render/MaterialXGenOgsXml/OgsXmlGenerator.cpp

@@ -94,6 +94,7 @@ const pugi::char_t* DIFFUSEI("diffuseI");
 const pugi::char_t* ENVMATRIX("u_envMatrix");
 const pugi::char_t* ENVRADIANCEMIPS("u_envRadianceMips");
 const pugi::char_t* ENVRADIANCESAMPLES("u_envRadianceSamples");
+const pugi::char_t* ENVREFRACTION(MX_REFRACTION_SUBSTITUTION);
 const pugi::char_t* FEATURE_LEVEL("feature_level");
 const pugi::char_t* FLAGS("flags");
 const pugi::char_t* FRAGMENT("fragment");
@@ -141,7 +142,8 @@ const pugi::char_t* VERSION("version");
 // here:
 bool isUnusedUniform(const std::string& name)
 {
-    return name == ENVMATRIX || name == ENVRADIANCEMIPS || name == ENVRADIANCESAMPLES;
+    return name == ENVMATRIX || name == ENVRADIANCEMIPS || name == ENVRADIANCESAMPLES
+        || name == ENVREFRACTION;
 }
 
 std::string DOT_COMBINE(const pugi::char_t* frag, const pugi::char_t* attr)