Merge branch 'main' into fix-swizzle-handling

AcademySoftwareFoundation · Aug 3, 2024 · 8633690 · 8633690
2 parents 51bf7bd + e98d05f
commit 8633690
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diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -180,10 +180,23 @@ if (MATERIALX_BUILD_USE_CCACHE)
     endif()
 endif()
 
+# Attempt to configure OSL testing if it can be found by cmake.
+# This will not override any explicitly provided oslc and testrender
+if(MATERIALX_BUILD_RENDER AND MATERIALX_BUILD_GEN_OSL AND MATERIALX_BUILD_TESTS)
+    # We currently only need the actual OSL binaries if we're running tests with Render and GenOSL enabled.
+    find_package(OSL QUIET)
+    if(OSL_FOUND)
+        if(NOT MATERIALX_OSL_BINARY_OSLC)
+            set(MATERIALX_OSL_BINARY_OSLC $<TARGET_FILE:OSL::oslc>)
+        endif()
+        if(NOT MATERIALX_OSL_BINARY_TESTRENDER)
+            # currently OSL does not export a cmake target for testrender, but once that's added this can be simplified.
+            set(MATERIALX_OSL_BINARY_TESTRENDER $<TARGET_FILE_DIR:OSL::oslc>/testrender)
+        endif()
+    endif()
+endif()
+
 # Add global definitions
-add_definitions(-DMATERIALX_OSL_BINARY_OSLC=\"${MATERIALX_OSL_BINARY_OSLC}\")
-add_definitions(-DMATERIALX_OSL_BINARY_TESTRENDER=\"${MATERIALX_OSL_BINARY_TESTRENDER}\")
-add_definitions(-DMATERIALX_OSL_INCLUDE_PATH=\"${MATERIALX_OSL_INCLUDE_PATH}\")
 if (MATERIALX_OSL_LEGACY_CLOSURES)
     add_definitions(-DMATERIALX_OSL_LEGACY_CLOSURES)
 endif()

diff --git a/documents/Specification/MaterialX.PBRSpec.md b/documents/Specification/MaterialX.PBRSpec.md
@@ -43,6 +43,8 @@ This document describes a number of shader-semantic nodes implementing widely-us
 **[Shading Model Examples](#shading-model-examples)**  
  [Autodesk Standard Surface](#autodesk-standard-surface)  
  [UsdPreviewSurface](#usdpreviewsurface)  
+ [Khronos glTF PBR](#khronos-gltf-pbr)  
+ [OpenPBR Surface](#openpbr-surface)  
 
 **[References](#references)**
 

diff --git a/documents/Specification/MaterialX.Proposals.md b/documents/Specification/MaterialX.Proposals.md
diff --git a/documents/Specification/MaterialX.Specification.md b/documents/Specification/MaterialX.Specification.md
diff --git a/documents/Specification/README.md b/documents/Specification/README.md
@@ -11,6 +11,7 @@ The documents in this folder comprise the complete MaterialX Specification, vers
 * [**MaterialX NPR Shading Nodes**](./MaterialX.NPRSpec.md) - specifies shading nodes that are designed for use in non-photorealistic and stylized rendering
 * [**MaterialX Geometry Extensions**](./MaterialX.GeomExts.md) - additional MaterialX elements to define geometry-related information such as collections, properties and material assignments
 * [**MaterialX Supplemental Notes**](./MaterialX.Supplement.md) - describes recommended naming and structuring conventions for libraries of custom node definitions
+* [**MaterialX: Proposed Additions and Changes**](./MaterialX.Proposals.md) - describes proposed future updates to various components of the Specification
 
 <p>
 

diff --git a/libraries/bxdf/open_pbr_surface.mtlx b/libraries/bxdf/open_pbr_surface.mtlx
@@ -23,7 +23,7 @@
            doc="Index of refraction of the dielectric base." />
     <input name="specular_roughness_anisotropy" type="float" value="0.0" uimin="0.0" uimax="1.0" uiname="Specular Anisotropy" uifolder="Specular" uiadvanced="true"
            doc="The directional bias of the roughness of the metal/dielectric base, resulting in increasingly stretched highlights along the tangent direction." />
-    <input name="transmission_weight" type="float" value="0.0" uimin="0.0" uimax="1.0" uiname="Transmission Weight" uifolder="Transmission" uiadvanced="true"
+    <input name="transmission_weight" type="float" value="0.0" uimin="0.0" uimax="1.0" uiname="Transmission Weight" uifolder="Transmission" uiadvanced="true" hint="transparency"
            doc="Mixture weight between the transparent and opaque dielectric base. The greater the value the more transparent the material." />
     <input name="transmission_color" type="color3" value="1, 1, 1" uimin="0,0,0" uimax="1,1,1" uiname="Transmission Color" uifolder="Transmission" uiadvanced="true"
            doc="Controls color of the transparent base due to Beer's law volumetric absorption under the surface (reverts to a non-physical tint when transmission_depth is zero)." />
@@ -75,7 +75,7 @@
            doc="The amount of emitted light, as a luminance in nits." />
     <input name="emission_color" type="color3" value="1, 1, 1" uimin="0,0,0" uimax="1,1,1" uiname="Emission Color" uifolder="Emission"
            doc="The color of the emitted light." />
-    <input name="geometry_opacity" type="float" value="1" uimin="0" uimax="1" uiname="Opacity" uifolder="Geometry"
+    <input name="geometry_opacity" type="float" value="1" uimin="0" uimax="1" uiname="Opacity" uifolder="Geometry" hint="opacity"
            doc="The opacity of the entire material." />
     <input name="geometry_thin_walled" type="boolean" value="false" uiname="Thin Walled" uifolder="Geometry" uiadvanced="true"
            doc="If true the surface is double-sided and represents an infinitesimally thin shell. Suitable for extremely geometrically thin objects such as leaves or paper." />

diff --git a/libraries/bxdf/translation/open_pbr_to_standard_surface.mtlx b/libraries/bxdf/translation/open_pbr_to_standard_surface.mtlx
@@ -81,7 +81,6 @@
     <output name="coat_roughness_out" type="float" />
     <output name="coat_anisotropy_out" type="float" />
     <output name="coat_IOR_out" type="float" />
-    <output name="coat_affect_color_out" type="float" />
     <output name="coat_affect_roughness_out" type="float" />
 
     <output name="thin_film_thickness_out" type="float" />
@@ -96,19 +95,101 @@
 
   <nodegraph name="NG_open_pbr_surface_to_standard_surface" nodedef="ND_open_pbr_surface_to_standard_surface">
 
+    <!-- Coat Darkening -->
+    <subtract name="coat_ior_minus_one" type="float">
+      <input name="in1" type="float" interfacename="coat_ior" />
+      <input name="in2" type="float" value="1.0" />
+    </subtract>
+    <add name="coat_ior_plus_one" type="float">
+      <input name="in1" type="float" value="1.0" />
+      <input name="in2" type="float" interfacename="coat_ior" />
+    </add>
+    <divide name="coat_ior_to_F0_sqrt" type="float">
+      <input name="in1" type="float" nodename="coat_ior_minus_one" />
+      <input name="in2" type="float" nodename="coat_ior_plus_one" />
+    </divide>
+    <multiply name="coat_ior_to_F0" type="float">
+      <input name="in1" type="float" nodename="coat_ior_to_F0_sqrt" />
+      <input name="in2" type="float" nodename="coat_ior_to_F0_sqrt" />
+    </multiply>
+    <!-- approximate Kcoat, "internal diffuse reflection coefficient" of coat  -->
+    <subtract name="one_minus_coat_F0" type="float">
+      <input name="in1" type="float" value="1.0" />
+      <input name="in2" type="float" nodename="coat_ior_to_F0" />
+    </subtract>
+    <multiply name="coat_ior_sqr" type="float">
+      <input name="in1" type="float" interfacename="coat_ior" />
+      <input name="in2" type="float" interfacename="coat_ior" />
+    </multiply>
+    <divide name="one_minus_coat_F0_over_eta2" type="float">
+      <input name="in1" type="float" nodename="one_minus_coat_F0" />
+      <input name="in2" type="float" nodename="coat_ior_sqr" />
+    </divide>
+    <subtract name="Kcoat" type="float">
+      <input name="in1" type="float" value="1.0" />
+      <input name="in2" type="float" nodename="one_minus_coat_F0_over_eta2" />
+    </subtract>
+    <!-- approximate base metal albedo estimate, Emetal  -->
+    <multiply name="Emetal" type="color3">
+      <input name="in1" type="color3" interfacename="base_color" />
+      <input name="in2" type="float" interfacename="specular_weight" />
+    </multiply>
+    <!-- approximate base dielectric albedo estimate, Edielectric  -->
+    <mix name="Edielectric" type="color3">
+      <input name="fg" type="color3" interfacename="subsurface_color" />
+      <input name="bg" type="color3" interfacename="base_color" />
+      <input name="mix" type="float" interfacename="subsurface_weight" />
+    </mix>
+    <!-- thus calculate overall base albedo estimate approximation, Ebase  -->
+    <mix name="Ebase" type="color3">
+      <input name="fg" type="color3" nodename="Emetal" />
+      <input name="bg" type="color3" nodename="Edielectric" />
+      <input name="mix" type="float" interfacename="base_metalness" />
+    </mix>
+    <!-- final base darkening factor due to coat:  base_darkening = (1 - Kcoat) / (1 - Ebase*Kcoat)  -->
+    <multiply name="Ebase_Kcoat" type="color3">
+      <input name="in1" type="color3" nodename="Ebase" />
+      <input name="in2" type="float" nodename="Kcoat" />
+    </multiply>
+    <subtract name="one_minus_Kcoat" type="float">
+      <input name="in1" type="float" value="1.0" />
+      <input name="in2" type="float" nodename="Kcoat" />
+    </subtract>
+    <subtract name="one_minus_Ebase_Kcoat" type="color3">
+      <input name="in1" type="color3" value="1.0, 1.0, 1.0" />
+      <input name="in2" type="color3" nodename="Ebase_Kcoat" />
+    </subtract>
+    <convert name="one_minus_Kcoat_color" type="color3">
+      <input name="in" type="float" nodename="one_minus_Kcoat" />
+    </convert>
+    <divide name="base_darkening" type="color3">
+      <input name="in1" type="color3" nodename="one_minus_Kcoat_color" />
+      <input name="in2" type="color3" nodename="one_minus_Ebase_Kcoat" />
+    </divide>
+    <multiply name="coat_weight_times_coat_darkening" type="float">
+      <input name="in1" type="float" interfacename="coat_weight" />
+      <input name="in2" type="float" interfacename="coat_darkening" />
+    </multiply>
+    <mix name="modulated_base_darkening" type="color3">
+      <input name="fg" type="color3" nodename="base_darkening" />
+      <input name="bg" type="color3" value="1.0, 1.0, 1.0" />
+      <input name="mix" type="float" nodename="coat_weight_times_coat_darkening" />
+    </mix>
+
     <!--Base-->
     <dot name="base" type="float">
       <input name="in" type="float" interfacename="base_weight" />
     </dot>
-    <dot name="baseColor" type="color3">
-      <input name="in" type="color3" interfacename="base_color" />
-    </dot>
     <dot name="diffuseRoughness" type="float">
       <input name="in" type="float" interfacename="base_diffuse_roughness" />
     </dot>
     <dot name="metalness" type="float">
       <input name="in" type="float" interfacename="base_metalness" />
     </dot>
+    <multiply name="baseColor" type="color3">
+      <input name="in1" type="color3" interfacename="base_color" />
+      <input name="in2" type="color3" nodename="modulated_base_darkening" />
+    </multiply>
 
     <!--Specular-->
     <dot name="spec" type="float">
@@ -154,9 +235,10 @@
     <dot name="subsurface" type="float">
       <input name="in" type="float" interfacename="subsurface_weight" />
     </dot>
-    <dot name="subsurfaceColor" type="color3">
-      <input name="in" type="color3" interfacename="subsurface_color" />
-    </dot>
+    <multiply name="subsurfaceColor" type="color3">
+      <input name="in1" type="color3" interfacename="subsurface_color" />
+      <input name="in2" type="color3" nodename="modulated_base_darkening" />
+    </multiply>
     <dot name="subsurfaceScale" type="float">
       <input name="in" type="float" interfacename="subsurface_radius" />
     </dot>
@@ -195,12 +277,9 @@
     <dot name="coatIOR" type="float">
       <input name="in" type="float" interfacename="coat_ior" />
     </dot>
-    <dot name="coatAffectColor" type="float">
-      <input name="in" type="float" interfacename="coat_darkening" />
-    </dot>
-    <dot name="coatAffectRoughness" type="float">
-      <input name="in" type="float" interfacename="coat_darkening" />
-    </dot>
+    <constant name="coatAffectRoughness" type="float">
+      <input name="value" type="float" value="1.0" />
+    </constant>
 
     <!--ThinFilm-->
     <multiply name="thinFilmThicknessConversion" type="float">
@@ -267,7 +346,6 @@
     <output name="coat_roughness_out" type="float" nodename="coatRoughness" />
     <output name="coat_anisotropy_out" type="float" nodename="coatAnisotropy" />
     <output name="coat_IOR_out" type="float" nodename="coatIOR" />
-    <output name="coat_affect_color_out" type="float" nodename="coatAffectColor" />
     <output name="coat_affect_roughness_out" type="float" nodename="coatAffectRoughness" />
 
     <output name="thin_film_thickness_out" type="float" nodename="thinFilmThickness" />

diff --git a/resources/Materials/TestSuite/pbrlib/surfaceshader/transparency_hints.mtlx b/resources/Materials/TestSuite/pbrlib/surfaceshader/transparency_hints.mtlx
@@ -0,0 +1,15 @@
+<?xml version="1.0"?>
+<materialx version="1.39" colorspace="lin_rec709">
+  <surfacematerial name="geom_hint" type="material">
+    <input name="surfaceshader" type="surfaceshader" nodename="geometric_opacity_hint" />
+  </surfacematerial>
+  <open_pbr_surface name="geometric_opacity_hint" type="surfaceshader">
+    <input name="geometry_opacity" type="float" value="0.5" />
+  </open_pbr_surface>
+  <surfacematerial name="transp_hint" type="material">
+    <input name="surfaceshader" type="surfaceshader" nodename="transparency_weight_hint" />
+  </surfacematerial>
+  <open_pbr_surface name="transparency_weight_hint" type="surfaceshader">
+    <input name="transmission_weight" type="float" value="0.8" />
+  </open_pbr_surface>
+</materialx>
diff --git a/source/MaterialXCore/Definition.cpp b/source/MaterialXCore/Definition.cpp
@@ -100,6 +100,19 @@ InterfaceElementPtr NodeDef::getImplementation(const string& target) const
     return InterfaceElementPtr();
 }
 
+const StringMap NodeDef::getInputHints() const
+{
+    StringMap hints;
+    for (InputPtr input : getActiveInputs())
+    {
+        if (input->hasHint())
+        {
+            hints[input->getName()] = input->getHint();
+        }
+    }
+    return hints;
+}
+
 bool NodeDef::validate(string* message) const
 {
     bool res = true;

diff --git a/source/MaterialXCore/Definition.h b/source/MaterialXCore/Definition.h
@@ -146,6 +146,13 @@ class MX_CORE_API NodeDef : public InterfaceElement
     ///    an Implementation element or a NodeGraph element.
     InterfaceElementPtr getImplementation(const string& target = EMPTY_STRING) const;
 
+    /// @}
+    /// @name Hints
+    /// @{
+
+    /// Return list of input hint pairs of the form { input_name, hint_string }
+    const StringMap getInputHints() const;
+
     /// @}
     /// @name Validation
     /// @{

diff --git a/source/MaterialXCore/Interface.cpp b/source/MaterialXCore/Interface.cpp
@@ -20,6 +20,10 @@ const string InterfaceElement::TARGET_ATTRIBUTE = "target";
 const string InterfaceElement::VERSION_ATTRIBUTE = "version";
 const string InterfaceElement::DEFAULT_VERSION_ATTRIBUTE = "isdefaultversion";
 const string Input::DEFAULT_GEOM_PROP_ATTRIBUTE = "defaultgeomprop";
+const string Input::HINT_ATTRIBUTE = "hint";
+const string Input::TRANSPARENCY_HINT = "transparency";
+const string Input::OPACITY_HINT = "opacity";
+const string Input::ANISOTROPY_HINT = "anisotropy";
 const string Output::DEFAULT_INPUT_ATTRIBUTE = "defaultinput";
 
 //

diff --git a/source/MaterialXCore/Interface.h b/source/MaterialXCore/Interface.h
@@ -219,6 +219,28 @@ class MX_CORE_API Input : public PortElement
     /// for this input.
     InputPtr getInterfaceInput() const;
 
+    /// @}
+    /// @name Hints
+    /// @{
+
+    /// Return true if the input has a hint
+    bool hasHint() const
+    {
+        return hasAttribute(HINT_ATTRIBUTE);
+    }
+
+    /// Return the code generation hint
+    const string& getHint() const
+    {
+        return getAttribute(HINT_ATTRIBUTE);
+    }
+
+    // Set the code generation hint
+    void setHint(const string& hint)
+    {
+        setAttribute(HINT_ATTRIBUTE, hint);
+    }
+
     /// @}
     /// @name Validation
     /// @{
@@ -232,6 +254,10 @@ class MX_CORE_API Input : public PortElement
   public:
     static const string CATEGORY;
     static const string DEFAULT_GEOM_PROP_ATTRIBUTE;
+    static const string HINT_ATTRIBUTE;
+    static const string TRANSPARENCY_HINT;
+    static const string OPACITY_HINT;
+    static const string ANISOTROPY_HINT;
 };
 
 /// @class Output

diff --git a/source/MaterialXGenShader/Util.cpp b/source/MaterialXGenShader/Util.cpp
@@ -16,10 +16,10 @@ using OpaqueTestPair = std::pair<string, float>;
 using OpaqueTestPairList = vector<OpaqueTestPair>;
 
 // Inputs on a surface shader which are checked for transparency
-const OpaqueTestPairList inputPairList = { { "opacity", 1.0f },
-                                           { "existence", 1.0f },
-                                           { "alpha", 1.0f },
-                                           { "transmission", 0.0f } };
+const OpaqueTestPairList DEFAULT_INPUT_PAIR_LIST = { { "opacity", 1.0f },
+                                                     { "existence", 1.0f },
+                                                     { "alpha", 1.0f },
+                                                     { "transmission", 0.0f } };
 
 const string MIX_CATEGORY("mix");
 const string MIX_FG_INPUT("fg");
@@ -116,6 +116,23 @@ bool isTransparentShaderNode(NodePtr node, NodePtr interfaceNode)
         return false;
     }
 
+    // Check against nodedef input hints
+    OpaqueTestPairList inputPairList = DEFAULT_INPUT_PAIR_LIST;
+    NodeDefPtr nodeDef = node->getNodeDef();
+    StringMap nodeDefList = nodeDef ? nodeDef->getInputHints() : StringMap();
+    for (auto &item : nodeDefList)
+    {
+        string inputName = item.first;
+        if (item.second == Input::TRANSPARENCY_HINT)
+        {
+            inputPairList.push_back(std::make_pair(inputName, 0.0f) );
+        }
+        else if (item.second == Input::OPACITY_HINT)
+        {
+            inputPairList.push_back(std::make_pair(inputName, 1.0f));
+        }
+    }
+
     // Check against the interface if a node is passed in to check against
     OpaqueTestPairList interfaceNames;
     if (interfaceNode)
@@ -167,8 +184,8 @@ bool isTransparentShaderNode(NodePtr node, NodePtr interfaceNode)
             NodePtr inputNode = checkInput->getConnectedNode();
             if (inputNode)
             {
-                NodeDefPtr nodeDef = inputNode->getNodeDef();
-                string nodeGroup = nodeDef ? nodeDef->getAttribute(NodeDef::NODE_GROUP_ATTRIBUTE) : EMPTY_STRING;
+                NodeDefPtr inputNodeDef = inputNode->getNodeDef();
+                string nodeGroup = inputNodeDef ? inputNodeDef->getAttribute(NodeDef::NODE_GROUP_ATTRIBUTE) : EMPTY_STRING;
                 if (nodeGroup != NodeDef::ADJUSTMENT_NODE_GROUP &&
                     nodeGroup != NodeDef::CHANNEL_NODE_GROUP)
                 {