Add code generation hints support

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." />

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>

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;

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
  /// @{

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";
 
 //

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

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)
  {