source/blender/nodes/shader/materialx/nodes/bsdf_principled.cc

@@ -8,22 +8,7 @@ namespace blender::nodes::materialx {
 
 NodeItem BSDFPrincipledNodeParser::compute()
 {
-  auto enabled = [](NodeItem &val) -> bool {
-    if (val.node) {
-      return true;
-    }
-    if (!val.value) {
-      return false;
-    }
-    if (val.value->isA<float>()) {
-      return val.value->asA<float>() != 0.0f;
-    }
-    if (val.value->isA<MaterialX::Color4>()) {
-      auto c = val.value->asA<MaterialX::Color4>();
-      return c[0] != 0.0f || c[1] != 0.0f || c[2] != 0.0f;
-    }
-    return true;
-  };
+  NodeItem zero = value(0.0f);
 
   /* Getting required inputs
    * Note: if some inputs are not needed they won't be taken */
@@ -32,7 +17,7 @@ NodeItem BSDFPrincipledNodeParser::compute()
   NodeItem subsurface = get_input_value("Subsurface");
   NodeItem subsurface_radius = empty();
   NodeItem subsurface_color = empty();
-  if (enabled(subsurface)) {
+  if (subsurface != zero) {
     subsurface_radius = get_input_value("Subsurface Radius");
     subsurface_color = get_input_value("Subsurface Color");
   }
@@ -44,10 +29,10 @@ NodeItem BSDFPrincipledNodeParser::compute()
 
   NodeItem anisotropic = empty();
   NodeItem anisotropic_rotation = empty();
-  if (enabled(metallic)) {
+  if (metallic != zero) {
     /* TODO: use Specular Tint input */
     anisotropic = get_input_value("Anisotropic");
-    if (enabled(anisotropic)) {
+    if (anisotropic != zero) {
       anisotropic_rotation = get_input_value("Anisotropic Rotation");
       // anisotropic_rotation = 0.5 - (anisotropic_rotation % 1.0)
     }
@@ -60,7 +45,7 @@ NodeItem BSDFPrincipledNodeParser::compute()
 
   NodeItem clearcoat = get_input_value("Clearcoat");
   NodeItem clearcoat_roughness = empty();
-  if (enabled(clearcoat)) {
+  if (clearcoat != zero) {
     clearcoat_roughness = get_input_value("Clearcoat Roughness");
   }
 
@@ -68,7 +53,7 @@ NodeItem BSDFPrincipledNodeParser::compute()
 
   NodeItem transmission = get_input_value("Transmission");
   NodeItem transmission_roughness = empty();
-  if (enabled(transmission)) {
+  if (transmission != zero) {
     transmission_roughness = get_input_value("Transmission Roughness");
   }
 
@@ -90,11 +75,11 @@ NodeItem BSDFPrincipledNodeParser::compute()
   res.set_input("normal", normal);
   res.set_input("tangent", tangent);
 
-  if (enabled(metallic)) {
+  if (metallic != zero) {
     res.set_input("metalness", metallic);
   }
 
-  if (enabled(specular)) {
+  if (specular != zero) {
     res.set_input("specular", specular);
     res.set_input("specular_color", base_color.to_color3());
     res.set_input("specular_roughness", roughness);
@@ -103,26 +88,26 @@ NodeItem BSDFPrincipledNodeParser::compute()
     res.set_input("specular_rotation", anisotropic_rotation);
   }
 
-  if (enabled(transmission)) {
+  if (transmission != zero) {
     res.set_input("transmission", transmission);
     res.set_input("transmission_color", base_color.to_color3());
     res.set_input("transmission_extra_roughness", transmission_roughness);
   }
 
-  if (enabled(subsurface)) {
+  if (subsurface != zero) {
     res.set_input("subsurface", subsurface);
     res.set_input("subsurface_color", subsurface_color);
     res.set_input("subsurface_radius", subsurface_radius);
     res.set_input("subsurface_anisotropy", anisotropic);
   }
 
-  if (enabled(sheen)) {
+  if (sheen != zero) {
     res.set_input("sheen", sheen);
     res.set_input("sheen_color", base_color.to_color3());
     res.set_input("sheen_roughness", roughness);
   }
 
-  if (enabled(clearcoat)) {
+  if (clearcoat != zero) {
     res.set_input("coat", clearcoat);
     res.set_input("coat_color", base_color.to_color3());
     res.set_input("coat_roughness", clearcoat_roughness);
@@ -132,7 +117,7 @@ NodeItem BSDFPrincipledNodeParser::compute()
     res.set_input("coat_normal", clearcoat_normal);
   }
 
-  if (enabled(emission)) {
+  if (emission != zero) {
     res.set_input("emission", emission_strength);
     res.set_input("emission_color", emission);
   }

source/blender/nodes/shader/materialx/nodes/node_item.cc

@@ -108,6 +108,11 @@ bool NodeItem::operator==(const NodeItem &other) const
   return false;
 }
 
+bool NodeItem::operator!=(const NodeItem &other) const
+{
+  return !(*this == other);
+}
+
 NodeItem NodeItem::abs() const
 {
   return arithmetic("absval", [](float a) { return std::fabsf(a); });

source/blender/nodes/shader/materialx/nodes/node_item.h

@@ -37,6 +37,7 @@ class NodeItem {
   NodeItem operator%(const NodeItem &other) const;
   NodeItem operator^(const NodeItem &other) const;
   bool operator==(const NodeItem &other) const;
+  bool operator!=(const NodeItem &other) const;
 
   NodeItem abs() const;
   NodeItem floor() const;

source/blender/nodes/shader/materialx/nodes/node_parser.cc

@@ -111,7 +111,7 @@ NodeItem NodeParser::get_input_value(const std::string &name)
   return res;
 }
 
-NodeItem NodeParser::empty()
+NodeItem NodeParser::empty() const
 {
   return NodeItem(graph);
 }

source/blender/nodes/shader/materialx/nodes/node_parser.h

@@ -35,9 +35,15 @@ class NodeParser {
   NodeItem get_input_default(const std::string &name);
   NodeItem get_input_link(const std::string &name);
   NodeItem get_input_value(const std::string &name);
-  NodeItem empty();
+  NodeItem empty() const;
+  template<class T> NodeItem value(const T &data) const;
 };
 
+template<class T> NodeItem NodeParser::value(const T &data) const
+{
+  return empty().val(data);
+}
+
 #define DECLARE_PARSER(T) \
   class T : public NodeParser { \
    public: \