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

@@ -45,6 +45,17 @@ NodeItem GroupNodeParser::compute()
   return res;
 }
 
+NodeItem GroupNodeParser::compute_full()
+{
+  CLOG_INFO(LOG_MATERIALX_SHADER,
+            1,
+            "%s [%d] => %s",
+            node_->name,
+            node_->typeinfo->type,
+            NodeItem::type(to_type_).c_str());
+  return compute();
+}
+
 NodeItem GroupOutputNodeParser::compute()
 {
 #ifdef USE_MATERIALX_NODEGRAPH
@@ -98,7 +109,11 @@ NodeItem GroupOutputNodeParser::compute_full()
 NodeItem GroupInputNodeParser::compute()
 {
 #ifdef USE_MATERIALX_NODEGRAPH
-  NodeItem value = group_parser_->get_input_value(socket_out_->index(), to_type_);
+  NodeItem value = group_parser_->get_input_link(socket_out_->index(), to_type_);
+  if (!value) {
+    return empty();
+  }
+
   if (value.value) {
     NodeItem constant = create_node("constant", value.type());
     constant.set_input("value", value);
@@ -106,7 +121,7 @@ NodeItem GroupInputNodeParser::compute()
   }
   return create_input("input" + std::to_string(socket_out_->index() + 1), value);
 #else
-  return group_parser_->get_input_value(socket_out_->index(), to_type_);
+  return group_parser_->get_input_link(socket_out_->index(), to_type_);
 #endif
 }
 

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

@@ -8,7 +8,7 @@
 
 /* TODO: pxr::UsdMtlxRead() doesn't perform nodegraphs.
  * Uncomment USE_MATERIALX_NODEGRAPH after fixing it. */
-/* #define USE_MATERIALX_NODEGRAPH */
+#define USE_MATERIALX_NODEGRAPH
 
 namespace blender::nodes::materialx {
 
@@ -21,6 +21,7 @@ class GroupNodeParser : public NodeParser {
  public:
   using NodeParser::NodeParser;
   NodeItem compute() override;
+  NodeItem compute_full() override;
 };
 
 class GroupOutputNodeParser : public NodeParser {

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

@@ -105,7 +105,7 @@ bool NodeItem::is_arithmetic(Type type)
 
 NodeItem::operator bool() const
 {
-  return value || node || output;
+  return value || node || input || output;
 }
 
 NodeItem NodeItem::operator+(const NodeItem &other) const
@@ -808,10 +808,16 @@ NodeItem NodeItem::arithmetic(const std::string &category, std::function<float(f
     }
   }
   else {
-    /* TODO: Some of math functions (sin, cos, ...) doesn't work with Color types,
+    NodeItem v = *this;
-     * we have to convert to Vector */
+    if (ELEM(type, Type::Color3, Type::Color4) &&
+        ELEM(category, "sin", "cos", "tan", "asin", "acos", "atan2", "sqrt", "ln", "exp"))
+    {
+      /* Such fucntions doesn't have implementation in MaterialX, converting to Vector types */
+      type = type == Type::Color3 ? Type::Vector3 : Type::Vector4;
+      v = v.convert(type);
+    }
     res = create_node(category, type);
-    res.set_input("in", *this);
+    res.set_input("in", v);
   }
   return res;
 }