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

@@ -33,20 +33,18 @@ NodeItem NodeParser::compute_full()
 
   /* Checking if node was already computed */
   res.node = graph_->getNode(node_name());
-  if (res.node) {
+  if (!res.node) {
-    return res;
+    CLOG_INFO(LOG_MATERIALX_SHADER,
-  }
+              1,
+              "%s [%d] => %s",
+              node_->name,
+              node_->typeinfo->type,
+              NodeItem::type(to_type_).c_str());
 
-  CLOG_INFO(LOG_MATERIALX_SHADER,
+    res = compute();
-            1,
+    if (res.node) {
-            "%s [%d] => %s",
+      res.node->setName(node_name());
-            node_->name,
+    }
-            node_->typeinfo->type,
-            NodeItem::type(to_type_).c_str());
-
-  res = compute();
-  if (res.node) {
-    res.node->setName(node_name());
   }
   if (NodeItem::is_arithmetic(to_type_)) {
     res = res.convert(to_type_);
@@ -73,12 +71,12 @@ NodeItem NodeParser::create_node(const std::string &category, NodeItem::Type typ
 
 NodeItem NodeParser::get_input_default(const std::string &name, NodeItem::Type to_type)
 {
-  return get_input_default(node_->input_by_identifier(name), to_type);
+  return get_default(node_->input_by_identifier(name), to_type);
 }
 
 NodeItem NodeParser::get_input_default(int index, NodeItem::Type to_type)
 {
-  return get_input_default(node_->input_socket(index), to_type);
+  return get_default(node_->input_socket(index), to_type);
 }
 
 NodeItem NodeParser::get_input_link(const std::string &name, NodeItem::Type to_type)
@@ -101,6 +99,16 @@ NodeItem NodeParser::get_input_value(int index, NodeItem::Type to_type)
   return get_input_value(node_->input_socket(index), to_type);
 }
 
+NodeItem NodeParser::get_output_default(const std::string &name, NodeItem::Type to_type)
+{
+  return get_default(node_->output_by_identifier(name), to_type);
+}
+
+NodeItem NodeParser::get_output_default(int index, NodeItem::Type to_type)
+{
+  return get_default(node_->output_socket(index), to_type);
+}
+
 NodeItem NodeParser::empty() const
 {
   return NodeItem(graph_);
@@ -117,7 +125,7 @@ NodeItem NodeParser::texcoord_node()
   return res;
 }
 
-NodeItem NodeParser::get_input_default(const bNodeSocket &socket, NodeItem::Type to_type)
+NodeItem NodeParser::get_default(const bNodeSocket &socket, NodeItem::Type to_type)
 {
   NodeItem res = empty();
   switch (socket.type) {
@@ -180,7 +188,7 @@ NodeItem NodeParser::get_input_value(const bNodeSocket &socket, NodeItem::Type t
 {
   NodeItem res = get_input_link(socket, to_type);
   if (!res) {
-    res = get_input_default(socket, to_type);
+    res = get_default(socket, to_type);
   }
   return res;
 }

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

@@ -42,6 +42,8 @@ class NodeParser {
   NodeItem create_node(const std::string &category, NodeItem::Type type);
   NodeItem get_input_default(const std::string &name, NodeItem::Type to_type);
   NodeItem get_input_default(int index, NodeItem::Type to_type);
+  NodeItem get_output_default(const std::string &name, NodeItem::Type to_type);
+  NodeItem get_output_default(int index, NodeItem::Type to_type);
   NodeItem get_input_link(const std::string &name, NodeItem::Type to_type);
   NodeItem get_input_link(int index, NodeItem::Type to_type);
   NodeItem get_input_value(const std::string &name, NodeItem::Type to_type);
@@ -51,7 +53,7 @@ class NodeParser {
   NodeItem texcoord_node();
 
  private:
-  NodeItem get_input_default(const bNodeSocket &socket, NodeItem::Type to_type);
+  NodeItem get_default(const bNodeSocket &socket, NodeItem::Type to_type);
   NodeItem get_input_link(const bNodeSocket &socket, NodeItem::Type to_type);
   NodeItem get_input_value(const bNodeSocket &socket, NodeItem::Type to_type);
 };

source/blender/nodes/shader/nodes/node_shader_ambient_occlusion.cc

@@ -55,6 +55,21 @@ static void node_shader_init_ambient_occlusion(bNodeTree * /*ntree*/, bNode *nod
   node->custom2 = 0;
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* TODO: observed crash while rendering MaterialX_v1_38_6::ExceptionShaderGenError */
+  /*
+   * NodeItem maxdistance = get_input_value("Distance", NodeItem::Type::Float);
+   * NodeItem res = create_node("ambientocclusion", NodeItem::Type::Float);
+   * res.set_input("coneangle", val(90.0f));
+   * res.set_input("maxdistance", maxdistance);
+   */
+  return get_output_default(socket_out_->name, NodeItem::Type::Any);
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_ambient_occlusion_cc
 
 /* node type definition */
@@ -69,6 +84,7 @@ void register_node_type_sh_ambient_occlusion()
   ntype.draw_buttons = file_ns::node_shader_buts_ambient_occlusion;
   ntype.initfunc = file_ns::node_shader_init_ambient_occlusion;
   ntype.gpu_fn = file_ns::node_shader_gpu_ambient_occlusion;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_attribute.cc

@@ -77,6 +77,16 @@ static int node_shader_gpu_attribute(GPUMaterial *mat,
   return 1;
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* TODO: some outputs expected be implemented within the next iteration (see nodedef
+   * <geompropvalue>) */
+  return get_output_default(socket_out_->name, NodeItem::Type::Any);
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_attribute_cc
 
 /* node type definition */
@@ -93,6 +103,7 @@ void register_node_type_sh_attribute()
   node_type_storage(
       &ntype, "NodeShaderAttribute", node_free_standard_storage, node_copy_standard_storage);
   ntype.gpu_fn = file_ns::node_shader_gpu_attribute;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_bevel.cc

@@ -39,6 +39,15 @@ static int gpu_shader_bevel(GPUMaterial *mat,
   return GPU_stack_link(mat, node, "node_bevel", in, out);
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* NOTE: This node doesn't have an implementation in MaterialX.*/
+  return get_input_link("Normal", NodeItem::Type::Vector3);
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_bevel_cc
 
 /* node type definition */
@@ -53,6 +62,7 @@ void register_node_type_sh_bevel()
   ntype.draw_buttons = file_ns::node_shader_buts_bevel;
   ntype.initfunc = file_ns::node_shader_init_bevel;
   ntype.gpu_fn = file_ns::gpu_shader_bevel;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_camera.cc

@@ -26,6 +26,15 @@ static int gpu_shader_camera(GPUMaterial *mat,
   return GPU_stack_link(mat, node, "camera", in, out);
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* NOTE: This node doesn't have an implementation in MaterialX.*/
+  return get_output_default(socket_out_->name, NodeItem::Type::Any);
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_camera_cc
 
 void register_node_type_sh_camera()
@@ -37,6 +46,7 @@ void register_node_type_sh_camera()
   sh_node_type_base(&ntype, SH_NODE_CAMERA, "Camera Data", NODE_CLASS_INPUT);
   ntype.declare = file_ns::node_declare;
   ntype.gpu_fn = file_ns::gpu_shader_camera;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_fresnel.cc

@@ -26,6 +26,16 @@ static int node_shader_gpu_fresnel(GPUMaterial *mat,
   return GPU_stack_link(mat, node, "node_fresnel", in, out);
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* TODO: some outputs expected be implemented within the next iteration (see nodedef
+   * <artistic_ior>) */
+  return get_input_value("IOR", NodeItem::Type::Float);
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_fresnel_cc
 
 /* node type definition */
@@ -38,6 +48,7 @@ void register_node_type_sh_fresnel()
   sh_node_type_base(&ntype, SH_NODE_FRESNEL, "Fresnel", NODE_CLASS_INPUT);
   ntype.declare = file_ns::node_declare;
   ntype.gpu_fn = file_ns::node_shader_gpu_fresnel;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_geometry.cc

@@ -58,6 +58,33 @@ static int node_shader_gpu_geometry(GPUMaterial *mat,
   return success;
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* NOTE: Some outputs don't have an implementation in MaterialX.*/
+  NodeItem res = empty();
+  std::string name = socket_out_->name;
+
+  if (name == "Position") {
+    res = create_node("position", NodeItem::Type::Vector3);
+    res.set_input("space", val(std::string("world")));
+  }
+  else if (name == "Normal") {
+    res = create_node("normal", NodeItem::Type::Vector3);
+    res.set_input("space", val(std::string("world")));
+  }
+  else if (ELEM(name, "Tangent", "True Normal")) {
+    res = create_node("tangent", NodeItem::Type::Vector3);
+    res.set_input("space", val(std::string("world")));
+  }
+  else {
+    res = get_output_default(name, NodeItem::Type::Any);
+  }
+  return res;
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_geometry_cc
 
 /* node type definition */
@@ -70,6 +97,7 @@ void register_node_type_sh_geometry()
   sh_node_type_base(&ntype, SH_NODE_NEW_GEOMETRY, "Geometry", NODE_CLASS_INPUT);
   ntype.declare = file_ns::node_declare;
   ntype.gpu_fn = file_ns::node_shader_gpu_geometry;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_hair_info.cc

@@ -29,6 +29,15 @@ static int node_shader_gpu_hair_info(GPUMaterial *mat,
   return GPU_stack_link(mat, node, "node_hair_info", in, out, length_link);
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* NOTE: This node doesn't have an implementation in MaterialX.*/
+  return get_output_default(socket_out_->name, NodeItem::Type::Any);
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_hair_info_cc
 
 /* node type definition */
@@ -41,6 +50,7 @@ void register_node_type_sh_hair_info()
   sh_node_type_base(&ntype, SH_NODE_HAIR_INFO, "Curves Info", NODE_CLASS_INPUT);
   ntype.declare = file_ns::node_declare;
   ntype.gpu_fn = file_ns::node_shader_gpu_hair_info;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_layer_weight.cc

@@ -27,6 +27,16 @@ static int node_shader_gpu_layer_weight(GPUMaterial *mat,
   return GPU_stack_link(mat, node, "node_layer_weight", in, out);
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* TODO: some outputs expected be implemented partially within the next iteration (see nodedef
+   * <artistic_ior>) */
+  return get_input_link("Blend", NodeItem::Type::Float);
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_layer_weight_cc
 
 /* node type definition */
@@ -39,6 +49,7 @@ void register_node_type_sh_layer_weight()
   sh_node_type_base(&ntype, SH_NODE_LAYER_WEIGHT, "Layer Weight", NODE_CLASS_INPUT);
   ntype.declare = file_ns::node_declare;
   ntype.gpu_fn = file_ns::node_shader_gpu_layer_weight;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_object_info.cc

@@ -30,6 +30,34 @@ static int node_shader_gpu_object_info(GPUMaterial *mat,
   return GPU_stack_link(mat, node, "node_object_info", in, out, GPU_constant(&index));
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* NOTE: Some outputs don't have an implementation in MaterialX.*/
+  NodeItem res = empty();
+  std::string name = socket_out_->name;
+
+  if (name == "Location") {
+    res = create_node("position", NodeItem::Type::Vector3);
+    res.set_input("space", val(std::string("world")));
+  }
+  /* TODO: This node doesn't have an implementation in MaterialX.
+   * It's added in MaterialX 1.38.8. Uncomment this code after switching to 1.38.8.
+   * if (name=="Random") {
+   *  res = create_node("randomfloat", NodeItem::Type::Float);
+   *  res.set_input("in", val(0.0));
+   *  res.set_input("min", val(0.0));
+   *  res.set_input("max", val(1.0));
+   *  res.set_input("seed", val(0));
+   *}*/
+  else {
+    res = get_output_default(name, NodeItem::Type::Any);
+  }
+  return res;
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_object_info_cc
 
 void register_node_type_sh_object_info()
@@ -41,6 +69,7 @@ void register_node_type_sh_object_info()
   sh_node_type_base(&ntype, SH_NODE_OBJECT_INFO, "Object Info", NODE_CLASS_INPUT);
   ntype.declare = file_ns::node_declare;
   ntype.gpu_fn = file_ns::node_shader_gpu_object_info;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_particle_info.cc

@@ -34,6 +34,15 @@ static int gpu_shader_particle_info(GPUMaterial *mat,
   return GPU_stack_link(mat, node, "particle_info", in, out);
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* NOTE: This node doesn't have an implementation in MaterialX.*/
+  return get_output_default(socket_out_->name, NodeItem::Type::Any);
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_particle_info_cc
 
 /* node type definition */
@@ -46,6 +55,7 @@ void register_node_type_sh_particle_info()
   sh_node_type_base(&ntype, SH_NODE_PARTICLE_INFO, "Particle Info", NODE_CLASS_INPUT);
   ntype.declare = file_ns::node_declare;
   ntype.gpu_fn = file_ns::gpu_shader_particle_info;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_point_info.cc

@@ -22,6 +22,15 @@ static int node_shader_gpu_point_info(GPUMaterial *mat,
   return GPU_stack_link(mat, node, "node_point_info", in, out);
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* NOTE: This node doesn't have an implementation in MaterialX.*/
+  return get_output_default(socket_out_->name, NodeItem::Type::Any);
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_point_info_cc
 
 /* node type definition */
@@ -34,6 +43,7 @@ void register_node_type_sh_point_info()
   sh_node_type_base(&ntype, SH_NODE_POINT_INFO, "Point Info", NODE_CLASS_INPUT);
   ntype.declare = file_ns::node_declare;
   ntype.gpu_fn = file_ns::node_shader_gpu_point_info;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_rgb.cc

@@ -26,6 +26,17 @@ static int gpu_shader_rgb(GPUMaterial *mat,
   return GPU_link(mat, "set_rgba", GPU_uniform(value), &out->link);
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  NodeItem color = get_output_default("Color", NodeItem::Type::Color4);
+  NodeItem res = create_node("constant", NodeItem::Type::Color4);
+  res.set_input("value", color);
+  return res;
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_rgb_cc
 
 void register_node_type_sh_rgb()
@@ -37,6 +48,7 @@ void register_node_type_sh_rgb()
   sh_node_type_base(&ntype, SH_NODE_RGB, "RGB", NODE_CLASS_INPUT);
   ntype.declare = file_ns::node_declare;
   ntype.gpu_fn = file_ns::gpu_shader_rgb;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_tangent.cc

@@ -86,6 +86,15 @@ static int node_shader_gpu_tangent(GPUMaterial *mat,
   return GPU_stack_link(mat, node, "node_tangent", in, out, orco);
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* TODO: This node doesn't have an implementation in MaterialX.*/
+  return get_output_default(socket_out_->name, NodeItem::Type::Vector3);
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_tangent_cc
 
 /* node type definition */
@@ -103,6 +112,7 @@ void register_node_type_sh_tangent()
   ntype.gpu_fn = file_ns::node_shader_gpu_tangent;
   node_type_storage(
       &ntype, "NodeShaderTangent", node_free_standard_storage, node_copy_standard_storage);
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_tex_coord.cc

@@ -71,6 +71,33 @@ static int node_shader_gpu_tex_coord(GPUMaterial *mat,
   return 1;
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* NOTE: Some outputs don't have an implementation in MaterialX.*/
+  NodeItem res = empty();
+  std::string name = socket_out_->name;
+
+  if (ELEM(name, "Generated", "UV")) {
+    res = texcoord_node();
+  }
+  else if (name == "Normal") {
+    res = create_node("normal", NodeItem::Type::Vector3);
+    res.set_input("space", val(std::string("world")));
+  }
+  else if (name == "Object") {
+    res = create_node("position", NodeItem::Type::Vector3);
+    res.set_input("space", val(std::string("world")));
+  }
+  else {
+    res = get_output_default(name, NodeItem::Type::Any);
+  }
+
+  return res;
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_tex_coord_cc
 
 /* node type definition */
@@ -84,6 +111,7 @@ void register_node_type_sh_tex_coord()
   ntype.declare = file_ns::node_declare;
   ntype.draw_buttons = file_ns::node_shader_buts_tex_coord;
   ntype.gpu_fn = file_ns::node_shader_gpu_tex_coord;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_uvmap.cc

@@ -67,6 +67,17 @@ static int node_shader_gpu_uvmap(GPUMaterial *mat,
   return 1;
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* NODE: "From Instances" not implemented
+   * UV selection not implemented
+   */
+  return texcoord_node();
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_uvmap_cc
 
 /* node type definition */
@@ -84,6 +95,7 @@ void register_node_type_sh_uvmap()
   node_type_storage(
       &ntype, "NodeShaderUVMap", node_free_standard_storage, node_copy_standard_storage);
   ntype.gpu_fn = file_ns::node_shader_gpu_uvmap;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_value.cc

@@ -38,6 +38,17 @@ static void sh_node_value_build_multi_function(NodeMultiFunctionBuilder &builder
   builder.construct_and_set_matching_fn<mf::CustomMF_Constant<float>>(value->value);
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  NodeItem value = get_output_default("Value", NodeItem::Type::Float);
+  NodeItem res = create_node("constant", NodeItem::Type::Float);
+  res.set_input("value", value);
+  return res;
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_value_cc
 
 void register_node_type_sh_value()
@@ -50,6 +61,7 @@ void register_node_type_sh_value()
   ntype.declare = file_ns::sh_node_value_declare;
   ntype.gpu_fn = file_ns::gpu_shader_value;
   ntype.build_multi_function = file_ns::sh_node_value_build_multi_function;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_vertex_color.cc

@@ -67,6 +67,16 @@ static int node_shader_gpu_vertex_color(GPUMaterial *mat,
   return GPU_stack_link(mat, node, "node_vertex_color", in, out, vertexColorLink);
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* TODO: some output expected be implemented within the next iteration (see nodedef
+   * <geomcolor>)*/
+  return get_output_default(socket_out_->name, NodeItem::Type::Any);
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_vertex_color_cc
 
 void register_node_type_sh_vertex_color()
@@ -82,6 +92,7 @@ void register_node_type_sh_vertex_color()
   node_type_storage(
       &ntype, "NodeShaderVertexColor", node_free_standard_storage, node_copy_standard_storage);
   ntype.gpu_fn = file_ns::node_shader_gpu_vertex_color;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }

source/blender/nodes/shader/nodes/node_shader_wireframe.cc

@@ -40,6 +40,15 @@ static int node_shader_gpu_wireframe(GPUMaterial *mat,
   }
 }
 
+NODE_SHADER_MATERIALX_BEGIN
+#ifdef WITH_MATERIALX
+{
+  /* NOTE: This node doesn't have an implementation in MaterialX.*/
+  return get_output_default(socket_out_->name, NodeItem::Type::Float);
+}
+#endif
+NODE_SHADER_MATERIALX_END
+
 }  // namespace blender::nodes::node_shader_wireframe_cc
 
 /* node type definition */
@@ -53,6 +62,7 @@ void register_node_type_sh_wireframe()
   ntype.declare = file_ns::node_declare;
   ntype.draw_buttons = file_ns::node_shader_buts_wireframe;
   ntype.gpu_fn = file_ns::node_shader_gpu_wireframe;
+  ntype.materialx_fn = file_ns::node_shader_materialx;
 
   nodeRegisterType(&ntype);
 }