message: create a default material list instead of blindly adding a material in sg
diff: @@ -22,7 +22,10 @@ namespace ospray {
  Geometry::Geometry(const std::string &type)
  {
  - createChild("material", "Material");
  + auto matList =
  + createChild("materialList", "MaterialList").nodeAs<MaterialList>();
  + matList->push_back(createNode("default", "Material")->nodeAs<Material>());
  +
  createChild("type", "string", type);
  setValue((OSPGeometry)nullptr);
  }
  