message: Fix for loading instanced pbrt files
diff: @@ -203,16 +203,17 @@ void make_scene_graph(
  if (it != mat2prop.end())
  {
  - sp = it->second;
  + sp = std::make_shared<sg::surface_properties>();
  + sp->material() = it->second->material();
  + sp->textures() = it->second->textures();
  }
  else
  {
  sp = make_surface_properties(sphere);
  -
  mat2prop.insert({ sphere->material, sp });
  + }
  parent.add_child(sp);
  - }
  bool insert_dummy = true;
  @@ -326,16 +327,17 @@ void make_scene_graph(
  if (it != mat2prop.end())
  {
  - sp = it->second;
  + sp = std::make_shared<sg::surface_properties>();
  + sp->material() = it->second->material();
  + sp->textures() = it->second->textures();
  }
  else
  {
  sp = make_surface_properties(mesh);
  -
  mat2prop.insert({ mesh->material, sp });
  + }
  parent.add_child(sp);
  - }
  bool insert_dummy = true;
  