message: Comment on potential SG bug and make it easy to reproduce.
diff: @@ -281,7 +281,7 @@ namespace ospray::sg {
  // XXX This messes things up when more than one model is loaded. Why?!?!?!
  // When creating a top-level transform, only the last of multiple models is rendered!
  // (same in glTF loader)
  -#if 0
  +#if 0 // XXX Define this to see the behavior where only the last model is rendered.
  auto &rootNode = createChild(baseName + "root_node_xfm", "Transform", affine3f{one});
  #else
  auto &rootNode = *this;
  