message: After clearing the scene, correctly recreate the material registry
diff: @@ -1437,8 +1437,11 @@ void MainWindow::buildMainMenuEdit()
  sg::clearAssets();
  // Recreate MaterialRegistry, clearing old registry and all materials
  + // Then, add the new one to the frame and set the renderer type
  baseMaterialRegistry = sg::createNodeAs<sg::MaterialRegistry>(
  "baseMaterialRegistry", "materialRegistry");
  + frame->add(baseMaterialRegistry);
  + baseMaterialRegistry->updateRendererType();
  scene = "";
  refreshScene(true);
  