Besides adding the PBR material manager, this commit hide some unnecessary features such as toggle wireframes and toggle normal smooth.
Add a regenerate button to indicate mesh is generating by showing a spiner, user can click this button to regenerate if the final result is not good.
Please note that, we generate the texture map by default compared to before we only generate texture map when user export glTF result. Current uvunwrap library cann't handle bad mesh very well, so it will crash on the wires model.
huxingyi