Basically if you generate a backdrop and then estimate light direction you can inverse render that onto the 3d model given all the depth information you get for free from the model
You should be able to do relighting with ControlNet. Basically render the model to all the maps you'd use for PBR (fullbright color/depth/reflectivity/etc), train ControlNets that hold all those constant and do img2img but let it make up the background.
Though I'm not aware of anyone already doing this, since I think research has moved on to NeRF models that act on 3D scenes directly.
Though I'm not aware of anyone already doing this, since I think research has moved on to NeRF models that act on 3D scenes directly.