Hernan S

You could also use groups from name sop. If I understand correctly what you want.

That all is the hand of how C4D handles USD. Im not a c4d user but I guess you can import USD scenes into it? If so yeah you can probably manipulate, meshes, etc.

Now for shading, I do not think c4d supports that but that will be a better question to ask in the RS forum. I highly doubt that you can edit rs shaders in c4d.

You can save an RS proxy Im sure you know. But you have pretty limited edit capabilities with proxies as well

Sorry to ask the obvious but are you sure this is a poly surface and not is pack yet or a poly soup? Sometimes when you unpack you still need to convert to poly after the fact. If that is not the case, can you post the file in question?