The quality of nanite heavily depends on your model. You can use photogrammetry scans or CAD exports directly, and nanite will make sure they'll look good. But

The quality of nanite heavily depends on your model. You can use photogrammetry scans or CAD exports directly, and nanite will make sure they'll look good. But if you just use existing videogame or fanmade assets (like here), the quality obviously suffers.