So I was curious today as to whether a high-poly object needed the same UV’s as the low-poly object in order to create a normal map, and it turn’s out I didn’t. I always retopologized then projected the detail back on the retopologized mesh because it was necessary in order to create a normal map in Zbrush. Why do some people go through the work of reprojecting the detail when sending a decimated version to a 3D application is much faster? I have a feeling I’m missing something here, so if someone could clear things up I would be grateful!
If they’re working entirely in zbrush, then its the only choice. Otherwise zbrush has some pretty sweet features to make it play well with other programs, so if you have access to them as well then that’s what I’d suggest for the retopology and baking stages. xnormal specifically is sweet for the latter, is free, can read polypaint data that zbrush exports in the obj, and gives you a real-time preview of the result.