See image below. I’m just learning, it’s a quick test. Suzanne duplicated, one copy was subdivided, sculpted some detail and used it to create normal map on low res copy’s UV. Now I know that uv is not good, it’s just a quick setup. btw it’s 1024*1024. The result looks very bad… maybe i expect too much from normal maps (zbrush has an option “smoothing lowres normals” which gives much better result, but I’d like to make my normal maps in Blender)
I’ve tried tpo play with distance/bias but doesn’t seem to help… and I don’t really know how to use them.