Very close! I’m talking about both displacement and bump. Bump mapping does sort of use the normal information when rendering, but it gets it from the face and not the texture the same way that displacement does. You can convert a bump map into a normal map by guessing the slope between different heights, but the direction of the slope cannot be gotten with the greyscale information, which is essential for normal mapping things like rounded corners. A normal map, however, can’t really be converted into a bump map since it lacks the height information. Does that help?
