I am going to implement parallax and relief mapping in my new engine, but I’ve some design releated questions.
Previously, I was loading normal maps with depth component in alpha using RGBA8 texture format from pregenerated TGAs. But I’ve came to conclusion that loading times from disk are way too long.
Moreover, it’s easier to model depth maps, without converting them to normal maps.
So currently I’m thinking about depth map, from disk and normal map recalculation on the fly.
What kind of texture format should I stick with - signed byte (RGBA16?), float textures? Which of them is less expensive performance wise? What’s happening with filters? Can anyone give me better recomendations (without 3Dc)?
Normal recalculation in pixel shader using dx/dy, is way too expensive I guess…
Target platform is GF 6x series and that like for now.
According to documentation at http://developer.nvidia.com/object/bump_map_compression.html
it might be a good idea yo use non tangent space bumpmapping. Anyone knows where can I read more about making this gradient map?