Monday, March 07, 2005

Normal Map Compression

I've added support for DXT5 "swizzled" normal map compression to the HLSL shaders on my shaders page. I got the idea to do it while I was working on finishing up the normal mapping tutorial. I did some tests and was really amazed by how high the quality was on the compressed normal maps - even after 4 to 1 DXT5 compression. The guy that came up with the idea should get a medal. It may have been one of the guys that wrote these papers on normal map compression:

NVIDIA - Bump_Map_Compression.pdf

ATI - NormalMapCompression.pdf

Normal map compression is going to be extremely important. This is especially true for next gen consoles which are rumored to have 10 times the processor power as current conoles, but only 2 times as much texture memory.

I'm probably going to need to write another tutorial that details the steps that need to be taken to get the compression to work correctly. It's not very hard to do - and I even created an Action for Photoshop that does it almost instantly. I'll create that tutorial and post the Action along with it in the next few months.