http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=displacement+mapping+pixel+shader&btnG=Google+Search
There's a PDF there on one of the first links which describes one method of doing it, but it does not sound at all like the simple method I read about on a game developer forum a while back. I'll look around for that.
There's a PDF there on one of the first links which describes one method of doing it, but it does not sound at all like the simple method I read about on a game developer forum a while back. I'll look around for that.