Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!ut-sally!husc6!think!ames!ptsfa!ihnp4!cuae2!killer!academ!uhnix1!sugar!peter From: peter@sugar.UUCP (Peter da Silva) Newsgroups: comp.graphics Subject: Re: Ray tracing and caustics. Message-ID: <413@sugar.UUCP> Date: Sun, 19-Jul-87 14:26:53 EDT Article-I.D.: sugar.413 Posted: Sun Jul 19 14:26:53 1987 Date-Received: Sun, 26-Jul-87 21:14:28 EDT References: <219@sugar.UUCP> <543@saturn.ucsc.edu> Organization: Sugar Land UNIX - Houston, TX Lines: 12 Keywords: ray-tracing caustics algorithm reality Summary: That sounds like an expensive method. > > [i made the original comment about caustics] > [an explanation of how someone did them, probably by taking a random > sample of vectors from any ray intersection with a matte surface] I thought of that, but assumed that it would lead to too much overhead. In most scenes you're not likely to get many caustics from non-reflective or transparent objects, which is why I suggested doing a pre-trace pass originating at the light source to paint the caustics on matte surfaces. Not nearly as accurate a technique, but likely much faster. Of course I could be completely wrong about the speed problem. It's been known to happen. -- -- Peter da Silva `-_-' ...!seismo!soma!uhnix1!sugar!peter (I said, NO PHOTOS!)