Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!rochester!cornell!uw-beaver!mit-eddie!ll-xn!ames!lll-lcc!ptsfa!hoptoad!academ!uhnix1!sugar!peter From: peter@sugar.UUCP (Peter DaSilva) Newsgroups: comp.graphics Subject: Ray tracing and caustics. Message-ID: <219@sugar.UUCP> Date: Thu, 25-Jun-87 08:41:43 EDT Article-I.D.: sugar.219 Posted: Thu Jun 25 08:41:43 1987 Date-Received: Sun, 12-Jul-87 10:52:42 EDT Organization: Sugar Land UNIX - Houston, TX Lines: 14 Keywords: ray-tracing caustics algorithm reality I was looking at a beautiful ray-traced image not so long ago and wondering why it looked less than real. There was something wrong with a transparent object in it. I had to refer to a *real* transparent object to figure out what it was: it had a nice diffuse shadow, but there was no caustic in and around the shadow from the refraction of light rays from the light source. It has occurred to me that I have never seen such an effect in ray-traced images. It shouldn't be too hard: you would have to reverse ray-trace from the light source for each transparent object and add the caustic to the texture map for each matte object it eventually falls on. Has anyone considered doing this? If this does lead to any breakthroughs, would this be the first time a usenet message was a reference in a technical paper :->?