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From: amamaral@elrond.CalComp.COM (Alan Amaral)
Newsgroups: comp.graphics
Subject: Re: Ray tracing and caustics.
Message-ID: <1037@elrond.CalComp.COM>
Date: Mon, 13-Jul-87 09:42:55 EDT
Article-I.D.: elrond.1037
Posted: Mon Jul 13 09:42:55 1987
Date-Received: Tue, 14-Jul-87 02:47:19 EDT
References: <219@sugar.UUCP>
Organization: Calcomp, A Lockheed Company, Hudson, NH, USA
Lines: 24
Keywords: ray-tracing caustics algorithm reality
Summary: It's been done...

In article <219@sugar.UUCP>, peter@sugar.UUCP (Peter DaSilva) writes:
> 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

It's been done by several people.  The one that I've been most impressed
with is the Rendering Equation by Jim Kajiya.  Basically, it is an
extension of distributed ray tracing that handles things like caustics
and subtle interactions of light bouncing from one surface to another
(i.e. light bouncing off of a red wall onto a white wall causing a pink
area to be formed).  The really neat thing about the rendering equation
is that it can be incorporated into a standard ray tracer without major
change.

It's written up in the '86 Siggraph conference proceedings.



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