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From: tomg@hpcvlx.HP.COM (Thomas J. Gilg)
Newsgroups: comp.graphics
Subject: Re: Ray tracing refraction
Message-ID: <101880003@hpcvlx.HP.COM>
Date: 30 Jan 89 19:24:44 GMT
References: <0XryqWy00Uo1875Ud-@andrew.cmu.edu>
Organization: Hewlett-Packard Co., Corvallis, OR, USA
Lines: 20

>> I'm trying to add refraction to a ray tracing program I'm writing in C. 

> How do people (or do they) manage refraction when the index of
> refraction is a function of the wave length of light and in a crystal
> the direction of light with respect to the orientation of the crystal
> itself.
> The reason that this would be valuable is that to ignore it
> life would be without rainbows and the fire of diamonds.

Question : is the index of refraction linear with repect to the
wavelength ?  I started writting a ray tracer and took liberty in
assuming linear response.  Any experts out there ?

As for crystal alignment, what about using the concept that a
surface is made up of micro-facets.  While this idea is used for
reflectivity, I would think a spin-off idea could handle your
problem.

     Thomas Gilg
tomg%hp-pcd@hplabs.hp.com