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From: grahaf@otago.ac.nz
Newsgroups: comp.sources.wanted,comp.graphics
Subject: Re: Ray tracing
Message-ID: <1991Jun27.155718.625@otago.ac.nz>
Date: 27 Jun 91 02:57:18 GMT
References: <383@bibsyst.UUCP>
Organization: University of Otago, Dunedin, New Zealand
Lines: 46

In article <383@bibsyst.UUCP>, ingar@bibsyst.UUCP (ingar) writes:
> I'm not sure i made myself clear the last time so I try again.
> 
> In my ray tracing program I am not able to ray trace cubes, or anything
> that contains a strait line. They always end up looking like deformed 
> spheres, a sphere with angels as a matter of fact. If i ray trace an 
> object in a room the walls alway ends up in looking like "bowls". 
> I have checked my types and they are all correct, and I have checked
> that all my vector lengths are correct.
> 
> Does anybody have an idea of what I am doing wrong, except the fact
> that I started to make a ray traceing program??
> 
Someone else had this problem and the answer posted was "You have a fish eye
lens problem.



Eye    View         Object
       plane                     This results in bent edges
        |           /------/
        |          /     / |
        |         /     /  |
/       |        |------|  |
\	|        |      | /
        |        |______|/
        |
        |


Try this.
                                     View           Object
Eye				     plane
				        |           /------/
				        |          /     / |
				        |         /     /  |
/				        |        |------|  |
\				 	|        |      | /
				        |        |______|/
				        |
				        |


Hope this helps,

Graham.