Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!blake!wiml
From: wiml@blake.acs.washington.edu (William Lewis)
Newsgroups: comp.graphics
Subject: Re: fast 3D algorithms
Summary: all-arithmetic perspective alg.
Keywords: no trig functions
Message-ID: <2018@blake.acs.washington.edu>
Date: 13 May 89 00:40:49 GMT
References: <May.11.20.01.50.1989.20285@topaz.rutgers.edu> <9666@watcgl.waterloo.edu>
Reply-To: wiml@blake.acs.washington.edu (William Lewis)
Organization: University of Washington, Seattle
Lines: 17

In article <May.11.20.01.50.1989.20285@topaz.rutgers.edu> sofmac@topaz.rutgers.edu (Sofus) writes:
>
>I m trying to make a fast procedure in graphics to simulate 3D.
>My algorithms consists of sin & cos, but they are too slow.  If 

   I have found an algorithm that uses only addition, subtraction,
multiplicatoin and division that >should< give a good perspective
transform. It unfortunately requires floating point operations, although
they could bve eliminated with a little work.
   The algorithm is passed an eye point. It 'looks' towards the origin
from this point. Moving the eye point in a circle will rotate the figure,
for instance.
   I have worked out the equations but have been unable to get it to work
correctly. I haven't spent much time at it, however; my probl;ems are probably
programming typos on my part.
   If you want the algorithm I will mail a description to you. If you can get
it working, please send me source...