Path: chuka.playstation.co.uk!news
From: sceetech <ps_yaroze@interactive.sony.com>
Newsgroups: scee.yaroze.programming.libraries
Subject: Re: Rotation Matrix Functions
Date: Wed, 09 Apr 1997 15:30:47 +0100
Organization: SCEE
Lines: 19
Message-ID: <334BA817.4A3C@interactive.sony.com>
References: <01bc4074$bd79ee80$d603e8c3@fred> <334A0C83.5959@micronetics.com> <3348D96D.289@interactive.sony.com> <334b2016.21064909@news.playstation.co.uk> <01bc4448$a37ddc80$0b16e8c3@fred>
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Michael Enoch wrote:
> 
> I'm after the latter of your (Lewis's(SCEETech)) two options, where the
> order matters, I had thought about fixing the matrix every so often and
> after your suggestion that seems to be the answer.  I don't suppose you
> could show me an example of how to do that, could you?
> 
>         Mike.


Take the rows (or columns) one at a time calculate the length
sqrt(x*x+y*y+z*z)
and divide the x,y,z by the length

The problem is that 4096 is one and sqrt is slow.
All this means is that before the divide you have to multiply by 4096,
and for the sqrt, only doing one row in a frame and not every frame.

Stuart