Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!mcsun!ukc!slxsys!ibmpcug!peterl
From: peterl@ibmpcug.co.uk (Peter Leaback)
Newsgroups: comp.graphics,connect.audit
Subject: RE:Errors in rotations
Message-ID: <1990Jan6.010548.13313@ibmpcug.co.uk>
Date: 6 Jan 90 01:05:48 GMT
Organization: The IBM PC User Group, UK.
Lines: 25


[this message has been resent because of CONTUNUEING problems at my end]

Many thanks to everyone who has replied by mail and here.

I think the most promising method i will follow up is a mixture of
Quaternions and normal rotations.

If i define my rotations as a Qaternion this poses another problem for
me, that of movement.I would need to extract something approaching a
direction vector from the Quaternion. This was simple with a rotation
matrix because i would just pick up the Z vector of the matrix and
multiply this with the speed to get the velocity. The Z vector of the
matrix can be found from a Quaternion but this requires 6 multiplications
which invalidates the speed advantage of Quaternions.

Would it be possible to use the vector part of the Quaterion as the
direction vector of the object ?

Peter Leaback.

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