[comp.graphics] quaternions

charles@cs.strath.ac.uk (Charles X. Chen) (03/09/90)

In article <8513@chaph.usc.edu> you write: 
>
> Would anyone out there enlight me what 'quaternion' entails in
> the area of computer graphics?
 
Quaternion is a very old mathematic concept. it has been used in computer 
animation for a while, mainly for doing interpolation calculations. 
Because each position of an object in the context can be expressed by
a quaternion, the interpolation between key-frames reduces to interpolating
between associated quaternions, linearly or spherically


Charles 


Charles X. Chen
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doug@xdos.UUCP (Doug Merritt) (03/11/90)

In article <2505@baird.cs.strath.ac.uk> charles@cs.strath.ac.uk writes:
:Because each position of an object in the context can be expressed by
:a quaternion, the interpolation between key-frames reduces to interpolating
:between associated quaternions, linearly or spherically

Know any references regarding harmonic analysis in quaternion space?
	Doug
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Doug Merritt		{pyramid,apple}!xdos!doug
Member, Crusaders for a Better Tomorrow		Professional Wildeyed Visionary

charles@cs.strath.ac.uk (Charles X. Chen) (03/13/90)

Doug,



Here are some references you might be interested in reading:


********************************************************************
Shoemake K.
"Quaternion Calculus and fast Animation", Siggraph 87 Course # 10 : "Computer
Animation: 3D Motion specification and Control", pp. 101-121

Shoemake K.
"Animating Rotation with Quaternion Curves"
Computer Graphics, 19(3), pp. 245-254, Proc. Siggraph 85

Pletincks D.
"The Use of Quaternions for Animation, Modelling and Rendering"
New Trends in Computer Graphics, Proc. CG International '88, Springer-Verlag
ISBN 3-540-19328-6



Here are two very old but important ones which I meself would like to find
and read:

Caley A.
"On certain results relating to quaternions"
Philosophical Magazine, 26, 141-145, (1845)

Hamilton W. R.
"On Quaternions: Or on a new system of imaginaries in algebra"
Philosophical Magazine, 25, 10-13 (1844)

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Hope this info is helpful.




Charles X. Chen

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