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Re: Finding all angles within a range of directions; an algorithm question [message #30284 is a reply to message #30266]

Wed, 17 April 2002 18:16

Craig Markwardt
Messages: 1869
Registered: November 1996

Senior Member

tbowers0@yahoo.com writes:

> Wow Struan! Your explanation was a bit beyond me. So, instead of just
> replying "Uhh.. Huh?" I did some surfing on rotation matrices and
> stuff and found the Matrix and Quaternion FAQ at
> http://skal.planet-d.net/demo/matrixfaq.htm. Educated myself a bit,
> but I'm still unclear. If I understand:

Hi Todd--

You definitely want to use the dot-product approach. It's fast, and
there's no room for screwing up the signs like there is in rotation
matrices. And, as you say, you can make a different cut, other than
90 degrees.

But, if you *did* want to use quaternions, then I have a whole library
for you on my web page :-)

Craig

Craig

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Craig B. Markwardt, Ph.D. EMAIL: craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
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		Finding all angles within a range of directions; an algorithm question By: tbowers0 on Thu, 11 April 2002 14:01
		Re: Finding all angles within a range of directions; an algorithm question By: Struan Gray on Thu, 18 April 2002 02:27
		Re: Finding all angles within a range of directions; an algorithm question By: Craig Markwardt on Wed, 17 April 2002 18:16

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