----- Original Message ----- From: "Peter Woodward" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, August 13, 2002 9:09 AM Subject: [JAVA3D] Computation of eigen axis
> Hello, > > I have a set of three rotations around the standar xyz axes. I wish to > concatonate them into a single rotation - I understood this to be called > Eigen axis- I guess there must be an algorithm, I believe the > aeronautical/space community need to do this. I've had a look at Matrix > and various other FAQ's to no avail. > > Does anybody out there have an algorithm or c/c++/java/j3d method ? Peter, It sounds like you're asking about specifying rotations as a sequence of Euler angles. The good news is that there are plenty of resources describing the transformation (a good place to start would be the Matrix and Quaternion FAQ at http://www.cs.ualberta.ca/~andreas/math/matrfaq_latest.html#Q36 or a wade through the gleanings from groups.google.com for [comp.graphics.algorithms +"Euler angles"]). The bad news is that plenty of the resources are written by people who don't quite understand what they're talking about. Evaluate the sources carefully in relation to what you're trying to do, and if you write your own routine, validate it against methods constructed by brute force from vecmath. If you stick to small or differential angles, specifically avoiding multiples of 90 degrees, you can ignore most of the dread and dire warnings. hth, Fred Klingener =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
