I just need a top level example of how quaternions work. If, for example, I have an object that I want to rotate 16 degrees about the body's Y axis and 5 degrees about the body's x axis, how do I do this in terms of a quaterion?

-- Dean Espitallier (dean.s.espitallier@lmco.com), July 10, 2003

Answers

Hello Dean:

There is no universal convention for the way people write 3x3 rotation matrices (few books define it the same way). The definition of a quaternion defined as a matrix has stayed stable with Hamilton's formulation. A great place to learn about the two ways of approaching rotations is in the following paper:

http://world.std.com/%7Esweetser/quaternions/ps/stanfordaiwp79-salamin.ps.gz

doug

-- Doug Sweetser (sweetser@alum.mit.edu), July 10, 2003.