In the relatively brief time (about 2 years) I've seriously been messing around with 3d graphics, I have never yet had the need to learn about the mystical quaternion. That is, until today...
I'm working on a project that has gradually been forcing me to realize that I needed to treat coordinate spaces in a uniform way, and make no assumptions about the axes that made up these systems. Almost needless to say, thinking in terms of Euler angles and rotations about cardinal axes made a mess of the whole system.
So, I "googled it" and quickly found a really nice and simple paper that just tells you how to rotate a point around an arbitrary axis, without actually explaining the theory or deriving the proofs. It just tells you how to do it, with an example. You gotta dig that :)
My esteemed colleague Tobias 'hObbE' Olsson and I were interviewed this week for the podcast show Emil-O-Rama, which focuses on indie game development. We talk about Spell of Play Studios and our ideas about game development.