I am having an issue figuring out how to implement quaternions. I was reading an article that suggested to use euler angles for the gameplay, but convert the euler angles to a quaternion only when you need to interpolate between two rotations. The article was written back in 1998 though so I am skeptical since this tech changes so often (http://www.gamasutra.com/view/featur...uaternions.php).

Is that the correct approach to using quaternions or is there a better way? And if there is a better way, are there any articles you can point me to so I can start heading in the right direction?

Lastly, and possibly the most helpful thing, could anyone post a link to some opensource OpenGL project that uses quaternions properly so I can just learn by reading the code?