Im using quaternions for rotation. I am getting the quats from key frames in a .3ds file. How do I concatenate these rotations? Simple quaternion multiplication doesnt seem to be doing the trick. Keep in mind that I am then translating the concatenated quaternion into a rotation matrix after the concatenation. Does anyone know how to get a proper concatentated rotation using quaternions? Thanks. Well, that was a waste of 2 minutes of my life. Now I have to code faster to get ''em back...

What do you mean ''concatenate'' ? The only meaningful way to concatenate rotation quaternions is to multiply. Don''t forget that the order of multiplication matters, and that a generalised transformation is not just a rotation: it may also involve a translation, e.g. a vector, you have to deal with.

Do you mean something else ? E.g. if you want to blend, i.e. interpolate, between quaternions, use SLERP or some other interpolation method.