END OF AN ERA, FRACTALFORUMS.COM IS CONTINUED ON FRACTALFORUMS.ORG

The trouble with doing it that way is that animations will look weird, because the 6 base rotations don't all commute (ie, A * B != B * A). and so the order matters (eg, if you want to double the rotation angles you go from ABC to AABBCC instead of ABCABC).

There's a better way to do it using a pair of quaternions, with a qslerp (quaternion spherical linear interpolation) technique for tweening rotational animations.

See:
which presents "a new form of the 4D orthogonal rotation matrix parameterized in terms of two separate 3-sphere coordinates", as well as the rolling ball algorithm for interactive orientation adjustment