source files: xtfm.[ch]
(XG.3D-COMBINE-ROTATIONS (<axis1-x> <axis1-y> <axis1-z>) <angle1> (<axis2-x> <axis2-y> <axis2-z>) <angle2> ...)
Combine a series of arbitrary-axis rotations into a single rotation. Angles should be specified in radians. The call will return a list of the form ((<axis-x> <axis-y> <axis-z>) <angle>).
This function is useful for combining the three principal axis rotations returned by the :DECOMPOSE method into a single rotation. (In fact, that is why it was written!)