Interface for an orientation in 3D. The orientation is defined by a single
vector, so the oriented object must have linear symmetry for this to make
sense. IOrientationFull3D can be used for an oriented object without linear
Rotate the orientation by the amount dt (radians) about the given axis.
If the given axis is considered "up" (out of the plane and toward the
viewer), then positive rotation is in the counter-clockwise direction.