Animation is often done by setting up a sequence of key orientations; represented by quaternions. The in between orientations are obtained by spherical linear interpolation (SLERP) of the quaternions; which then can be used to rotate the objects. However; SLERP involves the computation of trigonometric functions; which are computationally expensive. Since it is often required that the angle between each quaternion should be the same; we propose that incremental SLERP is used instead. In this paper we demonstrate five different methods for incremental SLERP; whereof one is new; and their pros and cons are discussed.