- To interpolate two orientations
- Could use linear interpolation on all entries of quaternion (i.e. treat as four-dimensional vector)
- Unfortunately, intermediate quaternions would not have unit norm
- Angular velocity would not be constant even if renormalized

- Solution: spherical linear interpolation, or the
*slerp*.- Consider the quaternions as vectors
- Find the angle between them:
- Given parameter , the slerp interpolated value is
- Numerical difficulties when .
Replace the slerp with a lerp.

- Also a problem with ;
Should probably be flagged with an error and/or a request for more keyframes.

CS488/688: Introduction to Interactive Computer Graphics

University of Waterloo

Computer Graphics Lab