Quaternion Rotation
- A quaternion is a 4-D unit vector q = [x y z w]
- It lies on the unit hypersphere x2+y2+z2+w2=1
- For rotation about (unit) axis v by angle ?
- vector part (sin ?/2) v = [x y z]
- scalar part cos ?/2 = w
- The rotation matrix corresponding to a quaternion is
- Quaternion Interpolation
- represent rotation as quaternion
- SLERP: linearly interpolate quaternions q1 and q2 and normalize
- convert to rotation matrix to apply the rotation