I have some existing code which does catmull-rom interpolation on two vectors (facing and up). I'm converting this to use quaternions instead (to replace the two vectors). Is there a general way to convert the vector based interpolation to a quaternion one?
The approach I'm using now is to exact the axis and angle from the quanternion. I then interpolate each of those independently and convert back to a quaternion. Is there a more direct method?