Yes, I thought about it and mentioned in the first post. A problem here is that when the angle changes from \pi/2 to -\pi/2 there is a discontinuity: direction vector changes sign, so all coeffs also have to.
Yes, I thought about it and mentioned in the first post. A problem here is that when the angle changes from \pi/2 to -\pi/2 there is a discontinuity: direction vector changes sign, so all coeffs also have to.