When do I need to use quaternions?

Question

I have been carrying out 2D and 3D operations, including graphics, for many years and have never used quaternions so I don\'t have a feel for them. I know that they can be used

Answer 1

The advantage of quaternions over matrices is not only faster computation, but mostly because a matrix representation of successive rotations around arbitrary angles eventually give in to dreadful floating-point round-off errors and no longer represent proper, affine rotations. "Restoring" a rotation matrix is computationally more expensive than normalizing a quaternion. Therefore, quaternions should be chosen over pure rotation matrices.