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

Compared to Euler angles they are simpler to compose and avoid the problem of gimbal lock.

Compared to rotation matrices they are more numerically stable and the representation (4 numbers) is more compact.