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

Pros of quaternions

1. Fast multiplication
2. Fast to/from matrix conversion
3. Avoid additional (from computation) noise (scale , shear) , and represent pure rotation
4. Simple rotation interpolation, in custom case for real time animation can be used linear interpolation.
5. Some tricky operations available, fast rotation integration, twist swing decompositions

Cons.

1. Transformation of vector is not so fast as with 3x3 matrix.
2. Contains 4 scalar, but compact rotation representation can use only 3.