one nice thing is that if you represent the state as a permutation matrix P, and have a matrix of starting piece locations x, rendering is just Px. Then, for smooth rotation animations, if your move is a permutation M, animation is just expm ( t logm( M)) P x with t going from 0 to 1

I blather about the permutation matrix of a rubiks cube for a long while at https://www.hgreer.com/TwistyPuzzle/