Was there some sort of special animation for this movie because it has never looked quite like other animation.
It was almost entirely rotoscoped, if that’s what you mean? That means it was drawn on top of live action film, which is how they got the realistic subtleties.
Whoa, that’s so cool. Wow.
And this, ladies and gentlemen, is rotoscoping done fantastically right.
Because all you really need to do is find some cheap animation produced by lesser-to-completely-unknown studios to see how horribly disturbing rotoscoping is when the artist cannot animate very well; if the frame rate is too slow? It looks jerky, choppy, and repulsively unnatural. It leaps right into the uncanny valley and sets up house there.