This is a really cool effect. The demo page doesn't say much, but there are parameters for speed, overlap, shading, and perspective. It would be cool if the first thing you see on the demo page is an unfolding menu that has clickable items to see other demos that show off these parameters a bit more.
The only other thing I'd note is that if you click the toggle button while the animation is loading, the animation snaps to the start of the next state and begins the animation. It doesn't fold up/down from its current position. That might be a tough thing to add, but it could go a long way.
The only other thing I'd note is that if you click the toggle button while the animation is loading, the animation snaps to the start of the next state and begins the animation. It doesn't fold up/down from its current position. That might be a tough thing to add, but it could go a long way.
Overall, I enjoy this effect. Nice work!