Tesseract
A hypercube turning through an axis you can't point at. Hue tracks the fourth coordinate: cold is far in w, gold is near.
Movements
Unfold
All eight cells are cubes. Folded, three cells share every edge you see; opened, they come apart.
Rotation planes
The three gold planes turn through w. Only they can make the cube pass through itself.
Fractal
Each copy is the solid put through its own rotation again. The ornament is the state, iterated — not decoration laid over it.
View
Checkpoints
Save the state you are looking at — angles, fold, net, colour, zoom — then travel between the saves.
Checkpoints live in this browser, for this site alone. A JSON file is how you move them somewhere else, or keep them safe.