Non-Euclidean Portal (in Nil geometry)

This time we are going into a portal that is actually non-Euclidean!

This is a portal in the shape of a Penrose staircase, living in a space with Nil geometry.

Nil geometry is a kind of non-Euclidean geometry which makes "impossible figures" like Penrose staircases possible (in some sense). See    • Playing with Impossibility (D. Celińs...   for an explanation.

If we do not take the portal into account, this is a closed manifold with Nil geometry (i.e, the space is wrapped like in Asteroids or in Manifold Garden).

Six worlds like described above are connected with portals. When we go through the inside of the Penrose staircase, we end up in another world. Each world has a 3x1 box of a different color. Each world also has fog of a different color.

Made with the HyperRogue engine aka RogueViz
Source code: https://github.com/zenorogue/hyperrog...
A playable Windows exe at http://roguetemple.com/z/sims/notknot... (works in VR too!)