[Sharlin]

A teleporter is just a portal that you can’t see through.

> You could make some weird impossible geometries by just superimposing sections. Two sections could occupy the exact same coordinates, but movement and rendering were done across edges shared by sections and did not care about if there was some other section in the same space. As long as there was never a way to see those sections at the same time.

This is exactly what portals are.