Walls II

Allow me to elaborate...

A square room (top down view)

Ok so this is a square room. It consists of four lines (walls). So in-game, we draw four quads (one is behind the camera so we can't see it):

Square room in Gloom: three walls are visible

Alright. So let's say we have two connected rooms:

Two rooms!

What we do now is we connect the rooms by cutting a hole in the far wall, based on the difference in ceiling- and floor heights between the two rooms.

Back wall now has an opening in it to connect the rooms

The interesting thing is that these two are the only possibilities: a wall, or a wall with a hole in the middle. Yet you can build very complex and interesting architectures using this system. Just look at the maps in Doom!