The maximum size of a level in Quake is traditionally 4096 units in all directions, starting from (0 0 0). The map compiler can deal with bigger levels, but most engines will simply not allow you to cross the “line” ingame. You will get a HOM-like effect (Hall of Mirrors) when near the invisible border, and you’ll sometimes look out past the level geometry and see the other side of the map floating out there in “the void” that surrounds a level in Quake. Weird shit.
In this screenshot, you’ll see how a map creeps up on the +-4096 limit in the map editor. There are a couple ways around this – I could stop building in a certain direction, and simply put a teleporter at the end of a corridor that ports the player back into the “safe zone”, and continue building there somehow.
However, this map is a remake of an original Quake map, and hence a certain layout is roughly expected. I could wrap the map under or over itself, somehow, but it wouldn’t be the same map. Besides, the existing geometry of this level is already extremely three dimensional, which is hard to see in the top view, but it pretty much doesn’t allow to put a new branch of the level somewhere between the existing geometry without intersections.
I could try to stuff the rest of the level into the zone at the lower end of the available space, but I know what parts are missing, and I determined it wouldn’t fit that way either.
The temporary end of the map – it’s not finished – is in the lower left. You’ll notice it’s exactly on the critical line. Building additional geometry will break the unwritten law. I’m sorry, I’m just going to tell the unwritten law to fuck off, and alter the engine in such a way as to allow me to do it.
Cheating is often more efficient 😛