I've just finished a sort of generic "crime alley" map (not the Batman "Crime Alley" specifically, but the same idea of a dark alley with no outlet). Anyway, one of the cool things (cool to me, anyway) about this map is the idea of multiple elevations -- some elevated terrain being higher than others. That is, some buildings are taller than others -- indicated by little elevation markers in the corner of each elevated area.

This creates cool strategic opportunities with LOS, etc. Problem is, there aren't any official rules to cover such a thing. That doesn't mean I'm going to ditch the map, it just means I'll have to devise some house rules for it. I think the simplest would be that LOS to and from elevated terrain stay the same, but that the term "elevated" is relative, so that it means that one party is on a terrain higher than the other. That is:

XXXBXCXXX
XXXXXXXXX
XXAXXXXXX

A is grounded
B is on the edge of a 30' elevation
C is on the edge of a 60' elevation

In combat between A and B or C, this is as the normal rules.
In Combat between B & C, B is treated like the grounded character, because his elevation is lower than C's.

Has anybody dealt with this in their house rules? I would think that folks who build a lot of 3D maps would run into this a great deal. I'd love to hear your thoughts.