Death In A Flash by Imaginos
Screenshots of the map in Worldcraft
As you can see, things can get pretty confusing!
In this XY Window shot, you're looking at the Red Base from the top down. The building in the middle has a sub-basement, a basement, a first floor and a second floor.
Here is the same shot in the XZ Window.
The 3D View is just as confusing...
But now look at it with VisGroups enabled.
Here is a shot of just the basement in the Red Base.
As you can readily see, this makes it easier to make last minute changes and it's all thanks to Visgroups!