   outside-inside transitions
  Hey, I'm working on an isometric game and have a building rendered onto a quad with opengl. I can't seem to figure out how to do door colissions(sp?). I tried just checking for a colision in the middle of the bottom of the building(were the door is) but no luck. Here's 2 questions:1) How can I do this? and 2) Once I get a colision with a door, how would I respond?(wiping the map that places buildings and instead doing indoors, and when colliding again, put it back to buildings?)   
  I'd just fake it with a variable-sized "entity" that you lay on the floor and is treated as a map transition, which specifies the map to go to.Then just spread it in front of the door and go.   