I have a custom scenery addon I downloaded. Looks beautiful. However, if I have AI aircraft on, I have noticed they will taxi right thru the buildings (the Addon is a 3D addon replacing the default 2D). I assume there is some collision information that's probably missing so I was thinking about opening the scenery maker (which I've never touched before) and add whatever I need to, to get the AI to realize the building is there (they taxi right thru the building and just continue on their way). BUT, before I waste valuable hours of my time trying to learn the scenery maker, I wanted to be sure this was actually possible to fix. EDIT: BTW, I should also mention that the guiding lines I get when I file a IFR plan with ATC also tries to get me to run into the buildings as well.