Boolean  Giving our hangar an insideThis is a commonly asked question on my site  how do I add an 'inside' to my building? I like to model closed hangars (not to be confused with clothes hangers...) but there are a lot of reasons why we might want an open hangar. For instance, some folk like the realism of putting their aircraft away safe at night. There are issues with modelling the inside of a hangar, and I'll mention them briefly later, but I won't cover them in detail.
Basically, we want to model the 'space' inside our hangar as a separate, solid geometry, then use Boolean to subtract it from the solid hangar. With a simple hangar  that is, without the 'T' shape here  the simplest way to do this is to duplicate the hangar, shrink it slightly (without moving it), extend the base below the ground then use this copied, shrunk version as the boolean cut. That isn't going to work, here, though, because the hangar takes up just half the actual building. By the way, why would we need to extend the base below the ground? This brings up the question of whether or not we want a floor in our hangar. This is one of those 'issues' I mentioned a minute ago:) Now it might sound like a good idea to model the floor of our hangar  we could make it look really realistic, by applying some grease stains, dirt, paint etc to the floor, but there are some problems with this. The main problem is that any geometry close to the ground tends to have display issues  it may 'flash', all the time or just from a distance. This can be disconcerting. A simple solution is to model the floor using a technique which prevents these display issues  such as a simple AFCADstyle polygon quite separate from our GMAX model. But if you must have a floor, I'll leave it up to you to figure out how to do it well. So, we need to model the empty space in our hangar as a solid object first. We can use the techniques we already know for this  we just need to start with a box, slightly smaller than the hangar to allow the thickness of the walls, then pitch the 'roof'  or ceiling space in this case  the way we did it in the early tutorials. By the way, we are not adding a doorway yet, we are just making the inside space.
Here's our box sitting neatly inside the front half of our hangar. It helps to switch to wireframe view here, just to see inside our hangar! And below we've switched to a view where we can best match the shape of the pitched 'roof'.
Note that the new shape extends below the ground, so that we don't get a floor. Now we just need to make the boolean cut exactly the same as we did earlier...
The inside space is only visible from underneath the hangar at the moment, as we haven't cut the gap for the door yet. That uses the same technique, so I don't even need to show that here.. Oh, ok, let's finish it up.
