Boolean  making a simple cut or twoOops, we better find out where our boolean tool is first. This is located on the Command panel, Create tab, Geometry selector. Normally the dropdown menu is set to Standard Primitives, which is our basic geometry such as the Box we began with. However now we want to select Compound Objects.
A quick introduction to the boolean tool, but remember this isn't meant to be an indepth look at boolean, just one particular part  the boolean cut. The Rollout options for boolean allow us to choose an Operand  labelled as Operand B, as the currently selected object is assumed to be Operand A. It also allows us to choose how the result is created  we want to choose 'move' here, but I'll leave it up to you to explore the other options if you wish. We also get to choose the Operation. The Boolean Operation has various choices, but we want to subtract. Again, have an explore of the other options, but 99% of the time I use Subtract, in particular Subtraction (AB). This assumes that I have selected the hangar first, making it Operand A, and that B will represent the geometry which makes the cuts. So what is Operand B, and why do we need it? Basically this is a separate object, representing the geometry we want to cut from our hangar. In this case, we can just use a simple box on either side of the hangar. So we can create a couple of boxes of suitable size, and place them so that where they intersect our hangar, they represent the bits we want to cut out. This requires some measurement and alignment, but I'll leave this up to you. In this case I want to remove 3 metres on either side, and two varying lengths of the hangar. I can make the box bigger  and taller  than the actual cut, and shift it into place to represent the correct location of the cut.
I make sure that the top of the boxes actually clear the roof, so that the cut goes all the way up. Here I've actually Attached (convert one to Editable Poly, and Attach the other) our two boxes together to make one object. This isn't required, but it is something I tend to do for one important reason  boolean cutting is a complicated process, and it is also the main cause of damaged files on my system. By this I mean that the more boolean cuts I make, the more likely that I won't be able to open the file in the future! Making the minimum number of boolean cuts helps, as does converting our object into a normal Editable Poly after our cutting. Keeping a number of boolean cuts in the stack can be a recipe for disaster. So with our hangar selected, we can make our cut using the Boolean tool, using Subraction (AB) as the operation, Move as the Pick option and Display:Result as the display option.
We click on the box labelled 'Pick Operand B' and then click on one of the two boxes, which we've combined into one object. And there we go  the shape we want, with the minimum number of vertices, nice and 'manifold' for FSX.
Boolean has a number of uses, one of which is to open up the doors of our hangar, allowing us to model the inside. While we're here, lets have a quick go at that.
