# Boolean cuts in GMAX

Boolean! What is it good for?

This tutorial follows on from the Simple Building tutorial for FS2004 and FSX. In that tutorial, we learnt how we could design a building of any complexity using simple extrude and vertex manipulations. But this technique won't always give the best result, if we take 'best' as meaning a combination of simplest, most effective and optimal. Let's look at a different building. Here we have a hangar, but a little more complex than our simple box with a peaked roof. (This angle shows the back, the hangar entrance is the other end.)

Now we could use the same extrude method that we've done before, but there is one issue which complicates matters -- the roof. This is made up of three flat surfaces, which since we are 3D modellers we'll call polygons:) Now imagine if we built the basic shape -- a kind of fat, lopsided 'T' shape -- by extruding the two 'wings' out the sides. Then when we go to make the roof -- again using extrude -- we will get some strange bending around the wings, as there would be seams and vertices getting in the way of manipulating each roof polygon as a complete, flat shape. We could fix this by some fiddly vertex alignment, but there has to be a simpler way!

Designing in 3D -- especially for the flight simulator, where simplicity equals good performance -- requires a bit of forethought, and this can mean just looking at our object before we get stuck into modelling, and picturing it in it's simplest form.

So what we really have here, for simplicity's sake, is our simple building from the previous tutorial. So, we start with a simple box, based on Google Earth measurements. And like our previous tutorial, we make the peaked roof from collapsed vertices from an extruded roof. The only extra step from the previous tutorial is to shift one middle vertex towards the centre of the building. Here's another view showing just how simple this is. Now we are not looking at the 'wings' as extra bits extruded from our model, but we look at the empty space on each side which isn't a wing -- we just need a way to cut those out.

Our cutting tool of choice is Boolean. By the way, this tutorial is meant to show how to use Boolean to cut unwanted geometry, it isn't meant to show all the uses of boolean.