In this tutorial we are going to learn how to use CSG brushes to create our own game levels. CSG stands for Constructive Solid Geometry. Constructive Solid Geometry is a modeling technique that uses solid volumes. It has special properties that make it great for building game maps with. Automatic texture mapping means you can sketch our your level without worrying about adjustmenting texture mapping every time you make a change. CSG also allows boolean operations, which let you cut holes in walls to quickly make doors and windows.
Most game levels should be created with a combination of brushes, with some pre-made models added to provide small details here and there. In the image below, the walls, floor, ceiling, stairs, and other large features are made of brushes. The rails and other details are pre-made models placed in the scene. In this lesson we will learn how to use brushes to create the basic outline of our game level.
Creating brushes in your scene is a piece of cake, and with a few click you can start building. We are going to start out by creating a simple box brush. Click on the box icon on the Object Bar, if it isn't already selected.