Optimization Commands

showbudget

Before you start doing any optimizing on an existing map, you should know what to optimize -- it'll be a waste of time and effort to optimize, say, your world brushes if your dynamic lights are what are actually killing performance. So your first tool is showbudget. Get to know it well!

To effectively use showbudget, you should turn it on and run around your level. Look for areas that cause trouble (fps goes too low and/or some bars jump significantly to the right). These trouble spots should be the initial focus of any optimization. As to how low of an fps reading is too low, or how far a jump is significant... that's for you to decide. You might try comparing your readings to those of the sample maps.

mat_wireframe

The other major tool you can start using from the beginning is mat_wireframe. This is a console variable that shows everything that the graphics engine is trying to draw. You will very quickly find that it tries to draw a lot more than a human would think it should.

Notice that many brushes, especially large ones, are broken up several times. Some of this is unavoidable, but much of it can (and should!) be corrected. It is unavoidable that rectangular faces are converted into two (or more) triangles--Source only draws triangles, so this is fine. But sometimes a face is broken into dozens of oddly-shaped triangles, and this is a problem, since more triangles means that the map is slower. One aspect of optimizing a map is to reduce the number of triangles your world is broken into.

Usually, the engine will draw many props that are not actually visible. Another major aspect of map optimization deals with that problem: how to encourage the engine to draw only as much as it should. Hint brushes and occluders can help here; both are discussed later.

Try using mat_wireframe to compare the maps of beginners to those of professionals. If using you own maps, running the VIS stage of compilation will help.