This tutorial is an example of mitering, a technique that should be used by all mappers to reduce triangle counts ingame. The first image here is a screenshot from GTKRadient showing the sides of 2 buildings. The one to the left is how the building was originally designed in a minute which allows for easy changes and redesigns to be made.
On the Right we have the building after it has been optimised for triangle counts which took an extra minute or 2. Although we have used More brushes in the editor, their placement manually specifies how the compiler will divide these brushes into triangles.

The Second Image is the same two walls ingame. By looking at the wall to the left you can see that the compiler has added a vertex, (therbye splitting the face and adding an additional triangle) wherever a vertex from one brush intersects with the edge of another. This is particularly evident on the left and right most brushes that have each been split into 8 triangles each.
On the optimised building we can see that no additional vertices have been added and the only additional triangles are where a 4 sided brush has been split into 2 triangles.

The left design results in 71 triangles to represent this wall, whereas the right design results in 47 triangles. A saving of 40%.
This may not sound like much when a Quake3 scene generally supports up to 12000 triangles, however consider saving 28 triangles on each of 4 walls of a building, and then duplicating the building and variations of it 10 times within a scene. In this scenario mitering has just saved us 11200 triangles!!

click to enlarge pictures

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Copyright © 2009 Steven "Delirium" Krzanich. This document is released under the terms of the Creative Commons Attribution-Share Alike 3.0 Unported License, http://creativecommons.org/licenses/by-sa/3.0/