When it comes to making maps in Half-Life 2, one has to tread carefully. The two most basic problems builders run into at the beginning are:

• Spacing (how long is 128 units anyway?)
• Level Leaks

To combat these annoying problems many experienced designers will tell you to “Compiler Early, Compile Often.” This is absolutely sound advice. But there is another basic problem that can sneak up on a novice designer: texture mapping.

Setting-up the overall look and feel of a level is actually quite difficult if, as a designer, one paints every face with some “random ass textures” (a very irate Norm used that exact phrase once). The solution to this problem is the Development Texture Set (or “Orange Mapping” as some call it).

Valve had the foresight to include a special set of textures under the folder dev/ that were specifically designed to:

• Align more easily
• Keep the focus on the game play
• Allow for easier “texture uniformity”
• Separate the styling from the structure of the map
• Compile and test the levels more quickly

That last item is the kicker. With every wanna be ‘de_dust’ designer out there screaming “Compile Early, Compile Often!” The fact that using complex textures increases compile time is often overlooked.

From my experience using “orange maps” is actually quite nice, even for brush construction. Because the development textures are so standardized and aligned, once I get my basic spacing issues out of the way I can really go to town on brushing the buildings and obstacles.

Even better is the fact that my compile times soar through the roof and I can get in and play my levels much more quickly. Needless to say, I can’t even count the number of stupid mistakes I caught just by using dev textures early. Had they stayed, they would have cost ‘big time,’ on down the road.

So if you are planning on building a map, make sure you type dev/ in the texture browser’s filter and leave it there for a while. If you don’t then you are only hurting yourself, or possibly worse: your team.

(According to the source development wiki, Valve level designers will generally build maps with development textures before they style the level. So if you don’t believe me, trust them. [citation])