Decompiling Maps
Decompiling is the process of taking a compiled level and generating a source that can be opened in a map editor. Decompiled levels mimic the original source, they are not exact reproductions. This makes them useful for learning, measurement, and inspection, but not direct recompilation. The original source is ideal for reproductions or modifications.
Releasing reproductions, modifications, or approximations of another's work without permission nor credit is frowned upon and may be considered as a copyright violation.
Tools
Getting Dirty
The latest decompiler is called BSPSource and is written in Java. You need an updated version of the Java Runtime Environment (JRE), which can be downloaded from Sun to run BSPSource. Once installed, you are ready to decompile your first map.
Extracting Valve maps
- Install GCFScape.
- After you install GCFScape, go to
File >> Open.- For
Counter-Strike: Global Offensive maps, open \steamapps\common\Counter-Strike Global Offensive\csgo\pak01_dir.vpk - For
Counter-Strike: Source maps, open \steamapps\counter-strike source shared.gcf - For
Day of Defeat: Source maps, open \steamapps\day of defeat source.gcf - For
Half-Life 2 maps, open \steamapps\half-life 2 content.gcfand\steamapps\half-life 2 2007 base content.gcf - For Half-Life 2: Deathmatch maps, open
\steamapps\half-life 2 deathmatch.gcf - For
Half-Life 2: Episode One maps, open \steamapps\half-life 2 episode one.gcf - For
Half-Life 2: Episode Two maps, open \steamapps\episode two maps.gcf - For
Portal maps, open \steamapps\portal content.gcf - For
Portal 2 maps, open steamapps\common\portal 2\portal2\pak01_dir.vpk - For
Team Fortress 2 maps, open \steamapps\team fortress 2 content.gcf - For
Left 4 Dead maps, open steamapps\common\left 4 dead\l4d\pak01_dir.vpk - For
Left 4 Dead 2 maps, open steamapps\common\left 4 dead 2\l4d2\pak01_dir.vpk
- For
Note:Left 4 Dead, Left 4 Dead 2, and Portal 2 also have other folders for DLCs, for examples:
steamapps\common\portal2\portal2_dlc1\pak01_dir.vpk, steamapps\common\left 4 dead\l4d_dlc1\pak01_dir.vpk, steamapps\common\left 4 dead 2\l4d2_dlc1\pak01_dir.vpk .3. Browse the directory until you find a \maps\ folder. Each location varies per game.
4. Right-click on the BSP file you want, then click Extract or drag the file from the GCF into a folder.
Before You Go
Before you take this jump to run off and decompile a map take a second or two to think, "What am I trying to learn/do?". Read the included TXT files, you may just find the creator's e-mail, and that could be more helpful than you imagine.
Some mappers will offer up help and advice, they may even go so far as to provide perfect examples of what you were trying to "borrow" from the map.