The Source SDK (Source: Software Development Kit) is a software development kit compiled by Valve Software that is used to create maps or mods for the Source Engine. The Source SDK is distributed via Steam.


There are 4 utilities in the Source SDK:

  • Create a Mod: Dumps Source Engine code into a folder and places a mod directory under the SourceMods folder (Note: This does not appear in either of the Authoring Tools, and the Source 2009 version of the SDK cannot yet produce these files)
  • Refresh SDK Content: Checks for data updates and downloads/refreshes new data
  • Reset Game Configurations: Recreates game configurations with the basic games; mods mentioned in the configurations are removed unless manually edited
  • Edit Game Configurations: Edits individual game configurations, mostly for Hammer

There are also a number of smaller command line utilities used to process elements such as textures and models. Information on these are available at the Valve Developer Community.

Engine versionsEdit

The Source SDK currently has three engine versions. A user can choose the 2006 version of the Source Engine, which is only used by Half-Life 2: Deathmatch, Half-Life: Source, Half-Life Deathmatch: Source, and various mods built on old Source 2006 code. All other Source games have been updated to the most recent 2009 version of the Source Engine, with the exception of Episode Two, which used the 2007 version between May 11, 2010 and June 23, 2010, and various mods built on old Source 2007 code.

A separate program, called the Left 4 Dead Authoring Tools, was created as a version of the SDK for the Left 4 Dead version of Source, the same thing occurred for its sequel Left 4 Dead 2. Currently, neither allows new mods to be created.


There are three applications in the Source SDK, Valve Hammer Editor, Model Viewer, and Face Poser.

Valve Hammer EditorEdit

The Valve Hammer Editor is a program included in the Source SDK that allows users to create maps for the Source Engine. It can be used with many different game configurations, for Source games like Team Fortress 2, Counter-Strike: Source, and Portal.

Model ViewerEdit

The Model Viewer is a program that allows users to view models and can be used for a variety of different purposes, including development. Developers may use the program to view models and their corresponding animations, attachment points, bones, and so on. It can also be used to view props, weapons, buildings, and just about any other 3D object found except something which is a brush (an object created in Hammer that makes up the actual world - something like a floor, wall, room, skybox or terrain), the Model Viewer can't view game textures either (Hammer is used for that purpose instead).

Face PoserEdit

Face Poser is the tool used to access facial animations and choreography systems.

This tool allows one to:

  • Edit facial expressions, gestures and movements for characters (known as actors), allowing one to mix or blend several expressions on the fly.
  • Lip synch speech with the speech the characters use (and blend the speech with other facial expressions). The phonemes used for lip-synching can be extracted from existing spoken .wav files, the tool taking care of the real-time association between the spoken phonemes and the movements of the lips.
  • Sequence expressions and other acting cues and preview what the scene will look like in the Game engine. A scene can refer to multiple actors and thus can be used to block out fairly complicated interactions and dialogue between game characters.

External linksEdit

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