Source (game Engine) - Modularity and Notable Upgrades

Modularity and Notable Upgrades

Source was created to evolve incrementally as technology moves onwards, as opposed to the backwards compatibility-breaking "version jumps" of its competitors. With Steam, Valve can distribute automatic updates with new versions of the engine among its many users.

In practice however, there have been occasional breaks in this chain of compatibility. The release of Half-Life 2: Episode One and The Orange Box both introduced new versions of the engine that could not be used to run older games or mods without the developers performing upgrades to code and, in some cases, content. For both times, however, the work needed to update the version was significantly less than what one might have come to expect from other engines. This was demonstrated in 2010, when Valve updated all of their core Source games to the latest engine build.

Since Source's release in 2004, the following major architectural changes have been made:

High dynamic range rendering (2005, Day of Defeat: Source)

Simulation of a camera aperture and the ability to fake the effects of brightness values beyond computer monitors' actual range. Required all of the game's shaders to be rewritten.

"Soft" particles (2007, The Orange Box)

An artist-driven, threaded particle system replaced previously hard-coded effects.

Hardware facial animation (2007, The Orange Box)

Hardware accelerated on modern video cards for "feature film and broadcast television" quality.

Multiprocessor support (2007, The Orange Box)

A large code refactoring allowed the Source engine to take advantage of multiple CPU cores on the PC, Xbox 360 and PlayStation 3. On the PC, support was experimental and unstable until the release of Left 4 Dead. Multiprocessor support was later backported to Team Fortress 2 and Day of Defeat: Source.

Xbox 360 support (2007, The Orange Box)

Valve created the Xbox 360 release of The Orange Box in-house, and support for the console, unlike support for the PlayStation 3, is fully integrated into the main engine codeline. It includes asset converters, cross-platform play and Xbox Live integration. Program code can be ported from PC to Xbox 360 simply by recompiling it.

PlayStation 3 support (2007, The Orange Box)

Source first appeared on the PlayStation 3 in 2007, but with an engine port that was created externally and which was plagued with issues. Valve took the problem in-house for Portal 2, and in combination with Steamworks integration created what they called "the best console version of the game".

Mac OS X support (2010, multiple games)

In April 2010 Valve released all of their major Source games on Mac OS X. All future Valve games will be released simultaneously for Windows and Mac. Games will only use Direct3D on Windows, and only OpenGL on the other platforms.

Linux support (2012, multiple games)

The first of Valve's games to support Linux was Team Fortress 2, the port released in October 2012 along with the closed beta of the Linux version of Steam.