The Orange Box engine branch. It was introduced by Valve in 2013 to replace the archaic GCF file format with the VPK format introduced in the . Major shifts in content mounting occurred, and all games using the and engine branches were upgraded to this version. Half-Life: Source was also upgraded to this engine branch from the engine branch. The "custom" folder was added to make modding easier and was added as a mounting path for each individual Source game.engine branch (also called SteamPipe branch) is the final iteration of the
While SteamPipe was praised for simplifying how the Source engine mounts content and including previously-unreleased Team Fortress 2 code, it also broke countless numbers of mods and worsened problems already present in the Source 2009 branch. It also does not have most of the features that the engine branches from the Left 4 Dead engine branch onwards had. However, the engine branch has been polished over time and is now the main branch in use by modern non-licensed engine mods.
New since theengine branch is:
- Linux support
- The engine can now run on Linux. However, Linux support outside of official games may be spotty.
- Prop lightmaps
- Static props without bump maps can now use lightmaps.
- Per-texel color tint masking for models
$blendtintbybasealphais ported from the Left 4 Dead engine branch. Source 2013 includes an exclusive additional parameter,
- Swaying trees
- A material parameter that gives the effect of trees swaying in the wind.
- A powerful new scripting system primarily using Squirrel.
Gamecode for both the Source 2013 Multiplayer and Singleplayer branches is included in Valve's Source SDK 2013 repository.
Source 2013 Singleplayer
Source 2013 Multiplayer