Source Engine

The Source Engine is a 3D game engine developed by Valve. The first title using this engine was Half-life 2?, and the engine was specially developed for this game between about 1999 and 2004. It works similar to the Quake 2 Engine, on which Half-Life 2's precedessor, Half-Life was based on: It uses BSP Trees? to divide the 3D world and perform culling to increase the rendering speed. It supports D3D 7, 8, and 9, and uses the Havoc Physics? Engine as Physics Library.