Unreal Engine
Screenshots of Unreal Engine 3 were presented by July 2004, at which point the engine had already been in development for over 18 months. The engine was based on the first-generation, but contained new features. "The basic architectural decisions visible to programmers of an object-oriented design, a data-driven scripting approach, and a fairly modular approach to subsystems still remain [from Unreal Engine 1]. But the parts of the game that are really visible to gamers –the renderer, the physics system, the sound system, and the tools– are all visibly new and dramatically more powerful," said Sweeney. Unlike Unreal Engine 2, which still supported a fixed-function pipeline, Unreal Engine 3 was designed to take advantage of fully programmable shader hardware. All lighting and shadowing calculations were done per-pixel, instead of per-vertex. On the rendering side, Unreal Engine 3 provided support for a gamma-correct high-dynamic range renderer. The first games released using Unreal Engine 3 were "Gears of War" for Xbox 360, and "RoboBlitz" for Windows, which were both released on November 7, 2006.