with more time to add features like Forge mode. Bungie remained quiet as to what their new project was, leaving comments in their weekly update alluding to a "new project". The game was officially announced with a real-time cinematic trailer at E3 2006. In comparison with Halo 2s tight-lipped development, Bungie was more transparent about the process for Halo 3. Bungie kept the public informed on game development via weekly updates on their web site. During development, the game was divided into single player and multiplayer builds; this made debugging and testing the much smaller multiplayer files quicker. While details of Halo 3s multiplayer were widely disseminated in the sixteen months leading up to the release, the single-player aspect of the storyline was kept relatively secret throughout much of the development to build up interest. The first campaign screenshots did not appear until a year after the announcement trailer, on July 5, 2007, as a "tease" for the planned pace of marketing. A public beta test of the game's online multiplayer features, as well as saved films and file share, took place four months before the full release. Players required a Crackdown disc to play the beta. AI behavior was enhanced and improved; the behavior of enemy Brutes the player faces was modified, giving them a "pack mentality" that causes the aliens to perform similar actions at the same time and altering gameplay. Graphics Halo 3 utilizes a proprietary, in-house graphics engine. It employs graphics technologies such as high dynamic range, global lighting, and depth of field effects within cutscenes. Motion blurring was absent from the beta, but was added to the final game. Most dynamic objects in the game cast real-time shadows on themselves and the environment around them, including the game's plant life. Halo 3 uses normal, bump, and parallax mapping to give surfaces more detail without dramatically increasing the number of polygons. Players can see distances of up to away, all fully three-dimensional. The engine is capable of real-time reflections, but are often unused as Bungie considered it a waste of resources. Halo 3 uses two frame buffers instead of the usual single buffer, allowing Bungie to preserve as much of dynamic range as possible for the game's lighting without adversely affecting the frame rate. As a consequence, the game natively renders at 1152×640 resolution instead of 720p. The image can be upscaled to 1080p by the