sincerely thanks the player for their service during the crisis and proclaims them as the seventh Champion of Cyrodiil. Development The game was developed by the United States software company Bethesda Softworks. Ken Rolston, who was Morrowinds lead designer, oversaw the development team. The PC and Xbox 360 versions of the game were co-published by 2K Games and Bethesda. Work on Oblivion began shortly after the release of Morrowind in 2002. By mid-September 2004, Oblivion had been officially announced, and its title revealed. During Oblivions development, Bethesda concentrated on creating a system with a more realistic storyline, believable characters, and meaningful quests than had been done in the past. In comparison with previous titles in the series, the game features improved artificial intelligence thanks to the use of Bethesda proprietary Radiant AI software, and enhanced physics facilitated by the Havok physics engine. The graphics take advantage of advanced lighting and shader routines such as high-dynamic-range rendering (HDR) and specular mapping. Bethesda developed and implemented procedural content creation tools in the building of Oblivions terrain, leading to the expedited creation of landscapes that are more complex and realistic than in past titles. While designing Oblivions landscape and architecture, developers worked from personal travel photographs, nature books, texture images, and reference photographs. Procedural content generation tools used in production allowed for the creation of realistic environments at much faster rates than was the case with Morrowind. Erosion algorithms incorporated in the landscape generation tools allowed for the creation of craggy terrain quickly and easily, replacing Morrowinds artificially smoothed-over terrain. Oblivions view distance is far greater than its predecessor's, extending player sightlines to the horizon and giving views of distant towns and mountain ranges. According to a Microsoft press release, Oblivions game world is approximately 16 square miles (41 square kilometers) in size. Wilderness quests, ruins, and dungeons were added to fill surplus space. Content in the dungeons is more densely packed than in dungeons in Morrowind, with an increase in the frequency of creature encounters, quest-related NPCs, and puzzles. However, the populations represented in Oblivion do not match the "thousands upon thousands" described in previous in-game literature. The development team decided to set the NPC populations at a level that would play well, rather than one that would match game lore, since the presence of a large number of NPCs on screen would have caused the game to slow down. In response