broadened the game. The courses' look and feel were inspired by other Sonic games, including Sonic 3D Blast. The 3D models were based on 2D sketches from Sonic Team. All models and animations were developed using Softimage 3D, while Traveller's Tales created their own tools for the remaining game development. Implementing the two-player split-screen mode proved difficult; programmer Jon Burton stated that this was mainly because it was difficult to ensure cheating was not too easy, so shortcuts were made challenging, with a penalty incurred if players got them wrong. A major development goal was to maintain a consistent 30 frames per second frame rate during gameplay. A custom game engine was developed to take full advantage of the Sega Saturn hardware, and a graphical technique, described as "12 layer transparency", was used to transparentise distant textures to conceal the Sega Saturn's limited draw distance. Burton claimed that Sonic R could not have been replicated on other consoles during the timeframe, such as the PlayStation console, due to the technique developed specifically for the Sega Saturn hardware. Environment mapping was achieved by writing what Burton described as a software version of the PlayStation's hardware rendering, as the Saturn's hardware was incapable of it. An early build was unveiled at the Electronic Entertainment Expo in Atlanta, Georgia in June 1997, with Sega releasing screenshots of a "40% complete build" to various magazines shortly afterwards. The builds would be largely the same as the final game, with the exception of minor tweaks, such as the ability to play the "Resort Island" level being in sunset, rather than bright sunshine, a change that was made because of the level's music track titled "Can You Feel the Sunshine?". Traveller's Tales had used programming techniques inspired by those (such as a type of fog known as "Pixie Dust") used on the Nintendo 64. Hirokazu Yasuhara of Sonic Team went to England and fine-tuned the game due to lack of time for communication. Technical and scheduling issues caused Sato to change the game design, leading to a dispute with producer Yuji Naka, and Sato removed his name from the credits. The game's final release would be first in North America on 18 November 1997, with releases in other regions occurring in late 1997 for the Sega Saturn, and into 1998 for the PC version. The PC versions allowed the user to alter graphics details such as