The proprietary Rockstar Advanced Game Engine (RAGE) was used for the game. Garbut found "Grand Theft Auto IV"s technical design similar to "Grand Theft Auto III"s, with both games being the first in the series to be released on their respective platforms. He claimed that an operable game engine was not finalised until late in development, at which point "there's still plenty of guesswork" until optimisation near release. The character's physical performances were recorded using motion capture. Up to eight actors could perform on the motion capture stage at one time, each dressed in a full suit. The camera used to capture the performance included a teleprompter for the actors to read their scripts. Over a hundred moves would be captured in each day of production. The final product was taken from different performances by different actors to make them appear seamless and appropriate. The voice work by one actor could be composited over a different actor's physical performance for a specific outcome. The in-game animations were crafted similarly, using a combination of different motion capture performances.