Transformers is a 2007 American science fiction action film based on the Transformers toy line. The film, which combines computer animation with live-action, is directed by Michael Bay, with Steven Spielberg serving as executive producer. It stars Shia LaBeouf as Sam Witwicky, a teenager involved in a war between the heroic Autobots and the evil Decepticons, two factions of alien robots who can disguise themselves by transforming into everyday machinery. The Decepticons desire control of the AllSpark, the object that created their robotic race, with the intention of using it to build an army by giving life to the machines of Earth. Megan Fox, Josh Duhamel, Tyrese Gibson, Jon Voight, Anthony Anderson and John Turturro also star, while voice actors Peter Cullen and Hugo Weaving voice Optimus Prime and Megatron respectively.