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. Produced by Don Murphy and Tom DeSanto, they developed the project in 2003 and DeSanto wrote a treatment. Steven Spielberg came on board the following year, hiring Roberto Orci and Alex Kurtzman to write the screenplay. The United States Armed Forces and General Motors (GM) loaned vehicles and aircraft during filming, which saved money for the production and added realism to the battle scenes. Hasbro organized an enormous promotional campaign for the film, making deals with hundreds of companies. This advertising blitz included a viral marketing campaign, coordinated releases of prequel comic books, toys and books and, as well as product placement deals with GM, Burger King, and eBay.