Ralph Bakshi encountered Tolkien's writing early in his career. He had made several attempts to produce "The Lord of the Rings" as an animated film before producer Saul Zaentz and distributor United Artists provided funding. The film is notable for its extensive use of rotoscoping, a technique in which scenes are first shot in live-action, then traced onto animation cels. It uses a hybrid of traditional cel animation and rotoscoped live action footage. The film features the voices of William Squire, John Hurt, Michael Graham Cox, and Anthony Daniels. The screenplay was written by Peter S. Beagle, based on an earlier draft by Chris Conkling.