the character's voice is probably the only thing that can't be created with a computer. For that,you need a real actor. to do the voice of Princess Fiona, the film-makers got Cameron Diaz. For shrek they got Mike Myers, the star of the Austin Powers films. Neither actor had done an animated film before. it was fun because you don,t have to worry about your hair and make-up, the lights, or where the camera is, says Diaz. You just go out there and ploy.