When Peter Cushing turned to face the camera in Rogue One, Star Wars fans were as excited as they were confused. After all, the actor had died more than 20 years earlier, and yet, there was no mistaking him. For a major Hollywood movie, this is a clever trick. But not everyone is trying to entertain us, and you don't need a million-dollar budget to deceive. "You take the face of one person and put it on the body of another," said Jeff Smith, associate director at the National Center for Media Forensics at the University of Colorado Denver.