As computer-generated imagery has become cheaper and more sophisticated, the film industry can now convincingly recreate people on-screen even actors who have been dead for decades.

The art Department instead redesigned the aliens to be realized by animatronic masks rather than by computer-generated imagery.

But it's secretly got that other side to it, which is: 'Well, they're not really acting, and it's all about the CGI (computer-generated imagery).