With "Tron: Ares" opening in theaters this weekend, we take a look back at the 1982 original that revolutionized CGI and influenced nearly every science-fiction film to come — even though it wasn't even nominated for a visual effects Oscar. In the late 1970s , filmmaker Steven Lisberger began experimenting with backlit animation, a process in which colored light shines through clear sections of animation cels to create unique and beautiful effects. Lisberger achieved success applying the