When director Joachim Rønning came on board “Tron: Ares,” the third film in the Disney sci-fi series that began in 1982 with “Tron,” he knew there was one set piece that absolutely had to deliver.

Add Yahoo as a preferred source to see more of our stories on Google. In the late 1970s, filmmaker Steven Lisberger began experimenting with backlit animation, a process in which colored light shines ...