>>73
Tron's graphics were true 3D. MAGI, one of the companies hired to do the rendering (which used computers other than the famous SuperFoonly F-1), employed a bunch of scientists and wrote the first ray-tracer program, largely to do Tron.
Many of their parts, such as the light cycles, use the full Phong reflection model, which had been invented in 1973, almost a full decade before Tron hit theatres.