This is a video documentary about how one scene in Episode IV was prepared, the scene in particular is when the rebel pilots were planning how to attack the Death Star. The Commander showed them an animation of the Death Star and where to fire.
Of course, this is 1976, no high end computer graphics cards exists yet, so Larry Cuba describe the steps in the 3D modeling based on photographs of the real miniature models. Check how he's controlling the rotation in real time (awesome) with big controls (no mouse neither exists).
The final touch was to render each scene, shot by shot, in the computer screen with and automatic camera capturing in film.
Via Topless Robot.