In this vintage Star Wars workshop video, special effects artist Dennis Muren of Industrial Light & Magic describes how he and his team used stop motion animation to bring the large AT-AT Walkers to life for the Battle of Hoth sequence in Star Wars: Episode V – The Empire Strikes Back. The team of artists originally thought about using actual robot versions of the walkers, but that idea “proved to be too costly and complicated.”
Models were manipulated a frame at a time, animated in front of painted backgrounds instead of blue screen, with baking soda was used in place of snow. It was shot at 24 frames per second, resulting in about 5 seconds of footage per day of work. For explosions, high speed photography was used, and cutouts were used for background walkers.
video via Star Wars
via The Verge