According to the film's set designer, Erich Kettelhut, a glass plate was positioned halfway between the robot and the camera. The silhouette of the robot and throne were carefully drawn onto a piece of plywood to be used as a matte, and using a pair of circular neon lights of a diameter corresponding with the matte's silhouette. By covering the glass plate with grease and filming the moving lights through it the illusion of a light circle moving up and down was created.