The pencil-sketch animation technique used in the A-ha video "Take On Me" was known as what?
Rotoscoping is an animation technique that animators use to trace over motion picture footage, frame by frame, to produce realistic action. Originally, animators projected photographed live-action movie images onto a glass panel and traced over the image. Rotoscoping has often been used as a tool for visual effects in live-action movies. By tracing an object, the moviemaker creates a silhouette (called a matte) that can be used to extract that object from a scene for use on a different background. While blue- and green-screen techniques have made the process of layering subjects in scenes easier, rotoscoping still plays a large role in the production of visual effects imagery.
Rotoscoping was used in three of A-ha's music videos, "Take On Me" (1985), "The Sun Always Shines on T.V." (1985), and "Train of Thought" (1986).