technique where individual frames from live action footage are traced onto paper, used as a guide for naturalistic movement or as reference points for mattes
One of the most famous early uses can be seen on the dancing skeletons in the 1932 Betty Boop
cartoon Minnie the Moocher
Used throughout the Disney
blockbusters (Snow White
was completely rotoscoped) and Ralph Bakshi
infamously rotoscoped the entire cast in his version of The Lord of the Rings
Also the name of the projecting machine used to trace the images.