Long before Ed Catmull became president of Walt Disney Animation Studios, he headed up the computer graphics group at Lucasfilm, which eventually spun into Pixar, the maker of so many cutting edge animated films. And before all of that, Catmull went to graduate school at the University of Utah, where he cut his teeth on emerging animation technologies, and put himself in a position to develop this -- a very early (and apparently the first) 3D digital movie.
Working with Fred Parke, Catmull shot A Computer Animated Hand in 1970. The hand makes only a brief appearance -- about 20 seconds -- and the rest of the film shows you what went into making the hand (and other animated body parts). NerdPlusAlert has more on the animated reel.