Nestor Burtnyk and Marceli Wein at the National Film Board of Canada were particularly interested in figure animation and the use of key frames to produce realistic movement. Unlike most of the other computer animators, they did not have access to an SC4020 and used a much cruder system early on photographing a CRT.
The system MSGEN allowed the animator to define key frames and the system would define the in-between frames. Linear interpolation gives strange results in some cases particularly when large rotations are involved. In consequence, they added the ability to promote in-between frames to key frames which they then modified. The system also allowed you to define skeleton's to which you added flesh and the ability to inbetween using a point about which rotation took place.
There was a lot in common between Computer Image's analogue CAESAR system and their digital computer system.
An early film, Metadata, was produced using the system by Peter Foldes. This was followed by the excllent film, La Faim.