Inbetweening

[1] The process of inbetweening in traditional animation starts with a primary artist, who draws key frames to define movement.

After the testing and approval of a rough animation, the scene is passed down to assistants, who perform clean-up and add necessary inbetweening.

In large studios, a specialized inbetweener artist fills in the gaps between the key drawings.

When the number of in-betweens is too few, such as four drawings per second, an animation may begin to lose the illusion of the movement altogether.

The use of computers for inbetweening was enhanced by Nestor Burtnyk and Marceli Wein at the National Research Council of Canada.

They received a Technical Achievement Academy Award in 1997, for "pioneering work in the development of software techniques for computer-assisted keyframing for character animation".