Squash and Stretch is contracting and expanding movement within a shape as it moves through action. The squashing and stretching shows elasticity and volume, without it, characters would seem stiff and mechanical. These shape changes are usually exaggerate by the animator, but it's a good practice to maintain the volume of the caracter troughout the movements.
In the Example animation, notice how the ball changes shape as it approaches the bottom of the screen, and how it flattens as it hits the «ground». These techniques make the bouncing ball seem natural.
(Excerpts from The Disney Animation Studio User's Guide)
Demo from «Disney Presents ... The Animation Studio» for Commodore Amiga Computers and
IBM® PC, XT, AT, PS/1, PS/2 family and 100% compatibles; Tandy® 1000, 2500, 3000 series.
© 1990, 1991 Silent Software, Inc. and Walt Disney Computer Software, Inc.
Produced by Sam Palahnuk and Noah Dudley, members of the Walt Disney Computer Software team.
Designed by Reichart Von Wolfsheild.
Written by James Host, Scott T. Etherton, Edgar C. Tolentino
The copyright of The Animation Studio is owned by © The Walt Disney Company.
Walt Disney Computer Software is part of the magic of © The Walt Disney Company.