Squash and stretch

Figure 1.1

Figure1.2

Squash and stretch is a common animation technique applied to characters or objects in motion. The technique makes their actions more fluid, and it is generally exaggerated for a cartoonish effect. When utilized with more subtlety, it works just as well for realistic movements. Squash and stretch was used to great effect in early 1920s American cartoons such as Felix the Cat and Betty Boop. It can also be used in comics or still cartoon art.

When done in accordance with the principles of animation, squash and stretch keeps the volume of the character constant. This is often explained by analogy to a half-filled sack of flour. In one episode of Tiny Toon Adventures, Babs Bunny mentions that the technique makes cartoons inherently funnier.

Squash and stretch is the principle of how an object squashes (figure 1.1, left) or how it stretches figure(1.1, right). An example is a classic cartoon "take" (figure 1.2), where it helps make an animation more "life-like" and "solid". When squash and stretch is applied, it creates the illusion that a drawing has dimension and volume. Squash and stretch does not always have to be cartoonlike - when we crouch down in anticipation for a large leap, we squash. When we spring into the air, we stretch. A half-filled flour sack is an example of a more cartoonlike squash and stretch - when dropped the sack squashes a lot; when picked up it stretches a lot - but throughout the entire action, the volume never changes.

Microsoft Research has developed The Cartoon Animation Filter for use with a diverse array of media, including motion capture, video, and digital 2D and 3D animation. "The filter adds a smoothed, inverted, and (sometimes) time shifted version of the second derivative (the acceleration) of the signal back into the original signal. Almost all parameters of the filter are automated. The user only needs to set the desired strength of the filter." The filter automatically creates anticipation, follow-through, exaggeration, and squash-and-stretch effects.

See also

• 12 basic principles of animation
• Disney Animation: The Illusion of Life

References

• Thomas, Frank; Ollie Johnston (1981, reprint 1997). The Illusion of Life: Disney Animation. Hyperion. pp. 47–69. ISBN 0786860707.