Squash and Stretch

Something to keep in mind while you're thinking about your homework assignments...

Squash and Stretch
When real objects move only totally rigid ones, e.g., dishes and frying pans,, remain rigid in motion.  Most things deform in shape or form, or show movement within its shape, especially organic things.

When you bend your arm, your biceps contract and bulge out. They then lengthen and go back down when your arm straightens out. The squashed position shows the form contracted and the stretched position shows the form extended.    

Bounding animals will squash down and build energy before leaping into the air in a more stretched form.

A mouse jumping a large distance will squash its body considerably before leaping and stretching its body in a completely extended position.  Unfortunately you can't frame by frame it here.

Squashed form = form flattened out by pressure, or bunched up and pushed together
Stretched form = same form but in a very extended condition


Volume 

Tex Avery’s rules of squash and stretch:
1) All squashed or stretched objects must, eventually return to their original (default) shape.
2) Volume should be preserved. This means that no matter how you deform the ball, it should
maintain its original volume, so it is not seen as growing or shrinking


The volume of the object should remain constant at rest, squashed, or stretched. Violating this rule makes the object appear to shrink and grow beyond its actual volume, or become bloated when squashed and stringy when stretched.


Why Squash and Stretch in Animation

When an object squashes or stretches, it appears to be made of a pliable material.  Objects that do not appear rigid.  Lack of squash and stretch in an organic object makes that object appear stiff and inorganic.


Even solid objects can give the impression of squash and stretch.  A great example is Luxo Jr...






Exaggerating squash and stretch can break the realism of the thing you’re animating, but it can also be used to give something a more “cartoony” appeal.  Check out this clip from "Fun and Fancy Free" and look for the squash and stretch in the face in the anticipation of the sneeze, and then especially in the eyes during the sneeze to accentuate the action.

Overusing squash and stretch in this way can reduce believability as well.  We will be teaching you to use squash and stretch in ways to maximize appeal and believability, while at the same time maintaining the essence and truth of an object or character.