Twelve basic principles of animation

Disney's twelve basic principles of animation were introduced by the Disney animators Ollie Johnston and Frank Thomas in their 1981 book The Illusion of Life: Disney Animation.[a] The principles are based on the work of Disney animators from the 1930s onwards, in their quest to produce more realistic animation. The main purpose of these principles was to produce an illusion that cartoon characters adhered to the basic laws of physics, but they also dealt with more abstract issues, such as emotional timing and character appeal.

The book has been referred to by some as the "Bible of animation", and some of its principles have been adopted by traditional studios. In 1999, The Illusion of Life was voted the "best animation book[...] of all time" in an online poll done by Animation World Network. While originally intended to apply to traditional, hand-drawn animation, the principles still have great relevance for today's more prevalent computer animation.

The 12 Principles of Animation

Squash and stretch

The purpose of squash and stretch is to give a sense of weight and flexibility to drawn or computer-animated objects. It can be applied to simple objects, like a bouncing ball, or more complex constructions, like the musculature of a human face. Taken to an extreme, a figure stretched or squashed to an exaggerated degree can have a comical effect. In realistic animation, however, the most important aspect of this principle is that an object's volume does not change when squashed or stretched. If the length of a ball is stretched vertically, its width (in three dimensions, also its depth) needs to contract correspondingly horizontally.