Principles of animating a Bouncing Ball - 3

Squash and Stretch

Now onto something you hear a lot about in animation - Squash and Stretch. You also see it in the real world (a funny picture of this is shown on left). Actually the starting place of learning about it for all animators is with a bouncing ball. A basic explanation of it is that the ball is round at the top of an arc and as it travels it stretches as it speeds up and when it contacts the floor in squashes and as it bounces back up the next arc it stretches again and then back round and the cycle continues until the ball comes to a stop.

To start doing this use Key Poses; for our bounce it is going to be when the ball is a circle and when it squashes on the floor as you can see in my drawing on the left. This is all done to give the ball weight and is very important but you must make sure you keep the same volume area when squashed as it is round.


The speed the ball is going also depends on the amount of squash you have; in other words the faster it's travelling the more squashed and stretched it will be. I made the image on the right to explain this with squash on top and stretch below.

Next up you need to add the stretches which are the main breakdown drawings/poses, in a sense they are really in-between drawings that explain the action the ball is making. In-betweens are the poses that are between the Key Poses. Below is an update of the image I made with the Break Downs added in yellow.

As you can see, the marks we have used so far have all been in the centre of the poses so you can now see how they came in handy ;)

Any way, back to stretch; unlike with squash that mainly shows weight, stretch shows the speed a ball is moving although you do also need to take in its weight.


A great blog that has some posts on Squash and Stretch is HERE. It has some great examples and really explains what it is and its principles so if you want to know more I strongly recommend visiting it.