# bouncing ball ## part one - basic drop The inevitable bouncing ball animation that every animator starts out with. Just a simple ball bouncing up and down in smaller increments until it sets on the ground. Pretty easy, right? Turns out, there’s a lot you can learn about the complexities of animation by making that ball bounce. While it is fun to think about animation as getting to draw a bunch of cool stuff, the reality is that animation takes planning and organization and even a bit of math (_yikes!_). No worries, you can break it down into smaller, manageable pieces. For this first part, we are going to simply make the ball fall straight down and bounce a few times. Even something that simple can be broken down into smaller concepts. ![[diminishedBounces.gif|200]] ## vertical timing The first thing to learn is that a ball dropping straight down doesn’t move at a consistent speed. It starts out relatively slow and increases speed as gravity takes effect. Similarly, on the up-bounce, it starts out fast and slows down as gravity takes effect. This is the whole idea behind [[12 principles of animation#6 slow in and slow out|Animation Principle 6: Slow in and slow out]]. ![[verticaltiming.svg]] The diagram gives a good rough breakdown in timing for when you are drawing each frame yourself. You don’t necessarily need to measure out your frame exactly but can use this as a rough guide. Most animation programs have an **Easing** option that allows you to dynamically control the spacing between keyframes. ## squash & stretch Animation allows you to [[12 principles of animation#10 exaggeration|exaggerate]] reality by intensifying how everything looks. One of the best ways to do this is by enhancing how the ball [[12 principles of animation#1 squash and stretch|squashes and stretches]] when it hits the ground. You can even have the ball slightly distort as it nears the ground to show speed and add anticipation of the squashing effect that is about to happen. ![[squashStretch.svg]] Keep the ball the same size through most of the bounce but start deforming it in the frames just before the bounce. Increase the deformation as it nears the ground. Remember, the ball has to maintain volume, so as it stretches out in one direction, it has to get thinner in the other direction. Add an additional full squash frame that shows how the ball gets deformed as it hits the ground. Since it shows for only one quick frame, you can really exaggerate the deformation for effect. The more you push this, the softer and squishier it feels. The cool thing about this effect is that it also works as the ball bounces back up in the air. The big squash helps push the ball back up and you can show it slowly regaining its normal shape. At the top of the bounce, the ball is essentially weightless as it transitions from going up to going back down. ## diminishing bounces Due to the physics of the real world, the ball’s bounces are going to get smaller and smaller and quicker and quicker until it rests on the ground. Each bounce takes some energy out of the motion and gravity slows it down over time. We can plan for this diminished energy. ![[diminishedBounces.svg]] We move a shorter distance each bounce. We also use fewer frames for each successive bounce which means the timing is shorter/quicker. Notice that we use smaller squashes and less deformation at each successive bounce because there is less and less energy as the bounce slows down. ## the finished product Here’s the finished animation slowed down so you can see the individual frames… ![[diminishedBouncesSlow.gif|200]] ## next step: bouncing arcs Now that the ball is bouncing up and down, the next step is to make it [[bouncing ball - part two|bounce across the screen]]. --- tags: #animation #resources home: [[! animation]]