#bouncing balls

Just why

Hey folks, Paul here for MOTION MONDAY! Last week I posted some bouncing balls, and this week I’ve got some do’s and don’ts for animating them.

The example above (not perfect, but good enough for government work) shows that bounces should travel in arcs. This is because:

Change of direction at the apex is gradual, making a curve.

Change of direction at the impact is sudden, making an angle.

Let’s see what happens if we use too many angles:

If every change of direction is angular, there are no arcs; it looks like the balls are hitting an invisible bumper in the air.

Now, let’s see what happens if we use too many curves:

If every change of direction is curvy, we lose the sense of impact; it looks like the balls are fish jumping in and out of water.

Arcs are a major part of Disney’s 12 Principles, but that doesn’t mean “always use an arc for every motion.” It’s important to know when to use arcs, and when to use angles instead.