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Restitution (bouncing)

Restitution is how much energy a collision returns — 0 is a dead thud, 1 is a perfect bounce. These six balls are identical except for their restitution, so they bounce back to a staircase of heights. They’re lifted back to the top on a timer.

Drag to orbit

Loading physics…
Left to right: restitution 0.0 → 1.0.

How it works

Section titled “How it works”
for (let i = 0; i < 6; i++) {
  const restitution = i / 5; // 0.0, 0.2, 0.4, … 1.0
  world.createBody({
    type: "dynamic",
    shape: Shape.sphere(0.5),
    position: [x, 6, 0],
    layer: "moving",
    restitution,
    linearDamping: 0, // let bounce height depend only on restitution
  });
}

The floor is created with restitution: 1 so the ball’s own restitution dominates the bounce. When two bodies touch, Jolt combines their restitutions.

To restart the loop, each ball is teleported home and its velocity cleared:

body.setTransform([x, 6, 0], [0, 0, 0, 1]);
body.setLinearVelocity(0, 0, 0);
body.setAngularVelocity(0, 0, 0);
body.wakeUp();
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