---
title: "Bounce particles off a platform"
description: "Make falling particles rebound from a rectangle and settle after a limited number of bounces."
canonical: "https://terminal.lottiefiles.com/docs/how-to/bounce-particles-off-a-platform/"
last_updated: 2026-10-29
---

# Bounce particles off a platform

Make falling particles rebound from a rectangle and settle after a limited number of bounces.

Start with a downward stream and a rectangle layer under it. The screenshot uses **Falling
dots** and **Platform** from the **Bounces** lesson. The platform must be visible during
the particles' flight.

1. Click a particle to select its emitter. The rail (the Properties panel in After Effects
   or Figma) shows **PARTICLES**.
2. Scroll over the rail to **Add**. **+ collisions** appears.
3. Click **+ collisions**. The **Collisions** module is added with **floor** on.
4. Scroll down to **Restitution**. Two values control rebound speed.
5. Click the first **Restitution** value, type `0.8` and press `⏎`. The minimum rebound
   keeps 80% of impact speed.
6. Click the second **Restitution** value, type `0.8` and press `⏎`. Every particle uses
   that rebound strength.
7. Click your rectangle's name under **Colliders**. Its name lights up; the rectangle is now
   a surface particles can land on.
8. Click **Bounces**, type `1` and press `⏎`. Each particle rebounds at most once.
9. Press `0`, then `space`. Particles rebound and then settle on the rectangle.
10. Press `space` to pause after they land. The oldest particles rest on the platform.

![Falling dots rebound and settle on the selected platform.](https://terminal.lottiefiles.com/docs/assets/shots/more-particle-bounce-result.png)

If they still pass through, check that the collider is a rectangle or ellipse layer, is
selected under **Colliders**, and is visible at that time. `u` undoes each change.
Next: [Collision controls and limits](https://terminal.lottiefiles.com/docs/particles.md#collisions).
Watch: [Bounces](https://terminal.lottiefiles.com/bounces/).