---
title: particleBounceVariation
framework: scenekit
role: symbol
role_heading: Instance Property
path: scenekit/scnparticlesystem/particlebouncevariation
---

# particleBounceVariation

The range of randomized restitution coefficients for particles. Animatable.

## Declaration

```swift
var particleBounceVariation: CGFloat { get set }
```

## Discussion

Discussion Setting a nonzero value for this property randomizes the effect of the particleBounce property. SceneKit randomly adjusts the restitution coefficient of each particle by up to half the particleBounceVariation value. For example, if the particleBounce value is 1.0 and the particleBounceVariation value is 0.5, each particle uses a random restitution coefficient between 0.75 and 1.25 for physics simulation. The default value is 0.0, specifying no randomization. You can animate changes to this property’s value. See Animating SceneKit Content.

## See Also

### Simulating Physics for Particles

- [isAffectedByGravity](scenekit/scnparticlesystem/isaffectedbygravity.md)
- [isAffectedByPhysicsFields](scenekit/scnparticlesystem/isaffectedbyphysicsfields.md)
- [colliderNodes](scenekit/scnparticlesystem/collidernodes.md)
- [particleDiesOnCollision](scenekit/scnparticlesystem/particlediesoncollision.md)
- [acceleration](scenekit/scnparticlesystem/acceleration.md)
- [dampingFactor](scenekit/scnparticlesystem/dampingfactor.md)
- [particleMass](scenekit/scnparticlesystem/particlemass.md)
- [particleMassVariation](scenekit/scnparticlesystem/particlemassvariation.md)
- [particleCharge](scenekit/scnparticlesystem/particlecharge.md)
- [particleChargeVariation](scenekit/scnparticlesystem/particlechargevariation.md)
- [particleBounce](scenekit/scnparticlesystem/particlebounce.md)
- [particleFriction](scenekit/scnparticlesystem/particlefriction.md)
- [particleFrictionVariation](scenekit/scnparticlesystem/particlefrictionvariation.md)