---
title: particleFrictionVariation
framework: scenekit
role: symbol
role_heading: Instance Property
path: scenekit/scnparticlesystem/particlefrictionvariation
---

# particleFrictionVariation

The range of randomized friction coefficients for particles. Animatable.

## Declaration

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

## Discussion

Discussion Setting a nonzero value for this property randomizes the effect of the particleFriction property. SceneKit randomly adjusts the friction coefficient of each particle by up to half the particleFrictionVariation value. For example, if the particleFriction value is 1.0 and the particleFrictionVariation value is 0.5, each particle uses a random friction 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)
- [particleBounceVariation](scenekit/scnparticlesystem/particlebouncevariation.md)
- [particleFriction](scenekit/scnparticlesystem/particlefriction.md)