---
title: particleSizeVariation
framework: scenekit
role: symbol
role_heading: Instance Property
path: scenekit/scnparticlesystem/particlesizevariation
---

# particleSizeVariation

The range of randomized particle sizes. Animatable.

## Declaration

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

## Discussion

Discussion Setting a nonzero value for this property randomizes the effect of the particleSize property. SceneKit randomly adjusts the size of each particle by up to half the particleSizeVariation value. For example, if the particleSize value is 1.0 and the particleSizeVariation value is 0.5, newly spawned particles are randomly sized between 0.75 and 1.25 units wide and high. The default value is 0.0, specifying no randomization. You can animate changes to this property’s value. See Animating SceneKit Content.

## See Also

### Specifying Particle Appearance

- [particleSize](scenekit/scnparticlesystem/particlesize.md)
- [particleColor](scenekit/scnparticlesystem/particlecolor.md)
- [particleColorVariation](scenekit/scnparticlesystem/particlecolorvariation.md)
- [particleImage](scenekit/scnparticlesystem/particleimage.md)
- [fresnelExponent](scenekit/scnparticlesystem/fresnelexponent.md)
- [stretchFactor](scenekit/scnparticlesystem/stretchfactor.md)