---
title: particleSize
framework: scenekit
role: symbol
role_heading: Instance Property
path: scenekit/scnparticlesystem/particlesize
---

# particleSize

The rendered size, in units of the scene’s world coordinate space, of the particle image. Animatable.

## Declaration

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

## Discussion

Discussion SceneKit uses this value for both the width and height of the particleImage texture at render time. (If you use the stretchFactor property to stretch particles in their direction of motion, the particleSize value determines the width and height before stretching.) You can randomize the sizes of newly spawned particles with the particleSizeVariation property. The default value is 1.0, specifying that particle images appear one unit high and one unit wide in the scene’s world coordinate space. You can animate changes to this property’s value. See Animating SceneKit Content.

## See Also

### Specifying Particle Appearance

- [particleSizeVariation](scenekit/scnparticlesystem/particlesizevariation.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)