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# particleSize

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

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

## Discussion

SceneKit uses this value for both the width and height of the [`particleImage`](/documentation/SceneKit/SCNParticleSystem/particleImage) texture at render time. (If you use the [`stretchFactor`](/documentation/SceneKit/SCNParticleSystem/stretchFactor) property to stretch particles in their direction of motion, the [`particleSize`](/documentation/SceneKit/SCNParticleSystem/particleSize) value determines the width and height before stretching.) You can randomize the sizes of newly spawned particles with the [`particleSizeVariation`](/documentation/SceneKit/SCNParticleSystem/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](/documentation/SceneKit/animating-scenekit-content).

---

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