---
title: idleDurationVariation
framework: scenekit
role: symbol
role_heading: Instance Property
path: scenekit/scnparticlesystem/idledurationvariation
---

# idleDurationVariation

The range, in seconds, of randomized idle duration values. Animatable.

## Declaration

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

## Discussion

Discussion Setting a nonzero value for this property randomizes the effect of the idleDuration property. For each idle period, SceneKit randomly adjusts the duration by up to half the idleDurationVariation value. For example, if the idleDuration value is 1.0 seconds and the idleDurationVariation value is 0.5 seconds, the system idles for a period of 0.75 to 1.25 seconds between emissions. The default value is 0.0 seconds, specifying no randomization. You can animate changes to this property’s value. See Animating SceneKit Content.

## See Also

### Managing Particle Emission Timing

- [emissionDuration](scenekit/scnparticlesystem/emissionduration.md)
- [emissionDurationVariation](scenekit/scnparticlesystem/emissiondurationvariation.md)
- [idleDuration](scenekit/scnparticlesystem/idleduration.md)
- [loops](scenekit/scnparticlesystem/loops.md)
- [warmupDuration](scenekit/scnparticlesystem/warmupduration.md)
- [birthRate](scenekit/scnparticlesystem/birthrate.md)
- [birthRateVariation](scenekit/scnparticlesystem/birthratevariation.md)