---
title: velocity
framework: quartzcore
role: symbol
role_heading: Instance Property
path: quartzcore/caemitterlayer/velocity
---

# velocity

Defines a multiplier applied to the cell-defined particle velocity. Animatable.

## Declaration

```swift
var velocity: Float { get set }
```

## Discussion

Discussion Default value is 1.0.

## See Also

### Emitter Cell Attribute Multipliers

- [scale](quartzcore/caemitterlayer/scale.md)
- [seed](quartzcore/caemitterlayer/seed.md)
- [spin](quartzcore/caemitterlayer/spin.md)
- [birthRate](quartzcore/caemitterlayer/birthrate.md)
- [emitterMode](quartzcore/caemitterlayer/emittermode.md)
- [lifetime](quartzcore/caemitterlayer/lifetime.md)
- [preservesDepth](quartzcore/caemitterlayer/preservesdepth.md)