# ParticleSystem.SizeBySpeedModule

> Script interface for the SizeBySpeedModule.

## Definition

* **Type:** Struct
* **Namespace:** [UnityEngine](/engine/6000.7/script-reference/unityengine.md)
* **Assembly:** UnityEngine.ParticleSystemModule

```csharp
public struct ParticleSystem.SizeBySpeedModule
```

## Remarks

This module controls the size of particles based on their speeds.

Additional Resources: [ParticleSystem](/engine/6000.7/script-reference/unityengine/particlesystem.md), [\_sizeBySpeed](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeed.md)

## Properties

| Property                                                                                                         | Description                                                                                                      |
| ---------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------- |
| [enabled](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeedmodule/enabled.md)               | Specifies whether the SizeBySpeedModule is enabled or disabled.                                                  |
| [range](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeedmodule/range.md)                   | Set the minimum and maximum speed that this modules applies the size curve between.                              |
| [separateAxes](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeedmodule/separateaxes.md)     | Set the size by speed on each axis separately.                                                                   |
| [size](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeedmodule/size.md)                     | Curve to control particle size based on speed.                                                                   |
| [sizeMultiplier](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeedmodule/sizemultiplier.md) | A multiplier for [\_size](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeedmodule/size.md). |
| [x](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeedmodule/x.md)                           | Size by speed curve for the x-axis.                                                                              |
| [xMultiplier](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeedmodule/xmultiplier.md)       | Size multiplier along the x-axis.                                                                                |
| [y](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeedmodule/y.md)                           | Size by speed curve for the y-axis.                                                                              |
| [yMultiplier](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeedmodule/ymultiplier.md)       | Size multiplier along the y-axis.                                                                                |
| [z](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeedmodule/z.md)                           | Size by speed curve for the z-axis.                                                                              |
| [zMultiplier](/engine/6000.7/script-reference/unityengine/particlesystem/sizebyspeedmodule/zmultiplier.md)       | Size multiplier along the z-axis.                                                                                |