# gravitySource

> Specify whether to use the gravity strength from the 2D or 3D physics system.

## Definition

* **Type:** Property
* **Namespace:** [UnityEngine](/engine/6000.6/script-reference/unityengine.md)
* **Assembly:** UnityEngine.ParticleSystemModule

```csharp
public ParticleSystemGravitySource gravitySource { get; set; }
```

### Remarks

Additional Resources: [ParticleSystem.MainModule.gravityModifier](/engine/6000.6/script-reference/unityengine/particlesystem/mainmodule/gravitymodifier.md).