# Rigidbody

> Calculate the Particle System velocity by using a Rigidbody or Rigidbody2D component, if one exists on the GameObject.

## Definition

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

```csharp
Rigidbody = 1
```