# emitterVelocityMode

> Control how the Particle System calculates its velocity, when moving in the world.

## Definition

* **Type:** Property
* **Namespace:** [UnityEngine](/engine/6000.3/script-reference/unityengine.md)
* **Assembly:** UnityEngine.ParticleSystemModule

```csharp
public ParticleSystemEmitterVelocityMode emitterVelocityMode { get; set; }
```

### Examples

```csharp
using UnityEngine;
using System.Collections;

[RequireComponent(typeof(ParticleSystem))]
public class ExampleClass : MonoBehaviour
{
    private ParticleSystem ps;
    public ParticleSystemEmitterVelocityMode velocityMode;

    void Start()
    {
        ps = GetComponent<ParticleSystem>();
    }

    void Update()
    {
        var main = ps.main;
        main.emitterVelocityMode = velocityMode;
    }

    void OnGUI()
    {
        velocityMode = (ParticleSystemEmitterVelocityMode)GUI.SelectionGrid(new Rect(25, 25, 300, 30), (int)velocityMode, new GUIContent[] { new GUIContent("Transform"), new GUIContent("Rigidbody") }, 2);
    }
}
```