# ParticleSystemCollisionMode

> Whether to use 2D or 3D colliders for particle collisions.

## Definition

* **Type:** Enum
* **Namespace:** [UnityEngine](/engine/6000.0/script-reference/unityengine.md)
* **Assembly:** UnityEngine.ParticleSystemModule

```csharp
public enum ParticleSystemCollisionMode
```

## Fields

| Value                                                                                                 | Description                                    |
| ----------------------------------------------------------------------------------------------------- | ---------------------------------------------- |
| [Collision2D](/engine/6000.0/script-reference/unityengine/particlesystemcollisionmode/collision2d.md) | Use 2D colliders to collide particles against. |
| [Collision3D](/engine/6000.0/script-reference/unityengine/particlesystemcollisionmode/collision3d.md) | Use 3D colliders to collide particles against. |