# PhysicsEvents.TriggerBeginEvent

> An event produced when a pair of Shapes, one of which was a trigger, began touching. The shapes provided may have been destroyed so they should always be validated with _isValid. See _triggerBeginEvents.

## Definition

* **Type:** Struct
* **Namespace:** [Unity.U2D.Physics](/engine/6000.6/script-reference/unity/u2d/physics.md)
* **Assembly:** UnityEngine.PhysicsCore2DModule

```csharp
public readonly struct PhysicsEvents.TriggerBeginEvent
```

## Properties

| Property                                                                                                          | Description                                      |
| ----------------------------------------------------------------------------------------------------------------- | ------------------------------------------------ |
| [triggerShape](/engine/6000.6/script-reference/unity/u2d/physics/physicsevents/triggerbeginevent/triggershape.md) | The trigger shape involved in the event.         |
| [visitorShape](/engine/6000.6/script-reference/unity/u2d/physics/physicsevents/triggerbeginevent/visitorshape.md) | The shape that began touching the trigger shape. |