# PhysicsCallbacks.ContactCallbackTargets.ContactBeginTarget

> Contact begin event target for callbacks.

## Definition

* **Type:** Struct
* **Namespace:** [Unity.U2D.Physics](/engine/7000.0/script-reference/unity/u2d/physics.md)
* **Assembly:** UnityEngine.PhysicsCore2DModule
* **Implements:** [IEquatable\<ContactBeginTarget>](https://learn.microsoft.com/dotnet/api/system.iequatable-1)

```csharp
public readonly struct PhysicsCallbacks.ContactCallbackTargets.ContactBeginTarget : IEquatable<PhysicsCallbacks.ContactCallbackTargets.ContactBeginTarget>
```

## Properties

| Property                                                                                                                                    | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| ------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [beginEvent](/engine/7000.0/script-reference/unity/u2d/physics/physicscallbacks/contactcallbacktargetscontactbegintarget/beginevent.md)     | The event.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| [shapeTargetA](/engine/7000.0/script-reference/unity/u2d/physics/physicscallbacks/contactcallbacktargetscontactbegintarget/shapetargeta.md) | The callback target ([PhysicsShape.callbackTarget](/engine/7000.0/script-reference/unity/u2d/physics/physicsshape/callbacktarget.md)) associated with [PhysicsEvents.ContactBeginEvent.shapeA](/engine/7000.0/script-reference/unity/u2d/physics/physicsevents/contactbeginevent/shapea.md). This returns any implemented [PhysicsCallbacks.IContactCallback](/engine/7000.0/script-reference/unity/u2d/physics/physicscallbacks/icontactcallback.md) or NULL if not implemented or no target. |
| [shapeTargetB](/engine/7000.0/script-reference/unity/u2d/physics/physicscallbacks/contactcallbacktargetscontactbegintarget/shapetargetb.md) | The callback target ([PhysicsShape.callbackTarget](/engine/7000.0/script-reference/unity/u2d/physics/physicsshape/callbacktarget.md)) associated with [PhysicsEvents.ContactBeginEvent.shapeB](/engine/7000.0/script-reference/unity/u2d/physics/physicsevents/contactbeginevent/shapeb.md). This returns any implemented [PhysicsCallbacks.IContactCallback](/engine/7000.0/script-reference/unity/u2d/physics/physicscallbacks/icontactcallback.md) or NULL if not implemented or no target. |