# WorldTransformPlaneChange

> Event callback for a world transform-plane change event. This only fires when the mapping between 2D physics space and 3D world space actually changes. A world using PhysicsWorld.TransformPlane.Custom also fires this when PhysicsWorld.transformPlaneCustom changes, reporting PhysicsWorld.TransformPlane.Custom as both the old and the new plane.

## Definition

* **Type:** Event
* **Namespace:** [Unity.U2D.Physics](/engine/6000.7/script-reference/unity/u2d/physics.md)
* **Assembly:** UnityEngine.PhysicsCore2DModule

```csharp
public static event PhysicsEvents.WorldTransformPlaneChangeEventHandler WorldTransformPlaneChange
```

### Remarks

Do not treat a difference between the old and new plane as the test for whether anything changed, because a change to the custom transformation alone reports the same plane on both sides.