# PhysicsEvents.PreSimulateEventHandler

> Event handler for a pre-simulate event callback. This is called prior to the simulation running and is always called on the main-thread. See PhysicsWorld and PhysicsEvents.PreSimulate.

## Definition

* **Type:** Delegate
* **Namespace:** [UnityEngine.LowLevelPhysics2D](/engine/6000.3/script-reference/unityengine/lowlevelphysics2d.md)
* **Assembly:** UnityEngine.Physics2DModule

```csharp
public delegate void PhysicsEvents.PreSimulateEventHandler(PhysicsWorld world, float deltaTime)
```