# NavMesh.OnNavMeshPreUpdate

> Registers callback methods to be invoked before the NavMesh system updates.

## Definition

* **Type:** Delegate
* **Namespace:** [UnityEngine.AI](/engine/6000.0/script-reference/unityengine/ai.md)
* **Assembly:** UnityEngine.AIModule

```csharp
public delegate void NavMesh.OnNavMeshPreUpdate()
```

## Remarks

This is useful for updating the NavMesh and links before the agents are simulated during the update cycle.

Additional Resources: [NavMesh.onPreUpdate](/engine/6000.0/script-reference/unityengine/ai/navmesh/onpreupdate.md).