# TerrainCallbacks.HeightmapChangedCallback

> Use this delegate type with TerrainCallbacks.heightmapChanged to monitor all changes to the Terrain heightmap.

## Definition

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

```csharp
public delegate void TerrainCallbacks.HeightmapChangedCallback(Terrain terrain, RectInt heightRegion, bool synched)
```