# DirtyTextureRegion(string, RectInt, bool)

> Marks the specified part of the Terrain texture as dirty.

## Definition

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

```csharp
public void DirtyTextureRegion(string textureName, RectInt region, bool allowDelayedCPUSync)
```

### Parameters

**** (\[string]\(https\://learn.microsoft.com/dotnet/api/system.string)): The name of the Terrain texture.**** (\[RectInt]\(/engine/6000.0/script-reference/unityengine/rectint)): The rectangular region to mark as dirty.**** (\[bool]\(https\://learn.microsoft.com/dotnet/api/system.boolean)): Specifies whether to allow delayed CPU synchronization of the texture.

### Remarks

Use this function only after you manually change the GPU part of the Terrain texture, such as by using [Graphics.CopyTexture](/engine/6000.0/script-reference/unityengine/graphics/copytexture.md). Set the allowDelayedCPUSync parameter to true if you want Unity to perform immediate synchronization of the CPU part. If you set it to false, Unity queues the reading back of the dirty region until the next call to [TerrainData.SyncTexture](/engine/6000.0/script-reference/unityengine/terraindata/synctexture.md).

If the current active [RenderTexture](/engine/6000.0/script-reference/unityengine/rendertexture.md) contains your changes, and you want to copy a part of it into the Terrain texture, use [TerrainData.CopyActiveRenderTextureToTexture](/engine/6000.0/script-reference/unityengine/terraindata/copyactiverendertexturetotexture.md) instead.