# GatherAlphamap(TerrainLayer, bool)

> Gathers the alphamap information into sourceRenderTexture.

## Definition

* **Type:** Method
* **Namespace:** [UnityEngine.TerrainTools](/engine/6000.7/script-reference/unityengine/terraintools.md)
* **Assembly:** UnityEngine.TerrainModule

```csharp
public void GatherAlphamap(TerrainLayer inputLayer, bool addLayerIfDoesntExist = true)
```

### Parameters

**** (\[TerrainLayer]\(/engine/6000.7/script-reference/unityengine/terrainlayer)): TerrainLayer used for painting.**** (\[bool]\(https\://learn.microsoft.com/dotnet/api/system.boolean)): Set to true to specify that the inputLayer is added to the terrain if it does not already exist. Set to false to specify that terrain layers are not added to the terrain.

### Remarks

This function collects the alphamap data from all Terrain tiles in the PaintContext into `sourceRenderTexture`.

This function is called internally by [TerrainPaintUtility.BeginPaintTexture](/engine/6000.7/script-reference/unityengine/terraintools/terrainpaintutility/beginpainttexture.md).

Additional Resources: [PaintContext.ScatterAlphamap](/engine/6000.7/script-reference/unityengine/terraintools/paintcontext/scatteralphamap.md)