Source of smoothness value used in the underlying splat material of a TerrainLayer when TerrainLayer.diffuseTexture has an alpha channel.
When TerrainLayer.diffuseTexture has an alpha channel, you can set smoothness by TerrainLayer.smoothness or through the alpha channel of the diffuse texture.
| Constant | Smoothness value comes from TerrainLayer.smoothness. |
| DiffuseAlphaChannel | Smoothness value comes from the alpha channel of TerrainLayer.diffuseTexture. |