# Overlay

> Overlay (Advanced OpenGL blending).

## Definition

* **Type:** Field
* **Namespace:** [UnityEngine.Rendering](/engine/6000.6/script-reference/unityengine/rendering.md)
* **Assembly:** UnityEngine.CoreModule

```csharp
Overlay = 23
```

### Remarks

As specified in GL\_KHR\_blend\_equation\_advanced. This mode is currently available only on OpenGL hardware with GL\_KHR\_blend\_equation\_advanced or GL\_NV\_blend\_equation\_advanced extension support.