# MeshModificationCallback

> Callback signature for modifying generated meshes on a VisualElement.

## Definition

* **Type:** Delegate
* **Namespace:** [UnityEngine.UIElements](/engine/6000.7/script-reference/unityengine/uielements.md)
* **Assembly:** UnityEngine.UIElementsModule

```csharp
public delegate void MeshModificationCallback(MeshModificationContext ctx)
```