# Sandbox.Navigation.NavMesh.SetDirty

```csharp
void SetDirty()
```

Set the navgiation a dirty, so it will rebuild over the next few frames.
If you need an immediate rebuild, call [Sandbox.Navigation.NavMesh.Generate](/api/Sandbox.Navigation.NavMesh/Generate) instead.

Declared in [Sandbox.Navigation.NavMesh](/api/Sandbox.Navigation.NavMesh).
Assembly: `Sandbox.Engine`.