# Sandbox.UI.RootPanel.RenderStatistics.FrameNumber

```csharp
ulong FrameNumber { get; set; }
```

Engine frame number of the last completed render. Use RenderCount to distinguish an unrendered root.

Declared in [Sandbox.UI.RootPanel.RenderStatistics](/api/Sandbox.UI.RootPanel.RenderStatistics).
Assembly: `Sandbox.Engine`.