The objective of this was to demonstrate AR saving and loading, also known as AR persistence. This is a C# implementation of Apple's saving and loading demo

There are a few changes though, in order to get this demo to work I had to skip frames where the frame property was returning null and camera was also null.

[Export("renderer:updateAtTime:")]
public void Update(ISCNSceneRenderer renderer, double timeInSeconds)
{
   using (var currentFrame = _sceneView?.Session?.CurrentFrame)
   {
       if (currentFrame == null || currentFrame?.Camera == null)
       {
           return;
       }
   }
}

For front end elements I use the underscore prefix. For iOS, it's easy to find yourself in a freeze because you didn't run the UI changes on the main thread, I find this easy to disinguish what are UI elements are from the VS defined variables and thus correct the issue faster.