Question CollectSources

Hi All, am new to building the NavMeshBuilder API and just starting out with a few simple tasks just to get a feel but I seem to be stumbling at the first hurdle. I'm try to use NavMeshBuilder.CollectSources but it's not returning any sources. In my scene I have a parent object to which the Start method below is attached. As children of that object I have 2 planes and a cube. Default layer and set to static.

Code (CSharp):

1.     void Start()
2.     {
3.         List<NavMeshBuildSource> sources = new();
4.         List<NavMeshBuildMarkup> markups = new();
5.         NavMeshBuilder.CollectSources(transform, 0, NavMeshCollectGeometry.RenderMeshes, 1, markups, sources);
6.         Debug.Log("Sources found: " + sources.Count.ToString());
7.     }

With this simple setup I would expect to return the three sources below the transform, but no, I get 0.
Any pointers greatly appreciated. Apologies in advance if it's something stupid on my behalf.
Cheers
Chris

 

All good. I think I was barking up the wrong tree. Now using the Components and the NavMeshSurface. Though in my defence information was a little scattered and confusing for my pea-sized brain. The previous method looked like it should have worked and threw no errors