How to detect and mark underpasses?


Hi everyone,

I’m looking at thundreds of meshes that do or don’t have underpasses in their topology, and I would like to find a way to automatically detect and mark them.

I’ve attached an example of what I mean with ‘underpass’. You could also call it a ‘tunnel’. So there’s not hole in the topology and technically the mesh is fine, but these underpasses create issue further down processing.

The one in the image is very obvious, but in all the meshes I have they are sometimes very tiny and not visible until you zoom in all the way.

Any help is greatly appreciated, thank you!