Select Faces that touch a polysurface's naked edge

I have a polysurface with planar faces and one chain of naked edges.

I want to extend all of the naked edges, using the ‘extend surface’ component in Parakeet (you don’t need Parakeet to open my attached definition.)

In order to do this, I need to two trees to use as input:

  • a tree with all of the planar faces that have an edge at the naked edge of the polysurface, which should look like this:
  • a matching tree with all the edges of the above surfaces that are identical do one of the naked edges of the polysurface.

I have tried using the midpoints of the naked edges of the polysurface to match the midpoints of the naked edges of the subsurfaces, but I couldn’t get that to work. Using surface closest point gave me confusing results, too.

Please help. There must be a very easy way to do this that I’m just missing, right?
Open Brep (38.8 KB)

Is this what you are after?

Open Brep (32.8 KB)

1 Like

Thanks! That does the trick. I’ve never used colision one many before. This is a great simple example of what it’s good for.

This is part of a larger definition, which I have other questions about and will post shortly.