Polygon boundary of surface?

Hi there,

I’m new to rhino and I’m having some trouble figuring out how to obtain the vertices of a polygon surface from a model.

I’ve attached a file with a handful of “trimmed surfaces” that I extracted from a larger file.

simple_floorplan.3dm (4.0 MB)

I’m trying to get to the vertices so that I can export them to a file so I can use them in an external program.

What I’ve tried so far is reading through various parts of rhino3d, googling, etc for how to extract the polygon boundary from a surface, but so far no dice. I was able to convert the object to a mesh and export the mesh to DXF, but that is difficult to work with because the mesh is composed of triangulated faces – I really just need the polygon boundary vertices.

Is there a way to do something like: convert object to mesh → obtain boundary polygon → export boundary polygon?

As a secondary goal, if I can export the polygon boundaries to DXF (perhaps as POLYLINES), then I’ll be able to read them in with my existing external (python) code. But, if there’s another way to get the info I need, I can probably work out a way to get the data into my external code through some other parser.

Thank you,

Hi Joshua -

If I understand correctly, you can run DupBorder and then ExtractPt.

Thanks, DupBorder was the piece I was missing. From there I can export the curve to DXF and it is close enough to what I need! Thank you!!