How to join polylines/curves without overlapping vertices

I’m working on a CNC project, and my CNC software wants the vectors defining the paths it cuts to be joined in a reasonable way. In this case, that means a polygon for every enclosed area (see design below). I’m using Surface Split to do this.

It works for some of the desired polygons, but not others:
Screen Shot 2020-06-10 at 4.49.46 PM

My best guess on why was that Join Curves was outputting six different curves and not joining everything into one curve.
Screen Shot 2020-06-10 at 5.00.31 PM

After searching I discovered this was because the output curves don’t have shared vertices.

I tried using Topologizer because it has a function to split lines at crossings and create new nodes, but it wants lines and I have curves. I tried to convert them by dropping them into a Line container since none of them are actually curved, but that doesn’t work.

So my questions:

  1. Am I on the right track with this approach or was there an easier strategy I missed along the way?

  2. What is the best way to join overlapping polylines that don’t have shared vertices?

  3. What’s the best way to convert my (straight) curves into polylines?

Islamic Pattern Line Joining Test (16.2 KB)

Try Geometric Region from this plug-in:

1 Like

That’s exactly what I was looking for. Thanks @scottd .

Unfortunately it seems to cause Rhino to throw a lot of errors when it starts:

What OS, Rhino version are you running? You can run SystemInfo in Rhino and send the top of the results.

Rhino 6 SR26 2020-5-26 (Rhino 6, 6.26.20147.06511, Git hash:master @ 7788f6214ee9335d5793cc6177985a1c745e663b)

License type: Commercial, build 2020-05-26

License details: Cloud Zoo. In use by: Raam ()

Windows 10.0 SR0.0 or greater (Physical RAM: 4Gb)

Machine name: DESKTOP_A

Non-hybrid graphics.

Primary display and OpenGL: Parallels Display Adapter (WDDM) (Unknown) Memory: 2GB, Driver date: 4-13-2020 (M-D-Y). OpenGL Ver: 2.1 ATI-2.11.21

OpenGL Settings

Safe mode: Off

Use accelerated hardware modes: On

Redraw scene when viewports are exposed: On

Btw, Geometric Region is still returning incorrect results in some cases. I don’t suppose you happen to know another plugin offering the same functionality?

Screen Shot 2020-06-11 at 12.29.53 PM

Geometric Region and Network From Lines by Heteroptera might help…