Extracting specific parts out of a drawing!

Hi all,

The shortest and easiest way of asking my question is by using a snapshot of my issue.
Regarding the snip below (picture 1), i would want to extract two elements from a bunch of surfaces:

  1. The exterior border running all around the whole pack of surfaces (similar to the red line shown in picture 2)
  2. The negative space between the surfaces (similar to the blue surface shown in picture 3)

Does anyone know any simple way of doing this in Rhino or Grasshopper? If anyone by any chance has previously written a similar script that would kindly want to share? Or if anyone is familiar with a grasshopper plugin that does the similar job??

Looking forward to hearing back from anyone.
and thanks in advance :pray:

Picture 1:

Picture 2:

Picture 3:

Sample File
Sample File.3dm (565.7 KB)

Please post an example file as well. Thanks

Thanks Japhy,
I added a sample file…

Sounds like a job for the CurveBoolean command.
In an orthographic view, it takes any geometry as input, not just curves. Clicking inside a bunch of curves/srfs will create the interior boundry, clicking somewhere outside will give the complete exterior boundary.

The Hatch command, when invoked without preselection, will offer the ‘boundary’ option. When this is on, hatches can be created using CurveBoundary internally/automatically.

In GH, I’d like to know myself. Sounds tricky.

1 Like

Hi Sadegh - Make2d may help here - it’s a complicated set of parts with coincident surfaces, so I think there will be some work to do with CurveBoolean, but try it. Use the View option and uncheck all but ‘Scene sillhouette’. The resulting curves on the Scene Sillhouette layer will be most of the curves you need - however there are some mistakes where surfaces are coincident, it looks like, so you may need to pick some other curves that are on different layers, but the curves you need should be there.