Hello,

I’ve written a Python script that turns a **network of connected lines** into **polygons**.

The above image shows **three geometries**: the lighter, bigger polygon, the darker triangle, and the boundary polygon, represented by the pink outline.

This external hull is a problem that I encounter for some networks, but not all!

In my script I can’t get rid of this boundary right away - during the line sorting -, since it is ignorant towards checking for boundaries. It has no concept of all the possible polygons.

My hope is to sort them out afterwards.

Which would be an **efficient way to filter out boundaries**, starting from lines and indices of lines, forming polygons?

It’s possible that a whole bunch of polygons have to be checked. This is a rather simple example!

Furthermore, boundaries aren’t found for each line network. They mostly happen for cases like in the screenshot, where a smaller geometry (triangle) is included in a bigger polygon, and intersects the latter partially (with one side).

no_boundary.gh (10.0 KB)