Region curve Union Grasshopper

[ZY_Night (Night)]

Current Situation:​
I have multiple line segments—some may follow a pattern, while others appear disorganized. My goal is to extract their outer contour lines.

Issue:​
With ​Input 2​ and ​Input 3, my Grasshopper (GH) script successfully generates the desired contours.
However, ​Input 1​ fails to produce results, leaving me unsure how to proceed.

Question:​
Is there a more robust method to make the program compatible with diverse input cases and reliably extract contour lines?
It would be best if Python could solve this problem, as I’m not proficient with C++.

curve Union.gh (822.6 KB)

[AndersDeleuran]

I’m not entirely sure why the last branch fails (maybe check your inputs), but this seems to work otherwise:

unnamed.gh (754.4 KB)

Edit: Think I might have misunderstood the problem, but maybe it helps anyway

[ZY_Night (Night)]

This function appears capable of handling most issues—I’ll proceed with using it. Thank you very much!

[ZY_Night (Night)]

Simply break down the line segments—that works. I’ll test it on other lines as well.
This code solved a major challenge for me. Thank you so much!