Points Connection on Partially Overlapping Curve

Grasshopper
1

Hi,
I’ve generated irregular random curves that overlap at a moment. I’d like to connect specific point of them with polylines.
On the screenshot for example connect 4 to 18, 3 to 19, 2 to 20 and 1 to 21.

ConnectingPoints
ConnectingPoints1263×791 112 KB

Any suggestions ?

Thanks !

2

Do those curves overlap from top view?
By “connect” you mean creating a vertical line?
If both yes, you could extract all the points for curve A and curve B, then projecting all the points in XY plane, and for each point in list A finding the neares in list B, if the distance is less than “something” (hard to use =0 boolean) keep that point and draw a line.
For a better answer please upload your curves.

3

Hey, thank you for your answer !
Yes this is exactly the case here, they overlap from top view.
I understand what you mean but don’t have any idea how to do it on GH… i’m quite new.

Here is the file where you’ve got the curves, i added one because i’d like to do it with numerous curves if possible.
OverlapingCrv.3dm (3.0 MB)

4

OverlapingCrv
OverlapingCrv.png731×412 60.6 KB

OverlapingCrv.gh (9.3 KB)

This basically do:

  • get all the segments endpoint (you could also use “Discontinuity points” but result might be diffferent)
  • project to XY plane so we have alist with the same structure of 3d points, but flattened and projected to Z0
  • make another list without duplicate points
  • for each point in last list search for the 2 closest point from the complete (Z0) list, if the distance of BOTH points is smaller thant a given value, retrieve both points (from non-projected list) with dispatch.
  • draw the line
5

Thanks ! but…
It looks like exactly what I want on your picture but it doens’t work as well when I run it on my computer. I’ve got lines that appears on the bottom :

38
381145×873 33.7 KB

Am I missing something ?

6

41
Capture d’écran 2018-09-24 à 15.15.41.png1716×410 102 KB

It also seems that my script doesn’t look exactly like yours, I’m missing the doted line you’ve got on your script. Is that a problem ?

7

Sorry I’ve mistaken the script you give me works perfectly !
The mass multiplication box wasn’t here when I opened the file, I added and its works !

8

Thank you very much !

9

You’re welcome.
For the wires, i suggest you to turn on “Draw Fancy Wires” in the “Display” tab.
Useful to distinguish between “single item”, “list of items” and “tree” types of data.

10

Ok I’ll change that !

I’m wondering now if there is a way to use the lines to draw a surface that connect the closed curves together ?

41
411180×847 39.3 KB

Like a loft or a sweep maybe ?

11

Loft.
OverlapingCrv_V2.gh (12.4 KB)

Code was almost the same, but beware, some of you curves intersect eachother; loft works anyway, but you’ll get strange result working with the geometry after this… probably.

12

Great !
Yes you’re right i’ll pay attention to those messy intersections

Thanks again