Create a polyline around multiple surfaces

[rteuman]

Hello All,

I have three surfaces:

I would like to create a polyline using the edges of these surfaces with grasshopper as you see in this screenshot:

I thought I could take all the vertices and create a hull around these points, but it didn’t really work.

here’s the GH file:
polylinearoundmultiplesurfaces.gh (15.3 KB)

Any ideas on how I can achieve this?
Thank you all
Best,
Renan

[Joseph_Oster]

polylinearoundmultiplesurfaces_2022Oct3a.gh (15.3 KB)

[rteuman]

Thank you, this works great! I’m wondering how we could adjust the script so it could work let’s say if there were two sets of surfaces like this stacked on top of each other:

so with the same method we can get these lines:

and then loft

polylinearoundmultiplesurfaces_2022Oct3a (1).gh (28.2 KB)

thanks again

[Joseph_Oster]

You lost me with the third image? And I wonder what scenario comes next? I got it to work with multiple sets of surfaces… and as I write this, I wonder if it handles different surfaces in each branch? (it does!)

[
P.S. I created a PtLines cluster and used two of them (white group). Here’s that code:

I already found a condition where it fails… working with a single list (branch) of surfaces. This isn’t fun enough for me to pursue it further, enjoy.

P.P.S. I fixed the cluster so it handles a single list (branch) of surfaces. I replaced the first PShift with one I wrote myself:

Simplified shift path error

This is INSANELY annoying! This is a flaw that should be fixed, and I don’t care who’s code the fix might break. It’s a mistake to work as it does. I just created a “Smart PShift” cluster to handle this. pShift works for me, though perhaps could be done better? It is demonstrated in the following code, internal to another cluster crvXYZ that sorts curves by X, Y or Z of their midpoints. [PShift_smart_2020Apr28a2] [PShift_smart_2020Apr28a] PShift_smart_2020Apr28a.gh (42.2 KB)

polylinearoundmultiplesurfaces_2022Oct3c.gh (30.9 KB)

[rteuman]

This works, thanks so much Joseph, always very helpful!