Multiple Polylines With Data Tree Input

Hello I am a student who has recently just started using grasshopper, so working with the different data types is new to me.

I am working on a project to recreate a structural system of the Gherkin, using LunchBox’s diagrid structure component I have been able to workout most of this. However the one part of the diagrid I need to make are the horizonal members. So far I have taken the Structure Nodes output from the Diagrid Structure component and used Partition List to make a data tree that has each branch containing points with like Z values.

The issue is it seems the Polyline component doesn’t respect the branches of the data tree and tends to hop around? Causing my curves to have shifts and not be co-planar. I tried messing with the Closed boolean but this just made gaps throughout and did not resolve the original issue.


In top view these are circular in shape, but half the circles are offset vertically from the other.

please right click on your Geometry parameter, choose “internalize”, save the GH file and upload it with your post

Sorry, here is the grasshopper file with only components in the original post to not add confusion.
grasshopper-code.gh (33.5 KB)

if you look at the Panel after the Partition List, you will notice that even before going into the Polyline component, the points in each branch do not all share the very same Z value (this just to rule out the possibility of Polyline component non respecting data branches :slight_smile: ):

A maybe better way to group points by their Z value might be:

grasshopper-code (1)_Re.gh (34.8 KB)

[edit: reuploaded screenshot with Sunglasses to show component’s names]

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Yes, was looking through this and just started to notice that later down the list issues were occurring. Thanks for bringing up methods to sort through data sets based on actual values and not just guessing.

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of course you can apply the very same riddle to structure-lines middle points to group structure-lines by Z-level:


grasshopper-code (1)_Re_Re.gh (43.3 KB)

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