OpenNest - Transform superposition problem

Hi every one !

I recently discovered OpenNest, and i have to say, it’s amazing !

For now i managed to optimised my cuves on sheets for a laser-cutting purpuse but i wanted to had some more geometries on the same place as my original geometrie is.

I searched and read the forum and figured out i had to work with the “Transform” output of the OpenNest solver. When i do so, my new geometries are wild, impossible to make them superpose propely.

My goal is to have several curves with different colors for each curves (so i can tell to the laser cutter to cut black curve and engrave blue ones for exemple). I guess it’s a tree / data problem but i guess i still to beginner for now and i cant solve it by myself.

So if anyone can help me to figure this out, i will be so gratefull !

A little bonus thing, i have a same kind of data / tree management for the number tag, when the contours is cutting my geometrie in 2 or more surfaces on the same plane (like 3 montains of the same height cut by the same plane) my tag mumber can only label one the the 3 surfaces or will give a wrong number thincking it’s an other plan (1 plan can contain several closed curves or surfaces and should all have the same number) !

Decoupe terrain (265.4 KB) Recherches Decoupe Auto terrain LASER CUT.3dm (332.8 KB)

No one could help me with that ? i’m really close to the point but without help i wont be able to finish this tool and work with it :’(
I would really apprciate some hep ! :slight_smile:

Does this help?

You need to group inner curves to separate branches.
The nesting is performed on outer polylines and tou transform inner curves by transform matrices.


Hi Petras and thx for your answer, to tell the truth, i saw this topic and tried this solution without being capable to find the way. I’m still a beginner in GH and try to do my best but i’m stuck there…

Good morning,

I am pretty novice at GrassHopper/Rhino CAD as my career is more focused on IT Operations, so unfortunately I do not have to much to add.

I also have a similar need in which I want to group each ‘nested layout’ to be able to print them out one at a time. Take a look at the ‘Human’ plugin by Andrew Hueman. It may have some tools to offer that could help. I think his tool will help me to solve some of my issues after Petra’s tool takes care of the nesting amazingly.


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Can you prepare definition so that I would see clearly which elements you need to nest?

Sure ! I clean it a little bit and i post it here in about 10 minutes.

Here is the definition on my last try. i deleted most of my tries to make the file cleaner but it’s maybe be not the closest solution.Decoupe terrain (256.9 KB) Recherches Decoupe Auto terrain LASER CUT.3dm (332.8 KB)

Decoupe terrain (290.5 KB)
Try to follow data tree and hull logic.

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Wow !!! Thanx a lot Petras ! I’m so glad.
I still trying to understand data Tree but i dont get it for now (i bought AAD book from @Arturo_Tedeschi and i hope this will help me to get it finaly)
For hull logic, maybe my french native language is a barrier, even when i translate hull in french, it doesnt mean nothing and when i search in google about your hull tool, i cant find a thing.
Anyway, thx again for your plugin and for your help, i really appreciate both of them :slight_smile:

Convex hull
It is for grouping your polylines. If polygons are concave then you will probably need other method.

I just come back here a last time to thank you for your help. I just finished my work and it’s all thacks to you !


Hello may i join the discussion with my “cat looses eye” issue? i cant get it fixed to nest in ner contours…catlooseeye.3dm (51.7 KB) (16.3 KB)

this way for each surface you’re nesting only the longest contour curve
then you are applying the transformation to all the curves (11.2 KB)

Oh wow,@inno many thanks! so fast, so elegant.