Extracting cut curves after a boolean diff


I’m trying to make a script to save time for interlocking waffle structures. Theres probably a million scripts out there but I want to learn grasshopper, so understanding whats behind the spaghetti would be nice!

So far a have a script that takes the structure and cuts half the interlocking pieces out. What i would like to also have is a way of dog boning the cuts so that the CNC can cut it and not need hand finishing of the curved corners a CNC leaves.

As you can see below i need to manually input the edges and solid again. is there any way to extract the edges from the boolean difference?

Let me know if theres any other info needed! Thanks!

Welcom @slynch

A file would help See guide here

DOG BONE TEST.gh (14.2 KB) DOGBONE TEST.3dm (2.6 MB)

Here is GH and Rhino files. Thanks

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This script takes the largest face on the input Brep, which should mostly always be the one you’re after. I also included the addition of Dog Treat to do the dog boning.

Let me know how you go!

DOG BONE TEST_DZ.gh (282.4 KB)

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Thanks for taking the time out to help. When i opened this definition it said it was missing some python script and doesnt seem to work. Is that an install error on my side?

Sorry for the mishap. Dog Treat requires Lunchbox to work as it uses its Object Bake components. There’s also a bit of Python to speed things up but if you’re using Rhino 6 it should already come installed into Gh.

I can remove Dog Treat if you like and just give you the method I used to extract the largest face if you can’t get it going.

im still on Rhino 5 (planning to upgrade but never get around to it!)

Extracting the largest face would be great. How do you get the dog bone shape from there? i think im thinking too much like rhino and not planning ahead like you should in GH.

Here’s the script with Dog Treat removed. I included a method I use to locate all the points where the dog boning needs to happen and plugged them back into your method.


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Late to the party, I just tested the DOG BONE TEST_DZ.gh file and this is what I get: