@slynch (Slynch) posted a new topic, subject "Extracting cut curves after a boolean diff". It read:

   Hi,
    
    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.
    
    Canvas at 11;47;531346×337 58.7 KB
    
    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?
    
    Canvas at 11;53;261361×312 47.7 KB
    
    dog bone1335×768 41.1 KB
    
    Let me know if theres any other info needed! Thanks!

After which, @Fred_C added

    Welcom @slynch
    
    slynch:
    
    > any other info needed
    
    A file would help See guide here

Then @slynch (Slynch) said

    DOG BONE TEST.gh (14.2 KB) DOGBONE TEST.3dm (2.6 MB)
    
    Here is GH and Rhino files. Thanks

Then @djzelenko (Djzelenko) said

    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)

So @slynch (Slynch) replied

    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?

To which @djzelenko (Djzelenko) replied

    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.

After which, @slynch (Slynch) added

    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.

@djzelenko (Djzelenko) replied

    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.
    
    DOG BONE TEST_DZ.gh (21.8 KB)


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