How do I subtract one Brep or surface from another?

I’ve been trying to do this for three hours now. See image below. I have the Brep on the left, and I’m trying to subtract the Breps on the right so I’m just left with a latticework.

I’ve tried Solid Difference, Region Difference, Mesh Difference (casting it to a mesh type first). I’ve tried deconstructing and reconstructing it. I imagine there’s a simple solution I’m just missing.

Grasshopper Forum Subtract Surface.gh (67.0 KB)

This? Boundary Surface


Boundary_Surface_2021_Aug4a.gh (60.2 KB)

Exactly. Thanks Joseph.

Out of curiosity, why couldn’t I do a subtraction operation?

I don’t know, I don’t worry much about why something fails, I just look for another way and move on!

You might do some split things but then you’d have a bunch of fragments to sift through. You could do this but it takes MUCH LONGER (2.8 mins.!) and the result is the same:

Just be thankful that Boundary Surface is so smart.

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