Boolean Difference in Grasshopper

[Alyzee]

Hi,
I am new to grasshopper and I am still learning the basic commands. Currently I am making a house and I have these cylinders that I want to trim to create oculus openings in my roof but when I use Solid Difference and do preview off, it makes no difference.
Thanks for your help

[michaelvollrath]

Hi @Alyzee ,

Can you please upload your grasshopper file with any input geometry internalized by right clicking on the objects and choosing “internalize data”. This way you won’t have to attach the Rhino file.

Without seeing the actual file I can still see a little bit from your screen shot.

It appears that your cutting cylinders are not closed breps. I would run the “Cap” component on those open breps first to ensure they are solid/closed breps prior to your solid difference operation.

Separately from that you may have a grafting issue as you are trying to cut multiple objects at once with multiple shapes but I would need to see the actual file to check that.

Also the 2nd snip you show it appears that your rectangular objects have multiple overlapping copies of themselves in the same place, hence the darker red color vs. your first snip

Try creating solids out of the cylinders first with the method described above ^

[Alyzee]

Here is my grasshopper file
Work in Progress.gh (21.1 KB)

I wasn’t sure how to save it by choosing internalize data. But this is the rhino file
Grasshopper NEW.3dm (201.1 KB)

[Ryan14 (Ryan)]

Yep Just add a cap component to your extrusions. That was the problem as far as I could tell.

[Alyzee]

Thanks!