Can't get Boolean Difference to work with two brep objects in GH

Hey all,

I’m pretty new to using Grasshopper but have been using Rhino for a little while now, so this hopefully is a pretty simple thing and I’m just not searching the forms with the correct terms. I am trying to an intersect between two shapes. I’ve tried this with a brep and as a mesh and it’s not giving me the result that I am looking for.

I have a geodesic dome that I’ve created in Grasshopper, and I want to intersect it with a box so that the dome is a 1/2 sphere instead of a full sphere. I’ve tried a few different things to ensure that I was using the intersect currently… I can do an intersect with two boxes and it works, when I bake the GH brep’s I can do a Boolean Difference within Rhino I get the effect I am looking for. I am looking to get this done in GH to continue with the workflow in GH.

Should I be trying to do this with a mesh, brep, solid? Is it to do with the geodesic dome shape and the box? Any help and direction are greatly appreciated.

I’ve attached the .gh file and some screenshots for reference.

GH Nodes. Last one is a Difference node.

what it still looks like after the difference.

Doing the Union Difference in Rhino after I baked the GH brep. This is the effect I’m trying to create using only GH

I’ve attached the .gh file for reference and to give a better idea of what I have going on. (25.6 KB)

Thanks again!

Hi and welcome to this forum!

You were using the list of surfaces… you need to join them into a single brep.
Use [Brep Join] component.

Also you were doing solid difference with “box \ structure” , instead you want to do “structure \ box”

Check the screenshot.

Note: boolean solid operations usually are between closed polysurfaces (breps) for best results.
You can also do solid operations between surfaces, but that is not your case.
Your list of surface needs to be joined into a single object to do solid operations.

1 Like

Hey Riccardo,

Thanks! This was very helpful and got me to where I needed to go with the model. I appreciate the help and additional tips.