I have an IFC file and would like to transfer it to FEM software using Rhino and Grasshopper. Among other things, I need to convert 3D walls into 2D surfaces. The walls as such are no problem, but I have not yet found a way to include openings in walls.
Original
Desired result
Thanks in advance!
Hi @Clemens_Gutmann
At least for me, 2X _Explode gives me the wall as surfaces, opening included.
That would indeed be a possibility, but it would result in the destruction of the wall object. However, I picked up your idea and found the VisualARQ Explode component in Grasshopper, which does the same, but without destroying the original wall in Rhino. And that on the other hand is a working solution for me 
Another method without grasshopper is using DupFaceBorder + PlanarSrf + Delete
This gives you the curves around the perimeter of the wall, including the openings. Then makes a surface from those curves with uses the openings as a void. After that, just delete the curves while they are still selected. Unlike grasshopper, it only works on one wall at a time.
But how to DupFaceBorder in Grashopper?
I would think a pretty basic way would be to extrude the wall curve, get the plane of the surface, and intersect it with the exploded wall brep. It might not work on a bunch of complicated walls though. It definitely wouldn’t work with a curved wall.
You can try a similar method using the Solid Intersection SInt function in grasshopper. But those tend to be a little buggy in my experience.
