Cutting Mesh

paneling_jM.3dm (8.4 MB)
I want to cut mesh with box. but mesh is open, not closed. I used grasshopper, mesh split. how make closed mesh?

Mesh Difference will produce a valid closed mesh…

Mesh (1.7 MB)

Thank you Kim!
Your my hero bbb.

I have one more question… I divide mesh with some small size factors, but big size factors don’t work.
paneling_jM.3dm (2.9 MB)