When I join the geometries of the objects in the attached file together using Brep.JoinBreps, I can see in the debugger that resulting Brep has its IsSolid=false. When I subsequently run the SelClosedPolysrf command, the resulting joined object isn’t selected.
However when I select these same objects in Rhino and run the Join command, it results in a closed polysurface going by the fact that SelClosedPolysrf selects the resulting object.
I’ve inspected all the surfaces and they each seem to have their normals facing outward. And the fact that the Join command is able to join them together shows that I don’t have a piece missing (a “hole”). But I am obviously missing something here.
Could anyone help me by pointing out what I’m missing in this case? Why does Rhino’s Join command does create a solid, but Rhinocommon’s Brep.JoinBreps doesn’t?
TestJoinBreps.3dm (622.2 KB)