Insert STL Give 2 Shapes


I’ve made a shape that acts like a shell in Vectorworks. In my first prototype I was able to import it into Rhino and just mesh difference everything as a could with a shell leaving me with the desired holes. Now I want it to be more accurate.

But when I started with the mesh difference (on a fresh resized shape), suddenly it recognized the outer layer and the inner layer of the meshes separately. And not anymore as a shell/mesh?

How can this happen? And how do I get this outer STL and inner STL to act like a shell again.
Or can I create something directly into Rhino.

If it’s two distinct meshes that don’t touch, you can just use “Join” to join them into one “disjoint” mesh. --Mitch


I’ve been able to join it and that worked somewhat. After that I tried to difference another mesh and it when I press done.
It shows me a full mesh and not the Shell shape.

Rhino does not have the concept of hollow (disjoint) shells either in Mesh or Nurbs. --Mitch