Intersection of solids - export as step


I have a quite basic question, which is totally clear in other software packages but for some reason I can’t do in rhino.

Let’s assume I have a cube given as a surface and a sphere inside the surface. If I export these two object and import them in another software I can see there two objectcs (solids). In particular, I want to mesh these objects, but the result gives me two meshes that have an overlay…

I now have two questions:

1.) can I somehow export a solid which gives me the cube with a hole given by the sphere? So one solid represented by two closed polysurfaces?
2.) how can I export these two objects such that cube realises that it has the sphere in it, thus one object given by the sphere and one given by the cube with the hole?

I played a lot with all the different boolean commands but for some reason nothing does the expected.

I really appreciate any help!

Kind regards

If the surfaces doesn’t intersect, then one closed surface will not be a “hollow” inside another closed (hollow) surface, unless the surfaces intersects.

Rhino is a surface (only) modeler, only “fake solids” based on surfaces.

// Rolf

I see! thanks for clearing this up!

the hack is to connect them with a very small tube and remove it in your destination software.

this is a common trick for hollow parts off a 3d printer as well…