Inventorfag here, I'm working on making a mold that would

Not an inventorfag but you want a Boolean subtract I believe.

>>512312
Shell it?

>>512315
CADfag here. A Boolean subtract would just totally destroy the mesh if you insert it into a closed mesh.

CAD applications have an obsession with optimizing the result, so if you're trying to subtract a ball from a larger ball, the smaller one is just going to disappear because it wouldn't change the silhouette.

You still want to do a Boolean subtract, except instead of a single object, you want to do it against the two halves of the mold.

However, I'm going to stop here because I can't responsibly advise you on making molds.
That shit's complicated, and the result can be trash depending on how much resin you put in or if you can't pressurize the mold.

>>512312
This is am annoying problem a lot of cad software tends to run into because if your shape has any complexity whatsoever a boolean will fail.

My suggestion is to work with the object as nurbs. Intersect a plane through the middle, split the original nurbs and use the inside of the model as your 3d printed or milled surface. This is assuming you have a clean model.

Cut it in half, select all faces, extrude a fair distance out, merge verts that fall inside other extrusions so that there are no intersections, then bool a box down each side individually.

Can you not just 3D print this statue as is and make a physical mold from it?

>>512373
Yes, but the prompt of the project is that it's going to be a chocolate mold. So where as clay might do for a resin based mold, pouring hot chocolate into clay would probably fuck the integrity of the mold, and even if it held it would probably taste like shit.