Creating a volumetric mesh by wrapping a given volumetric ellipsoid
I have first created a surface ellipsoid using vtk tool (i.e. a .stl file). And then load it into gmsh and created a volumetric ellipsoid. Now what I want is that I need to wrap this volumetric ellipsoid in a box (I have wrapped with a box. See the attached image) and need to fill the region between two surfaces (i.e. ellipsoid surface and box surface) such that generating another volumetric mesh as a whole. I want to do this without changing the volumetric ellipsoid (i.e. without changing the tetra, triangles, etc of the ellipsoid). Is this possible? If so how can I do that? Can you please elaborate on an example or steps ? I herewith attached the surface ellipsoid (i.e. .stl file), .geo file, the generated volumetric ellipsoid (.msh file) for your further reference.