Ok that’s two materials then…
In Blender, make a sphere and give it thickness with a solidify modifier
and apply.
Use a boolean to cut out the port
Then go into face mode, and assign one material to the outside
and another to the inside.
Then just export as FBX and import to the engine. You can do all of it except the sphere thickness in geometry mode actually.
PS: In fact, I just figured out how to do a ‘thick sphere’ in the engine, but it’s more of a hassle. ( You have to make two, invert the normals on one, and merge them ).