Attached Link: http://www.softy3d.com/en/index.htm

I've never seen or heard of this program before, so I'll advertise for them. trying it out now, but the long and short is you can build models with "bubbles" then it generates a mesh of only the exterior. Exports to many formats after you register ($39 us) website has a few example models that you can download and use as you like.