Found this interesting video of a computerized twist to the old hydrographic printing technique. I wonder if you could paint miniatures with that? http://www.vocativ.com/video/culture/science/painting-3d-objects-with-a-computerized-bath/
Well, you'd need the 3D camera, the custom algorithm that designs the print, then something to print it with (I guess regular ink jet wouldn't cut it) and then the immersion arm thingie. And it looks like it takes a lot of space...