is there computer app or "virtual world" for assembling photos into models of multilayer 3D objects?

Factual Questions
1

in other words, suppose we want to create the virtual experience of “dissection” of an entity with many parts and layers, such as a frog, a car engine or a computer. We could do a bunch of such dissections, taking photos of steps with various levels of detail and then arrange the photos using a mix of picture hyperlinks for covered objects and “zoom in - zoom out” for visible objects. Then by playing around with this app, the user could get some notion of the structure of various parts of the thing being dissected.

Well, I guess this is pretty obvious and there ought to be lots of prior art. E.g. I have heard about such an app sold specifically for frog dissection for the benefit of squeamish students and stingy high school bio departments.

Ok, so is there a generic “game engine” or framework for this type of applications? I guess that a simple one could be hacked together in Flash for every given case, but maybe there is an “industry standard” quality system? Or maybe not quite industry standard but open source and up-and-coming one?

2

CAT and MRI scans take their pictures in slices, and the 3D views are asssembled from the slices in just this way. I haven’t a clue what software is used for this.

3

The technique is called “volume rendering” I’ve done alot of it myself (the coolest thing I’ve worked on being this).

If you are programming it yourself you can use any modern graphics API (OpenGL or DirectX) that supports 3D textures. There are numerous bits of “off the shelf” software out there for doing it as well (A quick Google turned up: Volview and 3D-Doctor).