There are two problems with this: 1) There's not good broad support for 3D views in PDFs; I imagine it won't work on most things other than Adobe Reader. What

There are two problems with this: 1) There's not good broad support for 3D views in PDFs; I imagine it won't work on most things other than Adobe Reader. What does it fallback on if it doesn't work? etc. And in any case, it's a corruption of what the PDF document format was "meant" to be, which is a document format guaranteed to display the same on all devices. 2) The 3D data isn't useful. It's raw information, rather than the metadata. If I'm looking at a 3D view of a crystal, I may want to export it to manipulate the structure myself or use it in my own simulations, so I want to know what atoms are there and information about boundary conditions, symmetry and the like. I specifically don't want a list of vertices and edges that, say, make up the individual spheres that represent the atoms.