One possible format is pdf 3D, which we did look at a while ago. It's either quite expensive to use an off-the-shelf solution, or else a lot of work to implement, but maybe it's something we can revisit in the future.
The format is quite useful; full 3d models embedded in pdf documents, which you can also view online if you have the right plugins. Take a look at some examples on
this page (I don't have the plugins installed, but if you download the demos and open in Acrobat they work fine).