The newly announced Corel DESIGNER Technical Suite X4 includes Deep Exploration Standard Edition that allows viewing and embedding 3D CAD models to PDF files. Which means support for over 80 file formats used in CATIA, Autodesk Inventor, Pro/ENGINEER, SolidWorks and Unigraphics NX.
Since a week or so SVN version of Inkscape can now render OBJ files. While the extension is called “3D Polyhedron”, it can actually render more than that 
I also tried the version of this elephant (found in Internet) with 10150 faces (that is 5500 grouped objects) and it renders, but working with such a document is a pain on my old Centrino laptop.
Makes me wonder if it would be possible to extract import/export filters from Blender and marry them to Inkscape. For now let’s say “Thank you!” to someone called inductiveload who posted this nice extension to LP 