<< Does Sketchfab has advantages compared with 3D PDF
an infinite free direct public data base like 3DWareHouse for Polygonal or GrabCad for the CAD (nurbs...) ;)
http://sketchup.google.com/3dwarehouse/
http://grabcad.com/
<< not MOI>>
But you can export some objects in polygonal format from MOi: see in the list following these with !!!
So no need to return in Sketchup for Sketchfab! ;)
> Blender (.blend)
> Collada (.dae),
> Wavefront (.obj) !!!
> FBX (.fbx), !!!
> Design Web Format (.dwf),
> OpenSceneGraph (.osg, osgt, osgb, ive),
> 3DS (.3ds), !!!
> Lightwave (.lwo, .lws), !!!
> Polygon File Format (.ply),
> Virtual Reality Modeling Language (.wrl),
> Open Inventor (.iv),
> Shape (.shp),
> Standard Tessellation Language (.stl), !!!
> Biovision Hierarchy (.bvh),
> Open Flight (.flt),
> ac3d (.ac),
> DirectX (.x),
> Designer Workbench (.dw),
> 3DC point cloud (.3dc),
> carbon graphics Inc (.geo),
> Generic Tagged Arrays (.gta),
> Keyhole Markup Language (.kmz).