Is there any plug-in that allow to export from Blender a 3D PDF file?
Or is there any converter to one of the Blender export formats to a 3D PDF file?
so, does there a way to keep the materials on?
The Meshlab program seems to import many of Blender’s export formats: 3DS, OBJ, Collada, etc. And exports U3D - the 3d pdf format.
Good luck.

Thanks!!
I had succseed to transfer an obj. file,
Now I’m looking for a way to export & Import the UV textures, or at least to reassign them.
Try RightHemispheres “Deep Exploration” ( http://www.righthemisphere.com/products/client-products/deep-exploration-standard-edition ). It’s the software we use to animate our company 3D-PDFs. It imports the obj-file along with any UV-Mapping (which is automaticly exported in a seperate file if you use blenders exporter afaik). It’s the only tool I know of that does the trick, as Adobe stupidly dropped Texturing-Support along with Acrobat Professional version 9 (introducing the 3D-Reviewer to “replace” Deep Exploration, which is quite useless…)
After a struggle with the obj. export setting, I’ve succseed to load an UV textured cube into the Mashlab, but the the Accrobat 9 Writer (& the Reader) does’t tend to recognize it’s u3d output.
So I guess I need the accrobat Pro Extanded, unless there is a freeware that can create 3D-pdf from a u3d?
If I get you right the “Deep Exploration” does both operation at once?
>>but the the Accrobat 9 Writer (& the Reader) does’t tend to recognize it’s u3d output.
<<
Sorry. I suggested it without trying it.
I don’t think Deep Exploration is free, but you can probably get by with the trial version for some time. This would seem to be the best option right now.
Daz3d has a commercial plugin - Photoshop Bridge - which is also supposed to write U3D. Price wise, this may be a better alternative (The quality of Deep Exp is probably a lot better)
Good luck 
Some further (still cryptic) info is on the meshlab wiki. Not quite certain how to employ latex here, but I may tinker with it a bit… ?
Thanks for your good willing. It’s o.k. anyhow it nice to get know to a nise tool as the Meshlab.