One of my customers asked me if possible to develop an application  is similar with Hotfolder Batch ReaderEnable , can batch convert 3D files to PDF documents with hotfolder support  for his company.

His company bought 3D PDF Converter™ from Tetra 4D, but it does not support batch convert function.

he has use hotfolder 3DtoPDF  now, and here is the feed back,

All works just fine. I will let you know if I will experience any problems and I will require your assistance.
Thank you very much for your support.

P.S.

3D PDF Converter is the world’s leading solution for converting native 3D CAD data into rich, interactive 3D PDF documents, including full support for accurate BREP geometry and PMI.  Exclusively authorized by Adobe to run within Acrobat X Pro, only 3D PDF Converter running inside Acrobat allows you to turn on the measurement, sectioning, collaboration and powerful security features within the free Adobe^® Reader.

The 3.3 release includes updated support for CATIA V6, PTC Creo Elements and Parametric, SolidWorks 2010/2011, Siemens NX 7.5, Inventor 2011/2012, and Solid Edge ST3.

Because my  MinGW Cross Compiling Environment includes compiled Qt4, after successfully compiled poppler-0.6.13 (with the Poppler Qt4 interface library, libpoppler-qt4), I decided to compile the last version of DiffPDF, after some effort, the Win32 Static version is out, is only 4M an only one exe file, without any library.

Feel free to download the last version from DiffPDF Win32 binary download page.

P.S. Change log of  1.1.5,

Slightly changed the .pro file to make it a tiny bit more helpful.

Added a Help button and separated Help and About information.

Updated the README for Mac users (thanks to Dirk Loss for the info).

It is a real case, and the author of Turn on Measure Tool in Reader for 25,000 PDF documents has been my customer, he bought my software Batch ReaderEnable, because he has already bought the license of Adobe Acrobat, so he just payed extra USD$39, and he can easily converted 25,000 PDF documents.
And, I’d like to correct something in his requirement,

I work for a city government and I have 25,000 scanned maps as PDF documents. Our users (they have Acrobat Reader(should be Adobe Reader) would like to be able to use the measure tool to measure distances on the maps.
From my research, it seems I need to turn on “Enable Usage Rights in Adobe Reader”(should be “Enable For Commenting and Analysis In Adobe Reader” aka “Reader Enable” and in Adobe Acrobat X Pro, it is called “Enable Commenting & Measuring…” ) in order for that tool to work in Adobe reader. Also from my research, it seems there is no way to automate, or batch process, these action for the 25,000 PDF files. There are some references on the web that LiveCycle can do this(Yes, Adobe LiveCycle can do it, but it is very expensive), but nothing confirmed, and when I called Adobe support they said in face, it was NOT possible to batch “enable usage rights“(“Enable Commenting & Measuring”). At. All. Period.
…

btw, Batch ReaderEnable Updates to Support Adobe Acrobat X Pro