Mac, I wrote the Cinema 4D plugin becuase C4D's .obj loading leaves a lot to be desired... I was in the process of modelling a humanoid with all the material zones and grouping you find in something like V3. C4D's loader (and/or exporter) botched everything up and I was losing all my material zones, etc. Anyway, while I was at it, I added the code to retain UV-Mapper regions, so I could re-import after doing some mapping and still have the regions around for more mapping etc. later. The above image is the export dialog for the C4D plugin.

Cinema4D Plugins (Home of Riptide, Riptide Pro, Undertow, Morph Mill, KyamaSlide and I/Ogre plugins) Poser products Freelance Modelling, Poser Rigging, UV-mapping work for hire.