CAD Exchanger is a paid application (you can download a 30-day trial for free). So far the price is not informed on their website, you must send them an email to ask, but they told me they are working on something easier *EDIT* There is now a link to the pricing page inside the CAD Exchanger application.
When the addon is installed (via the addon manager), you get a new "CAD Exchanger" preferences page in Edit -> Preferences -> Import / Export. From there, you can enable any of the file formats supported by CAD Exchanger. You must also specify the path to your CAD Exchanger Converter executable. Then, by using any of the file formats from standard FreeCAD import/export (FreeCAD must be restarted before), the converter will be ran under the hood and will convert to/from the given format to Brep, which is OCC's native file format, which always gives an impeccable import in FreeCAD.
There are two things that are pretty interesting:
- CAD Exchanger does a pretty fast mesh-to-shape conversion, so you can use this to import, for example, an OBJ file directly as a Shape. So far everything gets triangulated, though.
- The biggest interest is the support for additional file formats not available in FreeCAD, for ex. Parasolid XT, Rhino 3DM or ACIS/SAT files.
The CEO of CAD Exchanger is Roman Lygin, one of the former core programmers of OCC and a famous figure of the OCC world. I really hope we can achieve some good synergy here between a free software project and a commercial app, which can reach goals that are beyond our reach as an open-source project. They are hungry for feedback and feature requests on this, so don't hesitate to bury them under requests (DWG support anyone? )!
I'll notify them about this thread so they'll hopefully see any feedback or comments posted here.