Conversion from Navisworks to 3D PDF is not supported yet :(

Navisworks is a native file of Navisworks® project review software by Autodesk.

Navisworks files come in three formats: NWD, NWF, and NWC. An NWD is a single file that contains all model geometry, environment, viewpoints, and review markups. An NWF file is a list of links to the original files. It doesn't keep model geometry and, to be opened, requires access to the original CAD files. An NWC is a cache file created from any native CAD or laser scan files, when opened in Navisworks.

3D PDF is a PDF file with 3D geometry inside. Using any 3D PDF enabled viewer, rotation, zoom and part selection is available within the 3D view.

3D PDF is just like a normal PDF (Portable Document Format) file, which contains a 3D view somewhere on some page. Just like a PDF containing an embedded image, except when you put the mouse over it, you can rotate, zoom, pan and explore the scene in 3D (three dimensions). The file actually contains a 3D geometric representation of the scene, not just images from different viewpoints.