Conversion from Navisworks to OBJ is not supported yet :(

Navisworks

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.

OBJ

OBJ is a geometry definition file format (.obj extension) first developed by Wavefront Technologies for its Advanced Visualizer animation package.

The OBJ file format is a simple data-format that represents 3D geometry alone — namely, the position of each vertex, the UV position of each texture coordinate vertex, vertex normals, and the faces that make each polygon defined as a list of vertices, and texture vertices.

Vertices are stored in a counter-clockwise order by default, making explicit declaration of face normals unnecessary. OBJ coordinates have no units, but OBJ files can contain scale information in a human readable comment line.