How to convert Rhino
to FBX?

Rhinoceros (typically abbreviated Rhino, or Rhino3D) is a commercial 3D computer graphics and computer-aided design (CAD) application software. Rhinoceros geometry is based on the NURBS mathematical model, which focuses on producing mathematically precise representation of curves and freeform surfaces in computer graphics (as opposed to polygon mesh-based applications).

Rhinoceros is used in processes of computer-aided design (CAD), computer-aided manufacturing (CAM), rapid prototyping, 3D printing and reverse engineering in industries including architecture, industrial design (e.g. automotive design, watercraft design), product design (e.g. jewelry design) as well as for multimedia and graphic design.

The Rhinoceros file format (.3DM) is useful for the exchange of NURBS geometry. The Rhino developers started the openNURBS Initiative to provide computer graphics software developers the tools to accurately transfer 3-D geometry between applications. An open-source toolkit, openNURBS includes the 3DM file format specification, documentation, C++ source code libraries and .NET 2.0 assemblies to read and write the file format, on supported platforms (Windows, Windows x64, Mac, and Linux).

FBX (Filmbox) is a proprietary file format (.fbx extension) developed by Kaydara and owned by Autodesk since 2006. It is used to provide interoperability between digital content creation applications.

The format saw wider support from other 3D software packages such as Cinema 4D, SoftImage 3D, PowerAnimator, LightWave 3D and 3D Studio MAX. Today, FBX is also widely adopted among VR applications, which are typically built on top of major game engines.