Conversion from Inventor to Rhino3D is not supported yet :(

Autodesk Inventor is a CAD application for 3D mechanical design, simulation, visualization and documentation. It is built on ShapeManager, geometric modeling kernel by Autodesk.

Inventor enables 2D and 3D data integration in a single environment, virtually representing the final product. It allows users to check the form, fit, and functions of the product before it is built. The application provides strong parametric, direct edit and freeform modeling tools as well as multi-CAD translation abilities.

Rhinoceros (typically abbreviated Rhino, or Rhino3D) is a commercial 3D computer graphics and computer-aided design (CAD) application software developed by Robert McNeel & Associates. It is used in industries including architecture, industrial and product design, in multimedia and graphic design and runs on Microsoft Windows and OS X. Rhino uses Grasshopper, a visual scripting language add-on, developed by Robert McNeel & Associates.

Rhino is based on the NURBS mathematical model, so it focuses on producing precise representations of curves and freedom surfaces. It allows users to create, edit, analyse, and visualize NURBS curves, surfaces, solid bodies, point clouds and polymeshes.