How to convert OBJ
to Rhino3D?

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.

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.