How to convert IGES
to Rhino?

IGES (Initial Graphics Exchange Specification) was among first vendor-neutral CAD formats designed to enable interoperability between different CAD systems. The latest versions of IGES have been approved by ANSI (American National Standards Institute) and published by US PRO (U.S. Product Data Association). The latest officially approved version of the IGES standard is version 5.3 which was published in 1996. Nonetheless, IGES remains a broadly used format (along with STEP) supported by all major CAD/CAM/CAE systems such as CATIA, Autodesk Inventor, Solidworks, Solid Edge, NX, Pro/Engineer, Creo and multiple others. IGES files usually have *.igs or *.iges file name extensions.

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).