How to convert files from Rhino3D
to U3D?

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.

Universal 3D (U3D) is a compressed file format standard for 3D computer graphics data.

The format was defined by a special consortium called 3D Industry Forum that brought together a diverse group of companies and organizations, including Intel, Boeing, HP, Adobe Systems, Bentley Systems, Right Hemisphere and others whose main focus had been the promotional development of 3D graphics for use in various industries, specifically at this time manufacturing as well as construction and industrial plant design. The format was later standardized by Ecma International in August 2005 as ECMA-363.

The goal is a universal standard for three-dimensional data of all kinds, to facilitate data exchange. The consortium promoted also the development of an open source library for facilitating the adoption of the format.