How to convert files from Rhino3D
to X3D?

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.

X3D is ISO standard XML-based file format for representing 3D computer graphics. X3D features extensions to VRML (e.g. CAD, geospatial, humanoid animation, NURBS etc.), the ability to encode the scene using an XML syntax as well as the Open Inventor-like syntax of VRML97, or binary formatting, and enhanced application programming interfaces (APIs).

The X3D extension supports multi-stage and multi-texture rendering; it also supports shading with lightmap and normalmap. Starting in 2010, X3D has supported deferred rendering architecture. Now X3D can import SSAO, CSM and Realtime Environment Reflection/Lighting. The user can also use optimizations including BSP/QuadTree/OctTree or culling in the X3D scene.