X3D

X3D (Extensible 3D) is a set of royalty-free ISO/IEC standards for declaratively representing 3D computer graphics. X3D includes multiple graphics file formats, programming-language API definitions, and run-time specifications for both delivery and integration of interactive network-capable 3D data. X3D version 4.0 has been approved by Web3D Consortium, and is under final review by ISO/IEC as a revised International Standard (IS).

X3D is specifically designed to work across diverse devices by using the Web Architecture. X3D provides a range of 3D functionality through Profiles, from basic asset Interchange and CADInterchange to Interactive, MPEG-4 Interactive, Medical, Immersive, and Full Profiles. Anatomically thorough support is also available for Humanoid Animation (HAnim) body structure and motion. The ‘X’ in X3D means Extensible: custom vendor and research component extensions can be added to standard functionality.

X3D file format support includes XML, ClassicVRML, Compressed Binary Encoding (CBE) and a draft JSON encoding. Semantic Web support has also been demonstrated by a Turtle encoding. X3D became the successor to the Virtual Reality Modeling Language (VRML) in 2001.^[1] X3D provides multiple 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 compression, with strongly typed APIs including ECMAScript, Java, Python and other programming languages.

X3D rendering includes both classic (e.g. Blinn-Phong) and modern physically based rendering (PBR) methods matching glTF 2.0 capabilities. Use of custom shaders using three platform-specific shader languages is also defined. Authors can employ rich multimedia capabilities including various image and movie formats. Fully spatialized aural rendering applies W3C Web Audio API capabilities, plus audio inputs digitized using MIDI 2.0 or other sound formats.

All X3D file encodings and programming-language APIs have equivalent expressive power, matching functional definitions in the X3D Architecture standard. Thus X3D can work with open standards including XML, Document Object Model (DOM), XPath and others.