本标准采用ISO/IEC 19776-2:2015，该标准使用ISO/IEC 14772虚拟现实建模语言（VRML）中定义的技术，定义了X3D中抽象对象到特定编码的映射。每个经典VRML编码的X3D文件（a）支持AS ISO/IEC 19775中定义的X3D文件的所有用途；（b）以经典VRML格式编码X3D结构。如ISO/IEC 19775所述，可扩展3D（X3D）定义了一个集成3D图形和多媒体的系统。从概念上讲，每个X3D文件都是一个基于3D时间的空间，其中包含可以通过各种机制动态修改的图形和听觉对象。 经典VRML编码的X3D文件可以从使用其他编码的文件中引用，并且其本身可以引用使用其他编码编码的X3D文件。这些文件只能由符合所有使用编码的浏览器处理。

This Standard adopts ISO/IEC 19776-2:2015, which defines a mapping of the abstract objects in X3D to a specific encoding using the technique defined in ISO/IEC 14772 The Virtual Reality Modelling Language (VRML). Each Classic VRML-encoded X3D file (a) supports all of the purposes of X3D files defined in AS ISO/IEC 19775; and (b) encodes X3D constructs in Classic VRML format. AS ISO/IEC 19775, Extensible 3D (X3D), defines a system that integrates 3D graphics and multimedia. Conceptually, each X3D file is a 3D time-based space that contains graphic and aural objects that can be dynamically modified through a variety of mechanisms. A Classic VRML-encoded X3D file may be referenced from files using other encodings and may itself reference X3D files encoded using other encodings. Such files can only be processed by browsers which conform to all of the utilized encodings.