This document is ISO/IEC 19775-2:2025, Extensible 3D (X3D), Edition 4, corresponding to ISO/IEC 19975-1 X3D Architecture version 4.0. The full title of this part of ISO/IEC 19775 is: Computer graphics, image processing, and environmental data representation — Extensible 3D (X3D) — Part 2: Scene access interface (SAI).

Background	Clauses	Annexes
Foreword	1 Scope	A VRML scripting backwards compatibility
Introduction	2 Normative references
	3 Terms, definitions, acronyms and abbreviations
	4 Concepts
	5 Data type reference
	6 Services reference
	7 Conformance and minimum support requirements

The Foreword provides background on the standards process for X3D. The Introduction describes the purpose, design criteria, and characteristics of X3D. The following clauses define this part of ISO/IEC 19775:

1. Scope defines the problem area that the X3D scene access interface (SAI) addresses.
2. Normative references lists the normative standards referenced in this document.
3. Terms, definitions, acronyms and abbreviations contains the glossary of terminology used in this document.
4. Concepts describes various fundamentals of the X3D scene access interface.
5. Data type reference defines the data types used by the application programmer interfaces.
6. Services reference defines the functionality which may be accessed through the application programmer interfaces.
7. Conformance and minimum support requirements describes the conformance requirements for X3D implementations.

There is one annex included in the specification:

1. VRML 97 scripting backwards compatibility describes the manner in which X3D Scripting can be used to provide backwards compatibility with VRML 97 scripting.