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 consortium promoted also the development of an open source library for facilitating the adoption of the format.
The fourth edition provides definitions for higher order primitives (curved surfaces).
Applications which support PDFs with embedded U3D objects include: