ECMA-363
Universal 3D (U3D) File Format
This standard defines the syntax and semantics of the Universal 3D file format, an extensible format for downstream 3D CAD repurposing and visualization, useful for many mainstream business applications.
Salient features of the U3D file format described in this document include: execution architecture that facilitates optimal run-time modification of geometry, continuous-level-of-detail, domain-specific compression, progressive data streaming and playback, free-form surfaces, key-frame and bones-based animation, and extensibility of U3D format and run-time.
The U3D file format specification does not address issues regarding rendering of 3D content.
The U3D file format specification does not address issues regarding reliability of the transport layer or communications channel. It is assumed that reliability issues will be addressed by a different protocol layer.
The U3D file format specification does not address run-time extensibility of an implementation of the U3D architecture.
The U3D file format is defined by ECMA-363 and was originally introduced as part of PDF 1.7 (ISO 32000-1:2008).
The registered IANA Media type for U3D is model/u3d.
