U3D

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Title(s): Universal 3D (Standardized by Ecma International as ECMA-363)

Version ID: Ecma 363

Date Released: 2004-12

Creator: Ecma International

Contributors: Intel, Boeing, HP, Adobe Systems, Bentley Systems, Right Hemisphere

Relationships: The first version was created by Technical Committee 43 assembled by Ecma International. It was an attempt to create a unified open modeling format.

  • Previous Versions:

1st Edition released in 2004 by Technical Committee 43 (composed of the above contributors).

2nd Edition released in 2005 to the ISO/IEC for fast track processing.

3rd Edition released in 2006 with corrections received by the ISO/IEC DIS ballot process.

4th Edition released in 2007 with added support for Uniform and Non-Uniform Rational and Non Rational Free-From Curves and Surfaces.

  • Contains: None
  • Syntax:

A file is structured as a sequence of blocks. The first block is the File Header Block. The File Header Block is followed by declaration blocks. Continuation blocks may follow the declaration blocks. Each block contains size fields so that the loader can determine the end of a block if the data in that block is not required or if a decoder for that block type is unavailable.

Each block in the file, whether it is the Header Block, a Declaration Block or a Continuation Block, will follow a similar format. They begin with a Block Type section, a Data Size section and a Meta Data Size section. These sections say how the remaining sections of the Block will be sized. The start of these three beginning sections are all 32 bit aligned.

The following blocks are the Data block, the Data Padding Block and the MetaData and MetaData Padding blocks. The two padding blocks are used to ensure 32 bit alignment for all of the blocks, and therefore are variable size depending on their preceding blocks. The Data block contains the data for this block. The Meta Data block contains a set of Key/Value pairs to be interpreted based on the contents of the file.

  • Family Format: None