Home > Supported File Formats > U3D to COLLADA

How to convert U3D (Universal 3D, 3D PDF) to COLLADA (.dae)?

PolyTrans|CAD+DCC performs mathematically precise CAD, DCC/Animation, GIS and BIM 3D file conversions into all key downstream 3D packages and file formats. Okino software is used and trusted throughout the world by many tens of thousands of 3D professionals in mission & production critical environments, backed by respectable personal support directly from our core development team.

U3D

U3D is a semi-obsolete 3D mesh file formats from the 2000-2009 era of the 3D graphics world and whose history is little understood outside the confines of a few 3D graphics companies. Even so, U3D is still a fine 3D file format as a pipeline to get 3D data embedded within 3D PDF files, especially with the full and extensive implementation made by Okino.

For more details on the U3D file format, its core features and limitations, how to embed U3D files within 3D PDF files and the features of the Okino U3D import/export converters, please refer to this WEB page.

Generally speaking, U3D was implemented by a few 3D companies in the mid to late 2000s when it was pushed by Adobe+Intel as part of the line of 'Acrobat-3D' software packages. In very loose terms, U3D is used to convey and embed 3D model data within 3D PDF files, where PDF would be the container for the 3D data.

U3D started off in the 1990s as Intel's "IFX" gaming toolkit which was than thrust upon Macromedia, Alias Research, Softimage and other similar companies around the year 2000 to be accepted as a new "industry standard" 3D file format called "Shockwave-3D". The dotCOM bubble caused SW-3D to die pre-maturely after 2001 only to be rebranded as U3D or the "Universal 3D file Format" in 2004 (ECMA-363). Its specification PDF document described it as "An extensible format for downstream 3D CAD repurposing and visualization". However, U3D was highly profit/sales motivated/biased and not consumer/end-user motivated. As such, partly due to the 2008/2009 recession, those companies and their investments in U3D died away.

Okino is and was critical of U3D back in the day as it was the company which created the main conversion implementation of U3D for both import and export. It understood the limitations of U3D well and of its false promotion as a "universal file format" whose title should really have gone to those such as COLLADA, FBX, VRML2, etc. When implemented well U3D is a fine file format by itself but few companies invested enough time and money to support U3D import and export in a most ideal manner.

COLLADA

COLLADA (DAE) is a XML-based readable file format of the 2007/2008 era which had an original goal of allowing efficient cross conversion of 3D asset data between all of the major 3D DCC/Animation systems of that era. Many 3D software programs came to implement COLLADA but with varying levels of comformity and data reliability. COLLADA is more generally known as a polygonal mesh file format and not a MCAD/CAD/AEC/GIS format. Today people would usually use FBX over COLLADA, depending on the quality of the associated (and dated?) import/export converters.

Okino created one of the key implementations of the COLLADA file format in its import and export converters. However, it saw little need for them except for exporting into Cinema-4D from 2008 to 2012, as the primary gateway into Google Earth, and as our still-preferred method to move 3D assets into Blender (rather than FBX). COLLADA does have its place in these current and prior times.

Okino has a unique take on the COLLADA file format as Okino was at the very center of the DCC/Animation conversion world. In 2007 Rémi Arnaud and Mark Barnes argued that yet-another 3D file format was required and hence Sony funded their efforts to define COLLADA for the cross conversion of assets between (initially) 3ds Max and Maya. However, what they conveniently ignored was that Okino already had the defacto cross conversion system in place, for the prior decade, based on its BDF (binary data translation file format) for 3ds Max, Maya, Cinema-4D, Softimage, LightWave and others. In the mid 2000's there was a "not invented here" mindset and hence everyone wanted to stamp/force their own 3D file format on the industry: FBX (Autodesk), COLLADA (Sony), 3dxml (Dassault Systems), XAML-3D (Microsoft), U3D (Adobe and Intel), etc. There was little need or reason to have "yet-another" set of new 3D file formats. All, except FBX, would basically come and go as of 2007/2008. The implosion of the DCC/Animation industry of 2005-2007 and the 2008/2009 recession further hampered the long term adoption or need for COLLADA over Autodesk's FBX.

COLLADA is/was a very fine file format but it was really not needed at the time of its introduction in 2007. It only introduced yet-more confusion to the 3D graphics market as to which 3D file format to use to transfer 3D assets between packages. Developers generally implemented v1.4 of the COLLADA file specification then lost interest thereafter.

However, as a saving grace for COLLADA, all of the 3D software packages which had implemented a good COLLADA exporter became instant gateways to move their 3D assets into the then-new glTF file format of the mid 2010s, until such time that these same packages could add in their own glTF exporters.

Limitations of the U3D File Format

U3D import converter's overview

COLLADA export converter's overview