Product Design

How Open are Open 3D Data Formats?

19 Jan, 2006 By: Jeffrey Rowe

Examining the pros and cons of each option, Part 2: 3D XML


With all the attention surrounding so-called open data formats, I’ve wondered just how open are these formats, really? In the last issue of MCAD Tech News, I looked at UGS’ JT2Go format (click here to view the archives). This time I’ll cover Dassault Systèmes’ 3D XML. And in a third installment, I'll report the results of testing to determine which really is the most open.

3D XML
In the fall of 2004, Dassault Systèmes introduced 3D XML for PLM (extensible markup language for product lifecycle management), a design data file format intended to be universal and lightweight. It attempted to become a new 3D standard that featured metadata . (Metadata is information about data. For example, in a PLM environment, data might have values describing geometry, whereas metadata might contain information that describes the meanings of the values.) The most attractive feature of 3D XML, however, is how it compresses data, with files as much as 99% smaller than the original file.As improbable as this sounds, I’ve seen it demonstrated, and the files can indeed be compressed to that level.

This unique compression scheme enables rapid file transmission and shorter load times while maintaining the exact geometry of the files exchanged. Using 3D XML, users can drag and drop 3D files into other applications such as e-mail or Microsoft Office applications. The format has the potential to enhance collaboration that involves 3D information.

A free 3D XML player leverages 3D XML and extends the use of 3D beyond traditional PLM applications. 3D content can be incorporated into a variety of media, including technical documentation, maintenance manuals, marketing brochures, Web sites, e-mail communications and so forth. 3D becomes an actual communication medium that allows users to “see what you mean.” The 3D XML Player is designed to work with a range of application suites, including Microsoft Office applications, on the Web with the Internet Explorer browser and as a stand-alone application.

At the time the format was introduced, Dassault Systèmes CEO Bernard Charlès said, “Dassault Systèmes’ adoption of XML for 3D and PLM applications is the cornerstone of our contribution to open standards.”

Unlike virtually all other proprietary formats, 3D XML is based on standard XML. Therefore, in theory, any software program has the ability to read and write 3D XML content. Dassault was betting that this factor would facilitate broad adoption by other software developers and lower the cost of converting files from existing 3D formats. This reuse of 3D information was meant to broaden the base of 3D users.

Joint Effort
3D XML is actually the result of a partnership with and an extension of Lattice Technology’s XVL technique. Founded in 1997, Lattice Technology developed the standards-based XVL (extensible virtual world description language) to produce highly accurate and compressed 3D files in a lightweight, browser-based format. Dassault Systèmes brought to the table its mathematical strengths and suite of collaborative tools, and the two companies joined forces to create this format for exchanging 3D information.

Dassault Systèmes introduced this collaborative, open 3D format and approach in late September 2004 with V5R14 of its PLM products -- CATIA, DELMIA, ENOVIA and SMARTEAM -- and it’s part of the company’s SolidWorks and Spatial products.

About six months after the 3D XML announcement, Microsoft stepped into the picture as a strategic alliance partner with Dassault to jointly support Microsoft’s XAML (extensible application markup language) format, a variation of XML that complements Dassault’s 3D XML format. XAML is the format for Avalon, the code name of the presentation subsystem for the Microsoft Windows operating system. It provides native support for declarative, markup-based programming with XAML, making it simpler to build and customize Windows-based applications.

Compatibility between 3D XML and XAML was intended to allow users of 3D products to view, modify and customize 3D objects in an open environment and to take advantage of this 3D experience in any XAML-based application. Exactly how compatible the two are remains somewhat a mystery -- probably intentionally -- primarily because Microsoft does not want to side exclusively with Dassault in the PLM world. I really wouldn’t be surprised if by the time the new Microsoft Vista operating system is released later this year, 3D XML is nothing more than a memory for Microsoft.

Is it possible to make 3D pervasive in all parts of a business, not just design and manufacturing, with 3D XML? I would say yes, if users can derive value from improved process efficiency -- not just in the design phase of a product, but across its entire lifecycle. The potential business gains from new 3D-based PLM processes are big, because 3D data that can potentially be made available to everyone, from everywhere, and on different devices.

Crowded Field
But we can't forget that other vendors have their own so-called open formats that perform similar functions. As I discussed last week, UGS has its JT format, Actify has its .3D format, and on and on. 3D XML is XML-based, and Dassault has stated that it will be a “pervasive 3D open standard for PLM.” However, this format cannot be a truly open standard because it has been developed by a vendor -- actually, in this case, two vendors -- for use in a specific product set. A truly open standard is one that is made available under the auspices of ISO (International Standards Organization) or another standards organization.

3D XML could become a de facto standard in the future if it is adopted by other vendors that are able to develop 3D XML-based applications using format specifications. For the time being, the best it can hope to be is a de facto standard for Dassault customers. Will it ever move beyond the Dassault product family? I tend to doubt it, because there is too much at stake in the “open” format wars.


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