Issue No. 08 - August (2005 vol. 38)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/MC.2005.265
Proponents have long touted the impending popularity of 3D technology on the Web. They have contended that before long, gamers and online businesses would lead a parade of users to 3D approaches to creating Web content. However, these promises have not come to fruition.
"A major reason for this is that there has not been an open, affordable approach to making existing 3D content accessible across multiple platforms," said Richard Boyd, CEO of 3Dsolve, a vendor of 3D-simulation-based educational products and a 3D Industry Forum (3DIF) board member.
For example, a major use of 3D applications is in computer-aided design. However, CAD applications create data in proprietary formats, said Kathleen Maher, a senior analyst with Jon Peddie Research, a consulting firm. This prevents users on other platforms from working with CAD data. Even nonengineering employees of companies that create CAD data often can't work with the information.
The Intel-led 3DIF developed the Universal 3D file-format specification as a way to make CAD data usable on multiple platforms, explained Richard Benoit, forum chair and business development manager of Intel's Software Solutions Group. The 3DIF is a cross-industry group of about 40 developers and corporate users of 3D graphics technology.
Proponents hope U3D will let developers incorporate 3D CAD data into various applications, such as Web browsers, thereby making 3D use more widespread. This would also increase demand for 3D development tools and faster CPUs and graphics chips.
Intel and the 3DIF are working with Ecma International ( www.ecma-international.org), an industry-based standards-development organization. They ultimately hope to make U3D an ISO (International Organization for Standardization) standard.
However, U3D faces several hurdles to widespread adoption, including technical issues and competition from similar specifications.
The push for U3D
Users have created 3D objects with CAD applications such as CATIA, Pro/ Engineer, SolidWorks, and Unigraphics since the late 1970s, said Neil Trevett, vice president for embedded content at graphics-chip maker Nvidia and president of the Web3D Consortium, developer of the Extensible 3D (X3D) standard, a U3D rival.
However, Boyd said, the relative lack of standards and open, affordable tools has held back 3D development. Nonetheless, 3D use has grown.
For example, as Figure 1 shows, in a recent survey by market research firm Gartner Inc. of US engineers who use mechanical design applications, 72 percent of respondents said they mainly used 3D design in 2004, compared to 54 percent in 2000, noted Laurie Balch, a Gartner principal analyst for design and engineering.
Now that corporate and individual users have broadband Internet connections and computers with powerful processors, Benoit said, more people can receive, send, and work with 3D.
There is thus a demand by companies for a way to use their 3D CAD-related engineering data in nonengineering settings by customer service, marketing, sales, and other departments. However, CAD products create large data sets in proprietary formats that can take a long time to transmit and that nonengineering departments can't work with on the applications they use.
"Viewing CAD data in mainstream applications," Benoit said, "in the past has required proprietary software and high-end hardware."
"A number of software vendors have developed digital content creation tools to repurpose 3D data," Boyd noted. However, he said, the process is complex and expensive because CAD data generally requires significant massaging to yield content usable in business applications.
There is thus a demand for an open file format, such as U3D, that would enable easier, more widespread use of 3D CAD data, Trevett said.
The 3DIF has released a U3D specification, as well as sample runtime libraries. The ISO is slated to approve U3D later this year.
U3D, which would be added via plug-ins to commercial tools that handle CAD data, has already received some major industry support.
For example, Adobe Systems supports U3D so that its popular Acrobat 7.0 document-creation and -viewing software can work with repurposed CAD data.
Actify uses U3D in its newly announced SpinFire for Microsoft Office product, which embeds interactive CAD data directly into documents.
3Dsolve includes U3D support in its educational applications and its interactive, electronic, technical manuals for the US Department of Defense.
What U3D accomplishes
U3D is designed to compress and repurpose CAD data for use in other applications.
CAD data, already written in proprietary formats not accessible by other applications, includes considerable product model detail germane only to designers—such as part numbers, stress tolerance levels, and screw threads. This detail could slow rendering on a standard desktop computer.
CAD files allow engineers working on a product to examine, edit, and otherwise manipulate the data in numerous ways. U3D, on the other hand, strips out the engineering data and permits only the limited manipulation of an image that marketing personnel, sales staff, and other non- engineers would need to perform, such as changing viewing angles, zooming in and out, and looking at animations, explained Benoit. Personnel could use these files for many purposes, such as creating support, assembly, repair, and training manuals, as well as marketing material.
By stripping out most of the non-image-related material and some of the graphics-related information from CAD files, U3D makes it more efficient to distribute and stream CAD data over the Internet and private networks. In addition, this makes it easier for applications to work with the information.
The technology also offers continuous level-of-detail capabilities. In sending 3D models over networks, systems build up layers of polygons and details over time. Continuous level-of-detail capabilities let users interact with the material as it streams in. U3D thus reduces the time users spend waiting to work with files and lets them determine if they have the correct data without waiting until it all arrives. Moreover, users can stop the transmission of detail when they have enough to work with.
U3D also supports rigid-body and skeleton-based animation, which is necessary for mechanical and character animation and is thus important for any complex-design application.
The technology offers file-format and runtime extensibility via a plug-in architecture that allows the addition of new capabilities in the future.
Other 3D standards
There are several industry and formal 3D standards in addition to U3D.
For example, Autodesk, which makes digital-design and digital-content-creation software, developed the Design Web Format for 2D and 3D engineering design. However, DWF can only be used with the company's products.
Kaydara, a 3D character-animation and motion-editing products developer acquired last year by 3D graphics-software vendor Alias Systems, developed FBX, a platform-independent 3D authoring and interchange format. The product works with content from most 3D vendors and platforms. Because FBX is proprietary, companies can't build on it and must use Alias tools to work with the technology.
According to Boyd, U3D is more useful than DWF or FBX because it is open and gives users a high level of control over the level of image detail they work with. He said U3D is also preferable because it can be used with the popular Adobe Acrobat.
The 11-year-old Virtual Reality Modeling Language is supported by the Web3D Consortium, formerly the VRML Consortium. VRML uses vector graphics, an approach that creates digital images via a sequence of commands or mathematical statements.
"VRML is a 3D file format delivered over an Internet connection. The client software interprets the file format to render 3D models, their surface properties, visual effects such as lighting, and animated behaviors and user interaction," said Web3D Consortium director Tony Parisi, president of Media Machines, a vendor of 3D and other rich-media technologies.
Developers use VRML to build image sequences into Web pages. VRML can let users with the proper viewers or browsers interact with images by, for example, changing the way a digital room looks as they virtually walk through it.
Because processors and Internet connections were slow when VRML was developed, there was little demand for the technology, explained Jeff Drust, a vice president of business development for software vendor Lattice3D.
In 2002, the Web3D Consortium developed VRML's successor, X3D, which is backward compatible with the earlier technology. The ISO approved X3D as a standard in August 2004.
"We added state-of-the-art rendering and enhanced programming capabilities. We also added an XML-based format," said Parisi.
XML is key to integrating X3D with the Web services architectures that an increasing number of organizations use for creating cross-platform distributed applications, he explained. The ability to deliver X3D data via XML-based Web services is critical for its commercial adoption, he said.
X3D's mathematical model lets systems highly compress graphics for quick transport while still retaining considerable detail for display when decompressed.
This enables X3D, like U3D, to make CAD data easier to transport over networks, according to Lattice3D's Drust. The Web3D Consortium published its first X3D draft for CAD—the CAD Distillation Format—last year.
X3D generates images via encrypted, highly compressed algorithms that systems execute when they open graphics files. U3D generates 3D images via polygons and thus requires larger files than X3D to offer a given level of detail.
Developers are using X3D software to build educational applications, engineering programs, and more. Parisi predicted that in the near future, X3D will also be used in consumer applications such as computer games. However, the lack of many X3D tools limits the technology's usefulness, said Jon Peddie Research's Maher.
U3D's Potential downside
U3D may have an uphill adoption battle. Numerous attempts to create industry Web-based 3D standards have failed, including Adobe's Atmosphere, Microsoft's Chromeffects, and the Intel/Macromedia joint venture to promote Shockwave 3D on the Web.
They failed because of technical reasons in some cases; because 3D is a market with so many niches that it is difficult for a single approach to appeal to enough users to succeed; and because the technologies weren't controlled by an open standards body, said Nvidia's Trevett.
According to Maher, the existence of other 3D standards may keep some potential users from working with U3D.
In addition, product designers may well continue relying on their current CAD vendor's proprietary 3D visualization applications and format because of tight integration with existing authoring tools, stated Ken Versprille, a partner and product-lifecycle-management research director of Collaborative Product Development Associates (CPDA), a market-analysis firm.
And, according to Drust, because U3D removes data from CAD files, the technology loses some detail when rendering graphics, particularly when zooming in on an image. Moreover, he explained, U3D doesn't offer as much compression as X3D.
Finally, Drust said, U3D was designed to work with single-CPU systems, which have dominated the commercial-chip marketplace for years. However, he added, the market is now moving from single-CPU to multiple-CPU platforms, and U3D won't always work well with the latter.
U3D's future depends, to some extent, on the growth of 3D use. Said Maher, "3D use is growing on the Web, in design, and so on; not as fast as some people would like, but as fast as people need it to."
According to the CPDA's Versprille, U3D will likely command much of the market for viewing the technical documentation of products because it can be used with Adobe's popular technology.
Maher predicts that U3D will be most successful in CAD environments, for which it was specifically designed, while X3D will prosper in other areas such as Web development and entertainment-related design.
There's not much chance the groups promoting the two technologies will work to combine the standards because the 3DIF's core group of members had already been part of the Web3D Consortium before withdrawing in 2003, Parisi said.
Nonetheless, Maher said, U3D should have a future on its own. "The world needs ways to communicate between media-creation tools," she explained. "As long as there is a rich and wide variety of tools, there is a need for a rich and wide variety of interchange formats. U3D is one of these very useful formats."
David Geer is a freelance technology writer based in Ashtabula, Ohio. Contact him at firstname.lastname@example.org.