3D Animation Workshop: Lesson 82: VRML to Web 3D Continued | 2 | WebReference

3D Animation Workshop: Lesson 82: VRML to Web 3D Continued | 2

Lesson 82 - VRML to Web 3D Continued - Part 2

X3D will be backwardly compatible with VRML 97. As VRML 97 is bigger and more complex than the X3D Core, the plan is to develop a VRML 97 Profile for X3D. The whole idea of "profiles" and "extensions" of X3D is definitely confusing, but the drift is clear enough. A VRML 97 Profile will provide all the additional functionality (lacking in the core itself) to run VRML 97 files. Extensions to the core might be provided for NURBS models or other high-end or specialized features. The core of X3D will therefore form the basis for theoretically unlimited expansion of the standard.

But the "X" in X3D has a special significance. Another goal of the Web3D Consortium is to move the VRML-X3D language to XML. XML, the Extensible Markup Language, is a major theme in Web development today. There is large-scale agreement that we've run up against the limits of HTML, the standard language of Web pages, and that a new, and much more flexible toolset is required for the future. Those with any knowledge of Web development know that HTML is essentially a set of defined tags placed in text files that format a page for viewing in a Web browser. HTML tags determine the size of a font, the layout of a table, the source and dimensions of an image, and the presence of hyperlinks--among many other things. This has been good enough for the past, but the Web of the future (it is said) needs much more.

By contrast with HTML, in which all the tags have standardized meanings, XML provides for custom, user-created tags that can be freely defined. This raises the possibility of organizing all kinds of data into Web pages--not just text and images. The WWW (World Wide Web) Consortium has embraced XML as the future of the Web, and the Web3D Consortium has decided to jump on the XML train by converting VRML to XML for easier integration into Web pages. This change would not, as I understand it, affect the functionality of the VRML-X3D in any way. It only changes the way the language is encoded in a text file. For example, take a Viewpoint node (a camera) that is currently written in VRML as "DEF MyView viewpoint {position 0 0 10}". In XML syntax it might read "." Since VRML is already a text format, it's just a matter of changing the syntax to conform with what the Web3D Consortium believes to be the new standard.

I really don't understand very much about XML (although I've been trying very hard to), but I've figured out at least one very important thing. XML is not happening as planned. Despite wide assurances that XML would be supported in the major Web browsers by the end of 1999, Microsoft Internet Explorer 5 was released with only marginal XML support and Netscape still has none. No one can say when, and if, XML will become a working standard. It seems as though the entire XML thrust of the Web3D Consortium's X3D initiative is misplaced or seriously premature, and will undoubtedly compromise its plans to get a new generation of VRML up and running. (Readers interested in learning more about XML should refer to the new Webreference columns on this subject.

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Created: Dec. 24, 1999
Revised: Dec. 24, 1999

URL: http://webreference.com/3d/lesson82/part2.html