X3D which stands for "Extensible 3D", is the new open standard (still under development) for 3D content on the internet/web. In essence X3D is intended to be the new format or language that is used/required for 3D interactive worlds on the web (replacing/extending the existing VRML97 standard).
X3D is a file format specification with requirements on how that file is to be displayed. It will be the ISO standard for 3D graphics. The language is very robust and supports generalized 3D content for interactive web and other broadcast media.
Because the file is encoded in XML, it can be extended, making X3D more flexible than its predecessors. Efforts are underway for cross-support with MPEG (ie. make X3D the 3D component of the MPEG standard etc), SVG, CML, and MathML.
Yes. X3D is already a draft standard, and in January 2003 the X3D standard was submitted for ISO approval. At the moment only a few browsers are capable of making use of X3D files and as a result it may be a little premature to be choosing X3D as your primary format for 3D web content. Fortunately VRML97 (ie. X3Ds predecessor) files (ie. format supported by browsers) can be easily converted to X3D files, so at this time it is still best to develop in VRML and look to converting those files to X3D as the standard becomes better supported by browsers. This is the approach being taken by VRMLmagic (ie. currently it outputs VRML97, but as soon as X3D is supported VRMLmagic will output files in the X3D format).
That depends, if you have an interest in developing the X3D standard you will want to get in and learn what you can of the draft X3D versions and add your own contributions. However if you're like most of us and primarily interested in the complete final standard then it would be best to wait for that to be completed. Even when the standard itself is complete, spending the time learning how the X3D standard works may not be the best approach.
X3D is currently much like HTML was in the very early days of the web. Back then it was not uncommon to see pages being written by hand in HTML. However as we have seen with HTML, over time tools have been developed to enable development of web pages using interactive graphical tools that don't require the developer to have any knowledge of the underlying HTML format.
At the moment most of the interactive 3D pages that we see on the web are hand written using the older VRML97 format. X3D is still a format of the future in terms of mainstream use. Despite this, easy to use interactive tools are now beginning to appear for X3D/VRML development (eg. VRMLmagic). It is likely that (as was the case with HTML) as time goes by, the need for a detailed knowledge of the specifics of the X3D standard itself will become less relevant (and experience with the higher level world building tools will become a more useful skill).
X3D describes a format for 3D content. That content can be placed/incorporated into a range of places (now including tie ins with other multimedia formats such as MPEG, SVG etc). However the most likely place we will see X3D content incorporated is on the web.
X3D webpages, and content in general, works along similar lines to VRML (ie. X3Ds predecessor). See section on How VRML Works for more information on this. Despite the similarities there are some subtle differences, including:
The X3D standard defines how X3D pages work as follows:
X3D, defines a software system that integrates network-enabled 3D graphics and multimedia. Conceptually, each X3D application is a 3D time-based space that contains graphic and aural objects that can be dynamically modified through a variety of mechanisms.
The semantics of X3D describe an abstract functional behaviour of time-based, interactive 3D, multimedia information. X3D does not define physical devices or any other implementation-dependent concepts (e.g., screen resolution and input devices). X3D is intended for a wide variety of devices and applications, and provides wide latitude in interpretation and implementation of the functionality. For example, X3D does not assume the existence of a mouse or 2D display device.
Each X3D application:
There are several options for building X3D worlds, although at this stage with the standard still being developed the number of (development or viewing) tools available is limited, and developing by hand, with a draft standard to work with, is not ideal. In simple terms you can generate X3D pages in several ways including:
X3D is the evolutionary successor to the ISO standard VRML97. As a result X3D offers many features that are new, when compared to VRML, these include:
X3D is being developed by the Web3D Consortium. This is a group made up of parties interested in developing open standards for web related 3D technologies. Web3D is intended to be representative of the 3D community in general. Membership in Web3D is open to all interested parties and as a result control of the developing X3D standard is held by that broad community. For more information on Web3D take a look at our Web3D page.
X3D represents the next step in the evolution of 3D web content. With X3D, interactive 3D web content is now, for the first time, poised to become more than just a niche part of the web. X3D's improved functionality, and more importantly its flexibility open the way for 3D content to be more easily incorporated into numerous multimedia technologies.
We are also beginning to see X3D/VRML development tools become available. Bringing VRML/X3D development to the masses. We know that good development tools are a key to the proliferation of a technology, bringing a whole new set of developers into the market.
With the obvious demand for 3D content and the forward movement of standards like X3D the future for 3D web content looks bright.
VRML Information - our brief rundown of VRML, what it is and how it works
Web3D Information - our brief rundown of Web3D, what it is and how it works
VRMLmagic - our X3D/VRML Authoring Software
Web3D Consortium - the definitive source for all information on X3D