But a new realm has emerged to give 3-D creators a potentially explosive market for their work--the Web. Using a file format called VRML (Virtual Reality Modeling Language), 3-D­world creation has received an incredible shot in the arm. VRML won't require users to ramp up by dumping huge amounts of cash into the latest expensive software, broadcast-quality video boards, video decks, disk arrays, CD-Burners, or multiprocessor CPUs. Just as the Web and HTML have established a whole new genre of work for page layout and graphic artists, so will VRML do for artists creating virtual, navigable worlds. The future of 3-D work has never been more hopeful.

What is VRML? Simply put, VRML is a file format for describing 3-D interactive worlds and objects for the Web. It contains most of the commonly used semantics found in today's 3-D applications, such as object hierarchies, lights, animation, fog, materials, and texture mapping. VRML is extremely open because it describes 3-D spaces in an ASCII text format, which is ubiquitous in every platform. Consequently, VRML is capable of representing static and animated objects, and it can have hyperlinks to other media such as sound, movies, and images. Interpreters (browsers) for VRML are widely available for many different platforms, as are authoring tools for the creation of VRML files.

VRML supports an extensity model that allows new objects to be defined. It also features a registration process that allows application communities to develop interoperable VRML extensions. The common elements of VRML can be mapped onto commonly used 3-D application programmer interface (API) features.

The power of VRML becomes apparent when used in conjunction with the Web: users can create three-dimensional representations of complex scenes and put them up on the Web for anyone adequately equipped with a browser. VRML is a link between 3-D applications than a stand-alone 3-D platform. VRML is far more vital as a "Web emulsifier," allowing the other ingredients of the Web to connect, particularly 3-D.

Theoretically, VRML pages can contain anything: 3-D geometry, MIDI data, or JPEG images. Indeed, VRML provides the ticket to multiuser 3-D space--it is the first multiplatform specification designed from the ground up as a Web-based 3-D medium. With it, instead of simply looking at a picture and clicking to jump to another picture, the VRML Web experience will have you navigating through a scene. VRML is similar to HTML in that it serves as a multiplatform language for publishing Web pages. HTML simply doesn't contain the tools to deal with the intensive interaction, animation, and formats that VRML can handle. The specification detailing VRML 2.0 puts forth very plausible intentions for the standard; common among them is an open-ended architecture that allows for most platforms and existing formats, as well as other standards.

So how do you get started with VRML? Well, to check out stuff already on the Web, you will need to accept VRML documents or a VRML browser plug-in. Netscape Navigator and Microsoft Internet Explorer (3.0 or later) have VRML browsers built in. If you don't want to go with the big browsers, you can get any of a number of stand-alone VRML viewers, VRML-browser helper applications, or VRML plug-ins. The VRML Repository (http://www.sdsc.edu/vrml/browsers.html) has an extensive list of stand-alone browsers. Once you've downloaded a browser and installed it according to the directions that came with it, you will more than likely find that double-clicking on the icon for a file on your local machine whose name ends in ".wrl" will launch either your Web browser (which now has the capability of displaying those worlds) or a stand-alone VRML viewer.

As with any graphic-intensive application explored on the Web, a high-speed modem, fast CPU, and video card will speed things up. Creating a VRML site involves using an existing 3-D modeler to create a scene, and converting it to VRML using one of the many existing converters available. 3-D Studio Max and Infini-D are examples of modelers who have VRML translators. Several modelers are also available that will translate directly to VRML.

Once you have created and saved or translated a model as a .wrl file, you can place it on your server with a link to it just as you would an HTML file. In order for your file to be viewable as a 3-D world, your server must support the MIME type xworld/wvrml with the .wrl extension. If this is not the case, visitors to your VRML site will only be able to view the ASCII text of your file.

The latest implementation of VRML allows users to create ground-and-sky backdrops to scenes, add landscape objects in the distance, and environmental elements like clouds, and dim distant objects with fog. Another new node lets you easily create irregular terrain instead of using flat planes for ground surfaces. Also new are 3-D spatial sound-generating nodes to further enhance realism--you can add sound into a scene that can grow louder as you approach the origin of the sound (determined by the designer).

Also new are nodes that let you drag objects or controls from one place to another. Another kind of sensor keeps track of the passage of time, providing a basis for repetitive animations that can "loop through," saving memory. A new node describing collision detection ensures that solid objects react like solid objects; you bounce off of them (or simply stop moving) when you run into them. And terrain following allows you to travel up and down steps or ramps.

VRML 2.0 provides new animation objects called interpolators. These allow you to create predefined animations of many aspects of a world and then play them at some opportune time. With animation interpolators you can create "sprite-type" objects that move by themselves through or near the path of the Web visitor. Examples include a running horse, automatically closing doors, and objects that morph from one shape to another. You can also create guided tours that automatically move the user along a predefined path. New scripting features allow animated creatures or objects in a world to perform actions based on environmental changes caused by the visitor.

You can kick your HTML paradigms to the curb when conceiving a Web site in VRML. Okay, let's put your friendly neighborhood intergalactic space tavern online with VRML. The idea looks like this; first you start out in space near a floating sign that blinks brighter as you navigate closer. As it comes into focus, you see it says "Digital Drinks Ahead," and has a blinking arrow. Moving in that direction, you cut through some fog-encrusted asteroids that look strangely like drink coasters (advertising the tavern, of course). As you approach the floating structure, you can see two animated doormen (built as robotic events using interpolators); you see them opening and closing doors for others who are going into the tavern. The sign over the floating bar blinks on and off, which occurs because of the geometry under a switch node. As you approach the building, the doorman winks at you and the door swings open. The door is attached to a touchsensor that detects your click; the sensor tells a script node that you've clicked, and the script animates the opening portal, moving the geometry for each piece of the portal a certain amount at a time. The script writer only has to specify certain key frames of the animation; interpolator nodes generate intermediate values to provide smooth animation between the key frames. Depending on the amount of power you have at your disposal, a scene inside the bar can be busy or "dead."

A proximity sensor node inside the room can be set up to notice you coming in and send an event to other script nodes, which can, in turn, activate other script modes--you may be asked to sign in at a register, and having done so, you can take an open seat at the bar, where the latest bill of fare appears in front of you. A jukebox can be made to increase volume as you move closer. Any number of objects and robotic events can be included, and their actions can be customized, also. The possibilities are limited only by your creativity and the power of your server.

The market for translators and other VRML technology is wide open. Ligos Technology makes a few interesting VRML products. The first is called VRML Detector, which is a code-set formulated to confirm the existence and type of VRML viewer available on a client system and deliver the appropriate content. It was posted on the Ligos Web site (www.ligos.com) for free download beginning August 15 of this year. VRML Detector is an HTML and Java code set that is designed to be used when embedding VRML content in standard Web pages. It will automatically determine any visitor's browser type and version, and the VRML viewer type and version, providing webmasters with an automatic content switch for systems unable to view VRML content. Systems running a VRML-enabled browser will get the VRML-rich content. Systems without viewers will get an alternate image such as an animated GIF. V.RealmTM Builder is another interesting product, also by Ligos. V.Realm Builder allows Web designers and content providers to create visually enhanced Internet sites by providing them with a set of powerful tools that take full advantage of the unique capabilities of VRML 2.0. These tools allow seamless integration of VRML into traditional HTML.