Web Developer®'s Tips:
Beginning VRML

VRML first took shape in the spring of 1994, at the First International Conference on the World Wide Web in Geneva. Although a number of individuals played and continue to play a big part in VRML's development, the three most prominent shapers of the language include Mark Pesce (Labyrinth Group), who conceptualized VRML, Anthony Parisi (Intervista Software), and Gavin Bell (Silicon Graphics), who wrote the specification for the VRML 1.0 standard.

More specifically, VRML is referred to as a "scene description language," because it tells a VRML viewer, or browser, how to construct a 3-D environment. VRML differs from HTML in that it gives the browser instructions about where objects go and what color they are and then basically lets the browser "connect the dots." HTML, on the other hand, simply pieces together text and a number of different, pre-existing image files to form a 2-D page.

Both stand-alone and plug-in versions of VRML players should come with instructions for setting up the browser, although some vendors make this information available on their sites. Once you download the browser and configure it, you should be able to visit any VRML-enriched site on the Web. Note, however, that some vendors have added proprietary non-standard extensions to the standard VRML language. This may make some VRML worlds designed for specific browsers incompatible with the viewer you are using.

To aid you in your search for the best VRML browser, Web Developer® has compiled this listing of some of the most popular viewers and plug-ins:

VRML Browsers/Plug-ins

Browser	Company	Platform/OS	Check It Out	Get It!
Cosmo Player	Silicon Graphics	Windows 95, NT, Irix	Features	Download Cosmo
CyberGate	Black Sun Interactive	Windows 95, NT	Features	Download CyberGate
Community Place	Sony	Windows 95, NT	Features	Download Community Place
Microsoft VRML Add-In	Microsoft	Windows 95	Features	Download MS Add-In
Voyager	Virtus Corporation	Mac, Power Mac, Windows 95	Features	Download Voyager
V-Realm	Integrated Data Systems	Windows 95, NT	Features	Download VRealm
VR Scout	Chaco Communications	Windows 95, NT, 3.1	Features	Download VR Scout

When you enter a VRML world with Netscape's Live3D viewer, Navigator's background turns black and a navigation toolbar appears at the bottom left of the browsing window. Unless the scene has a very small file size, the toolbar will appear long before the world is downloaded completely. Wait until the status bar at the bottom of the browser reads "Document: Done", then the scene is ready for you to navigate. You now have several options to move around: you can use your mouse to move the cursor over the VRML scene, click and hold left mouse button and go (note: you'll move as if you were using a joystick: up=forward, down=backward, etc.). Or you can use the direction arrows on your keyboard to accomplish the same thing (note: use the arrows while holding down the control or shift key for added movement options). Finally, you can use a joystick with some VRML viewers, although it will have to be calibrated to work correctly.

Once you've learned the basics of navigating VRML scenes, you can now select various options to customize your experience. Using the navigation toolbar, you can simply click on the different options to change how you move (Walk, Spin, Look or Slide) and turn your "headlights" (Lamp) on or off. For even more options, however, move the cursor over the scene and click the right mouse button. This activates a pop-up menu, from which you can fine tune your navigation (Fly instead of walking!), change the look and amount of detail in the site (in the Lights and Detail menus) and even save your settings once they are customized (in the Options menu).

#VRML V1.0 ascii

This identifies the file to the VRML browser, so it knows to interpret, or parse, the contents of the file. The basic components, or objects, of VRML are called Nodes. There are three types of nodes: Shape nodes, which describe an object's geometry; Property nodes, which modify the way an object is drawn; and Grouping nodes, which group objects together as a single object. Different nodes are grouped hierarchically into Scene Graphs, which compose VRML worlds, or scenes.

• Shape nodes: VRML supports four pre-defined, or primitive shape nodes: Cube, Cone, Cylinder and Sphere.
• Property nodes: one of the most important property nodes is the Material node, which determines an object's color and appearance. Colors are defined using Red/Green/Blue (RGB) values expressed as fractions of 1.
• Grouping nodes: the most important grouping node is the Separator node, which allows the other nodes within it to be treated as a single object.

Using these few components, then, an example of a red sphere would look like this:

#VRML V1.0 ascii



Separator {



  Separator {

    Material {

      emissiveColor  1 0 0

    }

    Sphere {}

  }

}

<A HREF="http://www.webdeveloper.com/wdworld.wrl">Web Developer's VRML World</A>.

This option best serves external VRML browsers (as opposed to plug-ins) and "full-immersion" VRML worlds.

If you want to incorporate smaller scale VRML scenes as images on a Web page, however, one of the best methods is to use the <EMBED> tag. As with the <IMAGE> tag, you can control the height, width and alignment of the scene, so that a common embed tag line would be:

<EMBED SRC="http://www.webdeveloper.com/wdworld.wrl" HEIGHT=100 WIDTH=100 ALIGN=RIGHT>.

Sources and Resources for Further VRML Exploration