Silicon Graphics was naturally the first to have a fully compliant, commercially available VRML Web browser. WebSpace was its name, and it set the standard by which all other VRML browsers were to be compared. WebSpace was developed to run on SGI’s own workstations, but a third party, Template Graphics Software, has been allowed to develop a version for Microsoft Windows and other platforms. All versions of this browser now fully support the VRML 1.0 standard and make use of OpenGL to render the scenes.
WebSpace can be installed as a helper application in most WWW browsers. For installation instructions, see the README file for your browser. WebSpace loads VRML files with a .wrl extension as well as Open Inventor scene files with an .iv extension. In addition, the latest version of WebSpace from Template Graphics will automatically load .wrl files that have been compressed with gzip, a popular Internet file-compression format. This makes for substantially smaller files and thus faster loading.
There are two modes of operation for navigation in WebSpace. The first is the Walk Viewer, which lets you actually navigate through the model presented, such as a museum or architectural model. The second is the Examiner Viewer, which is used to examine objects in WebSpace, such as an airplane, tool, or piece of furniture. You’ll see both of these modes in action shortly.
Figure 20-2 shows WebSpace viewing a sample VRML scene in the Walk Viewer mode. This mode is used when the browser is being used to travel through a 3D scene. It could be a simple 3D terrain, an architectural view of a building, a shopping mall, or even a small city area (as shown).
Some objects in the scene may be hot-linked to other sites or to HTML documents, just like a 2D Web page. The controls at the bottom of the window are collectively called the Dashboard; they are used to navigate throughout the scene. The diamond on the far left is the Seek tool; it helps you rapidly navigate to a point of interest in the scene. To use the Seek Tool, simply click on it to activate the Seek mode and then click anywhere else in the scene. The navigator smoothly proceeds to that place without your having to use any of the other navigation tools.
The tool on the far right is an Arrow Pad that is used to slide the view of the scene vertically or horizontally. This view is only a translation along the x- or y-axis (side-to-side or up-and-down). The camera point of view is not tilted or rotated in any way.
Finally, in the center of the dashboard is the Joystick—used to move forward and backward through the scene, turn left and right, and tilt the view up and down. Simply click on the joystick and drag it up or down to move forward or backwards, and left or right to twist the view to the left or right.
There is a red knob on the right side of the joystick, called the Tilt Knob, that is used to tilt the view up or down. Click on the Tilt Knob and drag it up or down to view the ceiling or floor, respectively. In Figure 20-3, the Tilt Knob is being used to look up at the top of some buildings.
The Examiner Viewer mode is for exploring an object, rather than traveling through a virtual scene. Figure 20-4 shows WebSpace examining a model of the first Kitty Hawk airplane. Imagine walking through a virtual museum in the Walk Viewer, then clicking on a small picture of the plane. When the browser switches to the Examiner mode, you get a closer look at the plane. In addition, there may be other hypertext links to a report about flight, or the Wright brothers.
You’ll notice the Dashboard in Figure 20-4 looks similar to that of the Walk Viewer, but the joystick is now replaced by a Trackball and Thumbwheel. The Thumbwheel lets you move the object closer or farther away from the point of view. Click on the Thumbwheel and drag up to move the object farther away, or down to move the object closer. Figure 20-5 shows the Kitty Hawk airplane at a greater distance.
With the Trackball you rotate the viewed object in any direction. Click anywhere on the Trackball, and drag it to spin the object being viewed. If you release the left mouse button while moving the mouse, the Trackball will continue to spin the principle object.