-by Kelly Murdock
]In the chapters so far, you've seen a lot of image-creating techniques, from static images to dynamic animations. Before you're introduced to the promised land, where worlds update in real-time, it's time for a short field trip to look at a technology that falls somewhere in between.
Apple's QuickTime VR technology is an extension of their video technology, which enables users to rotate an object or spin about a panoramic scene. The view changes as you move the cursor about the scene, resulting in (for you, the viewer) a feeling of standing in one spot and panning your head back and forth (or even all the way around). How is this done? This chapter answers that question in detail, explaining the following topics:
Although QuickTime VR is somewhere between 3D graphics and VRML, it definitely can be considered as 3D graphics and it exists all over the Web, so it really belongs in this book.
Stop for a second and turn your head to the left. What do you see? Now look up. Is the view different? Unless you're in a padded room, your view changes as you move your head.
Now try picking up an object and turning it over. The object probably looks different from different angles. QuickTime VR takes images shot from several different positions and combines them to create a file that displays the correct view as you move around the scene.
There are actually two different types of QuickTime VR environments that you can create-panoramic movies and object movies. The first acts like a background and the second like an object you hold in your hand. These two environment types can be combined into one scene.
Have you ever been so captivated by scenery on vacation that you tried to capture the panoramic view by taking several pictures while rotating? You were probably disappointed that those pictures, when placed side-by-side, didn't quite capture what you saw. QuickTime VR can capture the pictures and give you that panoramic view.
To create the images, you can use a regular old 35mm film camera, a video camera, or any 3D RMA package. If you use a camera, a tripod helps line up the images. Simply take a picture and rotate the camera, then take another, and another, until you've captured a full revolution. Be sure to overlap the images so that the entire scene is captured without gaps.
Once you have the images, you need to digitize them into the computer. Users of 3D packages simply need to render and save the various images. Once all the images are ready, you can use the Dicer tool, part of the QuickTime VR Authoring Tools Suite, to stitch the images into a 360-degree environment. The results can be included on your Web page, like the one shown in Figure 10.1.
Figure 10.1: Lightscape created these 3D scenes as an example fo QuickTime VR technology.
The QuickTime VR Authoring Tools Suite is currently available only for the Macintosh, but QuickTime VR runtime plug-ins are available for both Macintosh and Windows platforms.
The view changes as you move the mouse around the image. The view can move left, right, up, or down. The Shift and Ctrl keys can be used to zoom into and out of a scene. Several views of the same room are shown in Figure 10.2.
Figure 10.2: By moving the cursor to the left of the window, the view updates in realtime.
QuickTime VR objects can be manipulated and rotated by moving the mouse, much like picking up a cantaloupe in the supermarket and turning it over to check for soft spots.
To capture images as QuickTime VR objects, you need to capture pictures of the object from several angles-around, above, and below the object. The best way to do this is to take pictures, starting at the top of the object and continuing all the way around until you get back to the top. Repeat the process around the equator of the object.
Once you have photographed the images, use the Dicer tool to stitch them together. A sample QuickTime VR object can be seen in Figure 10.3.
Moving QuickTime VR objects is very natural. The cursor changes to a hand and when the left mouse button is clicked, the object rotates in the direction you move the mouse. In Figure 10.4, the helmet spins to the left as you drag the cursor to the left, and it spins to the right as you drag the cursor to the right.
Figure 10.4: This QuickTime VR object enables you to view this Raiders helmet from all angles.
A Dicer tool is based on the Macintosh Programming Workshop and used to stitch images together and compress the final file. It does this by matching the various features in adjacent images.
Many 3D packages offer panoramic rendering, which means you don't have to stitch images together. The final stitched image, or rendered image, is output as a simple PICT file. This file can be loaded into an image editor, such as Photoshop, for some touch-up work before you create the finished QuickTime VR movie.
Figure 10.5 shows an example of a finished rendered image. Notice how the lines in the images bend and warp. This is necessary to map correctly to the 360-degree environment.
Figure 10.5: The top of this Web page shows the finished image before becoming a QuickTime VR movie.
When the image is loaded into the QuickTime viewer over the Web, the warp is removed, and the image appears as it would if you looked at it straight on.
QuickTime VR also enables you to specify hotspots throughout the environment. These hotspots let you activate audio clips, display text or images, or even launch another QuickTime VR file. By using hotspots, you can build connected environments called multi-node scenes.
Within a scene, you can detect a hotspot by watching how the cursor changes. Double-clicking on such spots loads the associated file.
In May, Apple announced QuickTime VR 2.0, scheduled to be released in August. You can check Apple's QuickTime VR Web site for the latest information and information for developers:
http://qtvr.quicktime.apple.com/Home.htm
The 2.0 version adds the ability to program how QuickTime VR files play and are controlled. You'll be able to make composite images, such as 3D sprites, so that you can have 3D characters fly around QuickTime VR scenes with 3D sound. You'll also be able to add URL hotspots that link to other Web pages.
Because QuickTime VR authoring is presently available only on the Macintosh, the only 3D packages that offer support for QuickTime VR are Macintosh products. One such product is Strata's Studio Pro.
Studio Pro is one of the first 3D RMA packages to include output options for QuickTime VR. It's a powerful piece of software. Though Studio Pro is currently available only on the Macintosh platform, Strata is working to have a Windows version out by the end of 1996.
One of Studio Pro's chief benefits is the ability to create scripts that automate certain functions. Included in Studio Pro is a scripted camera that creates images that can easily be made into QuickTime VR movies. The following steps show you how Studio Pro can be used to create a QuickTime VR object movie:
The resulting QuickTime VR object movie is ready to be displayed
on your Web page.
| Note |
Studio Pro also can be used to create QuickTime VR panoramic scenes. Select a camera. In the Render Dialog Box, choose QuickTime VR Panoramic as the Renderer setting and either QuickTime VR or QuickTime VR Large as the Size. The rendered PICT file can then be converted into a QuickTime VR movie with the Dicer tool. |
Once you've got the QuickTime VR file finished and you're ready to embed it into your HTML file, you'll need to get the QuickTime VR plug-in, available at the Apple QuickTime site:
http://qtvr.quicktime.apple.com/Install.htm
<A HREF="filename.mov"> QuickTime VR scene</A>
When a Web surfer with the QuickTime VR plug-in installed comes
to your site and clicks on this link, the file downloads and plays
in the helper application.
| Caution |
The QuickTime VR file must download in its entirety before the movie can be viewed. This can take a long time for large files on computers with low bandwidth connections. |
This detour into Apple's technology has shown you a valuable technology. QuickTime VR is appearing on many commercial CD products and popping up all over the Web. A natural fit for 3D software packages, it represents yet another way you can display your 3D content on the Web.
Though you need to get back on the beaten path to continue your trip, this section, as always, offers the proverbial fork in the road:
| Is there any way to embed the QuickTime VR files right in my Web page without relying on a helper application? | |
| Apple has teamed up with Netscape to build QuickTime functionality into Navigator 3. This will allow both QuickTime videos and QuickTime VR scenes to be displayed within Navigator without loading the helper application. You'll still need to download the QuickTime VR plug-in, however. | |
| I really like what QuickTime VR can do, but I'm running Microsoft's Internet Explorer browser. Is there any way to access QuickTime VR scenes in Internet Explorer? | |
| There has been no official word on support for QuickTime VR for Internet Explorer from either Apple or Microsoft. However, as a helper application, you can set up Internet Explorer to load QuickTime VR
programs, just as you would any other helper application. Using helper applications makes them independent of the browser.
You can assume that Microsoft or a third-party company will eventually create an ActiveX control to handle QuickTime VR scenes. | |
| Which 3D packages can I use to create QuickTime VR scenes? | |
| The two packages that have been the tools of choice for working with QuickTime VR scenes are Strata's Studio Pro and Specular's Infini-D. Check out these two products if you plan on creating QuickTime VR scenes from 3D-rendered images. |