How Shockwave 3-D Technology Works

Making 3-D Content Accessible
A simpler 3-D model has fewer polygons. This hand is composed of only 862 polygons.
A simpler 3-D model has fewer polygons. This hand is composed of only 862 polygons.

In the last section, we saw that Shockwave's new player is a new format for creating and viewing interactive 3-D content on the Web. The idea of posting this sort of content on the Web is nothing new, but technology companies and Web sites haven't had much luck in bringing 3-D to a lot of viewers. There are two main reasons for this:

  • It takes a long time to transmit 3-D "movement" over low-bandwidth connections.
  • You often have to download a new plug-in every time you want to view another site's 3-D content.

The new Shockwave player specifically addresses these obstacles, so it could finally make 3-D content a significant component of the Web. The majority of Web users already have the Shockwave player installed and would only need to download the most recent update to add 3-D capabilities. Macromedia has set up partnerships with many Web companies in order to get people using its technology. Previously, Macromedia has had a lot of success with both Shockwave and Flash formats because they work well with all of the main browsers and are easy to install and update. Intel, NxView and other companies partnered with Macromedia because the company has a good track record with disseminating its player technology.

The new format is specially designed to work well with all bandwidth connections, even connection speeds as low as 28.8 kilobytes per second (KBps). It does this in a couple of ways.

When you view 2-D animation on the Web, the Web site sends each successive frame to your computer. In this way, everything in the animation must be transmitted over the Internet individually. In Shockwave 3-D technology, the Web site sends you a complete image only once. Then, when you want to move the image, the site only sends the bare-bones information necessary to make the desired move. It tells your computer how the outer wire frame should be adjusted, and your computer does the rest of the work to fill in the polygons and textures.

Most personal computers made in the past five years have processors designed to handle the complex 3-D worlds of advanced video games, so they are well-equipped for the job. By relying mostly on the power built into the client machine (your PC), there is much less information that needs to be transmitted from the server machine (the computer storing the Web site). The only hefty download occurs when you bring up the initial image. After that, the site only has to transmit mathematical adjustments, which don't require extensive bandwidth.

But what about this big initial download? Shockwave's new player addresses this problem with something called adaptive 3-D geometry. Adaptive 3-D geometry is a collection of complex algorithms that automatically scales a 3-D model for a particular Internet connection. If you have a slower connection, the Web site transmits an image with simplified textures and fewer polygons. If you have a faster connection, you receive a more complex image.

To create a more detailed model, you have to add more polygons. This hand is composed of 3,444 polygons.

With these elements, you should be able to access 3-D content no matter kind of Internet connection you use. But how does somebody make Shockwave 3-D content themselves? In the next section, we'll find out what goes into producing a Shockwave 3-D animation and see how webmasters can put 3-D content on their site.