How Shockwave 3-D Technology Works
by Tom Harris
Browse the article How Shockwave 3-D Technology Works
Introduction to How Shockwave 3-D Technology Works
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To view the 3-D graphics in this article, you will need to download the newest Shockwave player. |
But what does all this mean? In this edition of HowStuffWorks, we'll find out exactly what Shockwave 3-D technology is and how it works. We'll also explore some applications of the new technology and check out some very cool 3-D images.
The Newest Shockwave
If you spend much time on the Web, you have probably encountered Shockwave, a graphics format for animation and interactive presentations. Shockwave files are created by a program called Director, which was originally developed for CD-ROM use. The format is very popular with webmasters because it allows them to create elaborate Web content that can be transmitted fairly quickly over the Internet. See the HowStuffWorks Animation Tour for lots of cool examples of work done in this format. A typical 2-D animation that might be created with Shockwave
- Frame animation is something like classic cartoons -- you see movement as a series of 2-D still images shown in a set sequence. Your viewpoint is set by the movie's creator.
- Vector animation uses 2-D objects (circles, squares, lines) that move with respect to one another. Since it is based on simple geometric equations, vector animation allows artists to create complex movies that have very small file sizes.
The newest edition of Director incorporates Intel Internet 3-D technology developed by Intel Architecture Labs. The program allows Web artists to create interactive 3-D animations and post them on the Web. The newest version of the Shockwave player allows most Internet users, even ones with dial-up connections, to view these intricate animations.
With Shockwave 3-D technology, users can actually download and manipulate 3-D models themselves -- they can become the director and move the camera. There are two ways to think about this:
- You can download an object and rotate the object in front of the camera to see it from different perspectives.
- You can download an environment and move the camera through it. This is basically the same thing you do when you play a first-person video game. The program puts you in a virtual 3-D world, and you control a "camera" in that world by way of your movements. You tell your camera to move left or right, forward or backward, through the environment.
The same object viewed from two different perspectives. |
Uses of Shockwave Technology
Adding 3-D to Shockwave enables access to all sorts of new Web content. One of the most obvious applications is Web-based 3-D gaming. First-person adventure games and other games with fully realized 3-D worlds have dominated the PC and game-console market for almost a decade. The new Shockwave capabilities allow this sort of game to be played over the Web. Web-based 3-D gaming is getting a lot of attention, but it is only one market for the new technology. 3-D capability is perhaps better suited for advancing e-commerce. Web merchants can give their customers a much clearer idea of products in their catalog if the customers can see the product as a 3-D image. With 3-D models, online shopping is a little more like in-store shopping -- customers can rotate the item around, checking it out from every angle. A 3-D model used to demonstrate a product on an e-commerce site |
This level of user interactivity is also a great addition to educational sites like HowStuffWorks. A 3-D model of an engine that you can turn around and interact with can offer a much clearer illustration of the mechanisms at work than a 2-D model -- it's more like actually handling and examining the engine yourself.
This 3-D model of a paintball gun makes it extremely easy to understand how paintball and BB guns work. Click on the image above to see the model.
As a demonstration of the new Shockwave 3-D technology, NxView has created this 3-D model of a four-speed manual transmission. |
To see more examples of Shockwave models, check out:
Making 3-D Content Accessible
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 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.
A simpler 3-D model has fewer polygons. This hand is composed of only 862 polygons. |
To create a more detailed model, you have to add more polygons. This hand is composed of 3,444 polygons. |
Developing New 3-D Content
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- You use a standard 3-D modeling package to create the 3-D object. For example, you might use 3D Studio Max or Maya. With these tools, you create the wireframe image and specify the polygons that cover the wireframe (see How 3D Graphics Work for details). You export from the 3-D modeling package using a new .W3D file format.
- You load the .W3D file into the Macromedia application called Director Shockwave Studio. This application helps you prepare the 3-D object for distribution on the Web. For example, you can:
- Apply different techniques, such as a multi-resolution mesh or subdivision surfaces, to limit the amount of bandwidth or processing power needed by the 3-D object on the user's machine.
- Add user-interactivity features. For example, you can make different parts of the 3-D object move in response to user requests.
- Add effects, such as fog or rain, to the object.
- The user then downloads and views the .DCR file using his or her browser and the Shockwave player (version 8.5 or higher). [See, for example, this example of a .DCR file, which shows a 3D model of a paintball gun.]