An Introduction to 3D, X3D and Atmosphere

What is 3D on the Web? How can anybody possibly manage to get a three-dimensional effect on a Web page through a crudely-pixellated two-dimensional screen? The answer, of course, is that they don't. There are two meanings for 3D on the Web, and neither comes very close to the old-fashioned idea of 3D found in movie theatres, where special spectacles and colored double-vision shadows give our eyes the illusion of real three-dimensional objects.

The first of the two meanings for the Web is boosting perspective and shadow on manufactured graphics to make them look more three-dimensional, more like real photographs, or exaggeratedly three-dimensional to go beyond the perspective and shadow found in genuine pictures.

Graphics programs like Xara3D do this - they enhance two-dimensional Web graphics to make them look more three-dimensional. There are scores more programs out there that do 3D enhancement, but when Web designers talk about 3D programs, they're often talking about something related but slightly different - the second meaning of 3D on the Web, which is changeable perspective viewing of objects, the creation of virtual worlds.

A typical 3D world is the environment found within a computer game. This kind of world can also be created for a chat room, where the participants create visual images of themselves called avatars - a word derived from the many manifestations of Hindu gods.

Within a 3D world, objects have the perspectives and shadows found in real life, but most importantly, these change when the viewer changes position. Changeable perspective viewing, the ability to see objects properly from different viewpoints, is at the heart of this second meaning of 3D on the Web.

Clearly this ties in closely with virtual reality (VR), and indeed the two concepts are intimately related. Some people say that 3D turns into VR when an extra sense gets involved, not just sight. The extra sense is usually touch or motion or both.

Here's an example of how closely the two terms are connected. The original open standard for changeable perspective viewing of objects was called Virtual Reality Modelling Language (VRML). This has now been updated and become 3XD - a name clearly derived from a combination of 3D and XML.

Another way to think of this second definition of 3D on the Web - and it's the second definition that we'll be concentrating on for the rest of this article - is to see it as object-oriented picture viewing. Inside a flat picture are objects - trees, cars, people, whatever - and in a 3D world the viewpoint can shift and all these objects must be rendered correctly from the new perspective.

In an IT world that increasingly revolves around object-oriented programming, it's inevitable that we'd finish up with this - an object-oriented image of reality. 3D worlds are full of objects, generally evenly-shaped objects close to spheres and cubes, because they're easier to deal with than the irregular shapes we find in the real world.

Thinking in terms of objects is also a short-cut to understanding the workings of the programs behind 3D worlds, because the items on display generally do conform to the definition of objects in a programming sense.

So What?

The market for 3D on the Web breaks down into three major sectors - Computer Aided Design (CAD), computer games, and user environments for shopping or chat.

The CAD market is seen as a distinct sector because it's so high-end. Industrial design and manufacturing companies are prepared to pay large amounts of money for the best software and will run it on tremendously powerful hardware. For these reasons it's a world unto itself.

High-end gaming also lives within its own world or 3D worlds, and they're generally created in proprietary formats and involve big transfers of data. They may also run on specialist machinery (consoles) because regular PCs aren't great at 3D rendering. PCs don't usually have the best API (Application Program Interface) or accelerators required to run wonderful 3D, though situation is improving and PC gaming fans have certainly created a demand for good accelerators.

Middle and lower order gaming has more of an association with the Web, and as bandwidths go up, this association can only get stronger. Already the planet is full of Everquest junkies, and there's room for more.

In theory, a simple 3D protocol would open up the Web to a massive amount of gaming interaction. Users could create their own 3D games, their own worlds for other people's games, and their own avatars that they could use in any 3D world they came across. To a minor extent this is happening now, but we're only seeing the beginning. Inevitably, interactive gaming, with users carrying their own custom modules from one game to another, is going to be very big - the only question is when it will reach take-off point.

This opportunity for users to create their own objects and transfer them to other 3D worlds also applies to futuristic 3D chatrooms. If it's been created under a common protocol, then you'll be able to transfer your avatar unchanged from one site to another. You can visit different chatrooms around the world and other users will see you consistently as the same character - maybe even recognise you and become avatar-friends. This is another 3D sector that will definitely be huge in the long term, and is exactly where Adobe has pitched its 3D product, Atmosphere. More on that later.

That leaves one last market subsector that we haven't discussed yet - 3D Web environments for shopping and marketing. Unfortunately this got off to a false start with the likes of boo.com getting well into 3D and ultimately proving to be all style and no substance. And after a false start like that, everybody is a little slower off the blocks. But there's a steady trickle of 3D marketing campaigns and some fine 3D views of products available on the Web. All it needs is for one version of 3D to win over its opponents and the area is ripe for exploitation. Which brings us on to the thorny issue of browser plug-ins.

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