Another  dimension

So long the stuff of techno fantasy, 3D screens are again focusing on the foreground. Paul Trotter investigates.

As futuristic technology concepts go, 3D screens have been right up there with the teleporter as an aspirational idea that could change the way we see the world, yet the idea still resides in the realm of the science fiction.
 
Screens that project images towards you have been shown on many future-focused documentaries, but, like many speculative ideas, most see it as a technology that won't reach the mass market in our lifetime. And this is despite the fact that 3D movies have been around since the 1950s, when the rather crude red and blue cellophane glasses were introduced. They impressed children of that generation, but since then 3D screens have been dismissed as gimmicky.

So it may come as a surprise to find that futuristic 3D screens are already available. The challenge to produce 3D displays has been ongoing, with developers in the US, Europe and Asia all enjoying varying degrees of success. This is a market that will be worth trillions, and the scientists behind the displays say they're being held back by the market's unwillingness to take a leap of faith and put massive investment behind it.
 
In their search for perfection, monitor experts generally criticise attempts at 3D screens, citing problems such as artefacts on the image, limited viewing angles, restricted number of users and, of course, price. But there also exists inertia among those who've seen the displays. Developers claim to receive a chorus of wows whenever their creations are shown to potential clients, but converting this interest into an acquisition is a different matter.
'Everybody loves it when they come and see it, but they don't want to follow it up. It needs someone to not take a risk, but to make a leap of judgement and then, if they get it right, it could change the world,' said John Holden from UK Central Research Labs (CRL, www.crl.co.uk).

Four eyes are better than two
Historically, the world has seen simplistic implementations of 3D over the past few decades, although idealists in the 3D monitor development community deem these more worthy of yesterday's world than tomorrow's.

Many people will be aware of the stereoscopic glasses that companies such as Stereographics have been selling to 3D gaming fans, while leisure attractions like Disney World and Universal Studios put the concept into use in auditoriums to amaze viewers.

The techniques capitalise on the way in which the brain fuses the images viewed by the left and right eyes respectively. Set roughly two and a half inches apart, the human eyes see two slightly different views of the same image, with each eye picking up information the other doesn't. These two images are combined by the brain to create a single view.

In the PC environment, the 3D effect is usually achieved through the use of shutter glasses. The monitor displays alternating images designed for either the left or right eye, and the shutter glasses run in sync with the changes of the image on screen, ensuring the left eye only picks up the image intended for it and vice versa.

Large auditoriums often use a different approach, although the practice of directing different images to each eye remains the same. This method uses two projectors and polarised glasses. Each projector polarises the light in such a way that it will only pass through the lens on the viewer's glasses which is similarly polarised. For example, the light intended for the left eye is polarised horizontally, as is the lens in front of the left eye. The image and lens for the right eye are polarised vertically. If you perpendicularly polarise the light forming the two images, you ensure each eye sees a different image.
          
However, critics rightly argue that working in groups is hindered by the fact that each user is hidden away in a virtual world in which interaction with others is considerably reduced. Experts also claim that by fooling the brain, this method causes eye strain and can lead to headaches.

This isn't a problem confined to the glasses approach, but to any method that directs a different image to a different eye. These, combined with the crude red and blue spectacles, form the cheap option in a development world that's dominated by venture capitalist start-ups and millions of investment dollars.

Thriller apps
Beyond 3D glasses and stereoscopic trickery, the applications are endless according to those living and breathing 3D. Most of the developers start by targeting niche, high-end markets, but all of them have long-term designs on every TV, monitor, information display and advertising billboard in the world. They believe we'll look back one day at the primitive 2D displays we use today and snigger at their lack of ingenuity.

German firm SeeReal Technologies (www.seereal.com) has been focusing its early attempts on the medical sector and is already claiming some success in this field.
 
The company says its displays are well suited to the field of minimal invasive surgery and, in February 2002, its D4D display was used by a team of ophthalmologic surgeons to aid an eye surgery operation. 'There's no doubt the medical sector is a market niche that's very interesting, because it involves serious usage and sets high standards for quality and function,' said SeeReal CEO Lars Povelsen.

Another developer, New Zealand's Deep Video Imaging (www.deepvideo.com), claims to have achieved success with fairly basic implementations of its multilayer display in the US military, where the 3D effect can be used to better illustrate weather and radar patterns.
The technology has also been touted for the gaming market, probably in arcades to begin with. It's a market that's based upon innovative ideas, and particularly the visual wow factor.

'A 3D computer game in an arcade would be fantastic,' said CRL's John Holden, 'rather like the first electronic tennis game, which had to be serviced after a couple of hours because the coin box was full. If you had a new 3D game, with images coming out of it, you'd get the same reaction.'

A slightly less awe-inspiring early adopter could be the financial services sector, in which traders typically have several screens in front of them displaying enormous amounts of information. 3D screens could be used to minimise the number of monitors required to hold information by allowing traders to bring certain stocks to the foreground while pushing less vital apps to the background when required.

This concept shows how 3D screens could find a place on the desktop in the mass market. If the technology was cheap enough, it's feasible that it could be brought into everyday use. Accountants juggling spreadsheets could use the technology to place active worksheets closer to the eye, while a click on the partially hidden sheet in the background brings it into full view. Artists working on graphics would be able to place toolbars closer to them. Microsoft's animated helpers in the guise of the paperclip could find a place in front of whic