Although 3D movies have existed in cinemas since the 1950s, it's only in the last few years that the idea has really taken off. This is largely thanks to the introduction of digital projectors into cinemas and the development of computer animation and advanced post-production techniques, which have made it easier to create and display movies in 3D.
Crowds have been flocking to see recent 3D movies like Up!, G-Force, Monsters Verus Aliens and The Final Destination, and with massive tent-pole movies like James Cameron's Avatar and Toy Story 3 just around the corner, the future for 3D cinema is looking very bright indeed.
Studios like Disney and DreamWorks Animation have vowed to make all of their future movies in 3D, with the latter's CEO Jeffrey Katzenberg recently proclaiming that “3D is as important to the cinema as the move from black and white to colour TV”.
Inevitably, the popularity of 3D among movie makers and cinema goers has created a huge demand for 3D systems in the home, and with pound signs popping up in their eyes, home cinema manufacturers have been busy developing ways of making it happen.
From the plethora of 3D products and concepts on display at this year's CES, IFA and CEATEC shows, it seems that the entire industry believes that 3D is the future of home cinema, and understandably everyone wants a piece of the action.
A scene from Avatar
But as is usually the case with new technology, getting the industry to agree on a single system is like getting a class of kindergarten kids to calm down, and as a result 3D for the home is far from a done deal. Several companies have proposed their own systems (shhh -did someone say format war?), but until the Blu-ray Disc Association unveils the specifications for Full HD 3D in December, the exact direction of 3D technology will remain unclear.
Blu-ray is crucial to the development of 3D for the home, as it boasts the necessary capacity to store the separate left and right images in full 1080p resolution.
So far the BDA has said that the standard will ensure that a 1080p image is delivered to each eye, as well as ensuring that 3D discs can be played on 2D players and 3D players can play 2D discs. But there's a possibility that the standard could also exploit the picture-in picture feature that's already part of the Blu-ray specification, making it easy to watch 3D on existing players.
Whatever happens, one thing's for sure - all of the proposed systems are 'stereoscopic', which means you'll need to wear glasses whether you like it or not. But before we go any further, let's make it clear that we're not talking about those cheap cardboard glasses used by the age-old 'anaglyph' approach.
This cheap and easy method of generating a 3D effect - still used on recent Blu-ray releases like My Bloody Valentine 3D - allows each eye to perceive a different range of colours using crude filters, but because each eye is denied the full range of colours of you don't see the movie's true palette. The new systems being proposed aim to avoid this problem and deliver a much more convincing 3D experience.
One of the methods is 'active shutter' technology, favoured by Panasonic and Sony, who have both announced plans to launch 3D-compatible TVs in 2010. Using this system, the TV displays the left and right images sequentially, while a pair of battery-powered, liquid crystal glasses containing optical shutters synchronises with the screen over an infrared connection and delivers the correct image to each eye, all in true 1920x1080-pixel resolution.
Director James Cameron with Panasonic 3D camera
Panasonic is currently leading the way in 3D technology and its system is based around its NeoPDP plasma technology, which it claims can deliver the clearest, smoothest 3D images possible thanks to its fast refresh rates. It also eliminates many of the problems associated with other 3D technologies, such as picture quality degradation caused by combining two images into one, reduced brightness and the need for line-by-line encoding of the movie (as required by polarised displays).
Sony's 3D-compatible Bravia LCD TV will also use 'frame sequential' technology with shutter glasses to give the image added depth. The problem with using shutter technology on LCD TVs is that refresh rates must be fast enough to avoid artefacts and blur that could spoil the 3D effect - plus picture processors that insert artificial frames between the real ones to increase the frame rate could cause havoc when displaying the left and right images correctly. How Sony will overcome this is still unclear but talk of rival Samsung having an ultra-fast 400Hz TV up its sleeve could be the key.
The other way of displaying 3D is polarisation, where the left and right images are displayed simultaneously, but the light for each one is polarised in different ways. To view it you need a pair of passive glasses that filter the light and direct the images to the correct eye.
On the plus side, passive glasses are cheaper than the powered ones required by the active shutter system and the process of displaying the images is simpler, but on the downside polarised images are typically interlaced, which means resolution is halved. LG, JVC and Philips are among the companies to have developed polarised 3D displays, with the latter displaying a prototype 3D Cinema 21:9 set at IFA 2009.
Philips is hedging its bets when it comes to 3D by developing active shutter and polarised systems, with the intention of bringing products to market when it feels that the market is ready in terms of consumer demand, content availability, delivery standards and technological developments.
So the short term future for 3D is looking good, but what about long term? Most are agreed that the next logical step for 3D technology is to get rid of the glasses. Companies like Philips and Samsung have already demonstrated 'auto-stereoscopic' displays, which deliver a 3D effect without the need for the viewer to wear glasses, but it'll be a long time before they're viable for home use given the limitations of current flatpanel TVs - it's likely that they'll take off when next-generation '4K2K' TVs become a reality.
With 1080p TVs now commonplace, the home cinema industry needs its 'next big thing' to give buyers an incentive to upgrade, and it looks like 3D is just the ticket. The popularity of 3D movies in cinemas - along with the public's apparent willingness to pay more to watch them, though many are no doubt peeved that cinemas tend to charge extra for the glasses - suggests that there's enough demand to make 3D in the home a success and not just another short-lived gimmick, provided there's enough content to sustain it.
But despite the industry's enthusiasm, it won't be an overnight success - as was the case with the hi-def revolution, the need to splash out on pricey new TVs and Blu-ray players will undoubtedly cause many people to sit on the sidelines at first while well-off early adopters have all the fun. But once prices start to drop, a lot more people will be eager to take their home cinema experience into another dimension.