Future 3D(AP Photo; Wong Maye-E)

3D TV is the latest innovation to arrive in our living rooms, offering a fantastic range of new entertainment options, from 3D Blu-rays to eye-poppingly immersive 3D PS3 games and new sports coverage and documentaries from broadcasters such as Sky and Virgin Media.

But what's the next step forward, beyond current HD and 3D tech? TV manufacturers are already experimenting with auto-stereoscopic (glasses free) 3D TVs, yet most of these are still way outside of the average TV buyer's budget.

As for the longer-term future, might we also see sci-fi style 4D holographic TV sets arrive on the market in the next decade? We polled a number of 3D tech experts, filmmakers and industry insiders to find out more...

What is 4D?
4D film is becoming an increasingly popular tech with theme parks and tourist attractions, although the term itself is a little misleading. It doesn't somehow 'add' an extra dimension to your viewing, but augments a 3D movie with physical effects such as wind, water sprays, smells and more.

The best way of experiencing 4D cinema in the UK right now is by taking a trip to the new 4D Experience at the London Eye, a ground-breaking (and heart-warming) short film about a young girl's day out in the capital, which features a number of cool in-theatre effects such as wind, bubbles and mist. A gimmick, for sure, but a hugely enjoyable one nonetheless.

Disney is also leading the way when it comes to 4D theme park attractions, with would-be Jedi Knights and hardcore Star Wars nuts soon set to be making the pilgrimage to California to take a virtual flight into George Lucas' imaginary world when the latest Star Tours: The Adventures Continues opens later this summer at Disneyland's Tomorrowland and Disney's Hollywood Studios.

However, the expense of setting up a decent 4D movie experience (not to mention the mess it might make in your lounge!) conspires against any commercial development of the tech for the home market right now.

"It's difficult to see a 4D experience in the home," says 3D cinematographer Dan Mulligan, MD of Rogue Element Films. "How would the fourth dimension (smell, touch and so on) be delivered? I dread to think.

"The cost is a huge natural barrier here also," Mulligan adds, reminding us that a lot of households have still only recently invested in full 1080p HD televisions, so a very quick re-investment in 3D TV is not going to happen overnight. It is still going to take five to ten years for 3D to truly go mass market."

A glasses-free holographic spectacle
There is also a widespread perception that putting 3D glasses on in a home environment is a turn-off for many consumers, who prefer to don the specs for big event movies at their local multiplex or on a visit to Disneyland.

"The alienation of putting on 3D glasses in a home, where social intercourse is expected, could prove difficult to overcome," agrees Mulligan. That said, the filmmaker thinks that as the costs of glasses-free 3D TV lessens, and the technology improves, "and films become more widespread and not seen as event cinema experiences, then 3D for the home may gain traction in the next ten years."

Mulligan also thinks that affordable holographic TV tech for the home is a long way off, again citing reasons of cost. Still, various holographic technologies have already been in development for some time, according to Norbert Hildebrand, senior analyst at display specialists Insight Media.

"Several distinct sub-categories are emerging," says Hildebrand. "Some of these may be ready for prototyping but not for general consumer use. Further development is required and it may take several years before we see decent prototypes. Another issue with holograms is the content creation. Today there is no infra-structure (or even plan) on how to acquire holographic content.

"In a true hologram you can walk around an object and look at it from all angles. This will require cameras being placed around the object to create a true 3D model. This model has then to be rendered for each viewing angle, creating a massive data manipulation issue. While certain technologies are being developed to overcome this problem, no clear winner has emerged so far."

However, one company that is investing time and effort into developing the use of holograms in the home is Sony Computer Entertainment, with studio director Mick Hocking revealing to Edge magazine recently that the company is looking into "techniques like holographics for the PS3 that I think will be very interesting for the future 3D games."

For Hildebrand, Ultra-HD tech is going to be more important to the development of 3D TV than holography in the coming years, offering the viewer a clean, smooth, very high definition picture.

"When designing an auto-stereoscopic display the number of pixels is divided by number of views presented to the viewer," says Hildebrand. "This means that the effective resolution to the eye is greatly reduced. To overcome this shortcoming higher resolution panels will be used together with other technologies to increase the effective resolution per eye without limiting the viewing angles too much."

3D superphones and tablets
One vocal evangelist of 3D gaming and entertainment in the UK is Ben Berraondo, UK PR manager for graphics specialist Nvidia, who predicts there will be 90 million 3D TVs in homes by 2015.

"This all amounts to a lot of people craving 3D content," says the Nvidia rep. "When you look at the adoption of HD I do not think there's any doubt that gaming is one of the key drivers in creating a standard. Moving several years into the future we'll see 3D on mobile devices such as superphones and tablets and its important companies are prepared for the rapid change."

All of the experts we've spoken with offer a tantalising glimpse into the future of home entertainment. Glasses-free 3D TVs with ever-better resolution, such as those being developed by Philips spin-off Dimenco are certainly going to own an increasing chunk of the fast-growing market for 3D TV. Plus, we will soon start to see some interesting experiments by games developers using holographic techniques to ramp up the sensation of immersion in their game-worlds.

Though as for the idea of a '4D box' that blows wind and rain and smells out as you attempt to recline on the couch... we'd rather that particular idea was left on the drawing board, please Sony!