It first hit the arcades in the early 90s, and there have been a few attempts over the years to create home versions without much success, but finally virtual reality is to move from niche interest to a mainstream gaming platform. This year sees the launch of major home VR systems, with Oculus Rift due to go on sale in May, and HTC Vive, Steam VR and PlayStation VR also due this year. With them will come a whole new world of the most immersive and graphics intensive gaming experiences ever.

　　The reason it's taken so long for high quality VR to arrive is that it's fraught with technological challenges. For VR to do its job properly it has to trick your brain into believing that you're actually in its artificial 3D environment – to the extent that, for example, you feel genuinely uneasy about falling from a cliff face in Crytek's free-climbing VR title, The Climb – and it has to do it without making you feel sick.

　　Oculus Rift.It turns out that this is a lot harder than the VR pioneers of the 1990s envisioned. When Virtuality's VR gaming pods started turning up in arcades in 1991 they were distinctly low-tech by modern standards, despite their $65,000 price tag. With a resolution of 276x372 and just 20fps they were just about acceptable for arcade gaming, where you pay your money and you're done a couple of minutes later. Sega and Nintendo's early attempts to bring similar technology into the home – where they'd be used for much longer stints – resulted in a lot of queasy gamers.

　　

VR: The basics

The basic VR system consists of a head-mounted display, in which each eye sees a slightly different image to create a stereoscopic illusion, and head tracking to ensure that when you look around, the virtual camera moves with you to give the feeling of presence. The trick is to do this without the need for a sick bag, and the latest VR systems are the best yet at combating motion sickness.

　　The main cause of motion sickness is latency: a delay between action or movement, and it playing out on-screen. Our brains are incredibly sensitive to the slightest mismatch between what they expect to see and what's actually coming in through our eyes, and even a short delay can mean motion sickness. Today's VR headsets keep latency below 20ms, and while even that may be too much latency for people susceptible to motion sickness, it works for most people.

　　Another issue is frame rate. Due to the persistent nature of mobile displays, which don't clear the screen between frames, earlier versions of the Oculus Rift suffered from unsightly motion blur, particularly when you moved your head around. While this problem has been solved by newer, low-persistence OLED displays that do clear the screen between frames, it comes at a cost, requiring a high frame rate to eliminate flickering. To maintain a sharp moving image without flickering – and the resulting eye strain – requires a frame rate of at least 75fps, and preferably faster: Oculus Rift is set to run at 90fps.

　　HTC Vive

Reducing tunnel vision

An important factor in creating a convincing VR display is field of view. While we tend to have a horizontal FOV of around 170 degrees, VR displays have always fallen short of that, with early VR systems providing a maximum FOV of around 45 degrees, severely reducing the feeling of being there; more like watching through a pair of binoculars. Thanks to modern displays, however, new systems have dramatically improved upon that; the Oculus Rift has a much more palatable 110 degree FOV.

　　The final hurdle is to combine all this with high resolution, high detail visuals, and that's where things get really difficult. If you consider the sort of PC setup you need to run the latest games in 1080p and 60fps with high detail settings, you'll get a fair idea of the challenges involved in running a game in VR, with two HD-equivalent displays running at 90fps or faster. To do it seamlessly takes a great deal more power.

　　Thankfully companies like NVIDIA are helping to improve the performance of VR, with smart technology such as VR SLI, which enables you to use multiple GPUs and assign them to specific eyes, and Multi-Res Shading, an innovative technique that renders each part of a warped VR image at a resolution that better matches its pixel density. Such technology can result in a 50% performance boost, while other features of NVIDIA's GameWorks VR toolkit, such as Context Priority and Front Buffer Rendering, can further help reduce latency.

　　

Is your PC VR-ready?

The hardware demands of VR can make the idea of getting into it now just a little daunting, but NVIDIA is helping consumers navigate the world of VR hardware with its GeForce GTX VR Ready program. It recommends the minimum setup you'll need to go with your VR headset:

　　a GeForce GTX 970 GPU or higher for desktop VR (or a GTX 980 if you're using a notebook)

　　a PC with USB 3.0 support

　　CPU: Intel Core i5-4590 equivalent or greater CPU

　　8GB+ RAM of Memory/RAM

　　2x USB 3.0 ports and HDMI 1.3

　　Windows 7 SP1 or newer

　　To help you quickly tell whether new hardware is up to scratch, NVIDIA has teamed up with leading PC makers, system builders, add-in card partners and retailers to identify VR-ready hardware with a distinctive GeForce GTX VR Ready badge. Look out for that when you upgrade and you can rest assured that you're all set up to be part of the biggest new thing in gaming in a very long time.

　　Jim McCauley is Editor-in-Chief of Tech and Games at Dialect, Inc.