Dip Before the Plunge
The stuff of science fiction in the mid-20th century, Virtual Reality (VR) simulates or replicates physical, three-dimensional occupancy in a computer-generated milieu. This environment can be either imaginary or based on real events or places. All of the user’s senses – sight, hearing, smell, taste and touch – “perceive the digital environment” of the computer technology to achieve the full sensation of total immersion. Common applications include gaming, military and medical uses.
Note that artificial reality (AR) and virtual reality are two different concepts. AR, according to wareable.com’s Sophie Charara, “overlays graphics onto your view of the real world” whereas VR strives to create a “life size, 3D virtual environment without the boundaries… usually (associated) with TV or computer screens.” VR technology has evolved from the primitive behemoth ‘The Sword of Damocles,’ created in 1968 as the first head-mounted display (HMD) system, to the recent ballyhooed virtual reality headset (VRH) Oculus Rift.
HTC executive director of marketing, Jeff Gattis wears the HTC RE Vive
Image Source: Maurizio Pesce
Taking the Plunge
Three basic prerequisites are generally required to operate VRHs:
- An app or game driver such as a console, PC or smartphone
- A headset to run the game or app’s display before the user’s eyes
- Input hardware such as head and hand tracking (see below), controllers, voice commands, trackpads or on-device keys.
A few key concepts should be mentioned when discussing VR. They include:
Latency – the time lapse between VRH head movement and the corrected view of the display. This interval can cause motion sickness in some users.
Field of View (FOV) – the scope of the perceivable world observed at any given time.
Head Tracking – the repositioning of the image in front of the user as she looks down, up, sideways, etc. VRH components such as gyrosensors, laser positions and accelerometer – collectively called a 6DoF, short for 6 Degrees of Freedom– create three axes (plural of axis) to accurately track head movements like roll (shoulder to shoulder), pitch (forwards and backwards) and yaw (side to side).
Hand Tracking – Per John Marco of virtualrealitytimes.com: “Hand tracking, in general, is a complex and abstract aspect of artificial intelligence that makes use of numerous algorithms and the principles of mathematics and physical sciences to bring real-time interpretation of hand movements, gathered as data and processed into tangible user input.”
Persistence – a subjective measure of motion blur. In reality, humans move their heads while keeping their eyes fixed at one point. In VR, there is a perceptible latency between focus and blur when the user moves his head yet, for example, keeps his eyes glued to the dials in the cockpit of a jet airplane. Toleration levels of persistence and latency, measured in milliseconds, vary between individuals. Users sensitive to persistence and latency may feel motion sickness. The Simple Law of Persistence, as postulated by Blur Busters is: “1 ms of persistence = 1 pixel of motion blur during 1000 pixel/second motion.”
Presence – shortened from “telepresence,” Wikipedia defines it as “a phenomenon enabling people to interact with and feel connected to the world outside their physical bodies via technology.” Valve Software’s R&D team names the following prerequisites to establish presence:
- A wide field of view (80 degrees or better)
- Adequate resolution (1080p or better)
- Low pixel persistence (3 ms or less)
- A high enough refresh rate (>60 Hz, 95 Hz is enough but less may be adequate)
- Global display where all pixels are illuminated simultaneously (rolling display may work with eye tracking.)
- Optics (at most two lenses per eye with trade-offs, ideal optics not practical using current technology)
- Optical calibration
- Rock-solid tracking – translation with millimeter accuracy or better, orientation with quarter degree accuracy or better, and volume of 1.5 meter or more on a side
- Low latency (20 ms motion to last photon, 25 ms may be good enough)
Below is Top 5 Best VR Headsets 2016, a YouTube video from Austria’s TechMagnet. Note that the VRHs in this video all use Smartphone apps and thus are different from PC-based systems like Oculus Rift or HTC Vive.
Immersive Concerns
Prolonged exposure to VR has caused unwanted side effects. Motion sickness, as noted above, is a malady commonly cited by users. Reportedly, social diseases such as conjunctivitis can be contracted from a VRH worn by an infected user. Some observers raise worries about virtual reality addiction, a condition akin to video game addiction. As a rule most VR systems caution consumers against protracted use.
But there are more cogitative worries. A number of writers have posited philosophical doubts regarding the social impact of VR technology. For example, Mychilo Cline – author of Power, Madness and Immortality: The Future of Virtual Reality – contends that as VR becomes more a part of everyday life, it will cause many significant changes in human behavior and activity. Will users attempt to reach Nirvana via VR? More importantly, will there be a steady “migration to virtual space,” affecting the culture, commerce and perspective of society? Such questions are likely to make critics wonder if VR has the potential to transform the world as did, for instance, the Industrial Revolution or the automobile. If so, what would the inevitable residual repercussions be?
The Plungers
For those interested in plunging headlong, so to speak, into the immersive world of VR, below are “the plungers” or the major players. The best VRHs according to wareable are:
- HTC Vive®, made by mobile technology company HTC and video game developer Valve Software, is (of course) compatible with Valve’s massive gaming platform. It includes 70 sensors supporting 360 degree head tracking and a 90HZ refresh rate. Latency aka motion sickness is supposedly less of an issue than with other VRHs. Another selling point is the “Lighthouse” room tracking which allows users mobility while wearing the headset. However, this mobility means a sizable space is needed. HTC claims 2 x 1.5 meters is sufficient while a reviewer suggests 3 x 3 meters is more appropriate.
- Oculus Rift, recently acquired by Facebook, connects to a computer’s USB and DVI ports. The latest version boasts a 2160 x 1200 resolution, with a 90 HZ refresh rate, operating at 233 million pixels per second. Described as a “big black box with a strap,” it aksi features a 360º tracking, Head Related Transfer Function (HTRF) – think 3D audio – and Touch controllers. It comes bundled with a XBox One controller.
- Samsung Gear, almost identical to Rift since the two share much of the same technology, is a case using a Samsung Galaxy Smartphone for its display and processor. The catch – and it’s a big one – is that only the Samsung headset can be used with the case. See the above video for how Smartphones work with VRHs. Great value compared with the Vive and the Rift, costing hundreds of dollars less, and has a repository of vid content from Milk VR plus a ton of games.
- Not available until October 2016, the Sony Playstation VR (formerly known as Project Morpheus) has been eagerly anticipated by gamers looking for a superlative VR experience on a familiar platform. According to insiders, the system features low persistence and a high refresh rate; reputed issues such as latency and tracking accuracy have apparently been resolved.
There are “starter” VRHs at a nominal cost; perhaps the best known is the Google Cardboard, which currently sells for US$15.
Coda
As Kyle Orland of arstechnica.com posits, “Virtual reality (has) been a pipe dream concept, well ahead of the technology needed to realize it.” It’s certainly not the holodeck from Star Trek: The Next Generation. Although within reach, a truly realistic and totally immersive VR experience is still well into the future.