Researchers with the European Space Agency in Darmstadt, Germany, exploring virtual reality for controlling planetary rovers and satellites in orbit
Virtual reality (VR) is an interactive computer-generated experience taking place within a simulated environment, that incorporates mainly auditory and visual, but also other types of sensory feedback like haptic. This immersive environment can be similar to the real world or it can be fantastical, creating an experience that is not possible in ordinary physical reality. Augmented reality systems may also be considered a form of VR that layers virtual information over a live camera feed into a headset or through a smartphone or tablet device giving the user the ability to view three-dimensional images.
Current VR technology most commonly uses virtual reality headsets or multi-projected environments, sometimes in combination with physical environments or props, to generate realistic images, sounds and other sensations that simulate a user's physical presence in a virtual or imaginary environment. A person using virtual reality equipment is able to "look around" the artificial world, move around in it, and interact with virtual features or items. The effect is commonly created by VR headsets consisting of a head-mounted display with a small screen in front of the eyes, but can also be created through specially designed rooms with multiple large screens.
VR systems that include transmission of vibrations and other sensations to the user through a game controller or other devices are known as haptic systems. This tactile information is generally known as force feedback in medical, video gaming and military training applications.Contents
"Virtual" has had the meaning of "being something in essence or effect, though not actually or in fact" since the mid-1400s. The term "virtual" has been used in the computer sense of "not physically existing but made to appear by software" since 1959. In 1938, Antonin Artaud described the illusory nature of characters and objects in the theatre as "la réalité virtuelle" in a collection of essays, Le Théâtre et son double. The English translation of this book, published in 1958 as The Theater and its Double, is the earliest published use of the term "virtual reality". The term "artificial reality", coined by Myron Krueger, has been in use since the 1970s. The term "virtual reality" was first used in a science fiction context in The Judas Mandala, a 1982 novel by Damien Broderick.
A "cyberspace" is a networked virtual reality.
Virtual reality shares some elements with "augmented reality" (or AR). AR is a type of virtual reality technology that blends what the user sees in their real surroundings with digital content generated by computer software. The additional software-generated images with the virtual scene typically enhance how the real surroundings look in some way. Some AR systems use a camera to capture the user's surroundings or some type of display screen which the user looks at (e.g., Microsoft's HoloLens, Magic Leap).Technology
The Virtual Reality Modelling Language (VRML), first introduced in 1994, was intended for the development of "virtual worlds" without dependency on headsets. The Web3D consortium was subsequently founded in 1997 for the development of industry standards for web-based 3D graphics. The consortium subsequently developed X3D from the VRML framework as an archival, open-source standard for web-based distribution of VR content.
All modern VR displays are based on technology developed for smartphones including: gyroscopes and motion sensors for tracking head, hand, and body positions; small HD screens for stereoscopic displays; and small, lightweight and fast processors. These components led to relative affordability for independent VR developers, and lead to the 2012 Oculus Rift Kickstarter offering the first independently developed VR headset.
Independent production of VR images and video has increased by the development of omnidirectional cameras, also known as 360-degree cameras or VR cameras, that have the ability to record in all directions, although at low-resolutions or in highly compressed formats for online streaming of 360 video. In contrast, photogrammetry is increasingly used to combine several high-resolution photographs for the creation of detailed 3D objects and environments in VR applications.History Before the 1960s The Sensorama was released in the 1950s. View-Master, a stereoscopic visual simulator, was introduced in 1939.
The exact origins of virtual reality are disputed, partly because of how difficult it has been to formulate a definition for the concept of an alternative existence. Elements of virtual reality appeared as early as the 1860s. French avant-garde playwright Antonin Artaud took the view that illusion was not distinct from reality, advocating that spectators at a play should suspend disbelief and regard the drama on stage as reality. The first references to the more modern concept of virtual reality came from science fiction.1950–1970
Morton Heilig wrote in the 1950s of an "Experience Theatre" that could encompass all the senses in an effective manner, thus drawing the viewer into the onscreen activity. He built a prototype of his vision dubbed the Sensorama in 1962, along with five short films to be displayed in it while engaging multiple senses (sight, sound, smell, and touch). Predating digital computing, the Sensorama was a mechanical device. Heilig also developed what he referred to as the "Telesphere Mask" (patented in 1960). The patent application described the device as "a telescopic television apparatus for individual use...The spectator is given a complete sensation of reality, i.e. moving three dimensional images which may be in colour, with 100% peripheral vision, binaural sound, scents and air breezes".
The VR industry mainly provided VR devices for medical, flight simulation, automobile industry design, and military training purposes from 1970 to 1990.
David Em became the first artist to produce navigable virtual worlds at NASA’s Jet Propulsion Laboratory (JPL), where he was Artist in Residence from 1977 to 1984.
The Aspen Movie Map was created at the MIT in 1978. The program was a crude virtual simulation of Aspen, Colorado in which users could wander the streets in one of the three modes: summer, winter, and polygons.
In 1979 Eric Howlett developed the Large Expanse, Extra Perspective (LEEP) optical system. The combined system created a stereoscopic image with a field of view wide enough to create a convincing sense of space. The users of the system have been impressed by the sensation of depth in the scene and the corresponding realism. The original LEEP system was redesigned for the NASA Ames Research Center in 1985 for their first virtual reality installation, the VIEW (Virtual Interactive Environment Workstation) by Scott Fisher. The LEEP system provides the basis for most of the current virtual reality helmets available today.
Atari founded a research lab for virtual reality in 1982, but the lab was closed after two years due to the Atari Shock (North American video game crash of 1983). However, its hired employees, such as Tom Zimmerman, Scott Fisher, Jaron Lanier, Michael Naimark, and Brenda Laurel, kept their research and development on VR-related technologies.
By the 1980s the term "virtual reality" was popularized by Jaron Lanier, one of the modern pioneers of the field. Lanier had founded the company VPL Research in 1985. VPL Research has developed several VR devices like the Data Glove, the EyePhone, and the Audio Sphere. VPL licensed the Data Glove technology to Mattel, which used it to make an accessory known as the Power Glove. While the Power Glove was hard to use and not popular, at US$75, it was an early affordable VR device.1990–2000
In 1991, Carolina Cruz-Neira, Daniel J. Sandin and Thomas A. DeFanti from the Electronic Visualization Laboratory created the first cubic immersive room, The Cave. Developed as Cruz-Neira's PhD thesis, it involved a multi-projected environment, similar to the holodeck, allowing people to see their own bodies in relation to others in the room.
Between 1989-1992, Nicole Stenger created Angels, the first real-time interactive immersive movie. The interaction was facilitated with a dataglove and high-resolution goggles.
In 1992 researcher Louis Rosenberg created the Virtual Fixtures system at the U.S. Air Force’s Armstrong Labs using a full upper-body exoskeleton, enabling a physically realistic virtual reality in 3D. The system enabled the overlay of physically real 3D virtual objects registered with a user's direct view of the real world, producing the first true augmented reality experience enabling sight, sound, and touch.A VPL Research DataSuit, a full-body outfit with sensors for measuring the movement of arms, legs, and trunk. Developed circa 1989. Displayed at the Nissho Iwai showroom in Tokyo
The 1990s saw the first widespread commercial releases of consumer headsets. In 1991, Sega announced the Sega VR headset for arcade games and the Mega Drive console. It used LCD screens in the visor, stereo headphones, and inertial sensors that allowed the system to track and react to the movements of the user's head. In the same year, Virtuality launched and went on to become the first mass-produced, networked, multiplayer VR entertainment system. It was released in many countries, including a dedicated VR arcade at Embarcadero Center in San Francisco. Costing up to $73,000 per multi-pod Virtuality system, they featured headsets and exoskeleton gloves that gave one of the first "immersive" VR experiences. Antonio Medina, a MIT graduate and NASA scientist, designed a virtual reality system to "drive" Mars rovers from Earth in apparent real time despite the substantial delay of Mars-Earth-Mars signals.
In 1991, Computer Gaming World predicted "Affordable VR by 1994". By 1994, Sega released the Sega VR-1 motion simulator arcade attraction, in SegaWorld amusement arcades. It was able to track head movement and featured 3D polygon graphics in stereoscopic 3D, powered by the Sega Model 1 arcade system board. Also in 1994 Apple released QuickTime VR, which, despite using the term "VR", was unable to represent virtual reality, and instead displayed 360 photographic panoramas.
The Virtual Boy was created by Nintendo and was released in Japan on July 21, 1995 and in North America on August 15, 1995. Also in 1995, a group in Seattle created public demonstrations of a "CAVE-like" 270 degree immersive projection room called the Virtual Environment Theater, produced by entrepreneurs Chet Dagit and Bob Jacobson. The same system was shown in 1996 in tradeshow exhibits sponsored by Netscape Communications. Forte released the VFX1, a PC-powered virtual reality headset in 1995, which was supported by games including Descent, Star Wars: Dark Forces, System Shock and Quake.
In 1999, entrepreneur Philip Rosedale formed Linden Lab with an initial focus on the development of VR hardware. In its earliest form, the company struggled to produce a commercial version of "The Rig", which was realized in prototype form as a clunky steel contraption with several computer monitors that users could wear on their shoulders. The concept was later adapted into the personal computer-based, 3D virtual world Second Life.2000–2015
In April 2001, SAS Cube (SAS3) became the first PC based cubic room, developed by Z-A Production (Maurice Benayoun, David Nahon), Barco, and Clarté. It was installed in Laval, France. The SAS library gave birth to Virtools VRPack.
By 2007, Google introduced Street View, a service that shows panoramic views of an increasing number of worldwide positions such as roads, indoor buildings and rural areas. It also features a stereoscopic 3D mode, introduced in 2010.
In 2010, Palmer Luckey designed the first prototype of the Oculus Rift. This prototype, built on a shell of another virtual reality headset, was only capable of rotational tracking. However, it boasted a 90-degree field of vision that was previously unseen in the consumer market at the time. This initial design would later serve as a basis from which the later designs came.
In 2013, Valve discovered and freely shared the breakthrough of low-persistence displays which make lag-free and smear-free display of VR content possible. This was adopted by Oculus and was used in all their future headsets.
In early 2014, Valve showed off their SteamSight prototype, the precursor to both consumer headsets released in 2016. It shared major features with the consumer headsets including separate 1K displays per eye, low persistence, positional tracking over a large area, and fresnel lenses.
On March 25, 2014, Facebook purchased Oculus VR for $2 billion. This purchase occurred after the first development kits ordered through Oculus' 2012 Kickstarter had shipped in mid 2013 but before the shipping of their second development kits in mid 2014. In that same month, Sony announced Project Morpheus (its code name for PlayStation VR), a virtual reality headset for the PlayStation 4 video game console. Google announces Cardboard, a do-it-yourself stereoscopic viewer for smartphones. The user places their smartphone in the cardboard holder, which they wear on their head. In 2015, the Kickstarter campaign for Gloveone, a pair of gloves providing motion tracking and haptic feedback, was successfully funded, with over $150,000 in contributions.
In February–March 2015, HTC and Valve Corporation announced the virtual reality headset HTC Vive and controllers. The set included tracking technology called Lighthouse, which utilized wall-mounted "base stations" for positional tracking using infrared light.2015–present The PlayStation VR headset, a 2016 virtual-reality headset exclusively for the PlayStation 4 video game console.
In 2015, Michael Naimark was appointed Google’s first-ever “resident artist” in their new VR division.
By 2016 there were at least 230 companies developing VR-related products. Facebook has 400 employees focused on VR development; Google, Apple, Amazon, Microsoft, Sony and Samsung all had dedicated AR and VR groups. Dynamic binaural audio was common to most headsets released that year. However, haptic interfaces were not well developed, and most hardware packages incorporated button-operated handsets for touch-based interactivity. Visually, displays were still of a low-enough resolution and frame-rate that images were still identifiable as virtual. On April 5, 2016, HTC shipped its first units of the HTC VIVE SteamVR headset. This marked the first major commercial release of sensor-based tracking, allowing for free movement of users within a defined space.
In early 2017, a patent filed by Sony showed they were developing a similar location tracking technology to the VIVE for PlayStation VR, with the potential for the development of a wireless headset.
At Facebook F8 2018, Oculus showed a new prototype codenamed Half Dome which has a varifocal display with 140 degrees field of view and has the same form factor and weight as their current consumer device.Applications Main article: Applications of VR
VR is most commonly used in entertainment applications such as gaming and 3D cinema. Consumer virtual reality headsets were first released by video game companies in the early-mid 1990's. Beginning in the 2010's, next-generation commercial tethered headsets were released by Oculus (Rift), HTC (Vive) and Sony (PlayStation VR), setting off a new wave of application development. 3D cinema has been used for sporting events, pornography, fine art, music videos and short films. Since 2015, virtual reality has been installed onto a number of roller coasters and theme parks.
In robotics, virtual reality has been used to control robots in telepresence and telerobotic systems. The technology is useful in robotics development such as in experiments that investigate how robots - through virtual articulations - can be applied as an intuitive human interface. For instance, researchers can simulate how robots are remotely controlled in different environments such as in space. Here, virtual reality not only offers insights into the manipulation and locomotion of robotic technology but also shows opportunities for inspection.
In social sciences and psychology, virtual reality offers a cost-effective tool to study and replicate interactions in a controlled environment. It can be used as a form of therapeutic intervention. For instance, there is the case of the virtual reality exposure therapy (VRET), a form of exposure therapy for treating anxiety disorders such as post traumatic stress disorder (PTSD) and phobias."World Skin, A Photo Safari in the Land of War" - Maurice Benayoun, Jean-Baptiste Barrière, Virtual Reality Installation - 1997
Surgery training can be done through virtual reality. With the supervision of experts to provide feedback, simulated VR surgical environment provide effective and repeatable training at a low cost, allowing trainees to recognize and amend errors as they occur.
Virtual reality has been used in rehabilitation since the 2000's. Despite numerous studies conducted, good quality evidence of its efficacy compared to other rehabilitation methods without sophisticated and expensive equipment is lacking for the treatment of Parkinson's disease.  A 2018 review on the effectiveness of mirror therapy by virtual reality and robotics for any type of pathology concluded in a similar way. 
VR can simulate real workspaces for workplace occupational safety and health purposes, educational purposes, and training purposes. It can be used to provide learners with a virtual environment where they can develop their skills without the real-world consequences of failing. It has been used and studied in primary education, military, astronaut training, flight simulators and driver training. Supplementing military training with virtual training environments has been claimed to offer avenues of realism in military and healthcare training while minimizing cost. It also has been claimed to reduce military training costs by minimizing the amounts of ammunition expended during training periods.
The first fine art virtual world was created in the 1970s. As the technology developed, more artistic programs were produced throughout the 1990s, including feature films. When commercially available technology became more widespread, VR festivals began to emerge in the mid-2010s. The first uses of VR in museum settings began in the 1990s, seeing a significant increase in the mid-2010s. Additionally, museums have begun making some of their content virtual reality accessible. Immersive VR engineering systems enable engineers to see virtual prototypes prior to the availability of any physical prototypes.
Virtual reality's growing market presents an opportunity and an alternative channel for digital marketing. It is also seen as a new platform for e-commerce, particularly in the bid to challenge traditional brick and mortar retailers. A study revealed that the majority of goods are still purchased in physical stores. For this reason, the simulated store environment made possible by VR technology has the potential to attract more consumers since it offers an almost similar experience in the physical store without the inconvenience of being there.In fiction and popular culture Main article: Virtual reality in fiction
There have been many novels that reference and describe forms of virtual reality. A comprehensive and specific fictional model for virtual reality was first published in 1935 in the short story "Pygmalion's Spectacles" by Stanley G. Weinbaum.
Laurence Manning's 1933 series of short stories, "The Man Who Awoke"—later a novel—describes a time when people ask to be connected to a machine that replaces all their senses with electrical impulses and, thus, live a virtual life chosen by them (à la "The Matrix", but voluntary, not imposed).
In the 1980s and 1990s, Cyberpunks viewed the technology as a potential means for social change. The recreational drug subculture praised virtual reality not only as a new art form, but as an entirely new frontier. The novels Snow Crash (1992) by Neal Stephenson and Ready Player One (2011) by Ernest Cline influenced VR engineers working in the early 21st century.Concerns and challenges Health and safety
There are many health and safety considerations of virtual reality. Most virtual reality systems come with consumer warnings, including: seizures; developmental issues in children; trip-and-fall and collision warnings; discomfort; repetitive stress injury; and interference with medical devices. Some users may experience twitches, seizures or blackouts while using VR headsets, even if they do not have a history of epilepsy and have never had blackouts or seizures before. As many as one in 4000 people may experience these symptoms, and they are more common among people under the age of 20, which is part of why most VR headsets advise against children using VR headsets. Other problems may occur in physical interactions with one's environment. While wearing VR headsets, people quickly lose awareness of their real-world surroundings and may injure themselves by tripping over, or colliding with real-world objects. 
A number of unwanted symptoms have been caused by prolonged use of virtual reality, and these may have slowed proliferation of the technology. For example, in 1995, Nintendo released a gaming console known as the Virtual Boy. Worn as a headpiece and connected to a typical controller, the Virtual Boy received much criticism for its negative physical effects, including "dizziness, nausea, and headaches". Virtual reality sickness (also known as cybersickness) occurs when a person's exposure to a virtual environment causes symptoms that are similar to motion sickness symptoms. The most common symptoms are general discomfort, headache, stomach awareness, nausea, vomiting, pallor, sweating, fatigue, drowsiness, disorientation, and apathy.Privacy
The persistent tracking required by all VR systems makes the technology particularly useful for, and vulnerable to, mass surveillance. The expansion of VR will increase the potential and reduce the costs for information gathering of personal actions, movements and responses.Conceptual and philosophical concerns
In addition, there are conceptual and philosophical considerations and implications associated with the use of virtual reality. What the phrase "virtual reality" means or refers to can be ambiguous. Mychilo S. Cline argued in 2005 that through virtual reality techniques will be developed to influence human behavior, interpersonal communication, and cognition.See also