TheInfoList

Virtual reality (VR) is a experience that can be similar to or completely different from the real world.
Applications of virtual reality Virtual reality applications are applications that make use of virtual reality Virtual reality (VR) is a Simulation, simulated experience that can be similar to or completely different from the real world. Applications of virtual reality inc ...
include entertainment (particularly
video game#REDIRECT Video game A video game is an electronic game that involves interaction with a user interface or input device such as a joystick, game controller, controller, computer keyboard, keyboard, or motion sensing device to generate visual f ...
s), education (such as medical or military training) and business (such as virtual meetings). Other distinct types of VR-style technology include
augmented reality Augmented reality (AR) is an interactive experience of a real-world environment where the objects that reside in the real world are enhanced by computer-generated perceptual information, sometimes across multiple sensory modalities, including v ...
and
mixed reality Mixed reality (MR) is the merging of real Real may refer to: * Reality Reality is the sum or aggregate of all that is real or existent within a system, as opposed to that which is only Object of the mind, imaginary. The term is also used to r ...
, sometimes referred to as extended reality or XR. Currently, standard virtual reality systems use either
virtual reality headset A virtual reality headset is a head-mounted device that provides virtual reality for the wearer. Virtual reality (VR) headsets are widely used with video games but they are also used in other applications, including simulators and trainers. The ...
s or multi-projected environments to generate realistic images, sounds and other sensations that simulate a user's physical presence in a virtual 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 A head-mounted display (HMD) is a display device, worn on the head or as part of a helmet (See Helmet-mounted display A helmet-mounted display (HMD) is a device used in aircraft to project information to the pilot's eyes. Its scope is similar to ...
with a small screen in front of the eyes, but can also be created through specially designed rooms with multiple large screens. Virtual reality typically incorporates auditory and
video feedback Video feedback is the process that starts and continues when a video camera A video camera is a camera A camera is an optical instrument used to capture an image An SAR radar imaging, radar image acquired by the SIR-C/X-SAR radar ...
, but may also allow other types of sensory and force feedback through
haptic technology Haptic technology, also known as kinaesthetic communication or 3D touch, refers to any technology that can create an experience of touch The somatosensory system is a part of the sensory nervous system. The somatosensory system is a complex ...
.

# Etymology

" 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 but made to appear by
software Software is a collection of Instruction (computer science), instructions that tell a computer how to work. This is in contrast to Computer hardware, hardware, from which the system is built and actually performs the work. At the low level lang ...

" since 1959. In 1938, French avant-garde playwright
Antonin Artaud Antoine Marie Joseph Paul Artaud, better known as Antonin Artaud (; 4 September 1896 – 4 March 1948), was a French writer, poet, dramatist, visual artist, essayist, actor and theatre director, widely recognized as one of the major figures of t ...
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 ''The'' () is a grammatical Article (grammar), article in English language, English, denoting persons or things already mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers or speakers. It is the definite art ...
'',
Antonin Artaud Antoine Marie Joseph Paul Artaud, better known as Antonin Artaud (; 4 September 1896 – 4 March 1948), was a French writer, poet, dramatist, visual artist, essayist, actor and theatre director, widely recognized as one of the major figures of t ...
, ''The Theatre and its Double'' Trans. Mary Caroline Richards. (New York: Grove Weidenfeld, 1958).
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 Damien Francis Broderick (born 22 April 1944) is an Australian science fiction and popular science Popular science (also called pop-science or popsci) is an interpretation of science intended for a general audience. While science journalism fo ...
. Widespread adaption of the term "virtual reality" in the popular media is attributed to
Jaron Lanier Jaron Zepel Lanier (, born May 3, 1960) is an American philosophy of computer science, computer philosophy writer, computer scientist, visual artist, and composer of contemporary classical music. Considered a founder of the field of virtual realit ...
, who in the late 1980s designed some of the first business-grade virtual reality hardware under his firm
VPL ResearchVPL Research was one of the first companies that developed and sold virtual reality Virtual reality (VR) is a Simulation, simulated experience that can be similar to or completely different from the real world. Applications of virtual reality i ...
, and the 1992 film '' Lawnmower Man'', which features use of virtual reality systems.

# Forms and methods

One method by which virtual reality can be realized is
simulation A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of models; the model represents the key characteristics or behaviors of the selected system or process, whereas the simulat ...

-based virtual reality. Driving simulators, for example, give the driver on board the impression of actually driving an actual vehicle by predicting vehicular motion caused by driver input and feeding back corresponding visual, motion and audio cues to the driver. With avatar image-based virtual reality, people can join the virtual environment in the form of real video as well as an avatar. One can participate in the 3D distributed virtual environment as form of either a conventional avatar or a real video. Users can select their own type of participation based on the system capability. In projector-based virtual reality, modeling of the real environment plays a vital role in various virtual reality applications, such as robot navigation, construction modeling, and airplane simulation. Image-based virtual reality systems have been gaining popularity in
computer graphics Computer graphics deals with generating images with the aid of computers. Today, computer graphics is a core technology in digital photography, film, video games, cell phone and computer displays, and many specialized applications. A great dea ...

and
computer vision Computer vision is an interdisciplinary scientific field that deals with how computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations automatically. Modern computers can perform ge ...
communities. In generating realistic models, it is essential to accurately register acquired 3D data; usually, a camera is used for modeling small objects at a short distance. Desktop-based virtual reality involves displaying a 3D
virtual world A virtual world (also called a virtual space) is a computer-simulated environment which may be populated by many users who can create a personal avatar An avatar (Sanskrit: अवतार, IAST: ; ), a concept in Hinduism that means "descent ...
on a regular desktop display without use of any specialized VR positional tracking equipment. Many modern first-person video games can be used as an example, using various triggers, responsive characters, and other such interactive devices to make the user feel as though they are in a virtual world. A common criticism of this form of immersion is that there is no sense of
peripheral vision Peripheral vision, or ''indirect vision'', is vision as it occurs outside the point of fixation, i.e. away from the center of gaze or, when viewed at large angles, in (or out of) the "corner of one's eye". The vast majority of the area in the ...

, limiting the user's ability to know what is happening around them. A
head-mounted display A head-mounted display (HMD) is a display device, worn on the head or as part of a helmet (See Helmet-mounted display A helmet-mounted display (HMD) is a device used in aircraft to project information to the pilot's eyes. Its scope is similar to ...
(HMD) more fully immerses the user in a virtual world. A
virtual reality headset A virtual reality headset is a head-mounted device that provides virtual reality for the wearer. Virtual reality (VR) headsets are widely used with video games but they are also used in other applications, including simulators and trainers. The ...
typically includes two small high resolution
OLED An organic light-emitting diode (OLED or organic LED), also known as organic electroluminescent (organic EL) diode, is a light-emitting diode A light-emitting diode (LED) is a semiconductor A semiconductor material has an Electr ...
or
LCD A liquid-crystal display (LCD) is a flat-panel display A flat-panel display (FPD) is an electronic display device s, LED display and Vacuum fluorescent display, VF display, top to bottom. A display device is an output device for presentation ...
monitors which provide separate images for each eye for
stereoscopic Stereoscopy (also called stereoscopics, or stereo imaging) is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis Stereopsis (from the Greek#REDIRECT Greek Greek may refer to: Greece Anything o ...
graphics rendering a 3D virtual world, a binaural audio system, positional and rotational real-time
head tracking Motion capture (sometimes referred as mo-cap or mocap, for short) is the process of recording the motion (physics), movement of objects or people. It is used in Military science, military, entertainment, sports, medical applications, and for vali ...
for six degrees of movement. Options include motion controls with
haptic feedback Haptics may refer to: * Haptics, any form of interaction involving touch ** Haptic communication, the means by which people and other animals communicate via touching ** Haptic perception, the process of recognizing objects through touch ** Haptic ...
for physically interacting within the virtual world in an intuitive way with little to no abstraction and an
omnidirectional treadmill U.S. Army Research Lab's ODT with CAVE Graphics An omnidirectional treadmill (ODT) is a mechanical device, similar to a typical treadmill, that allows a person to perform locomotive motion in any direction, allowing for 360 degrees of movement. ...
for more freedom of physical movement allowing the user to perform locomotive motion in any direction.
Augmented reality Augmented reality (AR) is an interactive experience of a real-world environment where the objects that reside in the real world are enhanced by computer-generated perceptual information, sometimes across multiple sensory modalities, including ...
(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. AR systems layer virtual information over a camera live feed into a headset or
smartglasses Smartglasses or smart glasses are wearable computer A wearable computer, also known as a wearable or body-borne computer, is a computing device worn on the body. The definition of 'wearable computer' may be narrow or broad, extending to smart ...
or through a
mobile device A mobile device (or handheld computer) is a computer A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations automatically. Modern computers can perform generic sets ...
giving the user the ability to view three-dimensional images.
Mixed reality Mixed reality (MR) is the merging of real Real may refer to: * Reality Reality is the sum or aggregate of all that is real or existent within a system, as opposed to that which is only Object of the mind, imaginary. The term is also used to r ...
(MR) is the merging of the real world and virtual worlds to produce new environments and visualizations where physical and digital objects co-exist and interact in real time. A
cyberspace Cyberspace is a concept describing a widespread interconnected digital technology. "The expression dates back from the first decade of the diffusion of the internet. It refers to the online world as a world 'apart', as distinct from everyday rea ...
is sometimes defined as a networked virtual reality.
Simulated reality Simulated reality is the hypothesis A hypothesis (plural hypotheses) is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method The scientific method is an Empirical evidence, emp ...
is a hypothetical virtual reality as truly immersive as the , enabling an advanced
lifelike experience "Lifelike" is an adjective that relates to anything that simulates real life, in accordance with its laws. Its goal is to immerse individuals into what is called a lifelike experience. It gets as close as possible to real life behavior, appearance, ...
or even virtual eternity.

# History

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. The development of perspective in Renaissance Europe created convincing depictions of spaces that did not exist, in what has been referred to as the "multiplying of artificial worlds". Other elements of virtual reality appeared as early as the 1860s. 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 Science fiction (sometimes shortened to sci-fi or SF) is a genre of speculative fiction which typically deals with imagination, imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, Parall ...

.

## 20th century

Morton HeiligMorton Leonard Heilig (December 22, 1926 – May 14, 1997) was a pioneer in Virtual Reality (VR) technology and filmmaker. He applied his cinematographer experience and with the help of his partner developed the Sensorama over several years from 1957 ...
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 The Sensorama was a machine that is one of the earliest known examples of immersive, multi-sensory (now known as multimodal interaction, multimodal) technology. This technology, which was introduced in 1962 by Morton Heilig, is considered as one of ...
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 A machine is a man-made Artificiality (the state of being artificial or man-made) is the state of being the product of intentional human manufacture, rather than occurring naturally through processes not involving or requiring human activity. ...

. 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." In 1968,
Ivan Sutherland Ivan Edward Sutherland (born May 16, 1938) is an American computer scientist A computer scientist is a person A person (plural people or persons) is a being that has certain capacities or attributes such as reason, morality, consciousness o ...
, with the help of his students including
Bob Sproull Robert Fletcher "Bob" Sproull (born c. 1945) is an American computer scientist, who worked for Oracle Corporation where he was director of Oracle Labs in Burlington, Massachusetts, Burlington, Massachusetts. He is currently an adjunct professor a ...
, created what was widely considered to be the first head-mounted display system for use in immersive simulation applications. It was primitive both in terms of
user interface In the industrial design Industrial design is a process of design A design is a plan or specification for the construction of an object or system or for the implementation of an activity or process, or the result of that plan or specificati ...
and visual realism, and the HMD to be worn by the user was so heavy that it had to be suspended from the ceiling. The graphics comprising the virtual environment were simple
wire-frame model A wire-frame model, also wireframe model, is a visual representation of a three-dimensional Three-dimensional space (also: 3-space or, rarely, tri-dimensional space) is a geometric setting in which three values (called parameter A p ...
rooms. The formidable appearance of the device inspired its name, The Sword of Damocles.

### 1970–1990

The virtual reality 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 The National Aeronautics and Space Administration (NASA; ) is an independent agency A regulatory agency or regulatory authority, is a Public benefit corporation Public-benefit corporation is a term that has different meanings in differen ...

's
Jet Propulsion Laboratory The Jet Propulsion Laboratory (JPL) is a federally funded research and development center Federally funded research and development centers (FFRDCs) are public-private partnerships which conduct research and development Research is " cr ...
(JPL) from 1977 to 1984. The
Aspen Movie Map The Aspen Movie Map was a revolutionary hypermedia system developed at MIT by a team working with Andrew Lippman in 1978 with funding from ARPA. Features The Aspen Movie Map enabled the user to take a virtual tour through the city of Aspen, Co ...
, a crude
virtual tour A virtual tour is a simulation of an existing location, usually composed of a sequence of videos or still images. It may also use other multimedia elements such as sound effects, music, narration, and text. It is distinguished from the use of live ...
in which users could wander the streets of
Aspen Aspen is a common name for certain tree species; some, but not all, are classified by botanists in the section (botany), section Populus sect. Populus, ''Populus'', of the ''Populus'' genus. Species These species are called aspens: *''Populus ...
in one of the three modes (summer, winter, and
polygons In geometry Geometry (from the grc, γεωμετρία; ''wikt:γῆ, geo-'' "earth", ''wikt:μέτρον, -metron'' "measurement") is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space t ...
), was created at
MIT Massachusetts Institute of Technology (MIT) is a private land-grant research university A research university is a university A university ( la, universitas, 'a whole') is an educational institution, institution of higher education, hi ...
in 1978. 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 (
field of view The field of view (FoV) is the extent of the observable world that is at any given moment. In the case of s or sensors it is a through which a detector is sensitive to . Humans and animals In the context of human and primate vision, th ...

) in the scene and the corresponding realism. The original LEEP system was redesigned for NASA's
Ames Research Center The Ames Research Center (ARC), also known as NASA Ames, is a major NASA The National Aeronautics and Space Administration (NASA; ) is an independent agencies of the United States government, independent agency of the Federal government o ...
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 modern virtual reality headsets. By the late 1980s, the term "virtual reality" was popularized by
Jaron Lanier Jaron Zepel Lanier (, born May 3, 1960) is an American philosophy of computer science, computer philosophy writer, computer scientist, visual artist, and composer of contemporary classical music. Considered a founder of the field of virtual realit ...
, one of the modern pioneers of the field. Lanier had founded the company
VPL ResearchVPL Research was one of the first companies that developed and sold virtual reality Virtual reality (VR) is a Simulation, simulated experience that can be similar to or completely different from the real world. Applications of virtual reality i ...
in 1985. VPL Research has developed several VR devices like the DataGlove, the EyePhone, and the AudioSphere. VPL licensed the DataGlove technology to
Mattel Mattel, Inc. () is an American multinational corporation, multinational toy manufacturing and entertainment company founded in January, 1945 and headquartered in El Segundo, California. The products and brands it currently produces include Bar ...
, which used it to make the
Power Glove The Power Glove is a controller accessory for the Nintendo Entertainment System. The Power Glove gained public attention due to its early virtual reality mechanics and significant marketing. However, its two games did not sell well, as it was no ...

, an early affordable VR device. Atari, Inc. founded a research lab for virtual reality in 1982, but the lab was closed after two years due to the Atari Shock (
video game crash of 1983 The video game crash of 1983 (known as the Atari shock in Japan , image_flag = Flag of Japan.svg , alt_flag = Centered deep red circle on a white rectangle , image_coat = Imperial S ...
). However, its hired employees, such as Tom Zimmerman, Scott Fisher, Jaron Lanier,
Michael Naimark 150px, Michael Naimark, NYC, Feb 2010 Michael Naimark is an artist, inventor, and scholar in the fields of virtual reality and new media art. He is best known for his work in projection mapping, virtual travel, live global video, and cultural pres ...

, and Brenda Laurel, kept their research and development on VR-related technologies. In 1988, the Cyberspace Project at
Autodesk Autodesk, Inc. is an American multinational Multinational may refer to: * Multinational corporation, a corporate organization operating in multiple countries * Multinational force, a military body from multiple countries * Multinational state, a ...
was the first to implement VR on a low-cost personal computer . The project leader Eric Gullichsen left in 1990 to found Sense8 Corporation and develop the WorldToolKit virtual reality SDK, which offered the first real time graphics with
Texture mapping Texture mapping is a method for defining high frequency detail Detail(s) or The Detail(s) may refer to: Film and television * ''Details'' (film), a 2003 Swedish film * ''The Details'' (film), a 2011 American film * '' The Detail'', a Canadian ...

on a PC, and was widely used throughout industry and academia.

### 1990–2000

The 1990s saw the first widespread commercial releases of consumer headsets. In 1992, for instance, ''
Computer Gaming World ''Computer Gaming World'' (CGW) was an American computer game magazine published between 1981 and 2006. One of the few magazines of the era to survive the video game crash of 1983 The video game crash of 1983 (known as the Atari shock in ...
'' predicted "affordable VR by 1994". In 1991,
Sega is a Japanese multinational Multinational may refer to: * Multinational corporation, a corporate organization operating in multiple countries * Multinational force, a military body from multiple countries * Multinational state, a sovereign ...

announced the
Sega VR The Sega VR is a unreleased virtual reality headset developed by Sega in the early 1990s. Planned as a add-on peripheral for the Sega Genesis and only publicly showcased at a number of trade shows and expositions, its release was postponed and l ...
headset for the
Mega Drive The Sega Genesis, known as the outside North America, is a 16-bit 16-bit microcomputer A microcomputer is a small, relatively inexpensive computer A computer is a machine that can be programmed to carry out sequences of arithmetic ...

home console. It used LCD screens in the visor, stereo headphones, and inertial sensors that allowed the system to
track Track or Tracks may refer to: Routes or imprints * Ancient trackway, any track or trail whose origin is lost in antiquity * Animal track, imprints left on surfaces that an animal walks across * Desire path, a line worn by people taking the shortes ...
and react to the movements of the user's head. In the same year,
Virtuality Virtual reality (VR) is a simulated experience that can be similar to or completely different from the real world. Applications of virtual reality Virtual reality applications are applications that make use of virtual reality Virtual ...
launched and went on to become the first mass-produced, networked, multiplayer VR entertainment system that was released in many countries, including a dedicated VR
arcade Arcade most often refers to: * Arcade (architecture) An arcade is a succession of contiguous arch An arch is a vertical curved structure A structure is an arrangement and organization of interrelated elements in a material object or syst ...
at
Embarcadero Center Embarcadero Center is a commercial complex of five office towers, two hotels, a shopping center with more than 125 stores, bars, and restaurants, two movie theaters, and a fitness center on three levels. There is an outdoor ice skating rink during ...

### Future forecast

In early 2017, a decline was starting for the public interest in Virtual Reality due to the low accessibility for general consumers and major competition with augmented reality titles that people could carry on their phones. Since 2017, major strides in the integration of Virtual Reality and Cognitive Behavioral Therapy have been made, focusing on how to tailor the experience to suit each individual patient. With the COVID-19 pandemic, COVID-19 restrictions in 2020, VR is experiencing an enormous rise. According to Grand View Research, the global VR market will grow to 62.1 billion dollars in 2027. Over the past 5 years, the popularity of Virtual reality technologies has been on a steady increase, and is striving as a new technology.

# Technology

## Software

The VRML, 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 software, open-source standard for web-based distribution of VR content. WebVR is an experimental JavaScript application programming interface (API) that provides support for various virtual reality devices, such as the HTC Vive, Oculus Rift, Google Cardboard or OSVR, in a web browser.

## Hardware

Modern virtual reality headset displays are based on technology developed for smartphones including: gyroscopes and motion sensors for tracking head, body, and hand tracking, hand positions; small High-definition video, HD screens for stereoscopic displays; and small, lightweight and fast computer 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 alongside the development of affordable omnidirectional cameras, also known as 360-degree cameras or VR cameras, that have the ability to record 360 interactive photography, although at relatively 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. To create a feeling of immersion, special output devices are needed to display virtual worlds. Well-known formats include head-mounted displays or the CAVE. In order to convey a spatial impression, two images are generated and displayed from different perspectives (stereo projection). There are different technologies available to bring the respective image to the right eye. A distinction is made between active (e.g. Active shutter 3D system, shutter glasses) and passive technologies (e.g. Polarizer, polarizing filters or Infitec). In order to improve the feeling of immersion, wearable multi-string cables offer haptics to complex geometries in virtual reality. These strings offer fine control of each finger joint to simulate the haptics involved in touching these virtual geometries. Special input devices are required for interaction with the virtual world. These include the 3d mouse, 3D mouse, the wired glove, motion controllers, and Optical tracking instruments, optical tracking sensors. Controllers typically use optical tracking systems (primarily infrared cameras) for location and navigation, so that the user can move freely without wiring. Some input devices provide the user with Haptic technology, force feedback to the hands or other parts of the body, so that the human being can orientate himself in the three-dimensional world through haptics and sensor technology as a further sensory sensation and carry out realistic simulations. This allows for the viewer to have a sense of direction in the artificial landscape. Additional haptic feedback can be obtained from
omnidirectional treadmill U.S. Army Research Lab's ODT with CAVE Graphics An omnidirectional treadmill (ODT) is a mechanical device, similar to a typical treadmill, that allows a person to perform locomotive motion in any direction, allowing for 360 degrees of movement. ...
s (with which walking in virtual space is controlled by real walking movements) and vibration gloves and suits. Virtual reality cameras can be used to create VR photography using 360-degree video, 360-degree panorama videos. 360-degree camera shots can be mixed with virtual elements to merge reality and fiction through special effects. VR cameras are available in various formats, with varying numbers of lenses installed in the camera.

# Visual immersion experience

## Display resolution

Minimal Angle of Resolution (MAR) refers to the minimum distance between two display pixels. At the distance, viewer can clearly distinguish the independent pixels. Often measured in arc-seconds, MAR between two pixels has to do with the viewing distance. For the general public, resolution is about 30-65 arc-seconds, which is referred to as the spatial resolution when combined with distance. Let’s look at the actual numbers. Given the viewing distance of 1m and 2m respectively, regular viewers won’t be able to perceive two pixels as separate if they are less than 0.29mm apart at 1m and less than 0.58mm apart at 2m.

## Image latency and display refresh frequency

Most small-size displays have a refresh rate of 60Hz, which will add about 15ms of additional latency. The number is reduced to less than 7ms with if the refresh rate is increased to 120Hz or even 240Hz and more. Participants will feel a lot more immersive as a result although higher refresh rates require graphics processing unit (GPU) powerful enough to process more frames per second (fps).

## Relationship between display and field of view

We need to consider our field of view (FOV) in addition to quality image. Our eyes have a horizontal FOV of about 120 degrees per side and a vertical FOV of some 135 degrees. Stereopsis vision is limited to 120 degrees where the right and the left visions overlap. Generally speaking, we have a FOV of 200 degrees x 135 degrees with two eyes. However, most of it is peripheral vision, which varies from one person to another. So we conservatively take the average, i.e. 160 degrees. Therefore, if we keep our eyes stationary, a regular participant will have at least a stereopsis of 160 degrees x 135 degrees or 1/6 of the 360-degree FOV. We can quantify the abstract concept of immersion with the immersive index by getting the ratio of display viewing area and 1/6 of the 360-degree FOV. $\frac=\mbox$

# Applications

Virtual reality is most commonly used in entertainment applications such as
video game#REDIRECT Video game A video game is an electronic game that involves interaction with a user interface or input device such as a joystick, game controller, controller, computer keyboard, keyboard, or motion sensing device to generate visual f ...
s, 3D cinema, and Virtual world#Social, social virtual worlds. Consumer virtual reality headsets were first released by video game companies in the early-mid 1990s. Beginning in the 2010s, 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, roller coasters and theme parks have incorporated virtual reality to match visual effects with haptic feedback. 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 (Posttraumatic stress disorder, PTSD) and phobias. Virtual reality programs are being used in the rehabilitation processes with elderly individuals that have been diagnosed with Alzheimer's disease. This gives these elderly patients the opportunity to simulate real experiences that they would not otherwise be able to experience due to their current state. 17 recent studies with randomized controlled trials have shown that virtual reality applications are effective in treating cognitive deficits with neurological diagnoses. Loss of mobility in elderly patients can lead to a sense of loneliness and depression. Virtual reality is able to assist in making aging in place a lifeline to an outside world that they cannot easily navigate. Virtual reality allows exposure therapy to take place in a safe environment. In medicine, simulated VR surgical environments were first developed in the 1990s. Under the supervision of experts, VR can 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 physical rehabilitation since the 2000s. 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. Another study was conducted that showed the potential for VR to promote mimicry and revealed the difference between neurotypical and Autism spectrum, autism spectrum disorder individuals in their response to a two-dimensional avatar. Immersive virtual reality technology with myoelectric and motion tracking control may represent a possible therapy option for treatment-resistant phantom limb pain. Pain scale measurements were taken into account and an interactive 3-D kitchen environment was developed bases on the principles of mirror therapy to allow for control of virtual hands while wearing a motion-tracked VR headset. A systematic search in Pubmed and Embase was performed to determine results that were pooled in two meta-analysis. Meta-analysis showed a significant result in favor of VRT for balance. In the fast-paced and globalised business world meetings in VR are used to create an environment in which interactions with other people (e.g. colleagues, customers, partners) can feel more natural than a phone call or video chat. In the customisable meeting rooms all parties can join using the VR headset and interact as if they are in the same physical room. Presentations, videos or 3D models (of e.g. products or prototypes) can be uploaded and interacted with. 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 Virtual reality in primary education, in primary education, anatomy teaching, military, astronaut training, flight simulators, miner training, medical education, architectural design, driver training and bridge inspection. Immersive VR engineering systems enable engineers to see virtual prototypes prior to the availability of any physical prototypes. Supplementing training with virtual training environments has been claimed to offer avenues of realism in militaryShufelt, Jr., J.W. (2006) A Vision for Future Virtual Training. In Virtual Media for Military Applications (pp. KN2-1 – KN2-12). Meeting Proceedings RTO-MP-HFM-136, Keynote 2. Neuilly-sur-Seine, France: RTO. Available from: http://www.rto.nato.int/abstracts.asp 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. VR can also be used for the healthcare training and education for medical practitioners. In the engineering field, VR has proved very useful for both engineering educators and the students. A previously expensive cost in the educational department now being much more accessible due to lowered overall costs, has proven to be a very useful tool in educating future engineers. The most significant element lies in the ability for the students to be able to interact with 3-D models that accurately respond based on real world possibilities. This added tool of education provides many the immersion needed to grasp complex topics and be able to apply them. As noted, the future architects and engineers benefit greatly by being able to form understandings between spatial relationships and providing solutions based on real-world future applications. 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. 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. However, a 2018 study revealed that the majority of goods are still purchased in physical stores. In the case of education, the uses of virtual reality have demonstrated being capable of promoting higher order thinking, promoting the interest and commitment of students, the acquisition of knowledge, promoting mental habits and understanding that are generally useful within an academic context. A case has also been made for including virtual reality technology in the context of public libraries. This would give library users access to cutting-edge technology and unique educational experiences. This could include giving users access to virtual, interactive copies of rare texts and artifacts and to tours of famous landmarks and archeological digs (as in the case with the Virtual Ganjali Khan Project).

# Concerns and challenges

## Health and safety

There are many health and safety considerations of virtual reality. A number of unwanted symptoms have been caused by prolonged use of virtual reality, and these may have slowed proliferation of the technology. 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. One in 4,000 people, or .025%, may experience these symptoms. Since these symptoms are more common among people under the age of 20, children are advised against 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. VR headsets may regularly cause eye fatigue, as does all screened technology, because people tend to blink less when watching screens, causing their eyes to become more dried out. There have been some concerns about VR headsets contributing to myopia, but although VR headsets sit close to the eyes, they may not necessarily contribute to nearsightedness if the focal length of the image being displayed is sufficiently far away. 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. Women are significantly more affected than men by headset-induced symptoms, at rates of around 77% and 33% respectively. The most common symptoms are general discomfort, headache, stomach awareness, nausea, vomiting, pallor, sweating, fatigue, drowsiness, disorientation, and apathy. For example, Nintendo's Virtual Boy received much criticism for its negative physical effects, including "dizziness, nausea, and headaches". These motion sickness symptoms are caused by a disconnect between what is being seen and what the rest of the body perceives. When the vestibular system, the body's internal balancing system, does not experience the motion that it expects from visual input through the eyes, the user may experience VR sickness. This can also happen if the VR system does not have a high enough frame rate, or if there is a lag between the body's movement and the onscreen visual reaction to it. Because approximately 25–40% of people experience some kind of VR sickness when using VR machines, companies are actively looking for ways to reduce VR sickness.

## Children in virtual reality

The relationship between virtual reality and its underage users is controversial and unexplored. In the meantime, children are becoming increasingly aware of VR, with the number in the USA having never heard of it dropping by half from Autumn 2016 (40%) to Spring 2017 (19%). Valeriy Kondruk, CEO of VR travel platform Ascape, says the app downloads in March 2020 increased by 60% compared to December 2019 and doubled in comparison with January 2020. According to Kondruk, normally, the busiest month for VR companies is December, which is associated with winter holidays and people spending more time at home. In early 2016, virtual reality headsets became commercially available with offers from, for example, Facebook (Oculus), HTC and Valve (Vive) Microsoft (HoloLens), and Sony (Morpheus). At the time and to this day, these brands have different age instructions for users, e.g. 12+ or 14+, this indicates a completely self-regulatory policy. Studies show that young children, compared to adults, may respond cognitively and behaviorally to immersive VR in ways that differ from adults. VR places users directly into the media content, potentially making the experience very vivid and real for children. For example, children of 6–18 years of age reported higher levels of presence and "realness" of a virtual environment compared with adults 19–65 years of age. Studies on VR consumer behavior or its effect on children and a code of ethical conduct involving underage users are especially needed, given the availability of VR porn and violent content. Related research on violence in video games suggests that exposure to media violence may affect attitudes, behavior, and even self-concept. Self-concept is a key indicator of core attitudes and coping abilities, particularly in adolescents. Early studies conducted on observing versus participating in violent VR games suggest that physiological arousal and aggressive thoughts, but not hostile feelings, are higher for participants than for observers of the virtual reality game. Experiencing VR by children may further involve simultaneously holding the idea of the virtual world in mind while experiencing the physical world. Excessive usage of immersive technology that has very salient sensory features may compromise children's ability to maintain the rules of the physical world, particularly when wearing a VR headset that blocks out the location of objects in the physical world. Immersive VR can provide users with multisensory experiences that replicate reality or create scenarios that are impossible or dangerous in the physical world. Observations of 10 children experiencing VR for the first time suggested that 8-12-years-old kids were more confident to explore VR content when it was in a familiar situation, e.g. the children enjoyed playing in the kitchen context of Job Simulator, and enjoyed breaking rules by engaging in activities they are not allowed to do in reality, such as setting things on fire.

## 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. Data from eye tracking sensors, which are projected to become a standard feature in virtual reality headsets, may indirectly reveal information about a user's ethnicity, personality traits, fears, emotions, interests, skills, and physical and mental health condition.

## 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

* 16K resolution * 360-degree video * AlloSphere * Computer-mediated reality * Diorama * Extended reality * Haptic suit * Holographic universe * Hyperreality *
Mixed reality Mixed reality (MR) is the merging of real Real may refer to: * Reality Reality is the sum or aggregate of all that is real or existent within a system, as opposed to that which is only Object of the mind, imaginary. The term is also used to r ...
* Virtual body * Virtual globe * Virtual machining * Metaverse * Virtual taste * Comparison of virtual reality headsets

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# External links

* Basic Concepts of Virtual Reality along with Research Challenges explained in simple words. * commons:File:Mixed Reality Scale.png, Mixed Reality Scale – Milgram and Kishino's (1994) Virtuality Continuum paraphrase with examples. * Interviews on the history and future of virtual reality by leaders in the field. * {{Authority control Virtual reality,