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VR（Virtual Reality）
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Virtual reality (VR) is a technology that allows users to interact with computer simulation environment, whether it is real or imaginary. Most current virtual reality environments are mainly visual experiences, which are displayed on computer screens or through special or stereoscopic displays, but some simulations include additional sensory information, such as sound through speakers or headphones. In medical and gaming applications, some advanced tactile systems now include tactile information, which is usually called force feedback. Users can interact with the virtual environment or virtual object (VA) by using standard input devices such as keyboard and mouse, or through multi-mode devices such as wired gloves, Polhemus boom arm and omni-directional treadmill. The simulation environment can be similar to the real world, for example, the simulation of pilots or combat training, or it can be very different from reality, such as in VR games. In practice, it is difficult to create high-fidelity virtual reality experience at present, which is mainly due to technical limitations in processing capacity, image resolution and communication bandwidth. However, over time, as processors, imaging and data communication technologies become more powerful and cost-effective, these limitations are expected to be finally overcome.
Virtual reality is usually used to describe various applications, and is usually associated with its immersive and highly visualized 3D environment. The development of CAD software, graphics hardware acceleration, head-mounted display, database gloves and miniaturization has helped popularize this concept. In The Metaphysics of Virtual Reality, Michael Heim defined seven different concepts of virtual reality: simulation, interaction, artificiality, immersion, telepresence, total immersion and network communication. This definition still has some futuristic romance. People often associate virtual reality with head-mounted displays, data packages and Steven King's The Grass Cutter.
term
The term artificial reality was coined by Miron Kruger and has been used since1970s, but the origin of the term virtual reality is uncertain. It is attributed to Damien Broderick's science fiction Judas mandala (1982), in which the context used is somewhat different from the above definition. The earliest use of the Oxford English Dictionary is in an article entitled "Virtual Reality" 1987 art icle, but the article is not about VR technology. Jaron lanier, a developer of virtual reality, claimed that he coined the term. The concept of virtual reality is popularized in the mass media through movies, such as Brainstorm and Grass Cutter (and other movies mentioned below). The upsurge of virtual reality research in 1990' s was partly promoted by Howard Rheingold's nonfiction book Virtual Reality. This book has played a role in restraining this theme, making it easier to be understood by researchers and enthusiasts who don't know much about technology, and its influence is similar to that of his book "Virtual Community" on virtual community research closely related to virtual reality. Multimedia: from Wagner t o virtual reality, edited by Randall Packer and Ken Jordan, first published in 200 1, explores the term and its history from an avant-garde perspective.
timetable
Morton Heyliger wrote in 1950s that an "experience theater" can contain all the senses in an effective way, thus attracting the audience to the activities on the screen. He built a visual prototype called Sensorama in 1962, and five short films will be displayed in it, using multiple senses (vision, hearing, smell and touch) at the same time. Before digital computing, Sensorama was a mechanical device, and it is reported that it is still in use today. In 1968, with the help of his student Bob proll, ivan sutherland created what is widely regarded as the first HMD system of virtual reality and augmented reality (AR). It is primitive in terms of user interface and authenticity. The HMD worn by users is so heavy that it must be hung from the ceiling. The graphics that make up the virtual environment are simple wireframe model rooms. The formidable appearance of this device inspired its name, the sword of Damocles. In the early hypermedia and virtual reality systems, it is also worth noting that Aspen movie map was created by MIT in 1977. The program is a rough virtual simulation of Aspen, Colorado, where users can walk the streets in one of three modes: summer, winter and polygon. The first two are based on photos-the researchers actually photographed every possible movement in the city street grid in two seasons-and the third is the basic three-dimensional model of the city. In the late 1980s, the term "virtual reality" was popularized by jaron lanier, one of the modern pioneers in this field. In 1985, Ranier founded VPL research company (from "virtual programming language"), which developed and established some groundbreaking "goggles n' gloves" systems in that decade.
future
It is not clear where the future of virtual reality will go. In the short term, the images displayed by HMD will soon reach a level close to reality. Audio capability will enter a new field of three-dimensional sound. This refers to the method of adding sound channels or holograms to individuals. .....