What is Virtual Reality?

Virtual reality technology (English name: Virtual Reality, abbreviated as VR), also known as spiritual realm technology, is a brand-new practical technology developed in the 20th century. Virtual reality technology includes computers, electronic information, and simulation technology. Its basic implementation is to simulate the virtual environment with a computer to give people a sense of environmental immersion. With the continuous development of social productivity and science and technology, the demand for VR technology in various industries is increasing. VR technology has also made great progress and has gradually become a new field of science and technology. ^[1]

Chinese name: Virtual reality, spirituality technology
Foreign name: Virtual Reality
Short name: VR

Meaning: Virtual and Reality Combine
Features: Immersive, interactive, etc.
Application: Film and television entertainment, education, medicine, etc.

Introduction to Virtual Reality

The so-called virtual reality, as its name implies, is the combination of virtual and reality. In theory, virtual reality technology (VR) is a computer simulation system that can create and experience a virtual world. It uses a computer to generate a simulation environment to immerse users in the environment. Virtual reality technology is the use of real-life data, electronic signals generated by computer technology, and combining it with various output devices to transform them into phenomena that people can feel. These phenomena can be real objects It can also be a material that we can't see with the naked eye, and it is expressed through a three-dimensional model. Because these phenomena are not what we can see directly, but the real world simulated by computer technology, they are called virtual reality. ^[2]

Virtual reality technology has been recognized by more and more people. Users can experience the most realistic feelings in the virtual reality world. The authenticity of its simulated environment and the real world are difficult to distinguish between true and false, giving people a sense of immersion At the same time, virtual reality has all human perception functions, such as hearing, vision, touch, taste, smell and other perception systems; Finally, it has a super simulation system that truly realizes human-computer interaction and enables people to operate in the process You can freely operate and get the most realistic feedback from the environment. It is the existence, multi-perception, and interactivity of virtual reality technology that has made it popular with many people. ^[2]

History of virtual reality development

1. The first stage (before 1963) the simulation of vocal dynamics is the stage that contains the idea of virtual reality

In 1929, Edward Link designed a simulator for training pilots; in 1956, Morton Heilig developed the multi-channel simulation experience system Sensorama. ^[3]

2. The second stage (1963-1972), the budding stage of virtual reality

In 1965, Ivan Sutherland published the paper "UltimateDisplay"; in 1968, Ivan Sutherland successfully developed a helmet-mounted stereo display (HMD) with a tracker; in 1972, NolanBushell developed the first interactive video game Pong . ^[3]

3. The third stage (1973-1989) the stage of the emergence and preliminary formation of the concept of virtual reality

In 1977, Dan Sandin and others developed the data glove SayreGlove; in 1984, the NASA AMES Research Center developed a virtual environment visual display for Mars exploration; in 1984, Jaron Lanier of VPL proposed the concept of "virtual reality" for the first time; in 1987, Jim Humphries designed the earliest prototype of the Binocular Omnidirectional Monitor (BOOM). ^[3]

4. The fourth stage (1990 to present) is the stage of further improvement and application of virtual reality theory.

In 1990, VR technology was proposed including 3D graphics generation technology, multi-sensor interaction technology and high-resolution display technology; VPL developed the first set of sensing gloves "DataGloves" and the first set of HMD "EyePhoncs"; since the 21st century, VR The technology is developing at a high speed, and the software development system is constantly being improved. Typical examples include MultiGen Vega, Open Scene Graph, and Virtools. ^[3]

Virtual reality classification

VR involves many disciplines, a wide range of applications, and a variety of systems. This is determined by its research objects, research goals, and application requirements. From different perspectives, different classifications can be made for VR systems. ^[4]

1.Classification based on immersive experience perspective

Immersive experiences are divided into non-interactive experiences, human-virtual environment interactive experiences, and group-virtual environment interactive experiences. The angle

Virtual Reality Emphasize the interactive experience between the user and the device. In contrast, the users in the non-interactive experience are more passive, and the experienced content is planned in advance. Even if the user is allowed to guide the scheduling of scene data to a certain extent, there is still no Substantial interactive behaviors, such as scene roaming, etc., the user has almost nothing to do; in the human-virtual environment interactive experience system, the user can interact with the virtual environment using equipment such as data gloves, digital scalpels, etc. , Such as driving a fighter simulator, at this time, the user can perceive the change of the virtual environment, and then can also produce various feelings that may occur in the corresponding real world. ^[4]

If the system is networked and multi-machined, so that multiple users share a set of virtual environments, a group-virtual environment interactive experience system, such as a large-scale network interactive game, is obtained. At this time, the VR system is not much like the real world. difference. ^[4]

2.Classify according to system function angle

The system functions are divided into several categories such as planning and design, display entertainment, training exercises and so on. The planning and design system can be used for the experimental verification of new facilities, which can greatly reduce the research and development time, reduce the design cost, improve the design efficiency, and can be used in urban drainage and community planning. For example, VR simulation water supply and drainage system can greatly reduce the original needs for Funds for experimental verification; display and entertainment systems are suitable for providing users with realistic viewing experiences, such as digital museums, large-scale 3D interactive games, film and television production, etc. VR technology was used by Disney for special effects movies as early as the 1970s; training The drill system can be applied to various dangerous environments and some areas where it is difficult to obtain the operation object or the actual operation cost is very high, such as surgical training, space station maintenance training, and so on. ^[4]

Virtual reality features

1.Immersive

Immersiveness is the most important feature of virtual reality technology, which allows users to become and feel that they are part of the environment created by computer systems. The immersiveness of virtual reality technology depends on the user's perception system. When users perceive the virtual world, When stimulating, including touch, taste, smell, and motion perception, they will resonate with the mind, cause psychological immersion, and feel like entering the real world. ^[5]

Interactivity

Interactivity refers to the degree to which the user can manipulate the objects in the simulated environment and the natural degree of feedback from the environment. The user enters the virtual space. The corresponding technology allows the user to interact with the environment. When the user performs certain operations, The surrounding environment will also react in some way. If the user touches the object in the virtual space, then the user should be able to feel it. If the user moves the object, the position and state of the object should also be changed. ^[5]

Multi-perception

Multi-perception means that computer technology should have many perceptual methods, such as hearing, touch, smell and so on. The ideal virtual reality technology should have the perceptual functions of all people. Due to the limitations of related technologies, especially sensing technologies, the sensing functions of most virtual reality technologies are currently limited to vision, hearing, touch, and motion. ^[5]

4.Conceptuality

Imagination is also called imagination. In the virtual space, users can interact with surrounding objects, which can widen the scope of cognition and create scenarios where the objective world does not exist or environments that cannot occur. The concept can be understood as the user entering the virtual space, absorbing knowledge according to his own feelings and cognitive abilities, diverging and broadening his thinking, and creating new concepts and environments. ^[5]

5.Autonomy

It refers to the degree to which objects in the virtual environment move according to the laws of physics. For example, when pushed by a force, the object will move in the direction of the force, or fall, or fall from the table to the ground. ^[5]

Key technologies of virtual reality

The key technologies of virtual reality include:

1.Dynamic environment modeling technology

The establishment of the virtual environment is the core content of the VR system, the purpose is to obtain the three-dimensional data of the actual environment, and establish the corresponding virtual environment model according to the needs of the application. ^[6]

2.Real-time 3D graphics generation technology

3D graphics generation technology is relatively mature, so the key is "real-time" generation. In order to ensure real-time, at least the refresh rate of the graphics is not lower than 15 frames / second, and preferably higher than 30 frames / second. ^[6]

3.Stereo display and sensor technology

The interactive capability of virtual reality depends on the development of stereoscopic display and sensor technology. The existing equipment cannot meet the needs. The research on mechanics and tactile sensing devices needs to be further deepened. The tracking accuracy and tracking range of virtual reality equipment also need to be improved. ^[6]

4. Application system development tools

The key to the application of virtual reality is to find suitable occasions and objects. Selecting appropriate application objects can greatly improve production efficiency, reduce labor intensity, and improve product quality. To achieve this, you need to study virtual reality development tools. ^[6]

5. System integration technology

Because VR systems include a large amount of perceptual information and models, system integration technology plays a vital role. Integration technologies include information synchronization technology, model calibration technology, data conversion technology, data management model, identification and synthesis technology, etc. . ^[6]

Application of virtual reality technology

1. Application in film and television entertainment

In recent years, due to the widespread application of virtual reality technology in the film and television industry, the first on-site 9DVR experience hall built on the basis of virtual reality technology has been implemented.

Virtual Reality Now. Since the completion of the first on-site 9DVR experience hall, it has had a great influence in the film and television entertainment market. This experience hall allows viewers to experience the feeling of being in a real scene and immerse the viewer in the virtuality created by the film Environment. At the same time, with the continuous innovation of virtual reality technology, this technology has also developed rapidly in the field of games. Virtual reality technology is the use of computer-generated three-dimensional virtual space, and three-dimensional games are built on this technology. Three-dimensional games contain almost all the technologies of virtual reality, which makes the game greatly Improved the realism of the game. ^[2]

2. Application in education

Nowadays, virtual reality technology has become a new educational method to promote the development of education. Traditional education just blindly instills knowledge to students, and now using virtual reality technology can help students create a vivid and realistic learning environment, so that students can enhance memory through real feelings, compared to passive indoctrination, using virtual reality technology Autonomous learning is easier for students to accept, and this way is more likely to stimulate students' interest in learning. In addition, universities and colleges have used virtual reality technology to establish subject-related virtual laboratories to help students learn better. ^[2]

3. Application in the design field

Virtual reality technology has little success in the field of design. For example, interior design, people can use virtual reality technology to show the interior structure and the shape of the house through virtual technology, so that it can be seen objects and the environment. At the same time, in the early stage of design, designers can simulate their ideas through virtual reality technology, and can see the actual effect of the room in the virtual environment in advance, which saves time and reduces costs. ^[2]

4. Application of virtual reality in medicine

Medical experts use computers to simulate human tissues and organs in a virtual space, allowing students to perform simulation operations in them, and allow students to feel the feeling of a scalpel cutting into human muscle tissue and touching bones, enabling students to be faster Master the essentials of surgery. In addition, the surgeon doctors can also create a virtual model of the patient's body before the operation, and perform a surgical preview in the virtual space, which can greatly improve the success rate of the operation and allow more patients to recover. ^[7]

5.Application of virtual reality in military

Due to the three-dimensional and real sense of virtual reality, in the military field, people compile data such as mountains and rivers on the map, oceans and lakes through computers, and use virtual reality technology to turn the original flat map into a three-dimensional three-dimensional terrain Map, and then project it through holographic technology, which is more conducive to training such as military exercises and improve China's comprehensive national strength. ^[7]

In addition, the current war is information-based war, and war machines are developing in the direction of automation. UAVs are the most typical products of information-based wars. Drones are popular in various countries because of their automation and convenience. During the training of soldiers, virtual reality technology can be used to simulate the flight, shooting and other working modes of drones. During the war, soldiers can also use drones such as glasses and helmets to conduct reconnaissance and assassination missions, reducing the casualties of soldiers during the war. Since the virtual reality technology can three-dimensionalize the scene captured by the drone, reducing the difficulty of operation and improving the efficiency of investigation, the development of drones and virtual reality technology is urgent. ^[7]

6. Application of virtual reality in aerospace

Because aerospace is a very expensive and tedious project, people use virtual reality technology and statistical simulation of computers to reproduce the space shuttle and flight environment in the virtual space, so that pilots can perform in the virtual space. Flight training and experimental operations have greatly reduced experimental funding and experimental risk factors. ^[7]

Limitations of virtual reality development

Even though VR technology has a bright future, as a rapidly developing technology, its own problems gradually emerge, such as the problem of product return stability and user visual experience. For VR companies, how to break through the current bottleneck of VR development and make VR technology mainstream is still an issue they need to solve. ^[8]

First of all, the use of VR devices by some users will cause dizziness, vomiting and other discomfort, which also causes the problem of poor experience. Part of the reason is the lack of sharpness, and part of the reason is that the refresh rate cannot meet the requirements. According to research, a resolution of more than 14k can basically make the brain agree, but at present, the VR devices used in China are far less than the requirements of the brain. Consumer discomfort may cause their concerns about whether VR technology will harm their own health, which will definitely affect the future development and popularization of VR technology. ^[8]

The high price of VR experience is also one of the reasons that restricts its expansion. In the domestic market, VR glasses generally cost more than 3,000 yuan. Of course, this is not a problem that can be solved in a short time. If users want to experience high-end visual enjoyment, they must pay high prices for their higher-end computers inside. If virtual reality technology is to be promoted, it is critical to ensure the stability of its content output and return. The production cost and experience of the content involved determine the extent to which consumers accept VR devices, and the return on this high-cost content is difficult to predict. The creation of VR original content will undoubtedly increase the difficulty. ^[8]