|Virtual reality, VR, is artificial reality, e-reality, a computer model of reality (from Lat. Virtus - potential, possible and Lat. Realis – actual, existing; Eng. Virtual reality, VR) – a world, created by technical means (objects and subjects), transmitted to a person (a guest of this world) through his senses: sight, hearing, smell and others. Virtual reality simulates both the action as well as the reaction to the action. To create a convincing sense of reality, the computer synthesis of properties and reactions of virtual reality is done in real time.
Usually, virtual reality objects behave identicaly to the behavior of similar objects of physical reality. The user can act on these objects in accordance with the actual laws of physics (gravitation, properties of water, collision with objects, reflection, etc.). However, often for entertainment purposes, the users of virtual worlds are allowed more than what is possible in real life (eg, the can fly, create any objects they wish, etc.).
Do not confuse virtual reality with augmented virtual reality. Their main difference lies in the fact that virtual reality constructs a new artificial world and augmented reality only makes some artificial elements in the perception of the real world.
Devices, which more completely, when compared to usual computer systems, simulate the action with the virtual medium by acting on all the five senses of the body are called "virtual reality".
The fat monitor can provide less of a stereo effect due to the varied speed of the image parts. The full stereo effect is ensured by providing pictures for each eye. The image can be formed by a color-shift monitor (anaglyph), or alternately displaying their images to each eye. LCD monitor’s are available, which form three-dimensional images due to the different angle of view.
The wide angle of view and a change in direction of the view along with the rotation of the head, in such a way that the image is in front of the eyes, which is ensured by a virtual reality headset with built-in gyroscopes, are necessary for the individuals immersion into a virtual world. The virtual retinal monitor is also used.
Presently, projection systems, made in virtual reality rooms (CAVE), are the most advanced virtual reality systems. Such a system is a room with walls having 3D stereo projection. The position of the users head rotations are tracked by tracking systems, which allows it to achieve the maximum immersion effect. Given systems are widely used in marketing, military, scientific and other purposes.
Multi-channel speaker systems allows to localize the source of sound, that allows the user to navigate in a virtual world with the help of audio.
Simulation of tactile sensations:
The simulation of tactile sensations has already found its use in virtual reality systems. These are so called feedback devices. Feedback devices are used for solving virtual prototyping and ergonomic design issues, the creation of various simulators and medical trainers and remote-operated robots including micro and nano systems for the creation of virtual sculptures.
With an aim to most accurately recreate the user's contact with the environment, user interfaces are used, which most realistically correspond to the model: a computer steering wheel with pedals, device-control handles, target designator in the form of a gun etc.
For contact-free control of objects, virtual reality gloves are used and the tracking of hand movements, accomplished with the help of video cameras. The movement of the hands is usually realized in a small area and does not require any additional equipment.
Virtual reality gloves can be part of a virtual reality costume, which tracks the changes in position of the entire body and also transmitting the tactile, temperature and vibration sensations.
The device for tracking the user's movements can be a free rotating ball, in which the user is placed by suspending the virtual reality costume in air or immersing it in liquid. Technical facilities are also developed for simulating odors .
Direct connection with the nervous system:
The above described devices act on the human sense organs but the information can be transmitted directly to nerve endings and also directly to the brain through brain interfaces. Similar technology is used in medicine to replace the lost sensory abilities but still, it is too expensive for daily use and does not attain the quality of transmitted information received for virtual reality transmission.
Virtual reality is used for occupational training, where the operation of real devices and mechanisms are associated with increased risk or high expenditures (the pilot of an aircraft, train operator, controller, driver etc).
The concept of artificial reality was first introduced by Myron Krueger in the late 1960s. In 1964, Stanislaw Lem, in his book "The sum of Technology", used the term "Phantomology" to describe the problem and essence of the answer to the question "How to create reality, which for wise creatures, living in it, did not differ from normal reality, but complies to other laws?". In 1989, Jaron Lanier introduced the more popular "virtual reality" term. In fantasy literature, the cyberpunk subgenre "virtual reality" is a way of communication between people within "cyberspace" – a certain medium of interaction of people and machines, created in computer networks.
The first virtual reality system was "Aspen Movie Map”, developed at MIT in 1977. This computer program simulated a walk around the city Aspen, Colorado, making it possible to choose different ways of displaying the locality. Summer and winter versions were based on real photographs.|