Virtual Reality

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ARCHITECTURE

A VR device is formed by a computer and specialized design software is in charge of creating the illusion of the virtual reality. The computer and the software obtain the necessary information to emit the appropriate reactions. The so-called virtual machine is the core of the computer system. The computer is responsible for controlling and managing the tasks of creating the virtual world (data entry, output and generation, operation and adminis- tration of virtual worlds). In addition, the computer must convert its digital model of a world into the appropriate pattern of points of light, viewed from the appropriate perspective and including audible waves, mixed in the most appropriate way.

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As virtual elements, glasses, gloves or specially designed headsets are usually used with movement sensors, microchips and liquid crystal displays for each eye that allow the images of synthesis to vary in perfect synchronization with our movements. [3] 

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CONTENT REPRESENTATION

The virtual world consists of polygons that are the basic build- ing blocks of computer graphics. The polygons formed in ”nets” serve to represent objects and scenes. The greater number of polygons in the description of an object or scenario, the higher the quality we perceive. On the other hand, the higher the number of polygons, the higher processing speed is required to present the image in real time. Viewing real world images represents a re- quirement of between 80 and 100 million polygons per second, while in a current ”reality machine”, you can at most produce be- tween 7,000 and 10,000 polygons per second. Nevertheless the human being has a very adaptable capacity of perception. In the case of Virtual Reality, we should:

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• Have three-dimension

• Synchronize the changes in perspective caused by the users

movements

• Treat the image through shadows and special effects.

• Have additional information about sound, touch and strength. 

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NETWORK STREAMING

Regarding the transmission of signals, virtual reality headsets have higher requirements for time delays than other simulators. If the system is too slow to react to movement, it can cause the user to feel virtual reality sickness, a kind of motion sickness. It is said that the ideal total delay would be between 7 and 15 milliseconds. An important component of this is the refresh rate, which should be at least 90Hz. The graphics processing unit (GPU) also needs to be more powerful for processing frames more frequently. [4] 

 

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VISUALIZATION

Headset lenses are responsible for the display of the screen. They have to map the screen to a wide field of view, while providing a distant focus point more comfortable. Humans have a binocu- lar view of about 180◦. However, it is enough to give the users a field of view of 100◦ to make them feel immersed. One challenge related to the visualization is to provide consistency of approach: because the eyes are free to rotate within the handset, it is impor- tant to avoid having to refocus to avoid eye fatigue. The lens in- troduces chromatic distortion, which is corrected in software. [4] 

Technology