Technology has moved us into a world where wandering in the fairyland can be made possible. Adventurous people are enjoying roller coaster between two high rise buildings and getting goosebumps because of Virtual Reality.
Virtual Reality is an Artificial Environment that is created using Computer Graphics and then presented to the user in such a way that the user believes it to be a Real Environment.
The simplest form of Virtual Reality is a 3D picture that can be viewed interactively at a personal computer(PC), usually by manipulating keys of keyboard or the mouse so that the content of the picture moves in some direction or zooms in or out.
The user is made to believe that he is entirely in the new world which response to his actions. The illusion is created with the help of headsets, special gloves and omnidirectional treadmills. The gets immersed in the non-physical environment mentally or physically and made to believe to be present in the virtual environment partially or fully.
The user is immersed partially or fully on the basis of a few parameters like the field of view, frame rate, latency, audio, and tracking etc. Field of view is the width of the picture the user sees. The high-end headsets provide 100 degree or 110 degree field of view.
The frame rate is the rate at which the display screen shows consecutive images. The screen shows approximately 60 frames per second were as television shows 30 frames per second. This way virtual reality provide high-end experience.
The latency should be as low as it can be because it is the time taken by the headset to change image according to the position changed the user. It is measured in the millisecond and is responsible for making brain believe that the environment is real. The latency should be 20 milliseconds or below.
Positional audio (multi-speaker audio, already common in home theatres) is used to create the illusion of a 3-dimensional world. Tracking is used to understand the movements of the user immersing him fully into the virtual world. You can also buy Google Cardboard or Samsung Gear VR as some virtual reality head-mounted displays utilize smartphone displays to experience the virtual reality.
Non-immersive simulations are the least immersive execution of virtual reality technology. In a non-immersive simulation, just a subset of the user's senses are stimulated, allowing for peripheral awareness of the reality outside the virtual reality simulation. Users enter into these three-dimensional virtual environments through a window or portal by using standard high resolution monitors powered by processing power normally found on ordinary desktop workstations. In simple words, Non-immersive simulations Virtual Reality affects only 1 sensory systems (e.g. hearing, vision, scent, touch)
Semi-immersive simulations give a more immersive experience, in which the user is partly but not completely immersed in a virtual environment. Semi-immersive simulations nearly look like and use a large number of the same technologies found in flight simulation. Semi-immersive simulations are controlled by high performance graphical computing systems, which are regularly then coupled with large screen projector systems or multiple television projection systems to appropriately stimulate the user's visuals. In simple words, Semi-immersive simulations Virtual Reality affects 2?3 sensory systems
Fully-immersive simulations give the most immersive execution of virtual reality technology. In a fully-immersive simulation, equipment's like head-mounted displays and motion detecting gadgets are used to stimulate all of a user's senses. Fully immersive simulations can give very realistic user experiences by delivering a wide field of view, high resolutions, increased update rates (also called refresh rate), and high levels of contrast into a user's head-mounted display (HMD). In simple words, Fully-immersive simulations affects ALL the sensory systems which gives user the ability to immerse fully into the virtual reality application/game.