Virtual Reality:

What is Virtual Reality:

Virtual reality (VR) is a simulated experience that can be similar to or completely different from the real world. Applications of virtual reality can include entertainment (i.e. video games) and educational purposes (i.e. medical or military training). Other, distinct types of VR style technology include augmented reality and mixed reality.

Currently, standard virtual reality systems use either virtual reality headsets or multi-projected environments to generate realistic images, sounds, and other sensations that simulate a user's physical presence in a virtual environment. A person using virtual reality equipment is able to look around the artificial world, move around in it, and interact with virtual features or items. The effect is commonly created by VR headsets consisting of a head-mounted display with a small screen in front of the eyes, but can also be created through specially designed rooms with multiple large screens. Virtual reality typically incorporates auditory and video feedback, but may also allow other types of sensory and force feedback through haptic technology.
SOURCE: WIKIPEDIA



In other words, Virtual reality is a way to create a computer-generated environment that immerses the user into a virtual world. When we put on a VR headset it takes us to a simulated set-up making us completely aloof from the actual surroundings. If you ever have put on the one you would know exactly what I am talking about.

While from an experiential perspective we do understand the concept but what about the technical backend that goes into making it all possible. Do you really know how virtual reality works? In this blog, we will understand the technology behind virtual reality and the basic terminology surrounding the development of a simulated ecosystem for a head-mounted display (VR headset).
SOURCE: NEWGENAPPS



How Virtual Reality Works!

The primary subject of virtual reality is simulating the vision. Every headset aims to perfect their approach to creating an immersive 3D environment. Each VR headset puts up a screen (or two – one for each eye) in front of the eyes thus, eliminating any interaction with the real world. Two autofocus lenses are generally placed between the screen and the eyes that adjust based on individual eye movement and positioning. The visuals on the screen are rendered either by using a mobile phone or HDMI cable connected to a PC.

To create a truly immersive virtual reality there are certain prerequisites – a frame rate of minimum 60fps, an equally competent refresh rate, and a minimum 100-degree field of view (FOV) (though 180 degrees is ideal). The frame rate is the rate at which the GPU can process the images per second, the screen refresh rate is the pace of the display to render images, and FOV is the extent to which the display can support eye and head movement.

If either of these doesn’t work as per the standards the user can experience latency i.e. too much time gap between their actions and the response from the screen. We need the response to be less than 20 milliseconds to trick the brain which is achieved by combining all the above factors in the right proportion. Another issue that needs to be catered here is to prevent tearing (cybersickness) resulting due to the inconsistency between the frame rate and refresh rate. If the GPU’s fps is more than the screen refresh rate then the image can become distorted. To counter this issue, we limit the framerate to the monitor’s refresh rate this done using a tech called Vertical Sync (VSync).

Among the major headsets available today, Vive and Rift both have 110-degree FOVs, Google Cardboard has 90, the GearVR has 96 and the new Google Daydream offers up to 120 degrees. As for frame rate, both HTC Vive and Oculus Rift come with 90hz displays, while the PlayStation VR offers a 60hz display.
SOURCE: NEWGENAPPS




Components of Virtual Reality:

Personal Computer (PC)/Console/Smartphone:
Computers are used to process inputs and outputs sequentially. To power the content creation and production significant computing power are required, thereby making PC/consoles/smartphones an important part of VR systems. The VR content is what users view inside and perceive so it is equally important as other hardware.

Input devices:
Input devices provide users a sense of immersion and determine the way a user communicates with the computer. It helps users to navigate and interact within a VR environment to make it intuitive and natural as possible. Unfortunately, the current state of technology is not advanced enough to support this yet. The most commonly used input devices are joysticks, force Balls/Tracking balls, controller wands, data gloves, trackpads, On-device control buttons, motion trackers, bodysuits, treadmills and motion platforms (virtual Omni).

Output Devices:
Devices that each stimulate a sense organ. Output devices are used for presenting the VR content or environment to the users and it is the utmost devices to generate an immersive feeling. These include visual, auditory, or haptic displays. Like input devices, the output devices are also underdeveloped currently because the current state-of-art VR system does not allow to stimulate human senses perfect ideal manners. Most systems support visual feedback, and only some of them are enhanced it by audio or haptic information.

Software:
Apart from the input, output hardware, and its coordination, the underlying software is also equally important. It is responsible for the managing of I/O devices, analyzing incoming data, and generating proper feedback. The whole application is time-critical and software must manage it: input data must be handled timely and the system response that is sent to the output displays must be prompt in order not to destroy the feeling of immersion. The developer can start with a basic software development kit (SDK) from a VR headset vendor and build their own VWG from scratch. SDK usually provides the basic drivers, an interface to access tracking data and call graphical rendering libraries. There are some ready-made VWG for particular VR experiences and has options to add high-level scripts.

Audio:
Virtual reality audio may not be as technically-complex as the visual components, however, it is an equally important component to simulate a user’s senses and achieve immersion. Most virtual reality headsets provide users with the option to use their own headphones in conjunction with a headset. Other headsets may include their own integrated headphones. Virtual reality audio works via positional, multi-speaker audio (often called Positional Audio) that gives the illusion of a 3-dimensional world. Positional audio is a way of seeing with your ears and is used in virtual reality because it can provide cues to gain a user’s attention, or give them information that may not be presented visually. This technology is already quite common and often found in home theater surround sound systems.

Human Perception:
Understanding the physiology of the human body and the optical illusions are important to achieve maximum human perceptual without side effects. The human senses using different stimuli, receptors, and sense organs.
As virtual reality is supposed to simulate the real world, it is important to know how to “fool the user’s senses” to know what are the most important stimuli and what is the accepted quality for subjective viewing? Human vision provides the most information that is passed to our brain followed by hearing, touch, and other senses. System synchronization of all stimuli with the user’s actions is also responsible for the proper functioning of the VR system.
SOURCE: TECHNICO



Also read: How RAM works? 

Let's discuss some interesting facts about VR:

1) Predominantly 21st Century Tech:
Virtual Reality became popular only in the last decade. Until the 1990s, virtual reality was largely a no-show since the devices were overpriced and quality was bad. 

2) It’s not only about Gaming:
Virtual reality is not only about just gaming but is being used in verticals like automotive, healthcare, education, military, and more.

3) Higher Penetration of VR by Smartphones:
Most VR  enablers are smartphones than computers.
VR is an add-on to smartphones, just like audio headsets.

4) Can be integrated with other Technologies:
VR can be integrated with artificial intelligence to help users in dealing with risky sectors. 
For instance, it can be used to monitor areas of nuclear power plants that can be dangerous for human health.

5) An advanced form of Communication:
Many academics have suggested that VR will evolve into an advanced way of communication. 
In the future, you may be able to meet and communicate with people in near-reality through VR.

6) Ultra-realistic Model:
Virtual reality is used as a 3D modeling tool by many manufacturing industries, as well as in healthcare. 
In the healthcare industry, it is being used to visualize and analyze the holistic condition of patients.

7) Education & Training:
VR enables both students and teachers to learn and experience concepts with ease.
They are also able to interact with these concepts in an immersive environment.

8) Adopted by U.S. Military:
In the U.S., virtual reality is used by all three branches of the military, to train personnel in various terrains and environments. 

9) Developing Technology:
Virtual reality is a fast-developing technology and there is more to its evolution. The next frontier is working with the human senses.  



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