What is VR?


Virtual reality (VR) is a technology that makes humans perceive an artificial environment as if it were real by making it immersive.
Nowadays, this technology is used for various things such as games and real estate property tours, and it is becoming familiar.
In this knowledge, we will describe the overview, mechanism and application examples of VR.

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Overview of VR

Virtual reality (VR) is a technology that makes humans perceive an artificial environment created by CG and live-action images as if it were real by giving them a sense of immersion.
It often appears in games, movies, science fiction novels, and anime.
Technologies similar to VR include Augmented Reality (AR) and Mixed Reality (MR). This is a technology for displaying a virtual object by superimposing it on the existing real world.

Mechanism of VR

To explain the mechanism of VR very simply, it is realized by artificially creating images that appear to both eyes when humans see the real world, and projecting them in real time to both eyes.
Therefore, in order to explain the details of the mechanism, we first explain how humans perceive the real world in three dimensions.

The human eye mainly captures the real world in three dimensions by combining the following four mechanisms.

  • Binocular Parallax
    • The left eye and right eye are naturally in different places, so they are looking at different images.
  • Convergence
    • The angle of the eyes is changed depending on the position of the gaze.
  • Motion Parallax
    • Changes in the image due to the relative movement of the observer and the object (e.g. distant objects appear to be moving slowly, near objects appear to be moving quickly). This difference tells you if it’s near or far.
  • Focus Adjustment
    • Humans adjust their eye lenses to focus when looking at an object.

In addition to the above, when humans look at an object of known size, he/she recognizes it as being large when it is close and small when it is far. Also, humans recognize that the object in the back is hidden by the object in the front when the two objects overlap. In addition, humans assist in cognition based on daily accumulated experience.
With the above mechanism, humans perceive the real world in three dimensions. It is necessary to express this virtually in VR.

However, humans have a visual field of about 60 degrees on the upper and nose sides, about 70 degrees on the lower side, and about 100 degrees on the ear side with one eye. Both eyes have a field of view of about 200 degrees.
If an image corresponding to this field of view is prepared in front of the eyes, it is necessary to prepare an image on most of the front surface of the face. Furthermore, for the places where the left and right eyes can see at the same time, it is necessary to prepare different images at the same place for each eye. This is very difficult.

For this reason, there are head mounted displays (HMD) and VR goggles as devices that artificially generate images for both eyes for this virtual environment.
By expanding the image through a lens and displaying the image in the full field of view, it is possible to prepare a large image that is artificially necessary for both eyes.
However, the image through the lens looks distorted, although it is expanded, as when looking through a magnifying glass.
In order to correct this distortion, there is a method of correcting the distortion by passing through multiple lenses, but the lenses are expensive, and using multiple lenses makes the HMD and VR goggles expensive.
Therefore, most of the currently popular HMDs and VR goggles use an image that is distorted in the opposite way to the distortion caused by the lens as the original image before passing through the lens. Then, by projecting the image through only one lens called an aspherical lens, the image is corrected and expanded at a low cost, thereby preparing an image with the full field of view of a person.

In addition, HMD and VR goggles use an acceleration sensor, gyro sensor, and magnetic sensor to measure where they are facing according to the movement of the human head. Then, they change the image in real time according to the change of the person’s viewpoint, and artificially generate and provide the image necessary for the virtual reality.

Currently, the following HMD and VR goggles are widely used.

  • Oculus (Go, Quest, Rift S) of Facebook Technologies, LLC
  • HTC Vive (Cosmos, Pro Eye, Pro) of HTC Corporation
  • PlayStation VR of Sony Interactive Entertainment Inc.

VR Use Cases

VR is currently being used in various fields such as games, amusement, video, shopping, and real estate.
An example is shown below.

  • Game
    • Various game software such as racing, shooting, and action/span>
  • Amusement
    • VR-based attractions at various theme parks
  • Video
    • Youtube 360 or 180 – degree videos
  • Shopping
    • “IKEA VR Experience” of furniture mass retailer “IKEA”
    • Apparel shop virtual store
  • Real Estate
    • Viewing by VR

VR precautions

There are some points to be aware of in VR. It is shown below.

  • VR Sickness
    • It is similar to motion sickness. It is caused by the difference in sense between the image viewed through the HMD and the actual image.
    • Google LLC. and others have announced best practices for content development that does not cause VR sickness.
  • Age Limit
    • Many of the compound eye lens type HMD and VR goggles have age restrictions.
    • As an example, Ocurus devices are prohibited to use under 12 years old as follows.

VR is an indispensable technology that will continue to develop in the future, as a new lifestyle is required under the influence of “COVID-19” in 2020.

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