Hey guys.
This post is the first one which is written in English.
Since English is not my native language, it is a little bit difficult to deliver the message.. but I will do the my to convey the contents:)

You might have heard about virtual reality (VR) and augmented reality (AR) for many times.

This post will cover the basics of virtual reality.

Virtual reality is a system that provides a virtual space literally.

Then, how the system can provide these virtual spaces?
As you may already know, these spaces are provided through headgears or head-mounted display recently.

(ref : http://www.insidertradings.org/2017/12/18/virtual-reality-market-is-expected-to-reach-usd-58-61-billion-in-2024/)

How would users perceive virtual reality from these headgear-like devices?
To know this, you need to know how people perceive 'three-dimensional information'.

Perceiving three-dimensional information

You are looking at the computer monitor now aren't you?
For a rest, let's briefly experience the 3D perception.

Place two items on your desk in front of you, put one--close to you and the other--a little farther away.

After that, cover your right eye and look at the two objects with your left eye, then hide your left eye again and see these two objects with your right eye.
You will easily notice that the relative position of two objects are perceived differently as you change your covered eye (left - right - left - right..).

It seems so natural and easy. However, this is a basic concept that explains how a person recognizes three-dimensional information.

Due to the relative difference (we call is binocular disparity) of information that the left eye and the right eye receives, one can recognize three-dimensional information.

Now, let's provide virtual reality to a user.

Providing virtual reality (VR)

The principle of providing virtual reality is exactly the same as the principle that a person accepts three-dimensional information.
Only you need to do is projecting images with binocular disparity to the left and right eyes simultaneously.
How?
You can create the left eye image and right eye image through your computer, and you can provide these images to the user through the device.

The schematic of the most basic virtual reality device is as follows.
Following one is Google card board which is the cheapest and simplest

(ref : 출처 :https://vr.google.com/intl/ko_kr/cardboard/)

The structure is really simple.
The smartphone is divided into half, one side shows the left eye image and the other shows the right eye image.
These images are projected into the human eyes through the lens.

It is not expensive, so I recommend you to buy it and try once.

There are various types of virtual reality devices, but the basic principle is same as Google card board,
which is,

Provide left eye image to the left eye and right eye image to the right eye

There are a variety of ways to generate binocular images and usually it is done by specific software such as Blender.

Thanks for reading:)