The Science Behind Virtual Reality
If you've ever had an experience with Virutal Reality using an HTC, Rift Oculus, Samsung Gear VR or just Google Cardboard ... You may have experienced a different sensation and have not gotten an exact name for that feeling. Vection , that's the name given to that feeling of moving when you're not really moving.
How does the body identify that I am not moving?
One of the most interesting things in the human body is that everything about sensations are sensory combinations processed by the brain to form an image and the sensation of locating where we are. In Virtual Reality it would be no different. Our eyes are the doors that bring information such as color, depth and distance, and in the case of Virtual Reality the most important is depth information. Using the location based on the objects in the environment in which we find ourselves, our brain turns our vision into a type of parallax.
I will explain better what the parallax effect is for those who do not know it, so that we can then understand Virtual Reality. But you can see a nice example by moving the scroll (ball) of your mouse on this SITE
Parallax effect on Virtual Reality. How does our body know that it is moving?
Within virtual reality the developers do not have many problems with the layers of the model parallax, since the great majority of the objects in the 3D models are arranged in a fixed space. The great challenge of the developers is actually linked to the movement of objects, which must happen in relation to how the user moves within that 3D space. Here comes the challenge, because it is inside the ear that we have the sensors responsible for the balance and locomotion of our body.
Our ears have something called the Vestibular System. They are components of an inner group of the ear (hair, tubes, bones and etc ...) that contributes strongly to our balance and locomotion. In simplified form, the inside of our ear has a "chamber" full of small hairs fixed on its wall. When we move, a type of liquid touches those hairs and stimulates them, sending to the brain the information of what is happening with our body.
Through these "hairs" our brain is able to detect the "movement and rotation" in which our body is in the following aspects:
Guidance - Am I in or is lying?
Movement - Am I moving? In which direction?
Acceleration - What is the speed of this movement or rotation?
Through another process called Proprioception (also known as kinesthesia) we are able to recognize the position of our body without having to be looking at it. For example, with your eyes closed you are able to know where your hand or foot is. But why are we mentioning all this? It is this combination that makes the whole process of perception of our brain work with Virtual Reality.
Auditory information is also important for our brains to understand what is happening. We realize a lot about the space that we find when we hear a car passing, or a song, something falling and etc ... An important detail that hinders the developers is that despite having all this importance in the real world locomotion and virtual reality, there are few studies on this field.
Now, sensory misalignment
So we come to the conclusion that several of our senses are responsible for our balance, notion of space and projection of our body in an environment. So we were developed to move in a physical space using several of our senses simultaneously. But ... What if one of our senses tells us something about our movement and another sense tells us something different? As mentioned earlier where our vision is aligned with any vehicle, but do we hear the sound of another vehicle? This sensation is called sensory misalignment.
There is not much research on how our brain reacts to this kind of confused and misaligned information. Until now, most of the virtual reality projects are focused precisely on the vision and "vestibular system" mentioned above. So here are the difficulties for developers to create the right feelings in virtual reality.
Passive movement and active movement in Virtual Reality
Some people may experience dizziness or motion sickness when they experience sensory misalignment. The body gets confused when trying to find out if it is projected forward, sideways or in other positions. Even your vision giving you all the information you need, your hearing can confuse your brain and mislead your senses. To deal with this misalignment of information what searches are being done in the "space" of virtual reality. This study / experience is divided into two categories: passive movement and active movement.
The passive movement refers to the movement you do, but your body does not control. Have you ever watched someone playing a first-person shooter and felt nauseous for not being the one controlling the character? Your eyes say that you are moving with certain speed and acceleration, but your vestibular system says the opposite. That way some people feel a little "out" after some time.
The Active Movement is just what happens in real life. It is your body controlling your movements. When a player experiences the virtual reality of an environment in a room prepared for use by the Rift or some other virtual reality glasses, walking physically, crouching and standing up, he rarely feels any sensory disorder.