VR: Vomit Reality
As I continue to explore the world of Virtual Reality one thing that interests me is how to make VR more palatable for those who get VR sickness. I am fortunate enough to not get VR sickness or motion sickness so am able to spend hours at a time inside VR without any repercussions (that I know of). How to make this possible for everyone is something that interests me.
Motion Sickness
Understanding motion sickness on a basic level seemed to be the first part. Motion sickness occurs when there is a conflict between the vestibular system, which is responsible for balance and spatial orientation, and visually perceived motion. For example, motion sickness in a car occurs when the eye sees things whizzing past and says we are moving while the vestibular system only senses that your body is sitting still. This conflict causes a variety of symptoms broadly known as motion sickness. There are three different kinds of motion sickness, motion is felt but not seen, motion is seen but not felt and motion that is seen and felt do not correspond. Virtual Reality can cause the last two where motion is seen but not felt and seen and felt do not correspond.
First Person Mobility in VR
Virtual Reality has its own kind of motion sickness called virtual reality sickness. The only difference is that VR sickness does not require real movement, while motion sickness does. The conflict in the brain is the same. Since VR sickness is all about movement in VR compared to movement in the real world, I wanted to examine a few common ways you move in VR. Some are far more likely to cause VR sickness than others. I will start with the most mild.
Fade/Blink
Fade/Blink is the most mild method of movement in VR. The player selects a location and triggers the movement with the controller. The scene fades or blinks out, the player moves, and the scene fades or blinks back in. This happens instantly and prevents the player from seeing any movement and so there is no conflict with the vestibular system. While this method helps prevent VR sickness, it is not ideal for a fast-paced VR experience.
Teleport
Teleport is very similar to Fade/Blink but instead of the scene going black, it stays active and whooshes past the player rapidly. This is so brief that it works for all but the more sensitive victims of VR sickness but for those, even that brief conflict between the visual whooshing and standing still can cause discomfort and disorientation.
Astral Body
Astral body is the only one of the mobility methods mentioned here that I have not experienced personally. When the player needs to move, their perspective changes to see the play area top down like in the Sims or Sid Meyer’s Civilization. They then select an area to move to, the player object moves and the player perspective goes back to 1st person. Depending on how the perspective shift occurs, this could be very disorientating or very mild. If the change is not a Fade/Blink style then moving into the sky and looking down might make some susceptible to VR sickness uncomfortable.
Game Controller Pad
I have Game Controller Pad lower on the list because of the potential speed of the movement as well as how the steering works. Since the player is seeing all the movement but is not really moving this can cause the movement seen but not felt VR sickness. Additionally, you steer by looking in the direction you want to go but can strafe right and left with the pad. This strange combination of ways to steer can cause seen motion and felt motion conflict kind of VR sickness, while you look one way but move the other. The benefit of this method of moving is it enables very fast paced experiences like the game Rigs.
Run in Place
I have Run in Place listed as last because of the way the player steers and moves. Run in Place requires a lot of real world movement. The player has to move their arms as if they are running and steer by facing their body in a certain direction. This gives them the opportunity to freely look around. However, this also can cause the seen and felt conflict type of VR sickness. The faster the movement the worse the sickness. The player may also experience the seen but not felt kind of VR sickness, especially when turning as they move around the game map but don’t actually move position.
Conclusion
Even just standing still in VR can be disporienting, especially for those who are highly susceptible to motion sickness. However, there are many accencdotoal reports that you can develop an immunity to VR sickness by starting with simple experiences that use methods like Fade/Blink or Teleport, and working your way up slowly. As the technology improves and become more and more pervasive in our lives, I predict that VR sicknes will become a problem of the past.
