VR makes you sick too

Oculus Rift: Tips Against Simulator Sickness

The Oculus Rift launched with an astonishingly large package of games. Many people are likely to have their first experiences with virtual reality with the Rift, or play longer VR titles for the first time - because up to now there have mostly only been short demos. However, virtual reality games have some special features that can trigger what is known as simulator disease. It is currently still the biggest obstacle VR developers have to overcome on their way to mass market.

The symptoms

The causes of simulator disease are primarily the different impressions that your eyes and inner ear transmit to the brain. Evolution theorists assume that the onset of nausea is a protective reaction with which the body wants to remove any poisons that it blames for the different sensory impressions - similar to an alcohol intoxication.

The symptoms affect the eyes (overload, blurred vision, accommodation disorders), the brain (headache, tiredness, dizziness, difficulty concentrating) and the stomach (belching, nausea). In previous scientific studies, actual vomiting only occurred in around one percent of cases - in contrast to seasickness. VR players can leave out the notorious vomit bag. If you have been hit before, for example, have drunk alcohol or are overtired, the problems get worse. VR is taboo for epileptics.

Symptoms can persist even after playing a VR game. Sometimes you have to get used to reality again. That is why experts recommend waiting 30 to 45 minutes before actively participating in road traffic again. So don't get into the car straight away after a long VR session.

Insensitive men

Previous studies have come to the conclusion that women are significantly more affected than men. Researchers see the causes in the different hormonal balance and in the fact that women have a larger field of vision than men.

Age also plays a role: children under the age of twelve are more likely to suffer from simulator disease than adults over the age of 20 because their sensory organs and brain are not yet fully developed and they are still learning to coordinate everything correctly. The sensitivity increases with age. So be careful if your children really want to try out the new VR glasses and only choose slow games with static camera positions.

When young men develop VR software themselves, they themselves belong statistically to the most insensitive group. In addition, they may have already got used to VR in the course of a project. To test whether your simulation is also well tolerated by other people, you should let your mother and her friends who have not yet had any experience with VR try it out for half an hour.

Pacemaker

Earlier VR systems, whose hardware was not as sophisticated as that of the Oculus Rift and HTC Vive, had more problems with latency: Their view on the VR screens was too much delayed compared to the head movement. The Vive and the Rift are not critical here. As long as the software has been programmed efficiently and the computer can maintain the required 90 FPS, there should be no noticeable delays. So do not operate the glasses on systems that do not meet the minimum requirements of Oculus and Valve. Tips for building a VR-compatible PC can be found in the upcoming c't 8/16.

If the frame rate is jerky or the picture is dragging, it is better to leave the game behind until the manufacturer has improved the performance or you have upgraded your PC to match. Sometimes it can help if you reduce the brightness, because in the dark people generally react more slowly to visual stimuli and tolerate latencies better.

Caution camera

The most important transition that VR game developers need to learn is camera control within the games. As much as you would like to play a fast first-person shooter in VR, it doesn't work that easy, because most players get sick very quickly because of the high speed.

If you take a closer look at the start-up portfolio of the Rift, you will notice various tactics used by the manufacturers to try to circumvent the simulator disease. The tower defense game "Defense Grid 2" and the action adventure "Chronos" are very conservative with the camera controls. In the first, the player looks at a miniature landscape in which he sets defensive towers that are supposed to stop new waves of attack. Here the player looks at the action like a god. Chronos works exclusively with static camera settings. As in the old "Resident Evil", the view jumps to the next corner when the hero enters a new room. Both are good entry-level titles for getting used to VR.

Never backwards

Developers Insomniac Games, who are about to release their first Rift game "Edge of Nowhere", have experimented a lot with continuous camera movements. It took the developers several attempts before they found a comfortable movement. In this way they largely forego turning in the game, at most a slight tilting is possible in order to be able to look up and down. Linear movements forwards, upwards, downwards and to the side are also unproblematic, only reverse gear should be avoided in VR. Since the camera in "Edge of Nowhere" mostly moves forward, the level structure is largely linear and not as branched as in previous action adventures.

The fast racing game "Radial-G" also takes advantage of the relative insensitivity to forward movements. Here, like in the old wipeout, the player races in a futuristic glider over tubular tracks. The pace is extremely high, but there are only short acceleration phases, so we can still handle the game quite well. Because the organ of equilibrium only reacts to acceleration, but not to constant speeds.

Ubisoft's "Eagle Flight", which is still in production, also uses a trick. When accelerating and when flying a curve, the game intentionally restricts the field of view with a black border, so that there is an artificial tunnel vision. We could therefore tolerate an extended trial session with a beta version.

"Technolust" has another trick in store: Here the player can choose whether he wants to move and turn smoothly with the analog stick, or whether this happens in short steps. If he switches on the step function, the image moves step by step every second - just like in the first 3D role-playing games 25 years ago. Other approaches, such as Epic's bullet train demo, allow the player to beam between specified portals only.

Spin slowly

Space games like "Adr1ft" and "Eve Valkyrie" are less squeamish. Here the player can turn around all axes. The developers are trying to reduce simulator sickness by rendering a spaceman helmet at Adr1ft and a huge cockpit at Valkyrie. These should serve as reference points for the eyes and can reduce the queasy feeling in the stomach. Because if a VR simulation can visually suggest to the player that it is not he who is moving, but the world around him, then the sensory impressions do not collide with those of the organ of equilibrium. However, despite these measures, we got queasy after a few minutes. The two space simulations are only for die-hard VR experts.

Oculus itself classifies the games into three categories, which largely depend on the speed and the camera movements in the game. In any case, you should limit the length of a VR session in terms of time. Depending on the game, you should take a break and relax after 20 to 30 minutes at the latest. Over time, your body will get used to VR. If you feel sick while playing a game, take a few days off and try again. So you can gradually increase the dose.