*UPDATED AND REVISED OCT 10, 2014* APPLIES TO DK1 & DK2
Motion sickness while in Virtual Reality is correctly known as VR Sickness, Cyber Sickness and Simulator Sickness. Users who begin to experience VR Sickness while using the Rift should limit their usage times to around 10 minute intervals in order to build a tolerance against it and consider the guide below. Don't try and fight symptoms as conditions will only persist and you can literally get to the point of vomiting. Keep in mind, VR Sickness is not a serious problem and there are methods in reducing and completely removing it from Virtual Reality experiences mentioned further below.
Originally, OculusVR knew very little about simulator sickness (VR sickness), however they have made great strides regarding the problem over the past few years.
Since 2012 I have been actively researching this topic and seem to be more versed than the United States Army and even NASA at this point after frequent reading of their past reports on the subject which are obsolete and out of date at this time. As such, I was required to hire a vestibular specialist who proved very valuable in solving more complex concerns and answering specific questions that were raised. Below is a summary of what I learned over the last couple years.
Early methods of correcting simulator sickness have been developed by NASA due to frequent reports of astronauts showing symptoms in space and during simulator testing. NASA's solution was to introduce a pair of electronic shutter glasses flashing at a specific frequency and dwell time. These systems are not very effective. The US Army conducted a costly and extensive report back in 2005 regarding simulator sickness. The consensus of the report didn't specify any solutions to the problem, only statistical findings.
Motion sickness is the direct opposite of simulator sickness however they both feature nearly identical symptoms with the exception that Motion sickness is known in creating a sense of post movement afterwards whereas cyber sickness typically leaves a feeling of dizziness as a result. Shared main symptoms by order include nausea followed by vomiting, dizziness, reduced spatial awareness, sopite syndrome (exhaustion), increase in appetite and frequent bowel movements.
The cause of these symptoms is due for two reasons. First, the brain receives conflicting cues namely from the visual cortex, posture and vestibular system and secondly from erroneous data that's processed from the users perceptual system as a result. The reason for these symptoms are to protect the body from a false positive of neurotoxins which the brain believes the user has ingested or absorbed based on conflicting processed data from the perceptual, vestibular, postural and visual system.
Susceptibility to simulator sickness is a complete random occurrence in individuals. Gender and race make no difference with the exception of the Asian population. Asian's statistically are reported to have elevated motion and VR sickness related issues. A popular household remedy in Asia is rub eucalypti leaves together and inhale the scent produced from them. Resistance training for sensitive individuals is very effective. It's one of the most effective methods for significantly reducing to completely eliminating symptoms. Around 5% of all individuals will never acclimate regardless how much they try to build a resistance to it meaning there is a confirmed minority of individuals who will never be able to us Virtual Reality as a mainstream product over their lifetime.
Surgical methods have been considered in the past for corrective treatment options however they are only used as a last ditch effort to correct patients with severe balance and vestibular issues. Chemical injections are almost always utilized in these cases and the majority of patients who undergo injections usually go deaf from the surgery as a result since the vestibular system is linked directly to the hearing system. Interestingly enough, deaf people don't suffer from any forms of motion sickness and likely simulator sickness as well.
PROVEN METHODS FOR CORRECTING VR SICKNESS
- Utilizing a software process called Comfort Mode developed by Cloudhead Games.
- Utilizing the Comfort Mode 2 I developed which considerably reduces VR Sickness and significant GPU throughput at the same while still maintaining a great experience. Is fully compatible with Comfort Mode 1.
(PM me for details)
- Positional tracking and experiences which don't create vestibular conflict such as sitting or standing on the spot. For all other walking, running and motion experiences, Omni directional treadmills and 6DOF rigs can substantially reduce vestibular conflict as well.
- Properly calibrate the developer kit to your specific eye settings. Everyone has different eye measurements and these include pupil distance, distance from your eyes to the screen (field of view) and lens center (distance from the actual center of the lenses). This needs to be calibrated in the game and it's the number one contributor to motion sickness if not tailored to suit your personal requirements
- Make sure that you deal with any additional visual issues relating to prescription eye wear and adjust in software if necessary. If your IPD is off, check out IPD adjusters by VR Gear at http://www.vr-gear.com
- Maintain lowest latencies and accurate head tracking possible within hardware. Nvidia 9 series graphics cards feature additional features on improving this.
- Run higher resolutions
- Maintain Focal depth (it's controversial whether this actually helps for the moment)
- Reducing the field of view below 30 degrees stops VR sickness completely however it's not a viable solution. The higher the FOV past 30 degrees VR sickness incrementally gets worse.
- Random shapes and sizes are more preferred as opposed to staight and jagged lines.
- Play more slowly, turn your brightness level down on the rift control module and turn the volume down. This makes a big difference.
- Eat or drink food products containing ginger. This really helps reduce nausea. Don't rely on this however as it doesn't treat any other symptoms associated with cyber sickness besides feeling nauseous.
REASONS THIS WAS MORE OF AN ISSUE IN THE PAST & A BRIEF HISTORY LESSON
- 3D Games weren't actually just that back in the day, they just appeared to be. A good example of this is Duke Nukem 3D which against common belief wasn't actually 3D. It was actually a cleaver representation of a 3D environment. Ken Silverman created a very effective engine that utilized this false imagery and people could get sick just playing his games on their monitor. A game he wrote called Ken's Labyrinth was the perfect candidate for brutal motion sickness even while playing from a standard display. Doom was also another VR compatible game that caused serious motion sickness issues with and without a VR headset. Dwayne "The Rock" Johnson actually got motion sickness the first time he played doom on the computer back in the day.
- Latency and frame rates were much worse back then. This makes a huge difference influencing motion sickness.
- The 3D dual image setups were not as accurate in the past. Again this makes a large difference regarding motion sickness.
- Head tracking wasn't as accurate and calibrations were likely not as accurate either. If the motion calibration is not 100% precise, our brains will subconsciously conflict what we are used to in the real world. Also if the tracker isn't accurate enough, this further enhances the problem. OculusVR actually built a temperature controlled room with a 100% level test bench for testing their exclusive motion system during development to ensure their system was as accurate as possible for developer kits. This in turn will significantly help users combat motion sickness.
- Graphics were not as representative to what we have today, poor resolution and motion blur was more of an issue as well. This actually has an effect and has only been improved. While game graphics, even for today's standards are still not perfect and motion blur still plays a role on HMD devices, these are mainly the only remaining issues that can cause motion sickness for Rift users. As game graphics are improved and made more accurate, resolution is improved and refresh rates in the actual screen are reduced, this will significantly improve over time.
- Positional tracking didn't exist.
HOW DEVELOPERS CAN REDUCE MOTION SICKNESS FURTHER
- Make sure the 3D rendering and shaders are setup perfectly. Provide an option for users to access full adjustment of their eye configurations. Everything has to be optically correct.
- Make in game motions as close as possible to 1:1. Slow walking speeds, a sense of jumping and awareness need to be consistent with how we experience the real world, this one is pretty obvious.
- Make games where a fixed reference point can be observed in the game world. For example a cockpit that makes the gamer feel they are inside an actual vehicle. Provide some form of solid reference in the game that gamers can focus on and to mentally understand their surroundings.
- Use darker textures, this claims to make an improvement for many users.
- Don't use repeated patterns, like checker board or strips and lines. Make natural dark textures that flow with nature.
- Use a proper sense of scale. If you feel really small in the game world, the ground will move even faster below you and this also sends conflicting messages to the brain.