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Virtual Reality Motion Sickness VR Simulator Illness Guide

OculusOptician
Explorer
*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Army and even NASA at this point after frequent reading of their past reports on the subject which are obsolete and out of date at this time.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.
34 REPLIES 34

joe
Explorer
A couple more things developers can do that I mentioned in my GDC talk:
* Don't ever change the horizon line.
* Don't ever take away headtracking and show a freeze frame
* Move the camera in the direction it is facing, or close to it. Moving the camera perpendicular to the direction it's facing seems to cause problems for some people.

OculusOptician
Explorer
Couple other good points for developers to consider.

Sawersadam
Honored Guest
Maybe this is the right thread to share an observation.

I suspect a number of people will have experienced sitting on a motionless train or bus looking out of the window at another motionless train or bus, when the 'other vehicle' starts to move off slowly.

There is very disconcerting moment or two where you perceive that you are moving but you don't 'feel' your movement. Usually I find myself looking out of the windows on the other side so as to check which of us is moving. It is physically quite confusing and dizzying.

Sometimes though, the train or bus I'm on is the one that is moving. In which case it's usually associated with a subtle, barely perceptible thunk, thunk or other vibration that kind of confirms what you are seeing and feels natural.

I'd like to experiment with a simple device that could be strapped to a users' chair that would generate a gentle pulse synchronised with game speed somehow (I'm thinking of the painted lines on a road that increase in frequency when nearing an intersection for example or the vibration of a car tires on a concrete road).

Even where in-world where one is walking or running rather than controlling a vehicle I'd bet this kind of physical feedback would help reduce nausea.

Alkapwn
Protege
After using the Rift for a while and getting the hang of things in VR, I thought I would step the game up and see if I could cause myself to get motion sickness.Two things that I quickly noticed. Strafing and strafe walking were the biggest culprits.

Strafing left and right repeatedly had an odd feel to it, I think due to the fact that we don't do it fairly often in real life, especially at that speed.

Strafe walking, as best as I can describe it is when you're moving forward/backward while also strafing. This has a very un-natural feel to it and is accentuated when you start turning/rotating while doing this. Most of my co-workers seemed to be fine until they started doing weird combinations of strafing and rotating together which seemed to bring on motion sickness quite rapidly.

I don't know if there's an easy way to solve for this in software aside from possibly lowering the speed of lateral movement or something like that. I think that something that would help this from a hardware standpoint would be an additional tracker. This tracker could then be placed on either the chest, back, or waist. Then the player movement would simply be forward, back, left and right. When the user wants to turn their character, they would rotate heir body to turn the character in game. This would be in a natural way that the player's body and mind would be used to. For some reason I found it easier to get nauseous while sitting down rather than standing up.

I hope this helps somehow.

vsn11596
Honored Guest
My hope is that this becomes one of the most active threads. As an Indie developer, it's a big financial gamble to bet on the OR as an early adopter and Motion Sickness is a show stopper. All of your tips are super important in design/game play pre-planning and greatly appreciated. As an Indie with limited resources one of my concerns is that I will not have enough "virgin" testers during development, making this thread and improvements to the commercial version of the Rift all the more critical.

I ran across an interesting paper that I thought I would share - How to cheat in motion simulation (funded by the Max-Planck Society dec 2001). 8 pages, worth the read. http://kyb.mpg.de/fileadmin/user_upload ... pdf635.pdf . Of particular note were these 4 points:

Summary of most commonly used “tricks”:

• Moving the observer below detection threshold to gain additional simulation space.

• Trading the gravity vector for an acceleration. This makes use of the fact that the we cannot distinguish well between, e.g., an absolute constant acceleration of 1.0g or 1.1g.

• Masking not-to-be-detected motions by noise (i.e., vibrations and jitter).

• Guiding the attention of the observer away from the imperfections of the motion simulation, e.g., by involving the observer in a difficult task, providing attention-capturing visual and auditory cues etc. Results from change blindness and inattentional blindness studies provide insights on how to do that.

I think it is also going to be interesting to see what types of alternate input and/or accessory tactile sensory devices spin off as a result of the OR. Many thanks again to all that post to this thread. I look forward to the ongoing discussions.

OculusOptician
Explorer
One good idea I have to deal with the strafing issue is when the head tracking consumer version roles out you will be able to simply move your head side to side at a 1:1 ratio to provide that immersive experience. However when you move your head to the sides even further you start to actually strafe in the game. This is a natural instinct I noticed when Imps were throwing fireballs at people playing Doom 3. I think this is the best idea and many people will appreciate it as it should seriously reduce motion sickness because this is a very natural concept and your brain will likely adapt to it very easily.

As for motion sickness being a showstopper for the Rift. It won't be a problem when people realize it's only because of how much more immerse and fantastic the experience is over existing technology. I'm confident a great amount of these motion sickness issues will be dealt with when the consumer version is released as well. Not to mention the fact that we can become tolerant to it over time.

I remember playing first person games on my computer and TV back in the day and getting sick to the point where I had to lie down. Although it didn't take too long before I never noticed it again.

If people complain about motion sickness, tell them to man up, drink a ginger ale and get back in the game. LOL. I can see it now, OculusVR t-shirts with a foaming ginger ale bottle on the front and a message saying "Ginger Ale - The Official Beverage Of VR" LOL. Technically VR should have an official beverage because gamers and hackers have Volt Cola, ha ha.

vsn11596
Honored Guest
"vsn11596" wrote:
If people complain about motion sickness, tell them to man up, drink a ginger ale and get back in the game. LOL. I can see it now, OculusVR t-shirts with a foaming ginger ale bottle on the front and a message saying "Ginger Ale - The Official Beverage Of VR" LOL.


Transcript from my first help desk call:

[me]: Thank you for calling Acme VR Games. How can I help you?
[gamer]: Uh, yeah, I just started playing your game and it made me puke. Can I have my money back?
[me]: Did you try drinking a ginger ale?
[gamer]: I'm only 10, don't you have to be like 18 to drink ale?
[me]: Man up kid - what size shirt do you wear?
[gamer]: Uh, small I think. Why? .... (click) .... hello? ....hello?

Last I heard his mom sold a slightly used, somewhat soiled OR on Ebay for $150. ("I went to Virtual Reality on vacation and all I got was this lousy T-Shirt") 😄

In all seriousness, I am hopeful to see the Rift as a therapeutic and learning aid for visual-spatial learners (ADHD, ASD, Bi-Polar, Etc) - my target audience may not be as forgiving as hard core gamers so I am super sincere when I express appreciation to OculusOptician and all that post to this thread - I just couldn't resist having a little fun - sorry.

SiggiG
Protege
Love the fact that you're collecting information, but I also think its counter-productive to have 2 posts on this subject 😛
CCP Games, EVE: Valkyrie developer | @SiggiGG

kingtut
Honored Guest
I've just created https://developer.oculus.com/wiki/ind ... n_Sickness to summarise the discussions. Obviously feel free to edit.

Note that discussions etc should definitely take place on the forums, but I think the wiki is a better way to collect and collate the different threads which can and will pop up on this subject.