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Games Entertainment

Motion Sickness In 3D Games? 37

James Ensor asks: "I've always been subject to pretty bad motion sickness ever since I was a kid. I especially have problems with some, but not all 3d games. Has anyone else had this problem and/or have any insight into why some games are worse than others/how to make games that don't cause it? An interesting side note, Games based on DirectX have been a much bigger problem for me than anything based on OpenGL. In fact, in games that support both, I often get sick playing the DirectX version, flip over to openGL and have no problems. Any thoughts?" I can see how some games might cause some motion sickness, but the DirectX/OpenGL connection is a new (but highly quesitonable) addition. Is anyone else afflicted with a similar malady?
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Motion Sickness in 3D Games

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  • I have had similar problems with 3D games, but in my experience, I haven't noticed a specific problem with DirectX. Asheron's Call, admittedly a Windows-only game, is based on DirectX, and I can handle it for embarassingly long hours. On the other hand, I can look at a Quake screen for about 20 seconds before I'm dizzy and nauseous. Does anyone know, is there maybe a different refresh rate these use? This article Preventing Motion Sickness [swmed.edu] says that motion sickness is caused by your brain getting signals that don't coincide - your body says you're not moving, your eyes are sending signals of a static car, and your inner ear is saying, whoa we're doing 60mph... So, is our brain actually taking the visual input of certain games and translating them as us moving while our inner ear is reporting that we're at rest?
  • Put a blanket over the monitor and over your head, like a tent.. this is a really silly looking solution (especially in an office situation), but seems to work for a buddy of mine..
  • Lower framerates in DirectX would be my bet for the culprit. I used to could never play Doom for more than about 5 minutes; after turning the brightness and contrast on the monitor all the way up and darkening the room the problem became manageable.
  • I get motion sicknes from Quake style games, but I've noticed that I can play flight sims (remember Terminal Velocity?) and racing games for hours with no problems. Descent was kinda in between for me: it would make me sick after 30-60 minutes, but Quake is 20 seconds.

    The other thing I noticed is that playing/controlling the action has a lot to do with it. The same kind of thing is seen in automobiles. The driver never gets sick. Passengers are the only ones that suffer. I can play some games, but can't watch.

    When I first saw the N64, I would watch people play Mario World and it would make me dizzy after 15 minutes. However, I watched people play Zelda: Ocarina of Time for weeks with no problems. People would come to my room in college after dinner, after lunch, middle of the night to play. It was a collective effort, and we all had a great time, and I never got sick.

  • I've never gotten motion sickness in my life. Never in a car, roller coaster, whatever. Never. I've also been playing Quake for years. Never had motion sickness playing it. A few months ago if someone had mentioned this to me, I would have laughed about such a suggestion.

    A few months ago I got UnrealTournament running in Linux. By about the second level, I start feeling sick to my stomach while playing. I sometimes have to look away from my monitor for a little while. At least in between boards, but sometimes I sit out a round. It's the craziest thing. I guess it's based on Direct X, but I play it in Linux (with Glide, of course). I really don't see much of a difference between playing it on the two different platforms, but it gets me almost every time. I don't have any sort of an explination for it, but there is a definate difference of some sort.

  • by nellardo ( 68657 ) on Tuesday June 06, 2000 @07:40AM (#1021858) Homepage Journal

    "Simulator sickness", the variant of motion sickness induced by immersive virtual environments, can be some of the most intense motion sickness around. Though I can't compare it with space sickness (yet :-), I can say that I almost never get motion sick except when using an immersive display, especially a head-mounted one.

    Last I read, the causes of motion sickness weren't well-understood, but the theory generally was that differences in visual and proprioceptic feedback is what induces nausea. "Proprioceptic" feedback is the knowledge (a sense, like touch or pressure, if you will) of where your body is in space and how the parts are positioned relative to each other. Proprioception is what lets you close your eyes and touch your left and right fingertips together.

    How does this apply to games? The one-word answer is lag, the bane of all researcher working in virtual reality (in augmented reality it is even harder). User input occurs, and it takes a certain amount of time for that input to be processed by the computer, for the machine to determine what to do, and then to produce the appropriate output. The difference between the user's input (action) and the computer's response (reaction) is the critical lag factor in VR, games, and simulation. Cognitive experiments suggest that, so long as this lag is less than about a tenth of a second (the number varies based on task), the user feels in control. Greater than a tenth, and the user feels like their actions don't correspond to the reactions.

    So, in VR, move your head. The screen needs to reflect this in under a tenth of a second. "No problem," you say, "because Quake runs at 60Hz on my machine." Yes, but frame rate is not the critical factor, but the length of time between your mouse click and the appearance of a missle on screen.

    Let's run some numbers. Just to keep the math easy, lets say we'd like to maintain a 100Hz frame rate and a 0.1 second lag. So, at worst, no more than ten frames can go by between the time the user moves the mouse and the screen changes to reflect the move (e.g., a new door becomes visible on the edge.

    • Suppose the mouse is sampled at 100Hz (that's fast, but let's keep the math simple). Then worst case the user's move occurs just after a sample is taken. That's 0.01 second of lag right there (it takes that long before the mouse is sampled again).
    • Now how often can the IO controller put info on the bus? Probably no more than a 100 times a second - after all, that's the sampling rate. So add 0.01 second of lag.
    • Now let's handle the IO interrupt. Add 0.01 sec of lag for the kernel-level context switch to deal with that. We're up to 0.03, with 0.07 left to spare, and we haven't yet hit the main CPU.
    • So the CPU finally gets the click. Let's pretend our game is really well-coded and so it only takes us 10 milliseconds to decode the click, look up the corresponding action (hope the event table didn't get swapped out :-), and get the geometry for that door to put on the screen (better hope you pre-loaded it and you don't have to get it from disk now - that would blow the lag budget right there). 0.04.
    • Now we run through all the other stuff going on in the game - monsters, AI, etc. Again, let's be generous - 10 msec. We're halfway to the "lag barrier" at 0.05 sec.
    • Now process all the geometry. Visibility, any transforms you can't do on the framebuffer card, etc. 10 msec, 0.06.
    • Another 10msec dealing with the bus and shipping all that geometry to the graphics accelerator. 0.07! Phew! We made it!
    • Nope. Haven't drawn everything yet. Let's say the card does all the geometry transforms, clipping, etc. in our math-friendly 10 msec. 0.08.
    • Now rasterize all those polygons. 0.09. Uh oh.
    • Ship the frame to the monitor - 0.10 - we just made it!
    • Bzzt. Try again. Your monitor refreshes at 100Hz, and you just missed it. 0.11 and we're over.

    We're not over "lag budget" by much, but that's not the point. This was a contrived example. Now add all the layers of software and such in there, speed up some parts (the bus), and slow down others (gee, that fancy new AI isn't so cool anymore). The point is, many parallel steps in the pipeline, and end-to-end lag can be dramatically higher than frame rate might indicate (more than ten times, in this case). Add network traffic and, ugh.

    So how is this relevant to the question of OpenGL vs DirectX? Well, it sounds to me that the original poster gets well and truly immersed, setting up the possibility for simulator sickness if lag gets ugly. And it would seem that the lag is just under the poster's nausea threshold with OpenGL and just over it with DirectX - the user moves the mouse and the screen keeps up with OpenGL, but lags behind in DirectX. Time to spew your cookies.

    This kind of stuff is a bear to manage - it is like real-time computing only you don't have the guarantees you usually have in a bona fide real-time environment. Usually, RT environments have a fixed number of tasks to deal with - you know how much time anything is going to take (it's still a bitch dealing with it, but at least you know the bounds). A game doesn't work that way. If the user's facing the wall (one or two big polygons) and suddenly looks back over her shoulder to see the glorious million-polygon Great Hall, well, you get the idea. Bounds shmounds. You've got no idea how long that will take to process.

  • I have worked on military flight simulators (A-10, F-16 in SIMNET). These were relatively cheap sims (the goal was team training, not procedures -- how to fly the aircraft -- training), so they had no motion platform. The rendering hardware was from the mid-1980s, so we had a 7 foot tall rack full of hardware that had one-tenth the performance of a TNT2.

    So, we had a somewhat-believable, but clearly not real, world. In spite of this, several Air Force pilots had problems with simulator sickness -- to the point that one pilot couldn't fly more than a few minutes before he became nauseous and got a splitting headache.

    It is interesting to note that there is a similar problem with pilots in real aircraft -- if you don't have the horizon in view, your inner ear will take over and try to tell you where up and down are. If you believe what your ears ("the seat of your pants") -- rather than your instruments -- tell you, you will end up very dead. It's called the Graveyard Spiral, and it is the favorite way for pilots to kill themselves. It's a fair bet that JFK Jr. killed himself in this way.

  • I'm a pilot, and when I was first learning to fly I got motion sickness a lot. I got over it as I became more confident and less overwhelmed by all the new stuff I was learning. Now I get motion sickness when I'm flying with a "hood", a view limiting device used to simulate flying in non-visual "instrument" conditions while your instructor is still in visual conditions and can watch for other aircraft. But I'm fully confident that I'll get over that as well, once I'm not overwhelmed by trying to fly in a new way while studying the approach plate, tune the radios and get the plane set up for the approach while the turbulence is throwing me around.

    I also sometimes get "monitor" sickness. I used to get it playing Quake 2, especially when playing it with software rendering. Getting a Voodoo II card was a major improvement. I think that supports the previous poster's theory that it has to do with the lag between doing something and the effects of that action getting rendered.

    However, if I want to get so sick that I have to lie down for a few hours, I only need to watch my daughters play Team Fortress Classic. I don't know exactly what it is, but I suspect it's because I'm not in control so I'm not "ready" when the viewpoint whips around. I can watch for about 15 minutes and then I'm so sick I have to lie down for hours. This is worse than a 3 hour instrument flying lesson.

    So sorry, I have no great insights as to how to cure it, but I would guess that a fast video card and bearing with it until it goes away might be the only things that will help.

    --
    A "freaking free-loading Canadian" stealing jobs from good honest hard working Americans since 1997.
  • by M-G ( 44998 )
    When Doom was all the rage, I enjoyed playing it, but always ended up getting motion sick. I always figured it had something to do with the wall textures and the way their motion was so apparent (like looking sideways out of the car window). As a result, I haven't had any interest in games like Quake...why play a game that makes you feel awful?

    Anyway, it's nice to know that others out there have the same problem.
  • What's up with the OpenGL vs. DirectX? It's never made much of a difference to me. Maybe you're using a different refresh rate in OpenGL. Look in to increasing that.

    BTW, the first time I played Descent, I got motion sickness, vertigo, and otherwise was very sick to my stomach. Cool game.

    ---------------------------------

  • by cr0sh ( 43134 ) on Tuesday June 06, 2000 @10:03AM (#1021863) Homepage
    All you have said is very true - but one thing you left out (or maybe only hinted about, if you read between the lines, so to speak), is one of the main reason motion sickness occurs:

    One set of senses are telling you one thing, while another is seeing (or perceiving, perhaps in the wrong way) another.

    Case in point, for the poster: He is obviously well immersed in the game, but most of his body is motionless - however, his eyes are perceiving that he is in motion. These two conflicting inputs (that of the eyes seeing motion, but his inner ear telling him he's not moving) help cause the motion sickness he experiences.

    How to help? Don't get immersed - have a frame of reference for your eyes that show them you aren't moving as well. Either sit farther away from your monitor, so that you see the edge of the screen, use a smaller monitor, or run the game in a window.

    A similar way to get sick is to ride an amusement park ride with your eyes closed in the late evening. Kinda the reverse of what the poster is experiencing.

    You talked about lag. In a fully immersed setup (High quality, 60 degree FOV or greater HMD, etc), lag can cause severe difference in inputs, if the lag is large enough. Say the screen is updating as you turn your head left, then you quickly turn your head to the right. The screen may still display the images of what you were doing when you were turning your head to the left, as you are really turning your head to the right (the Virtuality 1000 game system was notorious for this) - time to spew. Another problem with fully immersed systems can be sensor calibration - this would help cause motion sickness, either by say - an electrolic tilt sensor "sloshing" after physical movement has stopped - and hence displaying to the user they are still moving, or by the sensor being out of alignment with the users actual position - maybe in an extreme case giving the user the image of him looking up, when he is trying to look straight ahead.

    From my personal experience, I don't have a problem with immersed or semi-immersed virtual environments, even ones with bad lag. Maybe I have just adjusted, or for some other reason it doesn't bother me. What is strange though, is that I find reading while in an automobile (as the passenger, of course) makes me feel a little queasy - at least enough where I don't like to do it...strange...

    Here is a link to a paper done on simulator sickness for the U.S. Army Research Institute, by Eugenia M. Kolasinski:

    Simulator Sickness in Virtual Environments [phoenixgarage.org]
  • I experienced a similar problem with Super Mario 64. Eventually I discovered that it was because of the camera angles. The camera following Mario didn't react as I expected it to, so I'd get dizzy. After my brain learned what to expect, the symptoms went away.

    sdg
  • Moderators: This is not necessarily a troll. THC (the active ingredient in cannabis/marijuana) is known to combat nausea.

    This is why Chemotherapy patients do so much better if they take some THC.

  • I have found that there are a great number of people who get motion sickness with 3D games (especially those with full x/y/z rotation) only when they are not playing. When they are playing, they are fine (or last a lot longer). When they are jot playing and just looking over someone's shoulder, they get ill quite quickly. I think it has to do with perspective (since they are not centered on the action) and the fact that they cannot control the viewpoint. They are just along for the ride.

    Not certain if there is anything that can be done for it. It is a byproduct of the motion on the screen. (It would also be interesting to see if refresh rate is a factor here.)

    If you can't handle it, don't watch.
  • That's why I stock up on plenty of the drug grenades when I'm a medic in Quake 3, TF3.

    The swerving/wavy screen always make me feel motion sick, so I know it screws with my opponent real good!!!
  • by AlexA ( 97006 )
    I never had this motion sickness problem, but I wonder if the quality of the sound system attached to the computer has anything to do with it. Maybe motion sickness depends on both the accuracy of the visuals and sound, and gets worse based on how good/bad your sound system (speakers, amp, and sound card) is. Also, maybe having a Surround Sound system also affects sickness.

    Perhaps there's also a connection between the accuracy of DirectX/DirectSound and other non-DirectX sound engines that could affect sickness, which would partially explain James's observations.

  • i can't play that game more than 5 minutes without wanting to hurl. ironically, i bought it for myself, but my video card was too slow so i didn't play it for a couple of months. my wife gets a new imac, and we start playing it on that - i get sick even watching it, and she kicks ass on it. (even better: she's 28, never had a driver's license)
  • A couple of years ago I had a job that involved taking a variety of demonstrations around the country to show the benefits of cable modem service. One of our demos was of networked computer games. One of those games was a multiplayer motocross race. The physics of the jumps was visually very good.

    About one person in four had some problem with nausea while playing the game. No one ever actually puked, but one woman came pretty close. Closing your eyes usually corrected the problem almost immediately. Based on fuzzy recollections of various classes and readings, our conclusion was that the problem involved conflicting visual signals (I'm at the top of a jump and should be in free fall) and the signals from the inner ears (I'm just sitting in a chair at one gravity).

  • THC (the active ingredient in cannabis/marijuana) is known to combat nausea.

    Yeah, but it also mucks up your perception of distance and velocity. This isn't going to do much for your gaming.

    (Now awaiting a slew of "I got all my high scores while high" postings).

    Paul.

  • Could the polygon translation and rotation cause it? Or possibly the field of view?

    I've introduced several people into gaming and to get them started I will turn down the FOV because they will get motion sickness at the normal and higher ranges.
  • That would fit with most theories on the causes of motion sickness: your eyes perceive motion, ergo there is motion. Your inner ear does not detect motion, ergo there is none. Closing your eyes stops motion sickness. This is often visible on ships, people in the cabin get motion sickness, people on the deck don't. Ofcourse one can get used to it. the brain just has to find out that there is no discrepancy.

    //rdj
  • Don't know if this counts for anything, but it seems relatively easy to retrain yourself to handle the games better. I was trying to get a co-worker to play CounterStrike, but he refused saying that FPS games made him sick. Joking around, I told him Doom used to make me sick till I played it for 14 hours straight (that's true) and he should just spend the weekend playing it till he's cured. Saw him the next Monday, green and staggering, but smiling. Now he's the second best player in the office, without any of the previous problems. Another friend did the same, but popped a bunch of motion sickness pills before doing the long haul, and that seemed to work for him.

    What makes me curious now is exactly how long the "training" takes, and if it translates to other games, and other causes of motion sickness?
    1. "Experience the ultimate of video gaming action in your own home, with genuine interactive motion for IBM, and two of the most popular gaming platforms. Rock-N-Ride [rocknride.com] moves you and your monitor up to 55 degrees of rock and roll for the hottest gaming experience available today. Action flying and driving games will never be the same as you twist and turn through the game with unbelievable realism. Take a seat in a Rock-N-Ride simulator and fly into the future of home video gaming, the feeling is OUT OF THIS WORLD!!
    Unfortunately, it's going to be supported directly by the Linux version of Descent 3 [lokigames.com]. Add a few monitors using XFree v.4's Xinerama and/or multi-headed monitor support [xfree86.org], and you'll hurl with excitement!

    (On a serious note, good comments in this AskSlashdot.)

  • You know, a lot of people are considering this to be cheating. But yes, once you've gotten used to the kind of fisheyed view, it's more relaxing.

    //stalle - strike 'em down with romance

  • I totally agree. I used to have trouble watching friends play Wipeout XL for Playstation. The simulated speed, all the twists and turns and the eriely calming music just started to make me dizzy. It would sometimes get to the point that I would have to close my eyes and leave the room to prevent barfing. Then I tried the game. I felt fine. Even for hours at a time. Weird, huh?
  • I always get queasy playing 3D games. It's just a matter of how long I can hold on before it comes on. Usually it's worse when I'm watching someone else play, but give me about 20 minutes and I can feel the dreaded thing creeping up on me and I have to lay down.

    My solution: Take carsickness tablets. I find that a single tablet last me 4-5 hours and I feel great.

    One stange thing I've noticed is that if I play without tablets for 30 minutes each night, by the end of the week I can go for 2 hours without needing a tablet. It's as if I'm training my mind/body to cope. Sadly, if I stop playing for a week, I'm back to square one.

    Good luck!
  • Over the past several years while developing our "soon to be released" interactive fitness system we have done extensive user testing. We use real video, helmet cam POV shot on location. Started with Cinepack on the GBNF 3DO and now use MPEG2 on DVD ROM. The interactive part is that the video speed/frame rate is dynamically controlled by user input via aerobic fitness equipment (see www.exerscape.com for more detail) You pedal the bike faster, the video speeds up. We found significant problems with nausea when we tried video without following a rider. The slight camera jiggle is very disorienting to some people. When we have the cameraman follow a rider, it seems to give people something to focus on and almost all the nausea problems go away. Plus it is much easier for the cameraman to keep the shot framed during the long takes we typically do. Anyway, for some reason having something to focus on in the foreground seems to make it much easier on those with a tendency towards motion sickness, at least in our application.
  • when I was on a submarine in the Navy, it always sucked riding on the surface while I was belowdecks. Because a submarine has a round hull, there is nothing to prevent it from rockig back and forth. I never needed it but there was a patch you could put behind your ear that released medication. We called it the pussy patch. The way I kept from getting too nauseous was to be next to a vent with cold air blowing across my face. It was almost as if I was getting a fever.
    I remember back in summer of '93 playing Wolfenstein 3d on a 486/66 and getting extremely hot and nauseated after playing for about 30 minutes...even with the temperature set to about 68F.
    I find that Quake/Doom,etc does this to me, Descent does a little, but no flying games like F16, Extreme Velocity, or Rainbow 6: Rogue Spear do it to me at all. Oddly enough, Carmageddon doesn't make me sick, but Carpocalypse (Carmageddon sequel) did. Go figure.
  • I have had this on occasion with Quake, but the number one culprit, for those of a retro persuasion, was the Ultima Underworld series, with the swaying run.... Strange thing was I was fine for weks, then suddenly I could no longer play it for even a few minutes. No hardware changes, no screen setup alterations... Helpful, huh ? But I got to be nostalgic.
  • You *can* train yourself out of this. The UK RAF does this for pilots over a matter of months: its worst for navigators because they do the reverse of what we're speaking about: they look at a motionless screen while being subjected to motion. The USAF actually sends their vomiting pilots to the RAf to be debugged on this one...
  • I remember seeing a story a while ago (not nessiarily on slashdot tho) about these people who were making a device that could manipulate your inner ear with electrostatic forces (or something). They were planning on selling these things into the gaming market for the purpose of having a more imersive and better syncronised gaming experinece. That is, when you eyes tell you that you are tilting, your inner ear agrees with them.

    Games would have to be written to take advantage of this, but once it becomes available, it should help reduce nausea.

    I really wish I could remember the name of the company that was gonna make these things...
    --
    Will Dyson

  • I don't know what the primary source of this is, but in Steven Pinker's How the Mind Works, he mentions the following theory:

    A common symptom when a human ingests a toxin (e.g. alcohol) is that their eyes sense a different perception of balance and motion than their inner ear. So the body evolved to eject these toxins (vomit) when that symptom appeared. I could see a how a similar effect might happen if the visuals were delayed with respect to the anticipated motion.

    So the trick would be to lower the latency of the display as much as possible, or to get one of those nifty motion simulators [slashdot.org] when they come out.

    -Frank
  • I'm so glad other people are having this problem as well. I thought it was just me. Every person I have ever asked about this just looked at me like I was insane.

    I see a lot of similarity with some of the above posts. I can play Command and Conquer or Rainbow 6 for days on end but within 5 minutes of playing Quake or Halflife I get all dizzy.

    My worst case came after watching my buddy play Team Fortress Classic for less than 15 minutes. I had a splitting headache and the worst case of dizziness for the entire weekend. The strange thing is he was on a brand new Athlon 800 with a 32MB DDR GeForce video card, 512MB ram and a 21" moniter. Top of the line everything. That makes me wonder if the effects are the cause of hardware. It's sounds very plausible but seems a bit odd im my circumstance.

    My worst fear is about the future. Most sci-fi techno books paint a picture of a future with "virtual worlds" (i.e. Snowcrash). I'm just worried that I won't be able to participate because of my motion sickness.

    Suffice to say, I'm glad other people are having this problem. Up until now I thought I was the only one.

    LiNT

  • The reason why DirectX makes folks sick is the once-per-30-frames blurb of "Microsoft is your friend...", which induces nausea in people capable of critical thinking.....

    Seriously, though, I did get quite ill playing Turok at a friend's house last year. It was similar to what I feel like if I read in a moving car. Other than that, I've never had much of a problem with sickness.

    My worst problem has been tunnel vision. I feel like I'm looking through a paper-towel roll when I'm playing FPS. I don't know if field of view is configurable from game to game, but I'd like to play around with that to see if it makes a difference.
  • Virtual Motion [vm3.com] and their MotionWare technology. They use a system of vestibular stimulation (look it up on Google and on the IBM Patent Server) to do what they say they are doing. Vestibular Stimulation is nothing new - it has been in use in the medical community for quite some time studying balance (or loss thereof). But the devices/systems used were crude affairs - whereas Virtual Motion claims the ability to control direction of perceived forces, etc.

    A few years ago they were offering dev kits (and beta devices) to developers for around $2000 or so (maybe less - it has been awhile) - since then, I have seen nothing come out of them, though they still appear to be in business.

    You are right, though - this would help combat simulator sickness...
  • A long time ago (I don't remember where)I read an article about motionsickness, it naturally wasn't about simulation sickness, as there at the time weren't any simulators around(at home at least).

    The reason, they claimed, was that our ancestors, thousands of years ago, were very often eating bad food, poisonous berries, bad meat and such things. Because of this they developed this ability to throw up everything in the stomach when the body signalled that something was wrong with the thing they had eaten.

    So... What was the signal of poisoning? Anyone that have ever eaten something that makes you very sick knows that the symptoms are illnes and dizzieness! Yup, that's right. When they ate something bad their vision went crazy. And that was the signal to the body to get rid of all they had had for supper.

    I don't know if the theory is true or if science have found any better explanation, but it kind of makes sense to me...
  • Check out this system http://www.vm3.com/MotionWare/index.html

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