Do you get motion sickness?

[DeltaMike]

If you have a Reverb, and you've been experiencing motion sickness in VR, I'd be interested in your thoughts about the OpenXR mod.  

Studies suggest the main variable in VR sickness is latency.  In other words, the total amount of time that passes between when an action occurs, and the result is displayed in the monitor.  

Perhaps the most relevant action here would be head rotation.  If the world doesn't stop spinning when you do, reach for the bag.  

So this is what the sequence of events would look like in a G2 running under the SteamVR runtime:

1.  Headset detects movement.
2. Signal travels down the wire and through the bus to the CPU. 
3. CPU starts doing the math, and passing the results to the GPU. 
4. GPU starts figuring out what pixels to turn on.  (Ideally these two processes will occur as much in parallel as possible). 
5. At this point, DCS and Steam are done with their work.  Now it's up to WMR4SVR to pass information from Steam to WMR for processing.  
6. WMR distorts the image (so it looks right behind those crazy lenses) and passes that information to the display.
7. That information travels down the wire to the headset. 
8. Pixels are turned on. 

To measure how well we are doing latency wise, we typically look at render times, and the derivative of that, FPS (with render time being a far more accurate measurement).   Note, we can only measure steps 2 through 3, everything else is a mystery.  And in particularl, some kind of tomfoolery seems to be happening at step 4, in the way Steam hands stuff off to WMR.  Most of us experience that as stuttering.  You may experience it as nausea AND stuttering.  (Life is grand.) 

One way around that is to figure out a way to run DCS using OpenXR, the same runtime the Microsoft Flight Simulator uses.  Your headset likes OpenXR, it runs it natively and doesn't need a translator.  

My theory is, bypassing WMR4SVR should reduce latency considerably.  If so, perhaps it would cause less motion sickness.  

I'd be really interested to know what you think.  

[DerekSpeare]

VR induced discomfort is common in folks who are new and for those who have low end pc's.  I got VRID back in 2014 when I first got the DK2, but learned how to tune the pc AND what to do to prevent it (that being to stop when it creeps in).  Anyhow, nowadays I don't get it...and having a pc that can run all the steps as you intelligently articulated above helps. 

Of course, with increased frame times/decreased frame rates so goes to rate at which the potential for VRID can occur.  As you've recognized, there are a number of links in the chain of processing a visual image once one moves their head to cause it.  If ED ever reads their forums, perhaps they will come to the same conclusion, but that's a mystery unto itself.  Indeed us WMR users are in that gap of additional processing/render times I believe the Vive and Oculus folks do not occupy. 

I'm all for the implementation of OpenXR.  It makes sense to me.  I've not tried a head to head comparison on my PC with WMR4SVR against openXR, but I am guessing it would give a performance gain; right now there's too much fiddling around to get to work, something I am not interested in doing.

So reducing the potential for nausea and discomfort among the ED Customer Base who use VR is always a good thing.  While it's not the chief reason to do it, it's another legitimate one to support openXR, that is if your hypothesis is correct   (which I believe it is)

[CybrSlydr]

I didn't seem to get any nauseating feelings while using the headset in DCS (F-16 and Apache), but I did notice that after I took it off and I moved my head around quickly or my eyes that I felt a little uncomfortable.

[Baldrick33]

I believe the biggest cause of nausea in VR is the mismatch of visual and vestibular inputs the same (well reverse) as motion sickness in cars or boats when we don't look outside.

Our brains assume the mismatch is a result of being poisoned and tell us to throw up. Therefore we have to train our brains that this is normal. The result of which is variable and some simply never gain their "VR legs"

I am sure reducing latency as much as possible would improve the experience but having gone through the "VR isn't for me!" day one illness with Project CARS (also in 2014) with a DK2 to having tried a number of devices (CV1, Odyssey+, Pimax 5K+, Index, G1, G2, Vive Pro2) I can't say I have noticed any apparent issue with WMR and SteamVR to highlight it as a problem. Conversely I find MSFS less smooth than DCS at the same fps (running reprojection).

Of course reducing the steps to render makes a lot of sense but I am not yet convinced it is the magic bullet we might hope.

Edited March 25, 2022 by Baldrick33

[dburne]

I got nausea when I first got my Rift CV1 back in Jan 2017. It settled down after a couple of weeks and not been an issue for me since with any of the headsets I have owned.

[DeltaMike]

©Baldrick33

Agree. 

Minecraft is what makes me puke, it's the movement without vestibular input that sets me off I think.  

Problem for my experiment is, people get tolerant quickly. Gotta find me some newbies

 

 

 

[Baldrick33]

2 minutes ago, DeltaMike said:

Problem for my experiment is, people get tolerant quickly. Gotta find me some newbies

 

I am not sure that will help, as any VR headset is going to make some ill.

I would have thought that wireless headsets had potentially bigger issues with latency than WMR devices

[98abaile]

I haven't had any motion sickness in VR. occasional eye strain and vertigo, but never felt sick. For me OpenComposite has made things buttery smooth and opened up some overhead for increasing settings. Hasn't improved my frame rate, but it is now rock solid.

[Svsmokey]

I have never experienced motion sickness in VR , running WMR and steam VR . I personally prefer a clean installation of DCS , so i have no thoughts on OpenXR . I would , however , try it if ED provided native support .

Edited March 27, 2022 by Svsmokey

[Marklar]

I suffered from motion sickness for a week when I first tried VR six years ago. The only time I get sick is when fps drop below 45 for an extended period of time. I also void playing "walking" games, they make me sick instantly. Flying and racing sims I can play for hours without any problems.

I tried OpenXR mod yesterday. I didn't notice any performance improvements but I did notice a lot more artefacts. OpenXR renders the game in 30fps and extrapolates new 60fps to make 90fps. It might feel smoother if your PC cannot render 45fps with SteamVR but for the price of more artefacts. 

[Baldrick33]

5 minutes ago, Marklar said:

I suffered from motion sickness for a week when I first tried VR six years ago. The only time I get sick is when fps drop below 45 for an extended period of time. I also void playing "walking" games, they make me sick instantly. Flying and racing sims I can play for hours without any problems.

I tried OpenXR mod yesterday. I didn't notice any performance improvements but I did notice a lot more artefacts. OpenXR renders the game in 30fps and extrapolates new 60fps to make 90fps. It might feel smoother if your PC cannot render 45fps with SteamVR but for the price of more artefacts. 

I can't do walking games either. i so wanted to do things like Medal of Honor in VR, just wasn't to be!

I am not sure about the 30fps with OpenXR. My understanding is that it will reproject at 45,30,22.5 depending on frame times.

[dburne]

Just now, Baldrick33 said:

I can't do walking games either. i so wanted to do things like Medal of Honor in VR, just wasn't to be!

I am not sure about the 30fps with OpenXR. My understanding is that it will reproject at 45,30,22.5 depending on frame times.

Just as an aside, I have played both Medal of Honor and Half Life Alyx seated, thoroughly enjoyed it.