In-game eye distance is wrong! How to correct?

[Nooch]

Hi there ladies and gents!

 

I've been using the Rift for about 2-3 weeks now and although I've configured everything as best as I could, one thing still remains off: the in-game eye distance doesn't match up with real life. I know, you have to adjust your IPD using the slider on the headset... and that's what I did. (mine is 66 millimeters by the way)

 

I have a clear picture on each eye and 66 mm is where it feels the most natural, crisp and effortless. I took some time to adjust it so I don't think my IPD adjustment is to blame.

 

Yet in-game, my left eye and right eye images don't align properly. They seem too far apart resulting in double vision, discomfort and even eyestrain after long sessions.

 

So my question is: can I do anything about it? Is there anyone else experiencing the same issue?

I'm pretty sure it can be tuned manually in the software but I don't know how. Any thought?

 

EDIT: It seems that in-game eye distance is perfectly fine and that the discomfort I experienced comes from the way VR headsets are designed and handle stereoscopic vision.

Edited September 14, 2017 by Nooch

[PreussLee]

Double vision is a Problem in dcs for me too, though its the only game i do experience that, so i dont think i has something to do with ipd adjustment...Never experienced it in asseto corsa or other games, but on the other hand dcs is the only one where you have to really look close sometimes searching for small objects...so maybe i just didnt notice it in other vr experiences...

[Nooch]

I don't know if the issue is also present in other titles but it's very much possible. I'll try some Assetto Corsa and let you know. I'd be really glad if there's a .lua file somewhere where you can tweak the viewpoint gap manually. That would basically solve my problem.

[grifo]

Hi! Optician here .. doubled vision or diplopy can occour in some stressing visual conditions. Using vr devices could be one of these for a sensitive eye or a particular convergence weakness (eterophoria). I strongly raccomand to check this problem with tour thrusted optician to find some lens solution if setting DPs doesn't solve this problem. You are right you didn't experienced before because of images size. Hope I was helpful :) Please let me know how you solve, just for my professional interest !

 

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Edited September 8, 2017 by grifo

[Nooch]

I may have figured out what was happening. I think it all comes down to what VR headsets are doing to give users distance perception. Basically they have to trick the brain into thinking you're looking at a more or less distant object when in fact you aren't because the screens (one for each eye) remain at the same distance from your eyes at all times.

 

Let me explain in more detail.

VR headsets change your depth perception using the stereoscopic ability of your eyes (two different points of view that your brain combines into one). For example, when you look in the distance, the angular difference between each point of view will be negligible. Depth perception will be minimal. On the other hand, when you look at something up close it will become quite important.

 

Problem is VR headsets do this but without making your eyes accomodate which of course confuses the brain, which isn't used to this kind of scenario. Your brain then sends signals to your eye muscles to make adjustments when in fact, there is no need for it, creating discomfort and eyestrain.

 

I could be wrong though. Please take what I said with a grain of salt.

Edited September 10, 2017 by Nooch
Making things clearer and using proper terms

[Mozart]

Hi.

 

There is a file to put in your simulated eye-distance. You can find the topic by searching a thread about "stereo.lua".

 

I copied this instruction out of one thread:

"As far as I know it's in \DCS World\Config\MonitorSetup\Stereo.lua

There is an "eye_shift" parameter, try changing it.

The sum of those two should be equal to your IPD (IIRC value is in meters, <0 for left eye and >0 for right eye, therefore in your case that should be -0.034 and 0.034)."

 

I used that a while ago and I think it is working well. I have 74 mm IPD and since I entered that value it feels normal, that my eyes are parallel looking at something far, and crossed looking at something near, but without a strain.

 

No information if that is old info or still necessary and if the HMD communicates the IPD value to DCS.

 

Am interested in your feedback.

 

Bye, Mozart.

[grifo]

Hi axelerator ! I find your explanation pertinent and almost correct. There is a specific term for process you described and is just called "accomodation". It's a complex eye ability, and starts to work automatically when seeing something near to us. What you described can cause off course motion sickness, the most common problem in using this kind of devices. Your brain has just to be "trained" for a while to avoid it. But proximity doubled vision you described is a more specific issue and can be often corrected with lenses. Let me know if you solve!

Cheers

 

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[Colmillo]

Hi axelerator ! I find your explanation pertinent and almost correct. There is a specific term for process you described and is just called "accomodation". It's a complex eye ability, and starts to work automatically when seeing something near to us. What you described can cause off course motion sickness, the most common problem in using this kind of devices. Your brain has just to be "trained" for a while to avoid it. But proximity doubled vision you described is a more specific issue and can be often corrected with lenses. Let me know if you solve!

Cheers

 

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Thanks for contributing, I have a professional consultation. Do you think that prolonged use of oculus can affect vision?

Thanks again

[Chic]

'Accommodation" is a term used to describe the vertebrate lens ability to change its dimensions to maintain retinal focus on images at varying distances.

[Nooch]

There is a file to put in your simulated eye-distance. You can find the topic by searching a thread about "stereo.lua".

I copied this instruction out of one thread:

"As far as I know it's in \DCS World\Config\MonitorSetup\Stereo.lua

There is an "eye_shift" parameter, try changing it.

The sum of those two should be equal to your IPD (IIRC value is in meters, <0 for left eye and >0 for right eye, therefore in your case that should be -0.034 and 0.034)."

I used that a while ago and I think it is working well. I have 74 mm IPD and since I entered that value it feels normal, that my eyes are parallel looking at something far, and crossed looking at something near, but without a strain.

 

Thanks! That's precisely what I was looking for. I'll have a look into this file and keep you guys updated.

 

There is a specific term for process you described and is just called "accomodation". It's a complex eye ability, and starts to work automatically when seeing something near to us. What you described can cause off course motion sickness, the most common problem in using this kind of devices.

 

Sorry, in my long post I just lacked the proper vocabulary. I'll make an edit. Actually I meant that VR HMDs change your depth perception using the stereoscopic ability of your eyes (two different points of view that your brain combines into one) but without making your eyes accomodate. Because your eyes aren't used to that in real life, I guess that's what's creating eyestrain. Again I could be wrong though.

Edited September 10, 2017 by Nooch

[Gunja]

Hi.

 

There is a file to put in your simulated eye-distance. You can find the topic by searching a thread about "stereo.lua".

 

I copied this instruction out of one thread:

"As far as I know it's in \DCS World\Config\MonitorSetup\Stereo.lua

There is an "eye_shift" parameter, try changing it.

The sum of those two should be equal to your IPD (IIRC value is in meters, <0 for left eye and >0 for right eye, therefore in your case that should be -0.034 and 0.034)."

 

I used that a while ago and I think it is working well. I have 74 mm IPD and since I entered that value it feels normal, that my eyes are parallel looking at something far, and crossed looking at something near, but without a strain.

 

No information if that is old info or still necessary and if the HMD communicates the IPD value to DCS.

 

Am interested in your feedback.

 

Bye, Mozart.

Oh this is very interesting. I will try ASAP.

By the way, if his IPD is 66, shouldn't he enter 0.33 and -0.33 and not 34 ? Or am i misunderstanding something?

Edited September 10, 2017 by Gunja

[grifo]

Well... accomodation is a more complex behavior than just mantaining focus on retina by lens ability.. off course this is part of the process , but not the only one. Automatically when looking nearby objects your iris will restrict to better focusing (miosys), your eyes will gain convergence for aiming the same point and, off course, eye lenses will accomodate. That's called "accomodation triad" and all tree processes acts at the same time. When using vr, device's lens system "cheats" your sight system making it believe you are looking at an infinite distance, as you correctly said, denying eye lenses to accomodate, but the other processes of the triad can't be bypassed and will acts as you are looking nearby. So, you are focusing at infinite distance, but your eyes convergence will acts as you are reading a book! For sure this is very stressful situation you have to be trained, but if you have a problem of latent misconvergence (eterophorya) that you are not aware about, this will likely force your eyes to diplopy. I'm not saying vr devices are dangerous and causes eye diseases, in a normal health condition sight system is strong enough to overtake this strange situation, but i raccomand to check user manuals for warnings if you know you have some sensitiviness. Hope it helps

 

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Edited September 10, 2017 by grifo

[Mozart]

Oh this is very interesting. I will try ASAP.

By the way, if his IPD is 66, shouldn't he enter 0.33 and -0.33 and not 34 ? Or am i misunderstanding something?

 

Yes, you are correct.

The values are examples without relevance to the values of the specific case.

[Nooch]

For sure this is very stressful situation you have to be trained, but if you have a problem of latent misconvergence (eterophorya) that you are not aware about, this will likely force your eyes to diplopy. I'm not saying vr devices are dangerous and causes eye diseases, in a normal health condition sight system is strong enough to overtake this strange situation, but i raccomand to check user manuals for warnings if you know you have some sensitiviness. Hope it helps

 

Thanks for your input grifo. You're right to point that out, convergence weakness could have been the cause of my problem. However last time an ophtalmologist checked my vision, I had strong convergence and 12/10 vision so I think I'm good on this front. Perhaps I should have said it earlier.

[grifo]

Thanks for your input grifo. You're right to point that out, convergence weakness could have been the cause of my problem. However last time an ophtalmologist checked my vision, I had strong convergence and 12/10 vision so I think I'm good on this front. Perhaps I should have said it earlier.

Glad to know about it! So the only solution seems to be some tweaking with device settings.. remember just IPD is non always a perfect half split.. p.e. 66 could be likely something as 32 - 34 according by eye dominance and anatomic constitution (PD) or by sight distance (AVD).

 

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[Nooch]

Last night I went and checked the file stereo.lua and indeed the default settings were wrong. But not by much. 0.032 instead of 0.033 so quite a small difference there. I fixed it and then launched the sim and stereo vision seemed a tad more comfortable.

 

The problem though: my eyes were still very much strained after my session. That could be because of many different things. I did a lot of kneeboard (checklist) reading that night in VR and the fact that I was struggling to read those blurry letters certainly didn't help. Low resolution and the fact that everything that is away from the center of the image is blurry (by design on current VR devices) are a bummer and certainly contribute to eyestrain...

 

Maybe the Rift isn't adjusted well on my head and I am either too far or too close to the lenses. Possible but really not likely because I spent quite a while adjusting the headset and tried multiple adjustments. Right now it sits tight (but not too tight) on my face and the image is as crisp as it can be. I can even see individual pixels at all times...

 

Very hard to tell what's wrong there but I guess it's the subject of another discussion. Either I'll finally figure it out a bit later or I'll just have to sell my Rift...

[Gunja]

snip... Low resolution and the fact that everything that is away from the center of the image is blurry (by design on current VR devices) are a bummer and certainly contribute to eyestrain...snip

 

I have learned to move my head a lot more than IRL because you need to keep the objects of interest in the center of your fov. Try moving your head more instead of glancing with your eyes.

 

BTW i also changed that stereo.lua value to fit my ipd and i think things look better so cheers for that tip.

[SpeedStick]

This sound interesting but Im not really sure I understand it.

Im guessing you need to have your exact IPD measured in order to get correct changes?

Or are the setting wrong by default so one should change it?

[Gunja]

Yes, i went to the optician and he measured my IPD in 30 sec.

To do this stereo.lua change, you need to know your IPD.

If you have IPD 64 than the default value is ok. Mine is 66 and i changed default value from 0.32 to 0.33 both + and - values (left and right).

[Nooch]

BTW i also changed that stereo.lua value to fit my ipd and i think things look better so cheers for that tip.

 

I'm glad this thread helped you as well! I will try to post something in the bug/problems section of the forum so that developpers can know about it. If things were done right, the correct value in stereo.lua should be set automatically without needing to edit it manually.

[some1]

Guys, stereo.lua is used only for 3D monitors. For rift/vive, the game receives the exact IPD value that the user has set using hardware lenses adjustment on the headset.

 

If you see difference after modifying the file, it's placebo.

[Nooch]

Guys, stereo.lua is used only for 3D monitors. For rift/vive, the game receives the exact IPD value that the user has set using hardware lenses adjustment on the headset.

 

If you see difference after modifying the file, it's placebo.

 

Are you sure about it? Cause I feel bad reading this, especially now that I've created a thread in the bugs section :doh: :lol:

[Mozart]

Guys, stereo.lua is used only for 3D monitors. For rift/vive, the game receives the exact IPD value that the user has set using hardware lenses adjustment on the headset.

 

If you see difference after modifying the file, it's placebo.

 

 

Hi guys.

 

I just tried different extreme values in the eye distance value in stereo.lua and it had no effect on my Vive. I remember that we used to change that value in the Oculus prototype days. At least the VR headsets are nothing but stereo monitors directly in front of your eyes.

 

However, the experimental results are: stereo.lua has no effect on my Vive.

 

Sorry guys, didn't mean to mislead anyone!

Edited September 12, 2017 by Mozart

[grifo]

I have learned to move my head a lot more than IRL because you need to keep the objects of interest in the center of your fov. Try moving your head more instead of glancing with your eyes.

 

BTW i also changed that stereo.lua value to fit my ipd and i think things look better so cheers for that tip.

Yes, this is absolutely the best way to get best results! Changing ipd (remember the right/left values are not an half split of the total) changes only the screen's position for both eyes. But lenses inside devices can not be centered according ipd like in personalized glasses.. results are prismatic effects and chromatic aberrations that causes strains and poor quality of images. When you look in a point far away from the focal center of the lenses, this is even more amplified at a distance of a few centimeters, no matter you are using correct ipd values for screens. Personally I will go oculus rift when they will take better care about quality and customization of lenses according to screen resolution, even I know it will translate in much higher cost.

 

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[Nooch]

Personally I will go oculus rift when they will take better care about quality and customization of lenses according to screen resolution, even I know it will translate in much higher cost.

 

You're right, after having played several hours with the oculus now I would definitely advise you to wait for the next gen. Right now the resolution is awful, so bad in fact that you cannot even read inscriptions in the cockpit and even in general, it's a big immersion killer. If you then add up the fact that everything out of the center of the image is blurry, plus the stereoscopic vision that feels uncomfortable right now, man... I don't know if it's actually better than a normal screen with Track IR...