VR IPD setting explanation and why you need it

The "Force IPD distance" on the VR tab can be misunderstood, I certainly did so I'm sharing. One may confuse it with some optional IPD software setting and think it does not apply to you or your headset manufacturer. I know there are lots of discussion posts but none of them explain it clearly and after reading them I had to test myself and thought I would share.

Pre-note 1: This is similar but not the same as Field of View which is a setting that also differs between modules and affects 2 Dimensional scaling of objects. Most noted between Hornet and Tomcat modules where people noticed carriers seemingly further away visually at the same distance in the Tomcat.

Pre-note 2: I use Oculus CV1 and have glasses inserts with correct up to date prescription and have 63mm IPD and am 6feet tall with standard proportions. This is relevant when comparing to others and all this is marked heavily with "Your mileage may vary".

What does "Force IPD" do?

Nutshell: It makes you bigger, or smaller, as an entity. Which makes the world feel bigger or smaller as a result. It simulates the apparent change in size of the entire world based on an estimate of the distance between your eyes. Larger IPD = bigger person and smaller cockpit and world. Smaller IPD = smaller person and thus the cockpit and world get larger.

It does not make anything blurry, give you headaches, kidney failure or anything, just the above.

Why do i need it?

Because not all the cockpits appear scaled the same way. This might be a number of reasons, I dont think it's pure scaling. Let's get over "why" this is so, it just is. In a perfect world, you could set one IPD that makes everything look the right size and it would mean all modules appear perfect, but you can't, so get over it quickly and your world will be easier to live in until this changes. The same IPD will make you feel either too small or too large in different modules. So you NEED IPD settings to fix that.

Which modules seem to me large or small or just right?

(Personal findings, YMMV)

Feels too large: A-10C, F-5, KA-50, Spitfire

Feels too small: F-16

I left out a bunch of modules because I haven't really done testing extensively or iterated my testing to the point of good confidence, because you are essentially "eyeballing" the size, which is quite hard to be measurably confident in. Hornet and F-14 felt good though. Place your own findings below, it's all relevant.

How can I change the IPD more simply?

Whilst in cockpit, press ESCape, Options, VR TAB and the IPD setting is available.

To activate the change, you are required to uncheck and recheck the checkbox to force IPD settings with a new number. Relevant numbers could be anywhere from 45 to 70 - YMMV but people are reporting similar results. This works in realtime, in multiplayer too, which is convenient. The cockpit sizing will change in the background immediately so you can see the change instantly, and tune it.

How do I know the correct IPD per module?

To work out if it's getting close to 1:1 'correct' is quite tricky. You need a yardstick, like your hotas, because not all cockpits are the same, some are tight IRL and some are more roomy, especially in width. It would help if you had sat in the relevant cockpit, immensely. The only one I sat in was an F-4 and I could barely fit, it was a revelation on how small they actually are. In simulation you have no helmet and no canopy over you to hit your head on. You can 'feel' with your shoulders a bit, but do not rely on your eyeball height, or the apparent closeness of objects to your face. In VR without the pilot body you have other things, like, the angle you are sitting at, the height your eyes are level at (you may be lower than you think in relation to the HUD, as a 6 foot man). But the best yardstick tends to be the Warthog stick and to scale the cockpit stick so it appears it would fit correctly in your imaginary hand. To some extent, the switches are fairly standard and you can use those too, as well as the MFD's if available.

Will changing the IPD help me see details better?

My findings are; "nope". It's a small change. Best to upgrade from CV1 :).

So what's the point?

Actually the immersive-ness with correctly balanced scaling is quite a big thing, and much more noticeable if you have more than one module as you should try to have consistent sizing between them, especially with square objects like MFD's that should be the same size. Inconsistent feelings or feelings that you are small (or large) in the cockpit have a subtle and large effect on the feeling of being "at one" with the plane, which is entirely the point and best part of VR. In fact, it can put you entirely off one of your favourite modules because it feels inexplicably 'wrong'.

Why no pictures?

I took some screenshots, firstly from the mirror, then internally, and you just don't have the same understanding of how the scale grows when its back in 2Dimensions. If I were to quantify the difference in the F-16 cockpit, for example:

Warthog stick at 63.5 IPD appears to be a childs toy 3-4 cm shorter and 1cm thinner than reality.

50 IPD is my own sweet spot for the Viper.

Finally, play this whilst you are fiddling with IPD:

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Thanks. Very detailed and informative. I sure did learn some new things about the Forced IPD.

ED should change the "IPD" to mean the world scaling. It would be far more clear to what it does. As now the IPD value scales the world, instead adjust the virtual cameras separation. And this is easily noticeable when you keep other eye closed and you change the DCS IPD, the world scales, while nothing else should happen that your FOV just slightly shift (almost unnoticeable) if it would be the IPD value.

The real IPD value would affect only to depth perception instead the world scaling when talking about few millimeters value changes like 58mm vs 62mm, but in DCS it is major world scaling effect.

Great post. Great song! Thanks.

Thank you for this, I'm going to mess with the Viper's IPD when I get home.

Yeah 100% with this. When I switch to the Viper from the Hornet and vice versa I have to change the setting. With the Hornet setting in the Viper, it feels tiny! And if I leave the Viper setting and jump in the Hornet it feels and looks huge! Like a 747!

if people need to adjust world scaling in DCS between modules, it means that ED has not confirmed a model true size to a standard. As no matter what, a 50cm stick should look 50cm stick in cockpit. As well ED needs to standardize the head position to be locked to the chair seat, not to the HUD or like that. If the player is too short or tall, they need to adjust ejection seat height as in real one. This guarantee that player doesn't feel to be taller or shorter than they really are.

Why do i need it?

Because not all the cockpits appear scaled the same way. This might be a number of reasons, I dont think it's pure scaling. Let's get over "why" this is so, it just is. In a perfect world, you could set one IPD that makes everything look the right size and it would mean all modules appear perfect, but you can't, so get over it quickly and your world will be easier to live in until this changes. The same IPD will make you feel either too small or too large in different modules. So you NEED IPD settings to fix that.

That's the worst part of that. If all modules would be scaled equally one "IPD" would be proper for all of them.

Even two newest ED modules Hornet and Viper seems to have very different scaling looking at the size of their sticks and throttles.

if people need to adjust world scaling in DCS between modules, it means that ED has not confirmed a model true size to a standard. As no matter what, a 50cm stick should look 50cm stick in cockpit. As well ED needs to standardize the head position to be locked to the chair seat, not to the HUD or like that. If the player is too short or tall, they need to adjust ejection seat height as in real one. This guarantee that player doesn't feel to be taller or shorter than they really are.

+1 :thumbup:

Edit: Forgot to mention that my World Scale settings (IPD is really the wrong term that ED is using in the DCS VR settings) is usually set from 48 to 50, which seems to work for most modules for my personal taste.

Perhaps it's just me then, but I don't see any problems with IPD. Of course the older modules have the wrong scale since they have cockpits designed before VR was supported, so the new models for Ka-50/A-10C/MiG-21/... will fix that.

I tried setting my IPD to 50 while sitting in the F-16 just because of this thread, and that just makes it feel like I'm sitting in a Su-27.

I set the IPD both in Oculus Home and DCS to my real-life one, and that works perfectly for me, both in the F-18 and F-16. Any other value is just weird.

(I'm 1.88m or 6'2" and my IPD is 66)

@Elysian Angel - for me, those higher numbers make everything just a little too small.

I always try to match my hand size to that of the virtual pilot in DCS where I can; when no pilot is available, I am looking at the virtual control stick vs my own joystick and try and match that - hence the 48-50 world scale in DCS.

My actual IPD is 69, which would - sitting in a DCS plane - feel like sitting in a scale model of it.

How does it impact spotting if at all?

I tried making a mission ready on ramp with soliders and humvee trucks and Huey around, eject then walk around and have a feel. Default feel fine to me. I know Ive seen A10s cockpit and it’s a lot smaller than the current.

There is a lot of talk about 'feel' in this thread.

Since I imagine DCS and their various developers had access to the aircraft and drawings in order to take measurements that the 3d models are in fact correctly scaled.

How many of the posters claiming they 'feel' this or 'feel' that have actually spent any time sitting in the various real-life cockpits of the modules they are flying. It has already been mentioned in another thread that the real F18 cockpit is significantly larger than the F16.

Anyone from DCS care to comment on the accuracy of the 3d models?

FWIW my Rift S is set to the default 63.5 and I haven't noticed any scaling issues with the modules I own.

There is a lot of talk about 'feel' in this thread.

 

Since I imagine DCS and their various developers had access to the aircraft and drawings in order to take measurements that the 3d models are in fact correctly scaled.

You can eject and walk to i.e. a static AI soldier as the pilot.

When i walk to him i see my head is at most 1.3-1.5m above the ground and the static soldier is a midget i see the scale is wrong.

Or i seat in an F-16 and the stick is A LOT smaller than my Warthog i see the scale is wrong.

There is a simple solution, (but i'm not a specialist so i may ommit some important thing):

1) All cockpits in the game should be scaled to the one uniform scale - that's no brainer.

2) There should be a virtual ruller of i.e. one meter in the game - you would compare this one meter with real life ruller in your hands, scale accordingly just one time and this way you would have all the game scaled properly.

You can eject and walk to i.e. a static AI soldier as the pilot.

When i walk to him i see my head is at most 1.3-1.5m above the ground and the static soldier is a midget i see the scale is wrong.

Or i seat in an F-16 and the stick is A LOT smaller than my Warthog i see the scale is wrong.

 

There is a simple solution, (but i'm not a specialist so i may ommit some important thing):

1) All cockpits in the game should be scaled to the one uniform scale - that's no brainer.

2) There should be a virtual ruller of i.e. one meter in the game - you would compare this one meter with real life ruller in your hands, scale accordingly just one time and this way you would have all the game scaled properly.

The ground environment is a fair point - it has already been demonstrated that the trees are far too big, but necessary to get the same perceived ground coverage with fewer trees. An understandable compromise.

Personally I like to spend as little time on the ground as possible. DCS is a flight simulator, not a SERE school simulator!

My point is that when people are claiming something 'feels' wrong with no real-world experience, perhaps it is actually their preconceptions which are wrong.

There is a lot of talk about 'feel' in this thread.

 

 

 

Since I imagine DCS and their various developers had access to the aircraft and drawings in order to take measurements that the 3d models are in fact correctly scaled.

Yes, that is what I would believe as it is like basic thing you do in the first tasks when setting up the modeling environment, and yet as long you model everything in the scale of the model, you can later rescale it to any size you want without problems.

But that is the problem for many, if a same stick in A-10C and in F-16C looks different in size, then it is a different in size. If you place your physical stick where it is in A-10 and where it is in F-16 and you can see that it doesn't feel at all as you feel in your hand about the size, then there is a problem.

If the 3D model is done correctly, and the VR sets the cameras correctly on each module, then everything should be exactly correct in size. But that ain't so.

FWIW my Rift S is set to the default 63.5 and I haven't noticed any scaling issues with the modules I own.

My issue is example the Mig-21, there is just something in that as every switch in the panels are like toothpicks when the cockpit is more right sized, but when scaling is done for the switches to be right size, the cockpit is larger than A-10.

That is just the problem of the 3D modeling that you need to get everything right.

2) There should be a virtual ruller of i.e. one meter in the game - you would compare this one meter with real life ruller in your hands, scale accordingly just one time and this way you would have all the game scaled properly.

This is what I recommended a while ago, and requested if someone would have a real specs of things like example aircraft cockpit width in specific position so one can make a actual physical stick of that length and then use it in hands to measure that part of the cockpit by feel.

You can get in that method the right side under 1 cm accuracy and that is far better than ie. 5-10 cm off with the wrong DCS world scaling default value.

@Pikey: Good topic!

ED should consider, on a short term, to add an IPD setting per aircraft in stead of a general one like we have now. Since a change in the IPD settings changes the scale imediattly i see no reason why this can't be implemented per aircraft so we could set them permanent instead of fiddling around with it every time we change pits.

I adjusted it last night and I'm happy with the results. I found it true that things seemed too small when set to my actual IPD. The Hornet looks fine, but the Viper looked small by comparison. I settled on a setting of 55 and it works vey well for me. The size of the controls and MFD's more realistically match the ones on my physical cockpit.

I set up a batch script that will copy the config.lua I want to use for that specific aircraft so I don't have to fuss with changing it all the time or remembering which setting was correct for which plane. Thanks for the thread, it's improved my Viper VR experience.

if people need to adjust world scaling in DCS between modules, it means that ED has not confirmed a model true size to a standard. As no matter what, a 50cm stick should look 50cm stick in cockpit. As well ED needs to standardize the head position to be locked to the chair seat, not to the HUD or like that. If the player is too short or tall, they need to adjust ejection seat height as in real one. This guarantee that player doesn't feel to be taller or shorter than they really are.

+1.

ED should consider, on a short term, to add an IPD setting per aircraft in stead of a general one like we have now. Since a change in the IPD settings changes the scale imediattly i see no reason why this can't be implemented per aircraft so we could set them permanent instead of fiddling around with it every time we change pits.

I like that idea! So a +1 from me. :thumbup:

Edit: While on it, ED should use spin buttons or a slider accessible with the mouse to allow us to change that setting; right now, wearing a VR HMD, one has to fumble blindly to get enter these values on the keyboard.

Just a small point - you don't need to un-check then re-check the box on the settings page as stated in the OP. Just change the IPD number directly in the box and it automatically updates.

Not to beat a dead horse here, but IPD IS in fact IPD.  If you play with the setting and set it to 600 then look through each eye independently, you will note that the position of each eye is near the left and right glass of the canopy.  This distance is exactly 600mm.  Now, whether ED has adjusted the scale of the cockpits correctly or not is another matter, but if they have IPD in millimeters and place the camera as such for each eye.  Then they should be able to measure the model and scale it to the proper size for each module.

The IPD absolutely is not similar to FOV and does not change FOV except that you will notice a small widening effect due to the eye position being wider if you play with the 600mm setting.


Fun experiment.  Go on a dogfight server during busy hours and use IPD 2000, then go to F2/F5 mode.  It's like watching miniature airplanes battle.

What we have in game is the virtual IPD adjustment. It does indeed change the sense of scale, hence the confusion https://xinreality.com/wiki/Interpupillary_distance#Virtual_IPD