The moon is too small now (in VR)

[draconus]

On 8/15/2024 at 4:09 PM, Czar66 said:

Warthog HUD

Yes, thanks, corrected. Was testing in both.

[Gun Jam]

With a little photo shop help you could move this to the equator.

Mill scale.

 

[RealDCSpilot]

1 hour ago, buur said:

You can just cover it up with your little finger on your outstretched arm.

 Guess what, i can do this in VR. And as expected, it's to small. Needs to be 2x bigger i guess... As i already said, i would expect the size of a pea, not a pinhead.

Edited August 16, 2024 by RealDCSpilot

[Czar66]

On 8/16/2024 at 4:51 AM, RealDCSpilot said:

About the "hard data"... he measured with using a scale "inside the problem".

The coin will always have the right diameter in millimeters, yes... but that seems not to be the problem here.

 

 

On 8/16/2024 at 12:40 PM, RealDCSpilot said:

 Guess what, i can do this in VR. And as expected, it's to small. Needs to be 2x bigger i guess... As i already said, i would expect the size of a pea, not a pinhead.

 

https://lco.global/spacebook/sky/using-angles-describe-positions-and-apparent-sizes-objects/

The human finger tip covers about 1º to 1,5º.

The moon has 31 arcminutes or 1/2°.

If the VR hand is in proper scale, it is possible that it can be off by a little too for usability, DCS seems correct.

You can try to photograph the moon at 1x at any day of the year, the results will always be mediocre if the composition doesn't ask for a tiny satellite. Been there, done that.

Edited August 17, 2024 by Czar66

[RealDCSpilot]

Alright, let's see...

Hmmmm...

and another two other sims examples...

So they are all wrong?

[buur]

vor 2 Stunden schrieb RealDCSpilot:

Alright, let's see...
 

Hmmmm...
 

and another two other sims examples...

So they are all wrong?

Yes, both are wrong. Go out, look in the sky! Don't look on pictures, thrust your eyes

[Czar66]

2 hours ago, RealDCSpilot said:

So they are all wrong?

Yes.
The moon is larger than 1º in BMS (?).
Unless FOV distortion is taking part there.

The image on the left, the moon is comically too big, sorry. Seems wrong from first sight.

The hand test: You need to extend your arm to make a fair measurement and still I wouldn't trust VR hands to do it. The HUD is the best option to make measurements in sim.

Your best option is to contact someone from ED dev team and figure it out the values they put it in and why.

Edited August 18, 2024 by Czar66

[Czar66]

...remember also, the VR hands are wearing gloves.

[RealDCSpilot]

7 hours ago, buur said:

Yes, both are wrong. Go out, look in the sky! Don't look on pictures, thrust your eyes

It's actually three different sims in those images. And no, i will definitely not "thrust" my eyes.

7 hours ago, Czar66 said:

The image on the left, the moon is comically too big, sorry. Seems wrong from first sight.

Well it's the oldest one in the comparison. Have to give it some slack here.

7 hours ago, Czar66 said:

You need to extend your arm to make a fair measurement

Did that, the hand object is touching the cockpit frame arc. And yes, of course a glove makes the fingers a bit bigger. But i can't bring any other reference object into the game.

7 hours ago, Czar66 said:

The moon is larger than 1º in BMS (?).

Well, isn't that interesting...? From all sims it actually gives me the best result how i can see the Moon in real life (size and darker surface details).

[Czar66]

4 hours ago, RealDCSpilot said:

Well, isn't that interesting...? From all sims it actually gives me the best result how i can see the Moon in real life (size and darker surface details).

'Best result' is subjective. For me the 'best result' is the moon at ~1/2º of diameter in the sky, measurable, and so on for other things yet to be improved.

These old games/based on old visual tech have some things wrong based on the tech limitations and media at the time. Lower end monitors...etc. Things based on nature were often disregarded.

The FOV setting present in the sim will affect how big the moon is. If FOV needs to be set high for peripheral vision distorting the moon size on the 2D plain of the screen (vr included, it is 2 screens) it is a limitation of the media/display philosophy/display ergonomics and the moon will appear smaller.

All sims are a bundle of compromises, no exception. Make your adjustments via config files for your taste if that doesn't break IC for you and it is all good. I'd prefer DCS to remain with real values for these stuff out of the box while I manage my own setup limitations.

4 hours ago, RealDCSpilot said:

Did that, the hand object is touching the cockpit frame arc. And yes, of course a glove makes the fingers a bit bigger. But i can't bring any other reference object into the game.

The best reference in the game, and would be IRL as well, is the HUD. It projects on the infinity its symbology regardless of your FOV/zoom setting.

If you were in a real plane IRL, that would be one of your best tools as well.

Edited August 18, 2024 by Czar66

[BJ55]

I have the same impression, the Moon is too small, almost impossible to see any surface detail even at max zoom (min FoV). Right now I'm downloading Stellarium, to compare dimensions with the same 70° FoV on a 2560x1440 screen.

Edit:

 

 

WT ? Ok, time to order a 64" curved monitor.

Edited August 18, 2024 by BJ55

[RealDCSpilot]

As i'm trying to point out all the time, it's about how big the moon appears in VR. I never use DCS on a monitor.
I still think that FOV for each eye could be the source of the moon being smaller perceived than in reality. Unfortunately, i can't change the FOV per eye anywhere. There is "VR spyglass zoom" which does that, but it only toggles from a min to max value and back if i hold the button. Can't bind it to an axis, which would help a lot in this case here.

Edited August 18, 2024 by RealDCSpilot

[Czar66]

1 hour ago, RealDCSpilot said:

As i'm trying to point out all the time, it's about how big the moon appears in VR. I never use DCS on a monitor.
I still think that FOV for each eye could be the source of the moon being smaller perceived than in reality. Unfortunately, i can't change the FOV per eye anywhere. There is "VR spyglass zoom" which does that, but it only toggles from a min to max value and back if i hold the button. Can't bind it to an axis, which would help a lot in this case here.

 

Look for the FOV value on Options -> System Settings while inside the cockpit. Press RALT+Num 0 (number pad) to save the FOV value. Alternatively:

<your windows root drive>:\Users\<your windows username>\Saved Games\DCS\Config\View, look for SnapViews Lua file and edit your field of view from there. I'm not sure if VR takes those values into account. Perhaps you have that elsewhere on your VR software or inside DCS options.

Forget about the Stereoscopic 3D image infographic. The moon is rendered at a infinite distance and the VR goggles are still two screens and will always be two screens. Changing the FOV value for the overall render would change directly the rendered moon size in relation to the whole screen. The perception of being small might come from the fact your FOV is too wide, not that reducing FOV to get the moon at the 'correct feeling size' would benefit your gameplay.

VR goggles are still an approximation to real life vision. You'll have to prioritize the best way to interact with the sim over something else eventually.

3 hours ago, BJ55 said:

I have the same impression, the Moon is too small, almost impossible to see any surface detail even at max zoom (min FoV). Right now I'm downloading Stellarium, to compare dimensions with the same 70° FoV on a 2560x1440 screen.

Edit:

 

 

WT ? Ok, time to order a 64" curved monitor.

 

Good call on Stellarium! Great app to check this out.

Edited August 18, 2024 by Czar66

[RealDCSpilot]

14 hours ago, Czar66 said:

Forget about the Stereoscopic 3D image infographic.

Okay, you didn't get the connection about FOV out of this. Let's get this more clear, this is the DCS VR camera rig:

For the spyglass zoom functionality, they manipulate the whole rig. It's a linear interpolation for about one second from a start FOV value to the much more narrow FOV value. They might even translate the IPD too for this. I've never seen this in any other VR game. While it works, it might have a slight flaw. The start FOV value which might be a couple of degrees bigger than it should be. While IPD is exposed and changes world scale, especially the appearance of very close objects, FOV has more impact on the appearance of Objects and especially on those that are extremely far away.

 

14 hours ago, Czar66 said:

SnapViews

... or any other exposed FOV setting does only apply to monitor usage. For VR it does nothing. There might be a .lua somewhere, but i couldn't find it yet.

Edited August 19, 2024 by RealDCSpilot

[draconus]

You can't manipulate fov in VR because any incorrection would break the 1:1 6-dof movement. You can make the moon image bigger for yourself but it will never be more correct or realistic than it is now, unless you want to simulate a pilot wearing binoculars.

Edited August 19, 2024 by draconus

[RealDCSpilot]

??? What? How?
I hope you know about image pre-distortion for VR HMD optics and that a screenshot of a display panel in a VR headset like this:

is the same like this:

Setting a couple degree more FOV would only add to an effect like concave lenses like in correction glasses for short-sighted people. Reducing a couple of degrees would have an effect of convex lenses like for far-sighted people. Inside the headset you wouldn't see much of a difference because everything looks related to each other and 6-dof movement isn't affected at all. What i'm trying to tell you the whole time is that we are looking at a "concave lens" effect all the time, that's why the moon looks smaller in VR than in real life. 

Edited August 20, 2024 by RealDCSpilot

[draconus]

2 hours ago, RealDCSpilot said:

What i'm trying to tell you the whole time is that we are looking at a concave effect all the time, that's why the moon looks smaller in VR than in real life. 

That would affect size perception of anything presented ahead of us, wouldn't it?

Edited August 19, 2024 by draconus

[RealDCSpilot]

12 hours ago, draconus said:

That would affect size perception of anything presented ahead of us, wouldn't it?

 

No, not entirely. It would have the most impact on everything that is rendered at infinity (skybox with moon patch on top and hud). The closer something is to the camera, the less it would be affected.

And i'm talking about a correction of 1-2° only. Let's say 2° less and the Moon + HUD will be rendered a bit bigger while still holding the correct measurement.

Here is something fresh from the night sky:

As soon as i stepped on the balcony i was reassured that something is wrong in VR in DCS. The real moon appears so much larger for the bare eye than it does in VR for the "bare" eye.
Of course this is all crappy cellphone photography, with no scientific value with stretching out arms and so on...

The camera also doesn't have the dynamic range the human eye has.

This is a montage, just for visualization:

I'm much more sure now that the whole thing is a FOV issue in VR. Decreasing the FOV angle by a couple degrees would also impact spotting distant objects in the skies, this is a problem in VR for years now. It would definitely improve it.

Edited August 20, 2024 by RealDCSpilot

[draconus]

1 hour ago, RealDCSpilot said:

No, not entirely. It would have the most impact on everything that is rendered at infinity (skybox with moon patch on top and hud). The closer something is to the camera, the less it would be affected.

And i'm talking about a correction of 1-2° only. Let's say 2° less and the Moon + HUD will be rendered a bit bigger while still holding the correct measurement.

Fov is fov - it affects near or distant objects the same way. Looks nice on the image but from the POV you'd see eactly the same amount of pixels in your "FOV change impact" measurements And for the moon to become 1.5 bigger you'd need the fov change of exactly 1.5x. Small change like 1-2° you wouldn't even notice.

Edited August 20, 2024 by draconus

[RealDCSpilot]

Man, you are really starting to waste my time. Optical FOV is fixed in every HMD. The screen space is also fixed - the rendered window on each display per eye. Pixels don't play a role here. How much perspective you cram into that fixed space is happening on the software side, in the VR camera rig. The VR spyglass zoom demonstrates this very well, but with a way to big value for this purpose here.
Did you never wonder why when you look around in the cockpit, the pilot model's feet look a bit tiny? Or the seat? Despite you have your IPD correctly dialed in in the VR HMD? That's a wrong FOV.

Edited August 20, 2024 by RealDCSpilot

[Slippa]

If the problem’s a FOV VR issue, Is the Moon still too small in 2D?

Also, next time you’re on your balcony holding one glove up to the Moon taking pictures, I hope someone comes in and asks what you’re up to. If and when that happens, could you post a recording of your explanation please? 

[RealDCSpilot]

6 minutes ago, Slippa said:

Is the Moon still too small in 2D?

Not if you keep your head on an exact fixed position with a fixed distance to the screen and have set up the correct FOV for that distance. May not be practical in most cases because you have to cut away a huge area. But a 3D world on a 2D monitor only is always a way bigger abstraction than VR. A half dome screen would be best.

[RealDCSpilot]

On 8/16/2024 at 1:57 AM, TOViper said:

What makes you confident that the newer DCS version has a different FOV?

That question kept me thinking and i got the idea for an experiment. Highly inaccurate of course without knowing on what values the cameras in DCS truly operate.
There is this tool which is pretty famous for being used measuring your VR HMD's optical FOV in a calibrated space.
https://knob2001.itch.io/testhmd

To get your horizontal FOV measured, you have to stare at the center of an image with two red bars left and right. Then you move those bars further and further into your peripheral vision until you can't make them out anymore. My current HMD gives me a result of 110° (depends on personal face shape and eye position).
So i did a simple test in DCS. Prepared a date and time with a full moon close to the horizon, centered my heading on it and started turning sideways until i reached 55° more (233° -> 288°). Always kept the yellow cross of the fixed mouse cursor in the center.

The moon was leaving my field of view at 292°. This basically means that DCS renders a FOV of 118° on my headset with 110°.
Would be nice if someone else could test this too on his end...

On top of that, i talked to a former Tornado WSO which also uses VR in DCS too and gave him the test mission. He said, from his memory, the moon definitely appears to small in DCS. By 30-50%.

Edited August 22, 2024 by RealDCSpilot

[freehand]

As I said before in 2017 things was different not sure about the moon but If I want size feeling real ish I having to mess about with ipd in game.

Edit: That being said could of just been the feeling  I had after taken the red pill for the first time.

Edited August 22, 2024 by freehand

[RealDCSpilot]

IPD should always be on your personal eye distance. This setting changes the world scale as perceived from a normal adult human to a toddler or a giant. Everything close to you in the cockpit will get bigger or smaller but it doesn't do anything to size perceived for very distant objects. Which makes sense and i also double checked if there is anything wrong with it.