nothing to fix The sensation of speed

[SharpeXB]

1 hour ago, Hiob said:

and then you're brain figures it out

Well that is in fact the answer. Your brain interprets your stereo vision. But that’s only part of it. A lot of depth perception is learned. There’s also the parallax shift when your viewpoint changes. 

2 hours ago, Hiob said:

how does a horizontal change in IPD makes objects larger in the vertical dimension.

Because when something is taller vertically it’s also farther away. There’s no way to separate the horizontal from the vertical. 

[Hiob]

16 minutes ago, SharpeXB said:

Well that is in fact the answer. Your brain interprets your stereo vision. But that’s only part of it. A lot of depth perception is learned. There’s also the parallax shift when your viewpoint changes. 

Again, I didn't ask about depth perception.

17 minutes ago, SharpeXB said:

Because when something is taller vertically it’s also farther away. 

What

17 minutes ago, SharpeXB said:

There’s no way to separate the horizontal from the vertical. 

That's not how physics usually works. X and Y are two very distinct dimensions ans you are only adjusting one of them. 

Nothing but claims - no explanation. 

[SharpeXB]

1 minute ago, Hiob said:

That's not how physics usually works. X and Y are two very distinct dimensions ans you are only adjusting one of them.

This isn’t physics. It’s 3D space. You can’t separate one dimension from the other. That should be fundamentally obvious. 

[Hiob]

Just now, SharpeXB said:

This isn’t physics. 

Then it's metaphysics? 

[SharpeXB]

1 minute ago, Hiob said:

Then it's metaphysics? 

No it’s such a simple concept it’s hard to explain. You’re asking why changing the distance between your virtual eyes in VR affects the vertical size of something? The answer is so obvious it shouldn’t need explaining. 

[Tippis]

Of course, one of the most extreme sensations of speed come from when that speed makes your four dimensions expand at different rates…

[RealDCSpilot]

22 minutes ago, Hiob said:

Then it's metaphysics?

Why all the fancy dancing around the matter? In VR options you can force IPD. Simply try 40mm vs 80 mm and check what happens. (Hint: one will transform you in a toddler and the other one into a giant.)

[Hiob]

1 hour ago, SharpeXB said:

No it’s such a simple concept it’s hard to explain. <…> The answer is so obvious it shouldn’t need explaining. 

1 hour ago, RealDCSpilot said:

Why all the fancy dancing around the matter? In VR options you can force IPD. Simply try 40mm vs 80 mm and check what happens. (Hint: one will transform you in a toddler and the other one into a giant.)

Nobody denied that. I just wanted an explanation why. And when it really only is IPD, than I‘d love to know how exactly that works.

But all I get is: „Duh, it‘s obvious - don’t ask stupid questions!“

[SharpeXB]

24 minutes ago, Hiob said:

I just wanted an explanation why

Moving your eyes farther apart would change your perception of three dimensions. The distance between your eyes, known as **binocular disparity**, is crucial for depth perception. This disparity allows your brain to compute the depth of objects by comparing the slightly different images each eye sees. If your eyes were farther apart, the disparity would increase, potentially enhancing your ability to perceive depth at greater distances¹².

However, it's important to note that human vision relies on a complex interplay of multiple cues for depth perception, not just binocular disparity. Other factors such as motion parallax, texture gradients, and occlusion also contribute to our three-dimensional vision². So, while increasing the distance between your eyes might alter your depth perception, it wouldn't necessarily improve it across all situations and might even make it harder for your brain to fuse the two images into a single 3D image¹.

Source: Conversation with Bing, 3/4/2024
(1) Stereoscopy - Wikipedia. https://en.wikipedia.org/wiki/Stereoscopy.
(2) Depth perception - Wikipedia. https://en.wikipedia.org/wiki/Depth_perception.
(3) Human eye - The perception of depth | Britannica. https://www.britannica.com/science/human-eye/The-perception-of-depth.
(4) Depth Perception: How Are We Able To See In 3D? - All About Vision. https://www.allaboutvision.com/eye-care/eye-anatomy/depth-perception/.

Edited March 4, 2024 by SharpeXB

[Tippis]

2 hours ago, Hiob said:

Nobody denied that. I just wanted an explanation why. And when it really only is IPD, than I‘d love to know how exactly that works.

But all I get is: „Duh, it‘s obvious - don’t ask stupid questions!“

Because the in-game IPD is fixed. Your virtual pilot's eyes sit a specific distance apart.

When you alter the player's IPD — because different players have differently shaped heads — you create a scaling factor between that in-game and out-of-game eye distance. To not make the world 3D-anamorphic, which would look very odd, that scaling factor needs to be applied equally to all axes. Thus, the whole world scales up or down to make sure it conforms to how it is supposed to look through that pilot's eyes.

It has nothing to do with depth perception. It has to do with linear scale and how it needs to be applied equally in every direction to not make the world go squish. This may create an effect where the world looks too large or small to you, because you are larger or smaller than the in-game pilot and aren't used to seeing the world around you through their… physique. If the game is fancy, you can also alter the in-game IPD, to reset the world to your expectations, but that just moves that one-dimensional scaling factor up or down, and it still needs to be applied equally to all axes.

 

edit #678: oh, and of course, there's also the issue of camera position over ground compared to where you expect your eye line to be, and how proportional the in-game character-height-to-character-IPD is in relation to your own proportions. If you've ever played around in Google Earth VR and flipped the switch between “always stand on the ground” vs. “always stay actual size” options, this is the relationship you're fiddling with.

Edited March 4, 2024 by Tippis

[draconus]

10 hours ago, Tippis said:

If the game is fancy, you can also alter the in-game IPD, to reset the world to your expectations, but that just moves that one-dimensional scaling factor up or down, and it still needs to be applied equally to all axes.

The thing is the game just moves the two viewpoints apart at the IPD value. No different scaling is applied, otherwise it could be seen in one eye view or the screenshots. Scaling happens inside the brain. If your RL IPD is 68 and you set it to 60 in DCS, you'll notice the scale is not right for you. Hand the headset over to your pal witch has RL IPD of 60 and he'll say it looks about right.

[RealDCSpilot]

@Hiob I don't really get why we have to explain this to you. Why are you not doing something simple as typing "Größenwahrnehmung und Augenabstand" in your search engine?

[Hiob]

2 hours ago, RealDCSpilot said:

@Hiob I don't really get why we have to explain this to you. Why are you not doing something simple as typing "Größenwahrnehmung und Augenabstand" in your search engine?

Simple. You don't have to when you don't want to. Nobody is forcing you to engage in this conversation. It is a question that came up with this topic, and I found the explanation for one certain (but important) detail lacking, I asked if someone could explain it to me.

Sure I can research it myself, but since some of the other guys seem so sure and confident about it, I figured someone could give a good explanation.

Sorry, if I appear dense - but for me it is was not so obvious, that a change in a horizontal dimension should affect the perception in a vertical.

 

Edited March 5, 2024 by Hiob

[Hiob]

15 hours ago, SharpeXB said:

Moving your eyes farther apart would change your perception of three dimensions. The distance between your eyes, known as **binocular disparity**, is crucial for depth perception. This disparity allows your brain to compute the depth of objects by comparing the slightly different images each eye sees. If your eyes were farther apart, the disparity would increase, potentially enhancing your ability to perceive depth at greater distances¹².

However, it's important to note that human vision relies on a complex interplay of multiple cues for depth perception, not just binocular disparity. Other factors such as motion parallax, texture gradients, and occlusion also contribute to our three-dimensional vision². So, while increasing the distance between your eyes might alter your depth perception, it wouldn't necessarily improve it across all situations and might even make it harder for your brain to fuse the two images into a single 3D image¹.

Source: Conversation with Bing, 3/4/2024
(1) Stereoscopy - Wikipedia. https://en.wikipedia.org/wiki/Stereoscopy.
(2) Depth perception - Wikipedia. https://en.wikipedia.org/wiki/Depth_perception.
(3) Human eye - The perception of depth | Britannica. https://www.britannica.com/science/human-eye/The-perception-of-depth.
(4) Depth Perception: How Are We Able To See In 3D? - All About Vision. https://www.allaboutvision.com/eye-care/eye-anatomy/depth-perception/.

 

 Depth perception wasn't in question, but how it affects the vertical size of objects.

However - I think I found the missing link in one of the articles you linked. "Aparent View Angle". (Note that we're talking the vertical angle here)

This is how I understand it now: The (vertical) size of objects on the displays doesn't change (we established that, thanks), but due to the fact that a smaller IPD makes them further away (depth perception), the apparent(!) vertical view angle is smaller. I hope I could put it in words properly.

Thanks guys for the patience!

[Tippis]

6 hours ago, draconus said:

The thing is the game just moves the two viewpoints apart at the IPD value. No different scaling is applied, otherwise it could be seen in one eye view or the screenshots. Scaling happens inside the brain. If your RL IPD is 68 and you set it to 60 in DCS, you'll notice the scale is not right for you. Hand the headset over to your pal witch has RL IPD of 60 and he'll say it looks about right.

Right. I was semi-purposefully vague there: it's not that the rendering is scaled but more that the instant you have a translation from one linear distance to another, all other dimensions have forcibly have to have the same translation applied to them or the world would go wonky in new and interesting ways. Exactly what parameters go into that translation can then vary depending on the game (and headset).

[MAXsenna]

 Depth perception wasn't in question, but how it affects the vertical size of objects.
However - I think I found the missing link in one of the articles you linked. "Aparent View Angle". (Note that we're talking the vertical angle here)
This is how I understand it now: The (vertical) size of objects on the displays doesn't change (we established that, thanks), but due to the fact that a smaller IPD makes them further away (depth perception), the apparent(!) vertical view angle is smaller. I hope I could put it in words properly.
Thanks guys for the patience!

Thank you for asking. I learned something too today!

Sent from my SM-A536B using Tapatalk

[Supernova-III]

While FoV is a major factor in the sensation of speed, it's not the only one, I even doubt that it's the main one. Look at this video:

 

There's a huge amount of videos where you see narrow FoV, but you literally see very high speed, event if it's subsonic, or even as "slow" as heli. And this is where we actually face one of the biggest flaws of DCS: graphics. You don't see too much details on the ground => you don't see how fast it changes => you feel a turtle. You don't need a wide FoV, you need first of all high level of detail inside your FoV. Again, more details in your FoV => more changes you see => more feeling of speed. With very low level of detail, you need to have wider FoV in order to see more information, more details about your environment and thus to have more sense of speed.

 

In DCS, try to change all graphics settings related to the level of detail on the ground to max, you will probably see the difference. I noticed a huge difference on low level helicopter flight, low level su-25 flight, also when rolling an aircraft just after landing (200 kmph). We need better textures, at  lower performance hit. It could be challenging for developers to do this.

 

UPD: of course, the peripheral vision plays a huge role, but it shines if you have  a good level of detail. Also, the peripheral vision is not employed at its full power with just wide 49'' monitor. You need maybe 3 monitors, or maybe semi-sphere to employ your peripheral vision completely. And you still need a great level of detail, otherwise the sense of speed might be not so great.

Edited March 11, 2024 by Supernova-III

[draconus]

12 minutes ago, Supernova-III said:

Look at this video

Of course RL has better "gfx" but I fail to see how the speed feels different in DCS apart from that camera shake, which is obviously not how pilot head behaves. I put on VR and it's the same.

[Hiob]

The problem with this whole topic is, that we are not talking about facts, but about feelings. 

[SharpeXB]

“A game on my computer screen doesn’t look like real life and by real life I mean some GoPro video”

[Supernova-III]

53 minutes ago, draconus said:

camera shake

no problem with camera shake in DCS, you can enable corresponding option in DCS and it will model such behavior

54 minutes ago, draconus said:

I fail to see how the speed feels different in DCS

this is fine, if you happy with that. I won't argue with you about how you feel. I'm trying to give some bit of my understanding of the problem to people that tend to see this difference.

49 minutes ago, Hiob said:

The problem with this whole topic is, that we are not talking about facts, but about feelings. 

this is not the problem, as long as there are some people that see the difference. I agree that this problem is rather relative to individual perception of different people, but as long as we have a number of such people, the question is real.

[SharpeXB]

3 minutes ago, Supernova-III said:

I agree that this problem is rather relative to individual perception of different people, but as long as we have a number of such people, the question is real.

This is apparently a personal “problem” for some players. But it has nothing to do with the game nor does anything here need fixing. I hope you do realize how ludicrous it is to post GoPro videos as if that’s any more “real” than what you see a game.

8 minutes ago, Supernova-III said:

no problem with camera shake in DCS

If you want to be realistic about it, your own vision doesn’t shake like that video. I trust you have eyes and can figure this out for yourself. 

[Hiob]

14 minutes ago, Supernova-III said:

....but as long as we have a number of such people, the question is real.

Nope - this is exactly where you went wrong.

[Supernova-III]

Just now, SharpeXB said:

This is apparently a personal “problem” for some players. But it has nothing to do with the game nor does anything here need fixing. I hope you do realize how ludicrous it is to post GoPro videos as if that’s any more “real” than what you see a game.

I accept your opinion. Of course I see the principal boundary between the gopro, real, and the game.  Here we are talking about an individual perception of the game. You know what does "individual" mean. Do you wanna argue about my feelings or feelings of any other people that see the problem? Do you wanna say that we have a weird feeling about the game? If not, and if there's no problem for you, why do you even post here?

2 minutes ago, Hiob said:

Nope - this is exactly where you went wrong.

same for you, read my answer to SharpeXB

[draconus]

21 minutes ago, Supernova-III said:

I agree that this problem is rather relative to individual perception of different people, but as long as we have a number of such people, the question is real.

The question may be real, but the answer is still the same. The game is correct in its graphical representation. Of course it can be better in details, effects and lighting, and it will with time, but at the cost of computational performance. Why do some feel something is off? There can be many reasons: fov vs display size, wrong IPD in VR, false comparisons, lack of real life flying experience, wrong expectations...