Cockpit view zoomed out distortion setting

[Terzi]

Hi all,

 

I want to describe the issue since I do not know the technical term for it.

 

While you are in the cockpit in DCS, and the view is zoomed out; the screen edges somehow becomes distorted. I want to have bigger field of view without that distortion. Is there any setting for that?

 

If that explanation is not enough please see this video where the cockpit is zoomed out:

 

Around the center of the screen things are smaller prettier and near the edges they are bigger and distorted. While you are moving your head they seem like elastic. How to prevent this?

[Flagrum]

Zooming out = widening the FoV

 

The thing is now, that the whole scene still has to be displayed within the limits of your monitor. That is what causing the distortion - sequeezing a larger picture into the same dimensions of the monitor. There is no way around that ... ("physics").

[Terzi]

Zooming out = widening the FoV

 

The thing is now, that the whole scene still has to be displayed within the limits of your monitor. That is what causing the distortion - sequeezing a larger picture into the same dimensions of the monitor. There is no way around that ... ("physics").

 

No, I am not taking about the view area or view angle. I am talking about the ratio of the objects while they are in the center or near edges. You can still show a wide area without distorting how big it seems compared to center.

 

Well, let me explain this way. Imagine 2 objects with a length of 10cm and we are in normal zoom. When we zoom out to 50% they both should become 5cm right? Centered objects become 4cm and edge objects become 6cm. This is what I try to tell.

[PiedDroit]

I'm not very good with this technology, but I understand the reason behind the distortion so I'll try to explain it.

 

This is due to the way the graphic engine creates the 3D view.

What is does is that it consideres a flat plane (a slice) taken in the 3D world, all from a single point in the 3D world (the view point).

What you see on your screen is how that slice is seen from the view point.

 

The FoV angle corresponds the angle at the view point to the edges of the slice being rendered.

 

The problem is that this slice is flat, so there is distortion as soon as you move away from the center (imagine you're close to a mural painting, what you see in front of you looks good, but the far edges of the painting are distorted).

 

I guess the 3D engine doesn't allow rendering a non-flat slice, ideally it should consider a spherical slice to map on the screen to eliminate these effects.

 

ps: I found this picture that explain that 3D rendering is done by projecting the objects on a flat plane.

When the FoV is small, there is no issue but if you make the projection plane very wide by increasing the FoV then try to squeeze it on your screen, you get funny effects on the sides.

The projection plane should be spherical to eliminate these issues, but then there will be some processing needed to adapt the spherical plane to the flat screen (similar to what transformations are done for VR rendering), this would still generate some graphic anomalies but that would still be much better on the sides.

 

https://gamedev.stackexchange.com/questions/136757/how-do-modern-game-engines-achieve-real-time-rendering-vs-blenders-slow-rende/136776

(not directly related question but it explains some stuff)

 

In this article the guy also explains that modern hardware is designed around this technique, which explains that trying to do something different might not be possible or cost extra processing power.

 

p.p.s.:

The other technique to avoid this is to render from more that one viewpoint, by fragmenting the view into multiple viewports side to side (in DCS you can do it with 3 viewports with the 3 cameras monitor setting). The problem is that it increases the work on the graphic engine to render 3 viewports instead of one, with makes FPS drop significantly.

Edited June 4, 2017 by PiedDroit

[Mars Exulte]

Extreme FoV ends up rendering things over your shoulder, etc,, with very obvious and understandable fish eye effects. However even lesser FoV does the same thing, just to a lesser effect.

 

For example, the typical flat screen monitor if it was a window, represents about a 90' FoV. If you display 90' you won't get this 'distortion', but you also can't see very well ) Most games compensate with a FoV of 100-110', so you can see 'peripherally' a bit more without much distortion. It's still there, but very minimal. This is also why everything tends to feel/look small when you walk up to it in most games, because you're seeing more of it than you really should.

 

DCS FoV, I would be surprised if most folks aren't running somewhere between 110-135' FoV so they can see around them a bit more and still read their gauges.

 

The only solution is to narrow your FoV, which gives the impression of zooming in. It's because you're trying to render stuff that's outside your 'real' FoV causing it to appear distorted around the edge. The wider the FoV, the greater the distortion and the closer to center it gets.

[Terzi]

I do not agree with that "you can't prevent fish-eye effect" idea. I have been flying Falcon BMS for long time and in that sim this effect does not exist. I don't know maybe some people like it but for me it feels bad.

Edited June 4, 2017 by Terzi
typo

[PiedDroit]

I do not agree with that "you can't prevent fish-eye effect" idea. I have been flying Falcon BMS for long time and in that sim this effect does not exist. I don't know maybe some people like it but for me it feels bad.

It's a different rendering engine, it has the same issue, but maybe the lower FoV used in that sim would make you think it is different, or the position of the viewpoint would trick you into thinking you have a higher FoV than what you actually get.

 

You can try moving the view back a little (RCtrl+RShift+KP/) to get a better view on the cockpit, without getting too much distortion.

 

Anyway, this is no place to make comparisons, you should put your DCS screenshots and your request in the wishlist forum.

 

P.S.:

An interesting article on the subject, where the author suggest to add barrel distortion to mitigate the high FoV distortion in video games:

http://www.decarpentier.nl/lens-distortion

Edited June 4, 2017 by PiedDroit

[toutenglisse]

Hi Terzi, PiedDroit is right. In Falcon BMS the maxed out field of view is limited to a natural field of view that match the width of your 16:9 screen (let's say cause I don't know Something like 110/115°) - in DCS the field of view is set in server.lua file between 20° and 140° for all modules.

And 140° is way bigger than your 16:9 screen can render without distortion.

Usually, while playing with screen, my way to do (cause I don't like fish eye effect) is to limit max FOV to 110° wich gives a natural field of view by making a "view mod" in JSGME that replace server.lua file by an other with my FOV settings. Also, rendering 140° decrease fps in comparaison of 110° fov.

[Terzi]

It's a different rendering engine, it has the same issue, but maybe the lower FoV used in that sim would make you think it is different, or the position of the viewpoint would trick you into thinking you have a higher FoV than what you actually get.

 

You can try moving the view back a little (RCtrl+RShift+KP/) to get a better view on the cockpit, without getting too much distortion.

 

Anyway, this is no place to make comparisons, you should put your DCS screenshots and your request in the wishlist forum.

 

P.S.:

An interesting article on the subject, where the author suggest to add barrel distortion to mitigate the high FoV distortion in video games:

http://www.decarpentier.nl/lens-distortion

 

I am absolutely not making comparison. Just wanted to mention that it can be overcome. This article is very interesting and it is exactly what I am talking about.

[PiedDroit]

I am absolutely not making comparison. Just wanted to mention that it can be overcome. This article is very interesting and it is exactly what I am talking about.

No problem :)

If it's not already there, this should be mentioned where it will be visible to the devs (e.g. wishlist) as we users can't do anything about it unfortunately.

[mkiii]

I run BMS on 3 screens, (5760x1080) at between 110 and 130 degrees with no distortion. Bearing in mind that the F16 head position is a fair bit further back than in all of the BMS aircraft due to the seat arrangement.

 

In BMS, the Ideal for the same setup is about 130 to 140 degrees, depending on aircraft. As a 1 screen setup there is always distortion, and with a 3 screen setup, no distortion, but I'm practically having to put my nose on the sight to avoid forward swept wings in smaller aircraft like the Spit. The default setup deals only with single monitors and is pretty useless for multiple monitors.

[Worrazen]

Actually, OP has a point if I'm not mistaken.

 

The zoom operation changes FOV, he's was expecting and/or suggesting that the whole camera should move as if you would move the head, without affecting FOV.

 

I'm not sure if head movements are supported in the game.

[Glowing_Amraam]

Actually, OP has a point if I'm not mistaken.

 

The zoom operation changes FOV, he's was expecting and/or suggesting that the whole camera should move as if you would move the head, without affecting FOV.

 

I'm not sure if head movements are supported in the game.

 

As in TrackIR? Or VR? :)

[Worrazen]

As in TrackIR? Or VR? :)

 

Heh, well, if it would be supported it would be unrealistic since you probably can't stick your head out that much without leaning forward, it would be limited, but if you had no limits moving the cockpit camera forward or backward would kinda work as a zoom without changing FOV.

 

We can't change FOV of our eyes like we can in software.

Edited June 7, 2017 by Worrazen

[mkiii]

Yes we can, using binoculars.

[Mars Exulte]

Just plane head movements are in thevgame already, no head tracking required. Key combos on the numpad.

[Rider1]

GO CONFIG> VIEW>SERVER.LUA

LOOK FOR THIS NEAR THE TOP

 

function default_fighter_player(t)

local res = {

CameraViewAngleLimits = {20.000000,140.000000},

 

Change the 140 value to something less. I use 110

 

This will eliminate any fish eye wonky distortions when zoomed fully out, and will make the cockpit fit your virtual body.