Adjusting FOV calculators for immersion ? We're not cyclops'...

ValseTriste

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Feb 7, 2020
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For years I have had blind faith in online FOV calculators but to try and get everything to align meant endless adjustments of seating position and rig components. But when I recently gave myself a long break from sim racing when I came back to it I immediately realised that the FOV was simply wrong. It seems our brains are very capable of adjusting to what we see or want to see and accept it as normal i.e. 2D as 3D. Above all the scale of geometry was clearly off.

So basically I’ve come to the conclusion that FOV calculators would be spot on if we were cyclopes. Since we are not and have two eyes it obviously explains why 3D and especially VR which use double imaging technology, one for each eye, are far more immersive. However for now at least I stand by the superior resolution of 2D.

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So having now made every effort to match wheel diameter, reach and tilt angle to the real world car I have discovered that by reducing the FOV calculator results by 8 clicks (so 5° vertical or 8° horizontal) almost every car in AC (and PC2) lines up perfectly with my wheel using the default cockpit cam, I’ve only had to adjust the seat height and view angle to match eye level to the horizon (I believe the developers have compromised the default view by simply lowering and/or tilting the camera for optimal instrument panel visibility) and thats it ! Its not perfect, its still a 2D compromise but its a game changer nonetheless. If you try this immediately without a break like I had of course its going to seem a little odd at first but everything then starts to make better sense:

Everything is to scale including the wheel
A-pillars are in the right place
Track scenery has real presence
Apexes are clearly visible
Circuit elevation is obvious
There is a clear line of sight through other vehicles
Wing mirrors are visible
And incedibly even the FFB is improved being more tight and precise

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Of course you unfortunately need a fully adjustable rig with the right size steering wheels at the right tilt angle and distance from you as your eye to screen distance needs to be fixed. For example my screen is 65.5" or 144cm across (16:9 1080p) with a 130cm viewing distance which if any closer will have pixelation issues so its basically the smallest screen size you can use as AC is at 30° vertical FOV but thats life…

Anyway hope you managed to get through this and that its interesting to some of you and might help if you were having the same doubts as I was. If you aren't convinced by VR and want a more immersive 2D experience and are willing to compromise then give it a try !
 
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gecco

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Of course you unfortunately need the right size steering wheels at approximately the right distance from you...
I can confirm that:thumbsup:
...also, you know you've gone one step too far, once your wife steps into your room, and with a sorrow-stricken look on her face, and a surprisingly calm voice asks you: "Hon, do you reaaally need 7 different steering wheels for this game?"...:redface:
 

JoelGL

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With 29°FOV, what monitor screen size do you use? And its 130cm away (4 feet away)?
 
Sep 11, 2011
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Tried vr, twice. Went back to Nvidia 3d vision 2, makes fov settings a whole game getting it right. Makes 2d flat screens impossible to race on.
 

ValseTriste

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Ok. May I ask what calculator you used, and the FOV it suggested w/ your monitor dimensions (to determine your final 29°FOV?
For example this one http://carsfov.moritzlawitschka.de/calculate which gives 58° horizontal, then convert in this one http://themetalmuncher.github.io/fov-calc/ to 35° vertical then reduce by 6° gives 29°. Same results here https://dinex86.github.io/FOV-Calculator/ using my 65" to 66" screen diagonal.

130cm is the closest I can be before pixelation is a problem, for me at least its great at this distance, the most important factor is screen motion blur/response time, the faster the better...
 
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Kek700

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Forgive my lack of understanding on this subject, this has bugged me from day 1.
I have used a car with a MoTec dash, size I know, then translated that on to the screen.
Looked at seating position first, the fact that I am in a seat, I have a wheel and steering shaft in front of me, I adjust seat position to match best I can that.
I am now left with the dash board, the MoTec dash, side pillars and an outside mirror.
I cannot still cannot relate the size of the MoTec dash even though I know it’s dimensions.
Because it is not actually in front of me, it’s perspective is that of a MoTec dash that is 60 odd cms away.

Tried to get into a Nissan GT-R Gt3 car at the auto sport show to at least get some sort of understanding of its proportions and perspective.
You thought that I had asked for something illegal, no hope there.

I though that would provide me with a perspective I could translate into other race cars.

help:confused:
 

Kek700

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just thought whilst writing this, I wonder if there is a way of moving the seat in so the MoTec dash is at the same dimensions as true life, when it is just that part of the dash in view.
Probably that leaves the seat position and FOV still in a situation of what is correct. If not seat position when looking at the dash, but the FOV.
Still confused.:(
 

ValseTriste

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Feb 7, 2020
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just thought whilst writing this, I wonder if there is a way of moving the seat in so the MoTec dash is at the same dimensions as true life, when it is just that part of the dash in view.
Probably that leaves the seat position and FOV still in a situation of what is correct. If not seat position when looking at the dash, but the FOV.
Still confused.:(

Without knowing anything about your setup I can only suggest these steps but your screen may unfortunately be too small, anyway :

1 - Using the Nissan GTR GT3 in AC reset the cockpit view to default and set the FOV using a FOV calculator and reducing the result by 6° ( if your screen is any smaller or further away from you than mine this won't be possible and you're out of luck :( ).
2 - Don't move the seat position forward or back ( it seems fine by default on 99% of the cars).
3 - Adjust the tilt angle to match the horizon with your eye level (Magione is best for this as its flat).
4 - Drive with identical vehicles and adjust seat height so that your eye level roughly matches the AI.

Thats it, works for me, here is what I see:

Assetto Corsa_1.jpg

Just to note, when everything is setup its extremely unlikely that you see a lot of dash in most cars, its frustrating but makes perfect sense as screens are generally too high for that. In general I see a slight amount of A-pillar (GT3 etc definitely more), maybe some instruments (GT3 etc definitely), a bit of rear view mirror and occasionally the top of the windscreen...

Hope that helps.
 
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Stereo

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just thought whilst writing this, I wonder if there is a way of moving the seat in so the MoTec dash is at the same dimensions as true life, when it is just that part of the dash in view.
Probably that leaves the seat position and FOV still in a situation of what is correct. If not seat position when looking at the dash, but the FOV.
Still confused.:(
If you want it to be the same dimensions, it needs to be the same distance away from you. So you'd need to set your seat position to be the same distance from the dash as your head is from your monitor. But of course then the steering wheel will be between you and the screen, so it'll appear to have larger dimensions onscreen than it would if you were holding it.

It's just how perspective works, you don't get "real dimensions" the same as if you measure how large a car is by marking a line on a window, the line will be smaller than the car.

Personally as I'm using triple screens I have no choice but the FOV that calculators suggest. That's the only one where objects transition from center to side screens without warping. So I'm used to it. The only way I can trick my depth sense is by closing one eye though, which is kinda tiring. If you want a real sense of depth you just need VR, there's no alternative.
 
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JoelGL

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For example this one http://carsfov.moritzlawitschka.de/calculate which gives 58° horizontal, then convert in this one http://themetalmuncher.github.io/fov-calc/ to 35° vertical then reduce by 6° gives 29°. Same results here https://dinex86.github.io/FOV-Calculator/ using my 65" to 66" screen diagonal.

130cm is the closest I can be before pixelation is a problem, for me at least its great at this distance, the most important factor is screen motion blur/response time, the faster the better...
First link seems wrong, though 2nd & 3rd are fine. Wait, is this converting ideal for single screens only? My triples FOV seem ok, except for some cars' seat positions.
 

ValseTriste

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Feb 7, 2020
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If you want it to be the same dimensions, it needs to be the same distance away from you. So you'd need to set your seat position to be the same distance from the dash as your head is from your monitor. But of course then the steering wheel will be between you and the screen, so it'll appear to have larger dimensions onscreen than it would if you were holding it.

It's just how perspective works, you don't get "real dimensions" the same as if you measure how large a car is by marking a line on a window, the line will be smaller than the car.

Personally as I'm using triple screens I have no choice but the FOV that calculators suggest. That's the only one where objects transition from center to side screens without warping. So I'm used to it. The only way I can trick my depth sense is by closing one eye though, which is kinda tiring. If you want a real sense of depth you just need VR, there's no alternative.
I agree totally, 2D can never be 3D which is why FOV calculators are definitely not technically or mathematically correct, period, they are based on the viewing angle of a single lens which is irrelevant to us. For those that prefer the resolution of 2D I personally think the best we can do is improve on the scale of things even if perspective will always be distorted. My suggestion of reducing the FOV does that, of course there is still distortion but then there was anyway. VR is truly great but I need the resolution...
 
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