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# HOW TO: Proper Triple Screens Setup FOV & Monitor Angles

Discussion in 'Automobilista' started by GTSpeedster, Jul 4, 2016.

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1. ### GTSpeedster

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I was browsing through the forums earlier today as I came across one of Niels_at_Home posts about triple screens and how it should be set up right and I finally found the will to write a more in-depth explanation on the subject of triple screens.

A proper mathematically correct setup reminds me of the Holy Grail: heard of by most, sought by many and achieved only by a handful few who endure the months and years of research and collecting of bits and pieces of information tucked away among mathematical theories and other empirical trials in order to become worthy of such prize.

In a way it should be like that but I'll try to expedite this search and hopefully to pave a less tenuous way with this thread.

GT SPEEDSTER'S TRIPLE SCREENS SETUP GUIDE

Whenever triple screens are employed for any kind of simulation only a mathematically correct RIG with a proper FOV should be acceptable, otherwise what is the point of all the labor, time and money invested on it?

1. MONITOR ANGLES

There is a unfortunate and widespread notion out there that the gMotor2 engine locks the monitor angles at 45 degrees...

This couldn't be more INCORRECT as the gMotor2 engine has never locked the monitors at any set angle but, on the contrary, has used a mathematical formula based off your FOV to calculate what monitor angles you should be using.

This "45º myth" probably started because a "common" distance that a good number of people have their monitors at works out to more or less around 45º... And because you'll only start noticing a bigger discrepancy when you either begin going really close or really far away to the screens. Regardless it is definitely set improperly for most of the people and your brain can tell it even if you don't realize right away what it is telling you.

The higher your FOV the higher the side monitor angles you should use.

It can't be emphasized enough: just like the FOV, the monitor angles as well are NOT a matter of subjectivity, taste or opinion! They must be set following the application of the MATHS (Mathematical Anti-Telharsic Harfatum Septomin).

The closer the monitors are from you the higher the vFOV, the higher the vFOV the higher the side monitor angle, it is all linked together along with you viewing distance and panel's width obviously.

For reference: MY RIG currently has its screens set at a mathematically dictated angle of 60º (~60,22º), with my viewing distance being 82,5cm from triple 95,7cm wide screens.

How to properly calculate the angles you should set your monitors at:

How to calculate the distance you should sit in order to be able to run certain angles:

OBS¹: When I say "viewing distance" I'm meaning the distance from your eyes to the center of the screen.
OBS²: InvTan (arc tangent or atan) can be found in any scientific calculator. Windows has one which you can set to scientific under file. To use it just press the buttons "Inv" and then "Tan").

2. FIELD OF VIEW

Keep in mind that FOV is not in any way subjective or a matter of opinion! A mathematically correct FOV does never feel off as it should represent exactly what the real world feels and looks like. Therefore if you're a triple screen user you'll want to use only a proper FOV, believe me!

FOV has many more important implications than people realize, it directly affects the way depth and height are displayed and perceived. If the FOV is too height then the straights will look way longer than they are, turns will look less sharp and heights will look shallower. An incorrect field of view provides "greater sense of speed" only because distances that appear longer are traversed in the same amount of time, thus defeating any purpose of simulation.

So, first of all I DO NOT RECOMMEND this "Project Immersion" calculator. I've seen it being mentioned many times and I think it has merit but its implementation of the maths is a tad too generic. Do not follow this but instead calculate yours yourself with the proper formula.

vFOV is easily calculated be taking half the height of the image (image, not screen!) and dividing it by the viewing distance (the distance between your eyes to the center of the screen). You apply inverse Tan on that result and then finish it by multiplying this by two.

The reason half the screen height is used is because you are supposed to line the center of the screen with your eyes. That half height divided by the distance to your eyes provides the viewable angle when inverse tan is applied. It only describes the triangle on half of the screen so the other half must be added which is equal to the first since the angles are the same as long as your eyes are lined up with the center of the screen.

For reference: MY RIG currently produces an image height (image, not screen!) of 52,25cm, with my viewing distance being 82,5cm from the center of the screens, which renders my vFOV at 35º (~35,14º).

How to calculate the proper vertical FOV:

3. HORIZONTAL FIELD OF VIEW

This doesn't really apply to rFactor, Automobilista or GSCE but since this is a triple screens setup guide it's worth mentioning.

And going back very quickly to the right triangles, we already know that "A = invTan(a/b)" and that we need to double "A" in order to get the entire monitor angle and to halve the width of said monitor in order to get to "a". All of that gives us the formula: MonitorAngle = 2 x {invTan x [MonitorWidth ÷ (2 x ViewingDistance)]}.

So... You can simply calculate the total horizontal FOV by multiplying A by 6 instead of only by 2. As in 3 monitors times 2. That happens because there are three monitors but we are only calculating half of the viewing angle.

How to calculate the proper horizontal FOV:

It goes without saying but in case you're in doubt, yes, the screen bezels' width must be corrected within the NVIDIA or AMD control panels regardless of the other calculations or adjustments in order to achieve a seamless transition between the screens.

Raise or lower your screens and/or seat in order to align your eye line with the middle of the screens that way you won't be constantly looking up or down in search for the horizon but facing forward in natural line as you should and as you do in real life. Ideally your eye line must align to the middle of the screen up to 20% above of that (or between 50% to 60% up from the bottom of the viewable area) but no more.

Always¹ try to get AS BIG OF SCREENS AS POSSIBLE and sit as close to it as you can since the closer your eyes will be to the image the lower the FOV you'll be able to use and the best visual experience you will get.

OBS¹
: Catch-22 here!
The larger the screen and the closer you sit in relation to it the higher your vFOV will be. And the higher your FOV the higher the side monitor angles should be... which can represent a problem after a certain point, say 50" or larger; or if you're sitting "too close" even smaller screens will require attention! When your monitor angles begin to get too high you then begin to experience a few problems, most noticeable the worse accessibility in and out of your seat and the increase of reflections from the other screens (better mitigated on projector setups). But not only that as you will now have (depending on your screens' size) a certain amount of your side screens far beyond your field of view, thus potentially keeping locked the full potential of the rig. All the measures talk to each other, always be mindful of that.

Turn off things like "virtual arms" and "virtual steering wheels", since you already have your real ones...

Level the horizon for the cockpit view of your favorite cars in your vehicle .CAM files:

Remove all the artificial cockpit vibrations in your .PLR files.

Turn off or set to 0% any look to apex and lock to horizon options you may have in-game or in your .PLR files.

This is not at all essential but I'd recommended you to customize and to attach some hood and skirts to your monitors as it will improve your experience by blocking potential distractions and by eliminating or reducing reflections (and will make your rig look even cooler). I cut MINE out of simple styrofoam sheets and then wrapped it in "carbon fiber" film, but you can use a whole bunch of other different materials to achieve similar or even better results.

And that's it for now. Later on I'll be adding more information on what to look for when choosing the right TV for sim racing as well as how to improve the overall eye candy factor for the various sims.

Mathematical perfection for practical application at its best!

Enjoy!

Last edited: Aug 9, 2017
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2. ### JoelGL

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Thanks @ConanMcloud! My current was pretty close after recomputing, but from this, I should have a lower vFOV of 22, as I was using 29 (triple 23"s). My problem with lowering the vFOV is the seat in some cars (ex. Boxer) could no longer be moved further back.

3. ### Robert Bachmayer

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I love fov discussions, should be great to watch.
Personally I've just about given up on my triple 27's as I can't go back from nvidia 3d vision 2 on center monitor. Depth for me adds the greatest immersion and makes it more real than triples.

4. ### Paulo Gomes

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@JoelGL You can move even further the seat position, inside the folder of the car, in the cockpitinfo.ini file.

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5. ### JoelGL

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Thanks. Something wrong with my outcome, can you pls help, @ConanMcloud ?

Trying my computed vFOV of 23 and this is how it looks like. The right panel shows the dash curved curved too much that I no longer see the right side mirror. You'll also notice the left mirror is quite far at the back. This is at the bezel-corrected resolution 5835x1080.

Also, can you post a sample in AMS? As your Rig shows AC only, in w/c I can set my triples correctly, no issues.

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6. ### Billy Pilgrim

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Here's a website that is dedicated to this question, and it's got a calculator that does the maths for you. You just have to input which sim you're using, seating distance and monitor size, triples or single monitor:
http://www.projectimmersion.com/fov/

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Could you share a Excel sheet with your formulas?

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8. ### GTSpeedster

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What do you mean? You could just grab a couple more panels that also allow for 3d vision, no? I'm not a huge fan of 3d but I've used a few times in my own rig without bigger issues as far as I could tell.

Last edited: Sep 2, 2016
9. ### GTSpeedster

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Deeply sorry for the absence @JoelGL.

You are running it with multiview on, right? That is absolutely crutial for each screen to be wrapped around properly. Just make sure you got that on.

Other than that I believe what you're seeing, from the screenshot you provided, is indeed the correct portrayal of what the vFOV of 23º should looks like.

HOWEVER, since you mentioned you're running triple 23" screens, I believe that's probably not the FOV you should be or would want to be using, unless you're sitting a bit further away than you should be from the screens. I'm running a vFOV of 35º with screens twice as larger as yours and if I'm guessing right we're probably sitting at more or less the same distance from the screens (I sit at 82,5cm measured from my eyes to the center of the screens).

Each rig is unique in its measures and therefore it is very hard to judge what the real issue might be without the actual numbers regarding the screens width, image height and viewing distance. Could you tell me what those are so I can get a proper picture of your rig?

But in any case, in general my advice is to always sit as close as you physically can to your monitors. The smallest they are the more import this is since by doing so will allow you to run higher FOVs which for smaller screens is almost a necessity. And you must follow those two formulas I provided in the first post regarding FOV and Monitor Angles to the letter!

Once you get your own mathematically correct FOV set and you're looking at screens that wrap around you without distortions, only then, if the result are still not ideal, you might begin considering compromising a bit your FOV.

A compromise is sometimes indeed necessary for setups with small screens where you're not getting a good view of mirrors, a proper sense of the dimensions of the car and so on. But in my experience that is rarely the case if you follow the instructions and such compromise regarding mathematical FOV should be taken only as last resort if your rig prevents you from physically move things around.

This is my panoramic view of 35ºvFOV (screens at an angle of 60º):
In game screen shot of 35ºvFOV:

And this is my panoramic view of 23ºvFOV (screens at an angle of 60º):
In game screen shot of 23ºvFOV:

Hope it helps! Cheers!

10. ### GTSpeedster

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I don't mean to sound repetitive, let alone bash that tool as it has, like I said, some merit. But the truth is that everything you need to set up your FOV are here plain and simple in those formulas I've posted, and it has to be said that their mathematical accuracy surpasses a good measure the one provided on that website. Plus, you don't need to rely on anything or anybody else but on pure math.

11. ### GTSpeedster

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I don't have any already made but I'll see if I can get it sorted and then update it within the main post later on. Cheers and thanks for the suggestion!

12. ### JoelGL

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Hi, no problem at all. Yes, I have multiview enabled.

For my reference, to see if I come up with similar values as you would compute using my values, here are my values (3 x 23" monitors, 16:9):
a. distance from my eyes to center of monitor = 69cm (nearest I can manage due to triple stand's foot),
b. Monitor width =59cm
c. image height = 29cm (so half =14.5cm),
d. side monitors angled at around 40º.

This results to vFOV = 23.7 or 24, and like in your last 2 images, results to the right-side mirror no longer in view. In this case, what are the best compromises I could look at?

Some clarification though. I tried calculating w/ these values again. First for MonitorAngle, and it results to 46º, w/c is weird because they have my side monitors too inward. The current 40º makes them more straight to my view at this viewing distance. Distance results to 81cm, w/c is farther than my current setup of 69cm.

Thanks again.

13. ### Robert Bachmayer

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yeah that would be nice just a little expensive to make run properly, am looking at HMD for future 3d immersion.

14. ### Ze70R

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Hi there GT Speedster , i want to ask you about Assetto Corsa`s triple screen support in game.Is the calculated fov mathematically correct ? Can i relay on that, and using the fov for similar sim racing games such as Dirt Rally. I`m asking you coz my rig is similar to yours (distance to screen 83 , side monitors angles 65) and Assetto corsa`s triple screen support shows me 56 vFov , but if i calculate it by your formulas below , it cames out 37 +/-.

GT SPEEDSTER'S TRIPLE SCREENS SETUP GUIDE

Whenever triple screens are employed for any kind of simulation only a mathematically correct RIG with a proper FOV should be acceptable, otherwise what is the point of all the labor, time and money invested on it?

1. MONITOR ANGLES

There is a unfortunate and widespread notion out there that the gMotor2 engine locks the monitor angles at 45 degrees...

This couldn't be more INCORRECT as the gMotor2 engine has never locked the monitors at any set angle but, on the contrary, has used a mathematical formula based off your FOV to calculate what monitor angles you should be using.

This "45º myth" probably started because a "common" distance that a good number of people have their monitors at works out to more or less around 45º... And because you'll only start noticing a bigger discrepancy when you either begin going really close or really far away to the screens. Regardless it is definitely set improperly for most of the people and your brain can tell it even if you don't realize right away what it is telling you.

The higher your FOV the higher the side monitor angles you should use.

It can't be emphasized enough: just like the FOV, the monitor angles as well are NOT a matter of subjectivity, taste or opinion! They must be set following the application of the MATHS (Mathematical Anti-Telharsic Harfatum Septomin).

The closer the monitors are from you the higher the vFOV, the higher the vFOV the higher the side monitor angle, it is all linked together along with you viewing distance and panel's width obviously.

For reference: MY RIG currently has its screens set at a mathematically dictated angle of 60º (~60,22º), with my viewing distance being 82,5cm from triple 95,7cm wide screens.

How to properly calculate the angles you should set your monitors at:

How to calculate the distance you should sit in order to be able to run certain angles:

OBS¹: When I say "viewing distance" I'm meaning the distance from your eyes to the center of the screen.
OBS²: InvTan (arc tangent or atan) can be found in any scientific calculator. Windows has one which you can set to scientific under file. To use it just press the buttons "Inv" and then "Tan").

2. FIELD OF VIEW

Keep in mind that FOV is not in any way subjective or a matter of opinion! A mathematically correct FOV does never feel off as it should represent exactly what the real world feels and looks like. Therefore if you're a triple screen user you'll want to use only a proper FOV, believe me!

FOV has many more important implications than people realize, it directly affects the way depth and height are displayed and perceived. If the FOV is too height then the straights will look way longer than they are, turns will look less sharp and heights will look shallower. An incorrect field of view provides "greater sense of speed" only because distances that appear longer are traversed in the same amount of time.

So, first of all I DO NOT RECOMMEND this "Project Immersion" calculator. I've seen it being mentioned many times and I think it has merit but its implementation of the maths is a tad too generic. Do not follow this but instead calculate yours yourself with the proper formula.

vFOV is easily calculated be taking half the height of the image (image, not screen!) and dividing it by the viewing distance (the distance between your eyes to the center of the screen). You apply inverse Tan on that result and then finish it by multiplying this by two.

The reason half the screen height is used is because you are supposed to line the center of the screen with your eyes. That half height divided by the distance to your eyes provides the viewable angle when inverse tan is applied. It only describes the triangle on half of the screen so the other half must be added which is equal to the first since the angles are the same as long as your eyes are lined up with the center of the screen.

For reference: MY RIG currently produces an image height (image, not screen!) of 52,25cm, with my viewing distance being 82,5cm from the center of the screens, which renders my vFOV at 35º (~35,14º).

How to calculate the proper vertical FOV:

3. HORIZONTAL FIELD OF VIEW

This doesn't really apply to rFactor, Automobilista or GSCE but since this is a triple screens setup guide it's worth mentioning.

And going back very quickly to the right triangles, we already know that "A = invTan(a/b)" and that we need to double "A" in order to get the entire monitor angle and to halve the width of said monitor in order to get to "a". All of that gives us the formula: MonitorAngle = 2 x {invTan x [MonitorWidth ÷ (2 x ViewingDistance)]}.

So... You can simply calculate the total horizontal FOV by multiplying A by 6 instead of only by 2. As in 3 monitors times 2. That happens because there are three monitors but we are only calculating half of the viewing angle.

How to calculate the proper horizontal FOV:

It goes without saying but in case you're in doubt, yes, the screen bezels' width must be corrected within the NVIDIA or AMD control panels regardless of the other calculations or adjustments in order to achieve a seamless transition between the screens.

Raise or lower your screens and/or seat in order to align your eye line with the middle of the screens that way you won't be constantly looking up or down in search for the horizon but facing forward in natural line as you should and as you do in real life. Ideally your eye line must align to the middle of the screen up to 20% above of that (or between 50% to 60% up from the bottom of the viewable area) but no more.

Always try to get as big of a screen as possible and sit as close to it as you can since the closer your eyes will be to the image the lower the FOV you'll be able to use and the best visual experience you will get.

Turn off things like "virtual arms" and "virtual steering wheels", since you already have you real ones...

Level the horizon for the cockpit view of your favorite cars in your vehicle .CAM files:

Remove all the artificial cockpit vibrations in your PLR files.

This is not at all essential but I'd recommended you to customize and to attach a hood and skirts to your monitors as it will improve your experience by blocking potential distractions and by eliminating or reducing reflections (and will make your rig look even cooler). I cut MINE out of simple styrofoam sheets and then wrapped it in "carbon fiber" film, but you can use a whole bunch of other different materials to achieve similar or even better results.

And that's it for now. Later on I'll be adding more information on what to look for when choosing the right TV for sim racing as well as how to improve the overall eye candy factor for the various sims.

Mathematical perfection for practical application at its best!

Enjoy! [/QUOTE]

Last edited: Oct 18, 2016
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15. ### Alex72

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Very nice write up, thanks! However i have two questions. First i cant find "INV" on any calculator. I cant remember my math, lol. Tested some scientific ones from windows 10 to online ones and not a single one has "inv". Ive seen "in" on some of them but not in Win10's version. Not sure if "in" is the right one?

Thank you!

Last edited: Jul 30, 2017
16. ### Emery

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Click this button in Win10 built-in calculator to get inverse functions:

Screen will then change to:

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17. ### Alex72

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Cheers bud.

EDIT for some reason INV arrow is greyed out... And online sci-fi calcs dont have that arrow. This was harder than i thought lol...

EDIT2: Ah its called "tan-1" now. 46 degrees for me wohoo so it was just as i had my screens lol.

Last edited: Jul 30, 2017
18. ### Javi288

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@ConanMcloud! When you use math formulas, monitor width (MonitorWidth) is including bezels?

Thanks and regards!

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This guide was a little confusing. I see the in-game FOV setting. Was that the one you're talking about? Is there some file I have to edit for anything?

I'm using NVIDIA, surround, bezel-corrected triples with AMS multi-view and it's pretty clear the game isn't taking the bezels into account. How could it? I didn't tell it the width.

I have this working in iRacing. How do I get it working in AMS?

I have a feeling we're talking about different things when we say "bezel-corrected". I used the NVIDIA Surround tool to deal with bezels but they only make sure everything aligns - they don't do what iRacing does with the width you tell it for the bezels (ie. hiding the image behind the bezel so it's not overly stretched).