Steering wheels too big ??

Discussion in 'General Discussion' started by 2ndLastJedi, Jan 7, 2019.

  1. 2ndLastJedi

    2ndLastJedi Registered

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    I have a new monitor (40"4k) and sitting with my eyes at 70cms from the screen i have calculated a 39 degrees FOV but the wheels in cars are massive at this distance and FOV ! is this just how it is or am i doing something wrong ?
    I didnt notice this until i drove the RSR GTE and needed to turn the wheel on fixed so i could have some dash,so thought i should check the McLaren because i have the McLaren rim from Fanatec to judge sizes and even that is to big in comparison !
    I took a screenshot Screenshot (8).png with the McLaren and have drawn lines at the distance my real rim sits compared to the virtual one !
    I have the base of my CSWv2 a centimetre from touching the screen .
     
  2. Lazza

    Lazza Registered

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    Objects close to the camera will resize quickly with changes in their distance from the camera. Your seat position (even if it's 0,0) may not be quite right relative to the steering wheel. You should be able to move the seat back a bit without changing the view of the cockpit too much, and it won't affect your view of the surrounding world (and corners) at all.

    The majority of game players are still using normal-size single screens, so the seat position won't always reflect reality (devs presumably aim for certain coverage with the default FOV and screen ratio). Plus any real life adjustments available to seat or wheel position aren't taken into account.

    Your FOV sounds right to me, by the way.
     
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  3. d0nd33

    d0nd33 Registered

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    At 70cm from your eyes, your screen is placed beyond the wheel. The projection on the screen of the objects that are between your POV and the screen, will be bigger than the very same objects.
    To check if the seat position in game is too forward, you can close one eye from your seat and check if the virtual wheel is as big as the projection of the real one. But it's not very useful: steering wheel position is adjustable in the real cars and the modeler of the virtual car may have placed it to his liking.
    To have a 1:1 scale of the wheel, you should mount the screen exactly over your wheel and use the correct FOV and virtual seat position.
     
    Last edited: Jan 7, 2019
  4. Louis

    Louis Registered

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    The problem i think it is because these fov calculators use the eye distance to the screen to calculate the size of the objects without considering that the virtual world doenst start at the screen but at your real life steering wheel.
    So, as @d0nd33 said, these calculator would be perfect if the screen was placed exactly at steering wheel, so close objects as dashboard and steering wheel would macth the cockpit as distance objects.
    To solve this problem i took half of the distance of the screen to my steering wheel to put as value to "distance from the screen" in these calculators so i compromisse half to far objects and half to close ones
    Example: My eyes are 70cm to the screen. My steering wheel is at 20 cm to the screen. Split that distance (20/2=10) and calculate fov as my eyes was 60cm away from the screen.
     
    Last edited: Jan 8, 2019
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  5. 2ndLastJedi

    2ndLastJedi Registered

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    I'm going to try using my screen distance at 60cm for calculations also and see how that works, thanks for your input peeps :)
     
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  6. Lazza

    Lazza Registered

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    There's no problem with rendering an object closer than your screen is. The bigger problem is that in the real car the eye-to-wheel distance might be 50cm while your real eye-to-wheel distance is 60cm (as an example). So from the start you can never match it perfectly, because then you move the virtual seat back to compensate and now you're farther from the cockpit than you should be and its size doesn't look right.

    FOV calculator results make the game 'squash in' the right amount of objects to match what your screen covers. You can easily project onto a wall 3m away instead, with the same image, and everything will look exactly the same size as it does now (despite the fact now the entire cockpit is closer than your screen). What's happening above is people see something isn't right and they're coming up with a theory to explain it.
     
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  7. d0nd33

    d0nd33 Registered

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    The calculations of FOV are correct even when the screen is not above the wheel. It's just that the projection of near objects don't match the real object size because you're comparing a projection with a real dimension.
    [​IMG]
    The calculation you talk about is your preference but it's not correct.
    As @Lazza says, you must know the virtual POV distance from virtual steering wheel. Adjust your real seat position so that your eyes are at this distance from your wheel, mount the screen above the wheel and calculate the FOV for the screen in this position. Only in this way you can have a correct 1:1 scale of the wheel. In my opinion this is an useless exercise, since the modeler placed the virtual steering wheel to his liking, not yours.
    I think the only way to know the virtual distance is to manually open the car model in a 3D editor.
     
    Last edited: Jan 8, 2019
  8. Stevy

    Stevy Registered

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    my command will not help.
    So please ignore this, BUT
    THANKS GOD with VR I don't have any more FOV or Scale problems :D:p
     
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  9. d0nd33

    d0nd33 Registered

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    I heard it's still a problem because of varying lens sizes? Someone requested a world scale factor to make everything bigger/smaller.
     
  10. Lazza

    Lazza Registered

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    No, this is not correct. Again, you could have the exact same image 10m away on a wall (but much larger, obviously, so it appears the same size to you), or 10cm away on a phone screen, and it won't change the apparent scale of different objects (no matter their virtual distance).

    The actual screen position makes no difference as long as its fov is configured correctly.
     
  11. d0nd33

    d0nd33 Registered

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    Sorry, I don't understand what contradicts my post. If the setup is how I said, the scale should be spot on to have a 1:1 wheel and correct proportions of other objects. So one could directly compare the real wheel with the virtual one, which is what OP wants to do.

    Correct FOV and matching distances (correct solution to OP's question):
    [​IMG]

    With correct FOV and any other virtual seat position, every object will still have correct proportions. The wheel will be correct, too, but its projection will not be 1:1 because it's projected on screen from a different plane (not useful for OP):
    [​IMG]
    You can match the sizes by moving the virtual seat position, but that would be "cheating" whether you're not sure if the two wheels are actually the very same.
    ---
    Screen beyond the wheel, correct FOV, same distance:
    [​IMG]
    Proportions are right because of correct FOV. Both projections match because of equal distance. Projection size is not equal to real size, they must not be compared directly (which is what OP mistakenly did).

    Screen beyond the wheel, correct FOV, unmatching distance:
    [​IMG]
    Even in this case there's still nothing wrong with any object if FOV is correct. The projection of virtual objects that are in between the POV and the screen will not match the "real projection" as it did previously, because of unequal distance. Generally one does not care about this and sets a virtual seat position to his own liking -as one does in real life with seat and wheel adjustments-, without losing any correct proportion.
    However, by moving the virtual seat position you can actually match the projection size to the real wheel size but you'd have to use an exaggerated backward virtual seat position. I don't recommend that because it's plain wrong, the projection must not match the real size in this and the other case above. This is why I did not mention it before.

    Is there a mistake in this reasoning?

    I simply turn off the virtual wheel since as we've seen it can't be used a reference point and it might disturb. Now if only the HUD would be customizable on the fly...
    I have a single screen too, sometimes I like to look at the whole cockpit (with virtual wheel on) so I use an higher FOV as @Louis does. But if the apex positions allow for the use of a more realistic FOV, I usually go for that (virtual wheel off).
     
    Last edited: Jan 8, 2019
  12. 2ndLastJedi

    2ndLastJedi Registered

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    I just sold my Rift and this is why I'm in this position, lol
    I just couldn't handle the resolution any longer! 16 months exclusive VR was enough for me.
    The dimensions in VR may have been near enough but the position of the wheel rarely lined up correctly and it was always a compromise of some sort while in VR and I've found going back to 2D rather liberating and rather impressive if I'm honest.
     
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  13. 2ndLastJedi

    2ndLastJedi Registered

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    I always had the wheel turned off until I drove a car with its dash on the wheel (Porsche GTE) and thought I'd turn the wheel to fixed just to have something to give me a Display and noticed the wheel being 3/4 the size of the screen and then my questions started.
     
  14. d0nd33

    d0nd33 Registered

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    Try to close an eye from your seat and see if the virtual wheel is almost the same size as the "shadow" of the real one.
     
  15. d0nd33

    d0nd33 Registered

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    A suggestion about something I don't find very often: for the best position, the center of the screen should be at the same height of your eyes. In this way the vanishing point will be correctly lined.
     
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  16. Louis

    Louis Registered

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    I cannot argue with angles,math and english at same time :D but i would like to make 2 questions about fov, if you permit

    Is it possible to make a visual tool like a half circle with 10cm diameter at the top of the screen, in the first "layer" (i dont know if it is the correct word) of the screen and you have to match with one that you hold externally thay you cut before with same diameter? or like: put your finger on the screen, when match with one in the screen. you are in correct fov

    Is it possible that modder make a car not in default scale and thats why when (we use the "correct fov") some mods have very diferentt seat positions (to compensate how close you are the wheel when changing mods)?
     
    Last edited: Jan 9, 2019
  17. Louis

    Louis Registered

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    yes.
     
  18. Lazza

    Lazza Registered

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    @d0nd33 I just wrote a reply and during that process realised we're talking about different things :)

    I didn't think the OP wanted the on-screen wheel to measure (at the screen) the same size as his physical wheel; I thought he wanted them to appear to be the same size from his driving position. For this second one to be true, they first obviously have to be the same 'physical' size to begin with (not guaranteed, but let's assume close enough for now), and then the real eye-to-wheel distance has to match the virtual one.

    Since the wheel is the closest object to the camera, its apparent size is most sensitive to viewing distance. So I think if the virtual wheel size is that much of a factor for him, moving the seat rearwards is probably the best solution as the wheel will 'shrink' faster than the cockpit while the surrounding track will barely seem to change at all.

    If @2ndLastJedi 's goal was to measure the wheel on his screen and have it match a measurement of his physical wheel then yes, he would need to have the screen right 'at' the wheel, or have some strange combination of screen distance vs virtual seat position in order that they match (with his current screen position, that would require moving it farther back than I was proposing, where the cockpit view could start to get more noticeably weird). This is all assuming we keep correct FOV of course.


    @Louis has never felt that what is drawn on-screen can match anything that's physically closer than the screen, something I disagree with and talked privately with him about, and his post #4 has misled me a little as I then read your (Dondi) post as saying a similar thing, when in fact you were talking about measuring the wheel at the screen (not a with-perspective comparison with the real wheel, from driving position).


    In summary: If the OP wants the virtual wheel to look the same size as his real wheel when driving, move the virtual seat back or move physically closer to the real steering wheel. If the OP instead wants to measure the on-screen wheel to be the same size as the physical wheel, do the same but moreso. And I still don't agree with Louis. :D
     
  19. Lazza

    Lazza Registered

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    And just to answer you directly Louis, rather than simply saying above that I don't agree with you... :)

    The thing with a single-object comparison is that it only holds true at that distance. You can have an object 20m away from the camera appearing to be the correct size (same size as it would be in real life) with a completely wrong FOV. So objects at any other distance are wrong, but at 20m they're perfect. The point with correct FOV is that objects at all distances appear to be the correct size (and yes, that includes objects closer (in the virtual world) than your screen is to you :))

    The whole car is possible, but unlikely. Certainly unlikely to be bad enough to cause a noticeable issue. Seat position and wheel position aren't so clear cut though, and I think that's where discrepancies can occur, because probably few of us have exactly the same eye-wheel distance, and even wheel sizes can vary. If someone is extremely fussy about steering wheel scaling and virtual eye position they better have an easily adjustable cockpit (or stick to a single car) so they can match them up.

    Overall car scaling is a really easy thing to get very close to correct with a few reference photos. But the steering wheel is so close to the camera that a slight change can make a big difference. (the moon can get 1000km closer and you won't notice it; a bull 5m away getting 1m closer looks a LOT bigger. The starting distance matters)
     
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  20. d0nd33

    d0nd33 Registered

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    Yes, but with some changes. The circle in the virtual world should be put at the same distance from POV as your screen from your eyes. A modder should know this distance to place the disk correctly in the car. Even if he does and he places the disk to match your real seat and if you manually adjust the FOV without any calculation until the two disks match, you'd reach the same FOV as the one calculated because there's only a correct one. This is the same thing that happens in the 2nd case in my post #11, with the exception of a fixed circle instead of the wheel. If the circle is placed in any other position, what @Lazza said in the post above applies.
    Moreover, modders place the POV to their liking, mostly it is at the virtual driver eye position. If this case is true and you want your rig to match the virtual car, you should not move the virtual seat nor change the FOV, but rather adjust your real life wheel position until its "shadow" -more correctly, projection- matches the virtual wheel on screen. The result may be uncomfortable for you, since you may not have the same body dimensions as the virtual driver.
    This aside, you can check if POV is right above virtual driver's eyes by pressing U and looking around with the mouse. Looking left and right you may understand if the virtual POV is too forward or backward relative to the virtual driver's eyes. If it is, you should adjust the virtual seat position. In this way you don't have to make any reliability on the modder's favorite POV.
    Either way, the virtual wheel on screen must not match the size of your real wheel if the screen is placed beyond your wheel (3rd and 4th case in post #11).
    I'd rather use an higher FOV (but incorrect) to have a wider look at the track and car interiors instead of moving the virtual seat in the trunk.

    Advanced POV only for PRO drivers:
    [​IMG]
     
    Last edited: Jan 9, 2019
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