Physics and tire models of racing sims

Discussion in 'General Discussion' started by Korva7, Apr 4, 2015.

  1. Korva7

    Korva7 Registered

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    Thanks for saying! :eek: I just was driving karts. It's good to test this now.
     
  2. hexagramme

    hexagramme Registered

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  3. Andregee

    Andregee Registered

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    The Ac ffb is a native one but you can add canned effects, which Kunos introduced a while after release because of some crying effect fans.
     
  4. Ivan Baldo

    Ivan Baldo Registered

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    The SAT (Self Aligning Torque) in AC is 3x more than in real life, that gives the impression of a more strong or solid FFB, and also, they use canned dampening so when you move the wheel it produces a contrary force to the movement so it feels heavier...
    Just for your information.
    Bye.
     
  5. Korva7

    Korva7 Registered

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    Hmm. Isn't it up to player to set the coefficent that determines the values of the SAT and other forces?

    Do you mean with canned dampening the forces that appears in slow speeds? I think that those forces are canned in rF2 too. Atleast there is separate coefficent for that force, and if you set it to 0 there is no resistance in steering when cars is stopped.

    I don't think that it is wrong even if there is some dampening resisting movement you make to the wheel even in higher speeds, because that kind of forces does exist in real life too.

    This makes me think that what is canned effect? If it is a effect that represents perfectly some phenomenon that exist in real life, can it be wrong some how?
    Is the problem that it is not produced by the core physics engine? I think that it might be better and more efficent in some cases to produce some effects by simble factors if it is possible to give the same effect with that as with complex physics modeling.

    In my opinion only the information we get through our senses matters. If the information is right, it doesn't matter how it is produced.
     
  6. Minibull

    Minibull Member

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    I remember reading something from the devs regarding the turning when stationary, something along the lines of you are actually feeling the tyre model gripping and sliding when you turn the wheel while stationary, but that depended on the method of damping you specify in the player file.
     
  7. Korva7

    Korva7 Registered

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    Just found out that you can adjust that dampening in rF2 too, witch is useful if you have good wheel with low friction.
     
  8. msportdan

    msportdan Banned

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    So.is.the ffb somewhat fake just like most other Sims then? I wont lie I prefer the ffb in gsc feels far more connected to the car and the tyre. RF 2 feels vague In some cars if not most. Just something about it I cant get on with it
     
  9. Guimengo

    Guimengo Guest

    1 - Don't be so concerned with others if you are enjoying something
    2 - Fake means it doesn't exist. Canned is a stupid term used to refer to pre-calculated values that feed from the game to correspond to a situation. It isn't fake, it just isn't dynamic
    3 - I do have issues with FFB being numb or nearly non-existent on certain cars. Some of it may be due to old tech, some of it may be due to values, some of it may be due to our wheels
     
  10. Korva7

    Korva7 Registered

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    Well there is lot of "effects" you can adjust from Controller json file. Does that mean that those effects is not produced in the core physics engine? I don't know. In the end it doesn't matter, if the effects are accurate with real life. Still there is no adjustment for things like road pumps etc.
    Haa! There was canned effect! But that is 0 as default.

    "Rumble strip magnitude":0,
    "Rumble strip magnitude#":"How strong the canned rumble strip rumble is. Range 0.0 to 1.0, 0.0 disables effect.",

    More connected feel in gsc might be partly product of higher (steering lock)/(steering wheel rotation) ratio = fast steering which has it's effect to ffb.

    After reading Guimengos post wanted to say that isn't gsc physics/tire model pretty much all about pre-calculated values.
    And it might be in rf2 too. I don't know but it wouldn't make rf2 less good sim.
     
    Last edited by a moderator: Apr 10, 2015
  11. Guimengo

    Guimengo Guest

    I think Stock Car Extreme is all basically look-up tables. Nothing wrong with it, just that it isn't the best.

    On that topic, in the game I run FFB set to Low because that aspect to my understanding gives me the info from tires and road only. Medium, High, Full, etc add additional simulation of feedback from other parts of the car.
     
  12. PRC Steve

    PRC Steve Registered

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    Isn't there a fair bit of stuff left over in the player.json and controller.json files ( .plr ) from rFactor1. I certainly know changing certain values in rF1 .plr had an effect but changing the same values in rF2 does nothing.
     
  13. Korva7

    Korva7 Registered

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    Okay. I have wondered what that setting does, but have been using full mostly. Will test low next time.
     
  14. Rich Goodwin

    Rich Goodwin Registered

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    Last weekend I raced in my iRacing league for the first time in months, first time I'd been on iRacing (for road racing) in months actually.

    I could not get on with it in the slightest any more. I'm not even being a fanboy. In terms of feel from the tyre there isn't just a difference, there is a gulf between iRacing and rF2 in my humble opinion.

    There is just a huge vagueness around the limit of adhesion (I had horrendous trouble with the rear). It was like a switch. I would have grip and then it would vanish and before I could react I was already in a lazy, unrecoverable spin.

    I have been voicing these thoughts with my community and I seem to be the only one effected. I do like to know what the rear is doing and I like to use the rear to rotate the car. It just didn't seem a viable method there. I seem to be the only one with the problem, though. I was pretty much the fastest on the server, so maybe I was more on the limit than most.

    For me I find the rF2 model so much more compliant and intuitive. I really quite like thew AC model and also the GSCE one. But after driving on iRacing again, I doubt I will be back there for the forseeable future despite having another two years on my subs and near enough 100% content owner.
     
  15. Guimengo

    Guimengo Guest

    I found the FFB in NR2003 to be better than when I was trialing iR, all four times.
     
  16. Korva7

    Korva7 Registered

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    Talk about tyre physics.
     
  17. Ivan Baldo

    Ivan Baldo Registered

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    Nope, it comes from the tires, here is the thread about that in Assetto Corsa forum:
    http://www.assettocorsa.net/forum/index.php?threads/self-aligning-torque-sat-why-so-high.19485/

    Nope, there is a constant dampening effect uploaded to the wheel to make it feel heavier, David Tucker of iRacing discovered it and added an option to iRacing to do the same, it makes G27s feel heavier and some people like it, it comes disabled by default in iRacing though and it is not in the UI yet.
    I am a bit lazy to search for that post in iRacing forums and only people with an active subscription can access it so I thought it isn't worthwhile, but let me know if you like to read it and I will repost it here.

    Exactly: it doesn't represent perfectly some phenomenon that exists in real life, thats basically the issue with canned effects.
    But sometimes they are good when there is no other way to represent the real life phenomenon in a better way.
    The problem with the constant dampening effect is that it hides a bit the other forces that could help you understand better what the car is doing so it is a compromise and is very subjective if it is good or not.
    But the dampening effect coupled with the highly unrealistic SAT in AC makes its FFB feel stronger and more realistic when in fact, objectively, it is not.
    So there is people that:
    1 - prefer AC's FFB even knowing that the SAT is exaggerated and comes with dampening on by default.
    2 - say that AC's FFB is the best in business without knowing what is happening with the SAT and dampening.
    People in the 1st group is OK, but people in the 2nd group should be made aware of this things so they can judge better...

    Have a great day!
     
  18. Ivan Baldo

    Ivan Baldo Registered

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    Maybe there is some setting that is wrong.
    For a G27 for example, set the Logitech Profiler to the default options except turning ratio to 900ยบ, this is very important.
    Then inside iRacing, set Min Force to 17% and Linear Mode disabled.
    Then go out to the track and drive watching the F bar (thats the force feedback level bar), you need to increase the FFB strength until you start seeing red/orange, so the bar should be mostly green when driving normally on track and only get red/orange when hitting curbs or some other abnormal circumstances.
    Hope this helps!
     
  19. msportdan

    msportdan Banned

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    The thing for me atm in rf2, is the feel of disconnect between the physics and the ffb. Again especially in the open wheelers and some tintops. I'm not even sure the new contact patch has convinced me much. How tyre wear and temps is done is perfect, its just the whole translation to the ffb.

    Dunno something is off
     
  20. Korva7

    Korva7 Registered

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    If i remember right you have t300, which is basicly TX with GTE rim? Some time ago i bought the gte rim for my tx, and i wasn't too happy with it because of it's weight. Compared to tx's original light plastic rim, it felt like the weight was dampening small subtle and high frequency things. And maybe felt little bit delayed also. Like belts would stretch before the force comes to my hands. But that might have been partly because of my loose belts which i just tightened few days ago.
    With formula cars problems was more bad. With roadcars and other softer cars the gte rim was usable.

    rF2's ffb also might be more subtle than in other sims which could explain why you are having more problems with it.
     

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