To Reiza: What physics do you actually want?

Discussion in 'Automobilista 2 - General Discussion' started by Richard Wilks, Jan 3, 2023.

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  1. WhippyWhip

    WhippyWhip Active Member AMS2 Club Member

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    i think this sums up tha grip problem on ams2, at 300 kph with tc1 the macc senna is constantly having the tc interfere on an oval,
     
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  2. Avoletta1977

    Avoletta1977 Well-Known Member AMS2 Club Member

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    In pcars1 it was possible to see single tire forces represented as vectors and with some mods decent results were achiveable in terms of progressiveness in grip/slip transition.

    From what I see the diff in this video was pretty much locked (as in pre-bug AMS2), but overall behaviour is quite convincing allowing for both drifting and clean high speed driving with 'natural' feel.



    Hopefully opening tire model/physics parametrs to modders as well will allow for faster development of such a powerful but complex and fairly unstable engine (as stated some posts ago 'fine' modifications may lead to huge changes in vehicle dynamics).
     
    Last edited: Jan 7, 2023
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  3. Avoletta1977

    Avoletta1977 Well-Known Member AMS2 Club Member

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    Still from modded pcars(1), look at how nicely this McF1 moves over suspensions.

     
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  4. Nolive721

    Nolive721 Active Member

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    if I may contribute:cool:
    to the point of AMS2 cars lacking of weight or having too low inertia leading to spinning out too easily, I can not agree more and despite the hours and hours of use of Custom FFB files and both file edit tweaking, I did not manage to take away this behaviour many have mentioned on this thread.
    Comparing to the rest of the Sims I own (RF2, AC,ACC, hell even RRE) its really in a sense putting me off AMS2 as I am almost scared:p to fire up the Game and drive

    in regards to PC2, I have been driving cars in this Sim for years with the help from Custom FFB such as Jack Spade to start with, then Karsten files -he knows- and finally settled using this guy effort in Racedepartment.
    PopsRacer FFB - w full SOP Chassis, full tire patch, and full carcass

    To the PC2 haters, you should give it a go and try for yourself but I personally enjoy the Sim, and even more since a week I have been proud owner of Logitech DD GPRO wheel. Its a blast, including with the 98T car:D
     
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  5. morpwr

    morpwr Active Member AMS2 Club Member

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    I wasnt sure thats why i asked. I know sometimes language barriers make things weird.:)
     
  6. morpwr

    morpwr Active Member AMS2 Club Member

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    Thats the problem i cant ignore it anymore. I really like Reiza and what they are doing but something is just off. I honestly have no idea what the actual issue is could be any number of things,throttle,tires,torque curves,etc or maybe a combination of things. All i know is cars dont behave anything like this irl.
     
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  7. steelreserv

    steelreserv Well-Known Member Staff Member AMS2 Club Member

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    Pushing a road car in a garage does indeed come with a degree of resistance cause by a preload.

    But while in action, even from a casual reader perspective suggesting that the diff clutches are in a constant state of kinetic friction, with the heat and wear & tear that goes along with such a suggestion shouldn’t pass the smell test. But wait theres more!

    There are distinct and observable differences between telemetry collected from open diff vehicles. Even if going around gradual corners with minor traction losses, wheel slip exists and can be detected. If you observe a car with an LSD this wheel slip difference does not occur.

    Here is some pretty clear telemetry of what an open diff looks like (green) and an LSD looks like (purple) at kansai circuit. Int he middle of the chart are the esses and dunlop. The wheel slip differences on throttle are clear.


    [​IMG]

    Furthermore, another way you can tell a clutch LSD locks the diff is by adding all the clutch plates and decreasing ramp angles. With this type of locking, when there is wheel slip, both wheels indicate the same amount of slip. Comparing this to more relaxed diff settings, the differences are stark.

    Furthermore, prior to the sticky diff issue AMS2 had over a year, during the coast phase cars like the Formula Retros would resist turning then all of a sudden the player would feel a sudden abrupt snap mid corner, which was almost uncontrollable. The telemetry did not indicate constant slip, instead the wheel slip data indicated no difference then a near instantaneous change to the wheel slip difference sometimes more than 10 % and un less than a millisecond. This represented a lock of the diff and a sudden unlocking.

    Furthermore, basic non-sim related research strongly suggests locking of the clutch packs to the clutch housing and that it is not some type of "law propogated in sim racing circles.":

    "Because this clutch is locking the wheels together, even if a wheel lifts off the ground the differential will stay locked and the vehicle will keep accelerating out of the corner."

    "The additional outward force exerted by the bevel pinions when one wheel starts to spin is then transmitted to the clutch plate pack. This causes both sets of plates to be squeezed together and as a result essentially locks the side gears to the housing."


    FYI all of the telemetry data collected operated functionally the same way PC2 and also similar to ACC, even with just a preload adjustment.
     
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  8. steelreserv

    steelreserv Well-Known Member Staff Member AMS2 Club Member

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    Its DRS would be fully deployed at dayona. A rather hair raising experience.
     
  9. Dicra

    Dicra Local Gamepad Ambassador AMS2 Club Member

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    Not being able to check currently, but I'm almost 99% sure you could do this with the F-V10 Gen2 as well. That car sure does apply traction control at weird places sometimes (especially whenever there's a high G's full throttle corner, like Hockenheim T6).
     
  10. steelreserv

    steelreserv Well-Known Member Staff Member AMS2 Club Member

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    To all here that feel like the tires are providing less than the grip required for the cars, its something that can be further reviewed, explored and globally implemented if deemed necessary.

    However, despite contemporary belief we do indeed attempt to make the cars perform close to their realistic capabilities. This includes tuning the grip of the tires very carefully. The Senna for example hits document lateral g benchmarks of 1.2g at low speed and 1.7g at high speed. Those are its limits and this is confirmed by the same methods I am attempting to explain in this thread. Simply "increasing grip" and those figures go up.

    We can't sacrificed hard data about things like HP and torque curves that cause wheelslip either. If you drive these cars within their grip limits they are well within expectations and feel. Its when pushing the tires beyond their limits that causes most of the issues.

    Very few people in there right mind, sim racers or otherwise, if given the opportunity to drive the BT52 at its limits would come even close to doing so. But in sim racing we have the hard data for the car and people can hop in and experience the thrill of being on the edge of grip without dying or risking a piece of F1 history. Its possible that Piquet drove hundreds of laps in the BT52 even before the season started and the team made constant adjustments.

    I'm not saying everything is perfect to perfection, I am saying we do have some rules that we take pride in abiding by and if there is something fundamentally problematic froma physics perspective, we can of course review it in due course.
     
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  11. steelreserv

    steelreserv Well-Known Member Staff Member AMS2 Club Member

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    The F-V10 relies heavily on GE downforce, the Senna being a road car, simply cannot.
     
  12. azaris

    azaris Well-Known Member AMS2 Club Member

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    The majority of PC2 cars are ridiculous weightless toys that spin on corner entry like shopping carts. Any "too low inertia" that exists in AMS2 exists 200% times worse in PC2.
     
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  13. Dicra

    Dicra Local Gamepad Ambassador AMS2 Club Member

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    Yes, that was my point, for the Senna it's kinda reasonable to use traction control at the Daytona Banking, if the FV10-G2 does so as well, that would be a bit weird.

    And I'm pretty sure it does, because I vividly remember excessively lowering the V10-Gen2's traction control around tracks like Hockenheim or Termas de Rio Hondo to stop it from activating in high-G full throttle corners.
     
  14. Maser V6

    Maser V6 Assume nothing._ Verify everything._Have fun AMS2 Club Member

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    Just my thoughts after trying 2 of the stated cars.
    Default: . Back to back this end. Tested both. For me the Ams 2 delivers more than pc2 on Historic tyres, I have no snap but controllable slide. The car is less of a killer than I recall (both sims) and easier.
    Tested dry and wet Monza Historic
    + TT default spa 1000 3laps
    Beta and Rc builds

    Agreed the car was a nutter on release and this end is as in Rl reports and not unexpected. weirdness. Tested 2 tracks Default setup
    In bold Roar has hit on something we have seen here before
    A suggestion is to post video with exactly what is happening with the problem cars. with pedal input and ffb in hud. this can then be replicated by others to confirm or display opposite.
    Seems once again we are playing different games = I expected same as or similar reported results not opposite, in my test
     
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  15. Richard Wilks

    Richard Wilks Active Member

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    But there is supposed to be slip with an LSD! It should not LOCK the wheels! The difference in speed is LESS ,but it SHOULD exist! Or else you are effectivelly getting a spool all of a sudden mid corner! Both wheels should NOT slip the same, because if they do, you went into total shaft lock, and then no wonder the rear decides its time to go sideways like a drift car. Why do you think they weld differentials?...

    Basic non sim related search? Locking the clutch pack to the housing is NOT locking both wheels together like even that video i posted showed. Didnt you watch it? They even say "while cornering, the diffs behaves like an open diff". When speed difference increases so does the pressure exerted which expands the case, either by gear pressure, or ramp angles in the case, so like any clutch, friction will build up, and so will the torque transfered to the other wheel. Ideally the wheels should never just lock together like the graphs you keep showing, but this transfer of torque should be seamless, and just help traction without affecting the vehicle trajectory.
     
  16. steelreserv

    steelreserv Well-Known Member Staff Member AMS2 Club Member

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    It might for different reasons. An F1's downforce would be hitting bumpstops to keep it off the ground around Daytona, this essentially stiffens the car massively, and its tires are for road courses as well. I envision the reason why TC pings on that car is due to the tires losing traction as the tires are essentially skipping over the tarmac.
     
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  17. Dicra

    Dicra Local Gamepad Ambassador AMS2 Club Member

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    OK, I get that for Daytona. But for Hockenheim and Termas (T11 specifically)?
     
  18. Richard Wilks

    Richard Wilks Active Member

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    Well thats not too much to go by now is it? Lateral peak Gs doesnt measure almost nothing in terms of vehicle dynamics. I dont think people are saying the car is too slow on a skidpad or a slalom, the are complaining about its dynamics.

    A better test should a direct one to one laptime with recorded inputs of both cars, and even that is a too controlled environment. Now i get those are hard to come by, but dynamics problems are not solved with grip. Many times more grip just makes things worse.
     
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  19. Aza340

    Aza340 Active Member

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    So have been out for a couple of hours , has anything been universally established ?
    I know one thing , FPS is down in general after the last update ! Kind of makes the physics irrelevant for me now.
    Carry on lol X
     
  20. Dicra

    Dicra Local Gamepad Ambassador AMS2 Club Member

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    Maybe to add to this: If I watch onboards like the following one, I just don't see the car struggling with traction on the curved exits as much as it does in AMS2. In AMS2, when coming out of the T7/8 complex, traction control would be heavily engaged. Also T3 and exit of the Motodrom hairpin (where Vettel crashed), to a lesser extent.
     

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