“ are rfactor2 physics broken” video

Discussion in 'General Discussion' started by GTClub_wajdi, Dec 29, 2020.

  1. Yzangard

    Yzangard Registered

    Joined:
    Dec 6, 2018
    Messages:
    351
    Likes Received:
    173
    The biggest difference being packers are solid state, can't compress, bumpstop can. Beside that, it is almost the same thing indeed.
     
  2. Yzangard

    Yzangard Registered

    Joined:
    Dec 6, 2018
    Messages:
    351
    Likes Received:
    173
    Downforce is maybe locked but ride height isn't, so changing rear wing would affect it, so we could compare 2 stints.
     
  3. Yzangard

    Yzangard Registered

    Joined:
    Dec 6, 2018
    Messages:
    351
    Likes Received:
    173
    You should try to use MOTEC, it is not that complicated and many of us have already pretty good workbooks to share, for all level of users.

    It seems there is also a way to "unlock" some channels but I won't share anything here as they are locked for a good reason BUT for testing purpose and to discuss directly with S397, maybe some of us may test stuff.
     
  4. vittorio

    vittorio Registered

    Joined:
    Jan 11, 2012
    Messages:
    1,118
    Likes Received:
    540
    @Slip_Angel, as Yzangard, Lazza, ... said: For someone that dedicated to physics as you, do yourself a favor and get MOTEC! If only for the reason to get objective data (able to compare and discuss with others data) and not only relying on subjective perceptions which are the cause of many misinterpretations and errors.

    So, get Lazza's latest rF2 DAMPlugin (link below) and i2 Pro V1.1.4.0454 (search google).
    For more information about rF2 DAMPlugin see: https://forum.studio-397.com/index.php?threads/damplugin-for-rf2.49363/
     
    Last edited: Jan 9, 2021
    Emery, Bruno Gil and Remco Majoor like this.
  5. Lazza

    Lazza Registered

    Joined:
    Oct 5, 2010
    Messages:
    10,974
    Likes Received:
    5,680
    Correct.

    BumpStopTravels is the new, current, parameter. It replaces (combines) BumpTravel and ReboundTravel. (I think they left all 3 in the skip as a reference; you can see the values are the same)

    This parameter defines how much vertical suspension movement is available (before contacting the bumpstops) at 0 ride height - in both bump and rebound directions. So a particular car might still have 20mm of bumpstop compression at 0 ride height, or it might only hit at 0, or it might still have 20mm of travel left (obviously we're talking about 0 packers here).

    But, the packers are on the spring/damper unit, so any motion ratio applies. Let's say you have a 2.0 motion ratio (for each mm of vertical wheel/suspension travel, the spring compresses 0.5mm), then every 1mm of packer will reduce the vertical suspension travel by 2mm.


    So, just to bring that back to an analysis viewpoint: without looking at the HDV, you can't easily see how much suspension travel you need to contact the bumpstops (with 0 packers), you can't see the motion ratio so you don't know what each mm of packer equates to in terms of ride height, and you can't tell where ride height is measured on the car body (on all 3 axes). Telemetry may allow you you to roughly work out the first two, while the last you can probably get a decent feel for (but I wouldn't advise making any conclusions about car or game behaviour based on exact figures).

    That's true, there's no hard limit. There is a rising component, proportional to displacement-squared, so quite quickly you get a lot of resistance with a decent amount of travel. I'd prefer they implemented a lookup table for this, and set a hard limit at the end, as this would give better behaviour in scenarios like you describe and avoid unrealistically strong forces in extreme situations. But that's my opinion in several areas, including FWLiftHeight(Plus) - which might have helped avoid some front wing aero bugs. But I digress...
     
    TJones likes this.
  6. Slip_Angel

    Slip_Angel Registered

    Joined:
    Jun 15, 2019
    Messages:
    588
    Likes Received:
    297
    No i was talking about ARB not rear wing. ARB should so some difference in left to ride ride height.
    Best way to test it would be on a flat surface and couple of corners with varying radius.
     
  7. Slip_Angel

    Slip_Angel Registered

    Joined:
    Jun 15, 2019
    Messages:
    588
    Likes Received:
    297
    You sure that I will be safe using lazza's plugin ? after all our arguments in past with me i'm sure he got something hidden specifically for me.
    /joke

    Look i understand Motec is very good for providing evidence but some of the stuff cannot be proven with motec.
    As posted in previous comment all the GT cars are very close data wise showing same cornering Gs etc.

    BUT they couldn't be any more different from driving and feeling perspective in all 3 titles (iracing, ACC and RF2 ).
    you can't tell this with Motec.
    I think we all sort of agree that cars in RF2 in general are easy, allow much extreme driving etc but this can't be proven in motec.
    This is where we can use our common sense of watching the real cars drive and seeing the difference with eyes instead of data is better option sometimes.
     
  8. Alwin Reid

    Alwin Reid Registered

    Joined:
    Mar 20, 2019
    Messages:
    6
    Likes Received:
    2
    it can actually be proven with motec, as you have measurements of steering angle, speed, tire slip, etc.

    rf2 is extremely easy to drive compared to iracing and the values in motec of the same cars on the same tracks would easily reveal why, rf2 tire model is over the top forgiving which is what permits hack setups. You force the model to be setup for compete mechanical grip and remove the aero, so you have no drag, max top speed and exploit the tire model for grip.

    anyone who isnt blinded by feelings should be able to admit rf2 physics are quite bad, the ffb on the other hand is phenomenal!

    fwiw iRacing also has hack setups but they are the opposite settings of rf2, high on wing, rake, camber
     
    J7166 and Slip_Angel like this.
  9. Yzangard

    Yzangard Registered

    Joined:
    Dec 6, 2018
    Messages:
    351
    Likes Received:
    173
    Yet it is still the same answer : since you have access to ride height in telemetry, you can get roll so you can check ARB modification effect.
     
    Slip_Angel likes this.
  10. Yzangard

    Yzangard Registered

    Joined:
    Dec 6, 2018
    Messages:
    351
    Likes Received:
    173
    Actually yes, we can, but not the way we think. We can see the reactions of the pilot to different elements, so we can "interpret" what the pilot feels.

    I grant you however that it will not be as obvious as pure telemetry but we can extrapolate.

    It is true however that telemetry can hardly prove a feeling, it can just show the reactions of the pilot.
     
    Slip_Angel likes this.
  11. Yzangard

    Yzangard Registered

    Joined:
    Dec 6, 2018
    Messages:
    351
    Likes Received:
    173

    The tire model is different indeed (we can say that the rFactor model is too permissive but the iRacing model is clearly too punitive, MUCH too much) but the feeling of the driver is also different and can alone explain the ease for the driver to act with more precision and less latency.
     
  12. Yzangard

    Yzangard Registered

    Joined:
    Dec 6, 2018
    Messages:
    351
    Likes Received:
    173
    Personally I don't find it easy to drive in rFactor, it's easier to control the car indeed (and probably partly because of a permissive tire model but also and I think mostly because you can feel perfectly the reactions of the vehicle, which allows you to react faster and more precisely) but when you're trying to save time, to go as fast as possible, everything becomes much more complicated. Take for example the Marussia MR01 (openwheel from S397), this car may seem easy at first glance but as soon as you try to drive to the limit, it becomes very easy to lose control or at least precious time.

    I don't find a real car more difficult to drive (I only have the experience of an Audi R8 LMS in real life, if not a BMW i8 but not really the same thing) and it's quite comparable to what I feel in rFactor 2: easy to go "medium fast" but it becomes much more complicated to drive at the limit. Ok the real car will be more punitive in case of a mistake but overall, the difficulty seemed to me to be about the same, difficult to say because you feel so much more in the real car that finally you are very aware of what's going on too. This is what I find well rendered in rFactor, the information sent to the driver is precise and helps a lot to control the vehicle.

    On the other hand, I also agree that rFactor 2 is too permissive when the limit is exceeded. Not by a big margin but still too much.
     
    Bruno Gil and TJones like this.
  13. hitm4k3r

    hitm4k3r Registered

    Joined:
    Jun 15, 2016
    Messages:
    1,126
    Likes Received:
    2,504
    And then you hop into the Skippy or the Marussia and all of a sudden the cars aren't easy to rive anymore. Does it make the physics better now?

    Your comment is a prime example of generalizing things you think are a game problem that could very well be car dependend, track dependend or simply due to the fact that rF2 has no ambient effects. The default track temp in rF2 is at around 20 degree celcius, wich isn't that warm. Who knows what happens at 40 degree track temp? Might be the case that tires start melting with the driving style exhibited in some of the videos here and all of a sudden your concept becomes questionable.
     
  14. Yzangard

    Yzangard Registered

    Joined:
    Dec 6, 2018
    Messages:
    351
    Likes Received:
    173
    This issue of track temperature should be one of the top priorities for S397 I think, all the other simulations take it into account, there is a crucial delay on this subject that I think it is urgent to make up for, in an obvious concern for realism.
     
    Alessio Feletto and Bruno Gil like this.
  15. Andregee

    Andregee Registered

    Joined:
    Jun 23, 2012
    Messages:
    869
    Likes Received:
    343
    Instead of removing the rear stabiliser, you can also make the front one harder.
    It is quite obvious that a softer or no anti-roll bar increases the grip on the off-setting axle, simply because the wheel load difference decreases, as both inner and outer wheels are loaded more evenly, since the car is supported more on the other axle against the lateral inclination. The simple physics of removing the anti-roll bar from the rear axle means that the front axle has to work harder in the bend. However, if you leave the rear anti-roll bar at its level and increase the value of the front anti-roll bar instead, you also reduce the wheel load difference on the rear axle, load the front axle just as much, but the result is a lower lateral inclination of the whole car than by detaching only the rear anti-roll bar and thus a lower shift of the centre of gravity of the entire vehicle and thus also a lower wheel load difference on both axles and thus more grip overall. Therefore, if you reduce or remove the rear anti-roll bar value instead of increasing the front one, you are making a mistake unless the vehicle does not offer a harder setting for the anti-roll bar at the front or the track is too rough for higher values. That a basically removed rear anti-roll bar in rFactor2 leads to more grip and better lap times is complete nonsense. On the contrary, I usually even increase the rear anti-roll bar for less understeer and drive much faster with it. Also, you can't completely compensate for low wing settings with a lower rear stabiliser, because the wing only takes effect at higher speeds and the non-existent rear anti-roll bar can't compensate for the low downforce at all, so you only get unnecessary understeer at low speeds.
     
    Bruno Gil likes this.
  16. Bruno Gil

    Bruno Gil Registered

    Joined:
    Oct 12, 2020
    Messages:
    119
    Likes Received:
    75
    This is my exact experience, after MANY tries of the "detach arb" "theory".
    Slip_Angel, strannix posted the test a few posts earlier - not sure if you missed it, but stiffer arb does decrease roll in ride height.

    I still stand by and have always thought as Yzangard says : while it might be a bit too much permissive on the sliding, the reason rf2 feels "easier" (note: not easier; more intuitive) is because when you get used to it, you get A TON of High Quality feedback, not only ffb but visual and auditory, which are probably more important even, so you can quickly say what's going on around you. However, when you do find yourself Trying to Go fast(er), thats where the challenge lies. The whole experience reminds me of karting ( I have no other real life Motorsport experience except karting, unfortunately) , way more than any other sim
     
  17. Slip_Angel

    Slip_Angel Registered

    Joined:
    Jun 15, 2019
    Messages:
    588
    Likes Received:
    297
    Then it looks like issues is with tire and aero.
     
  18. Stefan_L_01

    Stefan_L_01 Registered

    Joined:
    Nov 18, 2012
    Messages:
    595
    Likes Received:
    385
    Dont forget that taking away load by removing or lowering rear arb leaves more traction for acceleration out of the corner
     
  19. mantasisg

    mantasisg Registered

    Joined:
    Aug 17, 2016
    Messages:
    2,728
    Likes Received:
    3,658
    rF2 is not extremely easy to drive, some cars in rF2 are. And indeed the main suspect should be tires. It is mostly tires and aerodynamics that makes car behave the way they do. The rest of the cars physics including adjustable setups is mainly for managing tires in best way possible. If tires for certain car is configured in such way that they have very low frequencies and low grip amplitudes: slow progressions of into slides, slow progressions out slides, lowish friction differences between sliding and not sliding... Thats why there is not that much need for stiff stabilisers or highest aerodynamics and traction control, it simply does not mean that much for a tire to slide.

    If tire would be snapier then too low stiffness stabiliser aka anti roll bar aka anti sway bar would not stop chassis swinging before tires grips up, if tires grips up and chassis stays on the roll motion, it causes instability. But we also need to know actuall stiffness for rolling, because in terms of physics we can not say "stiff" or "soft", there are no physical units such as "stiff" or "soft". However, I think we can tell that tires are indeed quite pregressive. Perhaps it is awesome for casual gamers, but I feel the frustration of very capable eSports racers and simply very fast guys who are also observant enough to feel something is not right, they could deal with more demanding car and have more fun doing that and the competitions would count more.

    "Lazy" tire is also why lower wings tends to work. Downforce is there to prevent tires from sliding, obviously if it is not big of a deal to slide, then it starts to pay off to gamble with some less drag with slight more tire wear.

    Then for the TC it is the same again... if slippage is not that bad, then why prevent it ?

    And by the way... you are wrong. rF2 physics isn't bad, rF2 has great physics. You would be surprised to learn how much of the phenomenal rF2 FFB is actually simply physics. I don't know why, but people are just obsessed to think about FFB separately from physics... FFB in fact is dominantly physics at least in rF2, and thats why it is good.

    And I don't know much about iR physics issues, but it is almost certain that opposite to any other simracing title, the tires there are probably taken from year 2077, higher performance than real tires, and a lot more sharp, too sharp - which causes lots of frustration for drivers. I suppose there could be some exploits to make full use of tire before it slides, which probably is not some technique IRL that would be used now, but perhaps will be used in 2070 :D if cars will still have tires then.
     
    Bruno Gil likes this.
  20. Andregee

    Andregee Registered

    Joined:
    Jun 23, 2012
    Messages:
    869
    Likes Received:
    343
    Increasing the front anti-rollbar stiffness has the same or even a better result cause like i said you can keep the wheel load difference down and let the front axle take more load and the shift of the center of gravity to the outer side reduces the complete wheel load difference for both axles
     

Share This Page