Vehicle mass

Discussion in 'General Discussion' started by Slip_Angel, Aug 4, 2019.

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  1. Slip_Angel

    Slip_Angel Registered

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    I been playing good amount of RF2 but i noticed some things that vehicles here generally feels like they have very little mass.This behaviour is extremely noticeable when riding kerbs.
    I read somewhere that RF2 has fixed polar moment of inertia could this be the reason?
     
  2. mantasisg

    mantasisg Registered

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    Fixed polar inertia moment ? Wth. It is major component of vehicles dynamics.

    I am always confused when people aim at mass feel, it makes no sense.
     
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  3. Slip_Angel

    Slip_Angel Registered

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    like for example while trail braking i do lose rear tyre grip due to weight shift sometimes but it feels like only tyre grip is influenced due to weight shift other than entire weight of car.
    like in a mid engine race car the car comes to halt quite quickly under loss of traction under trail braking which makes things little bit easy and predictable.
     
  4. LokiD

    LokiD Registered

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    No disrespect but want real physics go drive a real race car. This is the closest it will get on a consumer rig. Nothings perfect
     
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  5. Slip_Angel

    Slip_Angel Registered

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    I wouldn't be playing any game at all if i could even own a family lowest budget car trust me. I'm not wealthy or lucky as some of you guys ffs i have never even seen a race car with me eyes in my life because that would cost traveling money etc.
    Besides i know that no game/sim is perfect i just wanted to know if this behaviour i'm experiencing is due to not having moment of inertia or something else.
    It is way to easy to say"go drive a real car if you don't like the game/sim" than actually answering the questions.
     
    Last edited: Aug 15, 2019
  6. davehenrie

    davehenrie Registered

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    This has been a topic, off and on over the years. Somebody made some tests by deliberately driving over some curbing at measuring how far the cars flew before returning to the ground. Other sims always seemed to land before rF2 cars.
     
  7. Korva7

    Korva7 Registered

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    Haven't heard of this. Maybe there is difference between sims in how aerodynamics is simulated. In rf2 with some cars on some tracks i get so much lift that the car starts to make wheelies.
     
  8. Slip_Angel

    Slip_Angel Registered

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    Aero maybe related to this idk but the car on kerb feels light like it doesn't affect the weight of the car.
    On trail braking or lift throttle situations i don't feel the momentum of car affect the handling especially in mid engine cars.
     
  9. Korva7

    Korva7 Registered

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    My aero comment was directed more to davehenrie's comment. I don't know if it is relevant to your problem. On the trail braking issue: Mass and inertia are so basic things that i would assume them to be properly simulated. Someone with modding experience could tell more about it. I think tires are more difficult thing to get right and more likely the source of problems. For examble, too much grip during slide could make the slide stop earlier than it should. And i happen to think that there might be this kind of problem, atleast with the gt3s.
     
  10. Lazza

    Lazza Registered

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    You lost me at "feels like". That something as fundamental as inertia could be so wrong that a new player can feel something is out of whack (yet no one developing the game, and testing against manufacturer-supplied data in initial development and later with licensed content, spotted a problem) defies belief. Add to that the introduction some years back of flexible chassis in rF2 (which has direct bearing on your question of polar moment of inertia - though to be honest I'm not sure that means what you think it does) and I really think anything you're feeling that doesn't seem right is either just an incorrect expectation of the car, a lack of familiarity with rF2 and therefore an incorrect 'read' on what's happening, or just a different feeling to other games (correct in their own physics or not) which is putting you off.

    There are many variables, and 'feeling' is the biggest. The reason real cars get mentioned (I think) is that what you can perceive in a game is very different to real life, so it's quite possible absolutely realistic behaviour (which we may never see in a game) will never feel the same as real life.
     
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  11. stonec

    stonec Registered

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    Inertia parameters for x, y and z axis are defined for each mod. Generally any parameter is an approximation of the real thing, but there is no reason to think the fundamental inertia or weight physics are wrong in a sim that is used in slightly modified version by real F1 teams (rF Pro). Now it could be that a specific mod has poorly estimated interia numbers, making the mod feel too light or heavy. This was the case for example with the EnduRacers Flat6 mod, which turned out to have around twice as high interia numbers as were to be expected. Such errors would obviously not creep into official content, so you need to be specific on what content you are having issues with.
     
  12. Comante

    Comante Registered

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    There are limits in every car simulation when we stop talking about tire/road interaction (the main purpose of the simulation) and we start talking about solid object interacions. Even if RF2 has flexible chassis I think it is still referred to suspension and tires, the simulation can't handle the interaction of a real kerb to a real car underbody : there are parts that flex, bend, chip, scrub, scratch, break, all those depart the simulated behaviour of a virtual box from reality. The most obvious instance of this departure is when we hit an excessive step in a kerb with a very low riding car: the whole car fly in the air while in a real world it would probably turn in a pile of smoking debris.
     
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  13. vitto

    vitto Registered

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    car wheelies, just go to youtube and type: le mans backflip
     
  14. mantasisg

    mantasisg Registered

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    I feel like if someone just mentioned something related with mass or/and weigth not being so and so, eventually everybody will interpret that in many various ways, because you know mass and weight is always there and the specific dynamics are countless, almost.

    So whats up about mass and kerbs ? You don't feel like the car bounces off the kerbs enough ? Car bounces off the kerbs too much ?

    By the way, I don't think gravity has a lot to do with intertia, but mass has an effect for inertia for sure, but mass not weight, as we know weight is gravity effect on mass, and weight is a force.

    These are very technical things and you can't stab in the dark like that. You need to be a little bit more technical. Sorry, but aiming at things like gravity, or polar inertia moments or weight transfer and so... is a bit stupid considering that this is high end vehicle simulation software, just like Lazza has pointed out. If you feel that something is not as you expect it is very likely that your expectations are messed up, also it could be that if you are right then the issue for you not experiencing what you want could be sorted out by parameters that are not as fundamental.
     
  15. mantasisg

    mantasisg Registered

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    If you disagree then back it in proper way. At least I have something useful in my mind. And I expect it from others too, especially in a community of very likely most realistic cars simulation software.

    And I could write more, but I try to keep it compact because no one needs to spend hours in forums everyday.
     
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  16. green serpent

    green serpent Registered

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    Moment of inertia is a measure of the amount of force (or 'torque') needed to rotate an object around its axis. A rigid object that has a large amount of it's mass close to its central axis will have a lower moment of inertia and will require less torque to make it spin. An object of the same total mass but with it's mass distributed further away from it's center will have a harder time rotating on it's axis.

    So to put it in driving physics terms, a mid-engined car (i.e a car that has a high amount of it's mass close to it's center) will rotate much easier around it's axis than a car that is front-engined and has a transaxle at the rear (mass spread further away from it's center compared to mid-engined).

    I'm not really sure exactly what 'rF2 has fixed polar moment of inertia' means, but if it means that every car in rF2 has the same moment of inerta, then I think we can safely say that that is totally false. I'm not discrediting what your saying, I'm just saying that your experience is not because 'rF2 has fixed polar moment of inertia'.

    What I will say is that in most sims I've played it seems very difficult (or even impossible) to flip a car while going around a corner and hitting a curb, whereas in rF2 it's very possible. How can anyone really know anything for sure, but for me If anything it lead me to believe even more that the physics in rF2 are more realistic than the other sims.
     
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  17. Slip_Angel

    Slip_Angel Registered

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    Maybe it is just the car i didn't like that much then lmp2 oreca.
    Overall though RF2 still has best f1 cars for me though.
     
  18. Slip_Angel

    Slip_Angel Registered

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    just a heads up they actually did something about things i mentioned here.(check out oreca changes the car with i had problems with)
    Latest Endurance Pack Updates!

    Porsche 991 RSR GTE
    v1.93
    - BoP (Balance of Performance)
    - Fixed headlight glass reflections

    Chevrolet Corvette C7.R GTE
    v2.01
    - BoP (Balance of Performance)

    BMW M8 GTE
    v1.73
    - BoP (Balance of Performance)

    Oreca 07 LMP2
    v1.69

    - Made the car a bit heavier to better correspond with real data.
    - Further adjustments to correct engine power/torque output
    - Adjusted downforce overall
    - Further improvements and adjustments to Le Mans aero package
    - Corrected engine inertia
    - Corrected gear changes that were slightly too short (gear shifts)
     
  19. Lazza

    Lazza Registered

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    I somehow doubt their 'bit heavier' corresponds to your "much too light" which you say is "extremely noticeable". And the only direct mention of inertia is unrelated engine inertia, though of course the car mass increase likely included a slight inertia increase. Notice any major difference driving?

    Please don't think they've changed the car because of this thread.
     
  20. Slip_Angel

    Slip_Angel Registered

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    i get it,you like RF2 okay.
    It is a perfect sim with no issues at all,happy now ?
    Edit: I knew that even after they fixed it you would still think i was wrong,you are like master defender of RF2 forces.
     

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