3. Lockup stops outbrake ABS ones - skid grip too high?
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Lockup stops outbrake ABS ones - skid grip too high?

  • M

    Hi all, i'm doing yet another 'realistic handling' mod (albeit something a bit different i hope), but i've hit a problem with the way the game implements ABS - per the title, i'm finding that with ABS disabled, a car with locked wheels is stopping in significantly less distance than when ABS is enabled!

    Obviously, it should be the other way around - ABS should stop you shorter..

    The difference appears to be around a consistent 30% - that's how much more distance is needed to come to a halt from a given speed with ABS enabled.

    Things i've tried already:

    • Fixing it from within Handling.meta - however reducing linear grip (accelerating/braking grip) seems to uniformly affect ABS braking too, increasing overall stopping distance but without sorting the problem - locked wheels are still 30% more effective.

    • Modding Materials.dat - same as above; overall stopping distances are increased uniformly, preserving the 30% advantage with locked wheels.

    Logically, ABS is doing its thing OK - preventing wheel lockup - hence the problem must be the amount of grip being assigned to skidding tyres. This value needs modifying, but i don't know where to find it!

    Somewhere, there must be a parameter that reduces traction or friction values when a wheel is locked and skidding..?

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  • A

    @MrVibrating
    afaik there's no separate parameter to isolate locked wheel/skidding grip/friction from the rest of the ABS ON/OFF braking calculations. You could do it with a script but I've never seen any specific parameters like that in the game files.
    I'm confident you will be able to get the result you require though :thumbsup: as I think it is just a matter of looking at the problem from a different perspective.
    As it stands I've made a few presumptions as to what you may want to achieve/why differences in ABS ON/OFF braking distance might be an issue for you etc. Hopefully I'm on the money but if not give me a better idea of the end result you want to achieve I'll have a more precise response for you :thumbsup:.

    I take it you are switching ABS ON/OFF using the 'strModelFlags' in the vehicles 'handling.meta' yeah?

    ABS strModelFlags

    My results:

    • 1 = ABS_STD - Small brake marks at end of skid
    • 2 = ABS_OPTION - Long dark brake marks
    • 4 = ABS_ALT_STD - Dotted brake marks (like real life ABS)
    • 8 = ABS_ALT_OPTION - Long dark brake marks (similar/same as '2')

    For me at least 1, 2 & 8 brake about the same. 2 & 8 may even stop quicker (quick test) but I don't like the heavy dark brake marks much.
    I take it you want the one that looks like real life? ie 'ABS_ALT_STD' ('4') dotted brake marks?
    Generally you would select 'ABS_ALT_STD' ('4') in the vehicles 'strModelFlags' line in 'handling.meta' & then compensate for the reduction in braking ability by increasing:

          <fBrakeForce value="increase_value_here" />

    If you are in the situation where you have 2 vehicles the same/similar using the same 'handling.meta' settings & you want one to have standard braking & the other to have ABS (dotted line etc & increased stopping ability, like real life) one way to solve that would be to create a separate & different handling profile & then point the ABS vehicle version's 'vehicles.meta' '<handlingId>' to the new ABS handling profile.

    Example (Standard):

    'vehicles.meta':

        <Item>
      <modelName>vigero</modelName>
      <txdName>vigero</txdName>
      <handlingId>VIGERO</handlingId>
      <gameName>VIGERO</gameName>

    'handling.meta':

        <Item type="CHandlingData">
      <handlingName>VIGERO</handlingName>
...
      <fBrakeForce value="2.500000" />
...
      <strModelFlags>440010</strModelFlags>

    Example (ABS ON):

    'vehicles.meta':

        <Item>
      <modelName>vigero</modelName>
      <txdName>vigero</txdName>
      <handlingId>VIGEROABS</handlingId>
      <gameName>VIGERO</gameName>

    'handling.meta':

        <Item type="CHandlingData">
      <handlingName>VIGEROABS</handlingName>
...
      <fBrakeForce value="3.250000" />
...
      <strModelFlags>440040</strModelFlags>

    Note: In the example above I've increased the '<fBrakeForce value=' by 30%. You'll obviously have to experiment to find the correct value for your liking :thumbsup:

    Let us know how you get on or if you have any more info to add etc :thumbsup:

    "Never imagine yourself not to be otherwise than what it might appear to others that what you were or might have been was not otherwise than what you had been would have appeared to them to be otherwise." - Lewis Carroll (Alice in Wonderland)

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  • M

    Sorry for late response, busy week - thanks mate for your thoughts, however the issue is that wheel-locked and skidding vehicles out-brake ones using ABS.

    Most "realistic handling" mods are nothing of the sort - they 'sculpt' each vehicle's handling in a top-down way, enforcing the handling specifications irrespective of one another using artificial and physically inconsistent values.

    The physics engine supports much more realistic handling than most people seem to realise, where the handling's determined in a bottom-up way, ie. cornering ability becomes a function of lateral friction and a properly-functioning suspension system controlling the weight distribution, rather than inputting a physically-inconsistent and much higher lateral friction value that approximates the specified cornering ability but regardless of whatever the suspension's doing, or not doing..

    Ditto for all aspects of linear accelerations - the "low speed friction modifier" that causes wheelspin at low speeds - what the hell kind of physics would cause that? It's Tonka physics. Zero that shit. Wheelspin should be purely a function of the current and dynamic balance of grip and power. Likewise, "flat-out velocity" is the speed at which aerodynamic drag balances against engine power as a function of the gearing ratio, road gradient, wind effects (if enabled) etc., and the engine in question won't necessarily be redlining at that speed - peak torque for an old V8 for example's likely to be nearer the middle of the rev range.

    And so also for stopping power - it should be determined by the same friction and suspension-dependent weight-distribution factors as everything else - for instance, most vehicles should have sufficient braking power to be able to lock their wheels at almost any speed. But if you brake progressively instead of suddenly, you shift the weight forwards, compressing the front end, and so can brake ever-harder without causing a lock-up until the last moment..

    You then further tune the brake balance at that point, to control which axle locks up first - obviously, if it's the front-end then this exerts a strong yawing tendency under heavy braking, as the rear end scrubs off momentum more slowly than the front, thus converting linear momentum to angular. Ideally, you want simultaneous lockup on both axles, with maybe a slight rear axle lead (so you can still steer up to the last second).

    It is only THEN that you enable ABS, if that's what the car should be fitted with...

    So the binary flag for vehicles with no ABS is "0". The old pony cars, most of the classics etc., have no ABS.

    The standard ABS, option "1", applies a constant ABS to all wheels independently, in ms timeframes

    Option 2 means "optional" - ie. it was an option on whatever RL car it's modelled on, not a standard fitment. So for example the Karin Sultan would use this setting. Some will spawn with ABS, some without. Applies also to your saved cars - you might have to respawn one a few times to toggle ABS on and off (someone should do a key toggle mod, cough cough IKT).

    Option 4 is a different kind of ABS, sampling the wheels one-at-a-time at much lower frequency (about 50 ms). Hence the wheels alternately spin and lockup in a left-to-right, front-to-back sequence, causing a weaving effect and instability.

    Like option 2, Option 8 fits option 4 ABS to 50% of spawns at random.

    So the values to use are 0, 1 and 2. But the whole raison d'etre of "1" is that it should out-perform "0"... yet it's 30% worse in every case.

    Some people have tried modding materials.dat to globally reduce friction values in the attempt to get realistic (ie. fun) handling physics - i've tried it too but it's unnecessary and kludgy, with dubious results - you only need to input self-consistent values into handling.meta to get naturalistic handling. But as i say, uniformly lowering friction has no effect on the ABS performance - overall stopping distances increase, but ABS stops still need 30% more distance.

    So the only logical explanation seems to be that there MUST BE a "skidding friction" modifier in action when a moving wheel locks up. Because if it were simply the linear friction value, then lowering it enough would eventually give ABS the advantage.. yet it does not.

    This modifier is obviously THERE, since we see its effects - yet it's not a vehicle-specific parameter...

    ..so it must be a lower-level setting, in the Rage physics engine? Dunno.

    Like i say, editing materials.dat is useless, likewise tyre effects. Dunno where else to look.

    It's a shame, you can have awesome sim-like fun handling, but for this one fly in the ointment..

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  • A

    @MrVibrating
    Yeah, I get that, I think the rage engine is just set up something similar to max grip = locked wheel & the ABS in the game is just fake ABS stopping the wheels locking up but reducing stopping power in the process as the wheels never get to there max grip (ie locked wheel status (totally unlike real life)).

    R* do stuff like that a lot. The "low speed friction modifier" for example. It's just there because R*'s engine doesn''t work very well for wheeled vehicles at the low end of the speed spectrum. Yeah, it's a shortcut/lazy programming/not perfect physics/not ideal etc but you'll find stuff like that in every game & even in engineering in real life. The important point is that whether ideal or not you CAN get the outcome you desire. You edit the brake force of vehicles individually on a per vehicle basis giving the vehicles with ABS a boost in brake force to compensate for their overall reduced stopping power. End result for player: Cars with ABS have better stopping ability than cars without.

    If you do suss out any other info on the matter (or find that parameter :slight_smile: :thumbsup:) do let me know. I'm favouring a 'don't ask too much of the game' approach here but the right person with a good idea & a moderate helping of tenacity & luck can break through knowledge barriers like this & improve the whole modding community's as a result. So I do wish you the best of luck :thumbsup: If I discover any new parameters that affect braking I'll be sure to let you know. :thumbsup:

    Edit: Not sure how much use this will be but I remembered a file I edited years ago called 'material_override_pairs.dat'. It's here:

    ...\mods\common.rpf\data\materials\material_override_pairs.dat

    May be useful to test forcing material friction/elasticity values & seeing if it changes anything to do with how normal braking & ABS relate to one another. :thumbsup:

    "Never imagine yourself not to be otherwise than what it might appear to others that what you were or might have been was not otherwise than what you had been would have appeared to them to be otherwise." - Lewis Carroll (Alice in Wonderland)

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  • You dont know anything about car physics, ABS prevents your wheels from locking up, but it does INCREASE braking distance, i think you never had a car with ABS (or other way around)

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  • A

    @Gerfsen said in Lockup stops outbrake ABS ones - skid grip too high?:

    You dont know anything about car physics, ABS prevents your wheels from locking up, but it does INCREASE braking distance, i think you never had a car with ABS (or other way around)

    Hmmm?! Where to start on this? Grammar? Punctuation? Manners? Laws of Physics? :slight_smile:

    Ooh, that's it...THIS will do nicely. Thank you Internet :thumbsup:

    Note: You can use '@' before a person's username to tag them in a post :thumbsup: (wasn't sure who you were talking to but hopefully the link puts you straight :thumbsup:)

    "Never imagine yourself not to be otherwise than what it might appear to others that what you were or might have been was not otherwise than what you had been would have appeared to them to be otherwise." - Lewis Carroll (Alice in Wonderland)

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  • quote from internet: "A well set up car in good conditions stopping in a straight line, proper threshold braking should beat ABS"
    So shut the hell up kiddo.
    And show me one grammar mistake :)

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  • A

    @Gerfsen said in Lockup stops outbrake ABS ones - skid grip too high?:

    "A well set up car in good conditions stopping in a straight line, proper threshold braking should beat ABS"

    Yeah, I found the page you were quoting. That's a whole lot of white space underneath it :confused:

    Only page on Internet

    HERE IS YOUR QUOTE FROM THAT LINK IN CONTEXT:

    Misleading?

    May I suggest you were a little misleading.

    At this point this next part is probably overkill but you did ask:

    Grammar

    Look, let's not drive the poor guys thread off a cliff (ABS would stop it before the cliff right enough (<I'm joking) :slight_smile:).
    Obviously in real world situations whether ABS is better is entirely case dependent. Thus the op is well within his remit to opt to have ABS beat normal brakes (all evidence (even the context of your quote) suggests that this is the modern standard). If you then choose to jump into this thread offering no real constructive contribution just an insult laden tirade, it is you sir that "dont know anything".
    ^That last part might be a bit harsh lol :slight_smile: I do not intend to continue to derail this thread past this point. You can reply if you wish, as is your prerogative, but I will not be listening.

    Really I just want to move on from this now & get on with my life. You should do the same. Forget about me. We are just too different. You like simple and categorical. I prefer complex and nuanced. That's life. Don't feel bad :slight_frown:. It was never meant to be. I would tell you it's me but it's not, it's you, it's very, very much you. (<^ humour, not entirely serious etc :slight_smile:)

    You won't realise this but 11 months ago, in my previous account I helped you out so let's just chill out, be polite & mod the fricking game already. :thumbsup:

    If you go to Quora for a lot of your info, may I suggest this page :slight_smile:

    All the best :thumbsup:

    "Never imagine yourself not to be otherwise than what it might appear to others that what you were or might have been was not otherwise than what you had been would have appeared to them to be otherwise." - Lewis Carroll (Alice in Wonderland)

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  • MODERATOR

    No need to get all up-close and personal.

    Preventing the wheels from locking up mainly helps steering under max possible braking pressure. Depending on the conditions and implementation it may or may not increase or decrease effective braking distance.

    Shouldn't be anywhere near that big number of 30% more distance with ABS though (unless on loose surfaces), so that might be something to look into.

    I haven't found anything useful to toggle ABS though I did a few experiments with scriptwise ABS.

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