FFB multiplier

Discussion in 'General Discussion' started by SuperMonaco_GP, May 8, 2021.

  1. SuperMonaco_GP

    SuperMonaco_GP Registered

    Joined:
    Jun 11, 2020
    Messages:
    46
    Likes Received:
    50
    yeah, thank you for the discovery. that was in my first post.
     
    Nieubermesch likes this.
  2. EricW

    EricW Registered

    Joined:
    Jun 2, 2017
    Messages:
    123
    Likes Received:
    85
    To hard to answer my question what reason you have to find this a issue?
     
  3. Lazza

    Lazza Registered

    Joined:
    Oct 5, 2010
    Messages:
    9,448
    Likes Received:
    4,468
    I think you're overcomplicating this at the game end. I'm not completely sure what you mean by "As I see it there are no adjustments made to the amplitude or strength of the FFB signal by choosing a certain wheel profile." but rather than have 5 posts back and forth clarifying and maybe explaining, I'll just go through some of what the game does and hopefully clear it up for anyone not sure. There's nothing to be gained from pissing contests (a "who knows more" competition - no one knows anything without learning it).

    The game outputs an FFB signal, -100 to +100%. That's it. What happens on the wheel end is up to the wheel and drivers, but it can't rectify any problems with what the game is putting out. (simucube 'reconstruction filter' is an attempt to fix clipped signals, but such a process should never be the first option - you can't recreate information you don't have)

    So what games generally do, and rF2 is the same, is take whichever car you're driving and scale its forces to that same FFB output range. Actually a lot of games don't do anything related directly to physics at all, and just create forces based on analysis of what the car is doing (and rF1 was mostly the same, with its internal steering arm force merely a component of the overall FFB - the RealFeel plugin later threw away everything except the steering arm force, giving raw physics output only and forcing the geometry of the car to be correct because the 'made up' forces were no longer there. rF2 has only ever done this raw output). So what this means is the indycar, which is known to produce strong wheel forces (~25Nm), and the skip barber which produces much weaker forces (~9Nm) are both scaled to that full -100 - +100 range. You don't make the skip barber a lot weaker, because consumer wheels producing 2.5Nm are already weak enough without then limiting them to 0.9Nm to reflect the physics of the current car. People will flock to a game that produces the full 2.5Nm their wheel can do, and generally even prefer a bit of clipping just so it feels stronger.

    Now, throw a DD wheel on there, and let's say it's a brute that can do 100Nm. Scale those forces the same way, and obviously both the indycar and skippy are stupidly strong. So you set the FFB Mult to 0.25, and now the indycar is correct, but the skippy is still way too strong. So you end up having to adjust each car based on what its actual forces are in order to create realistic forces at your wheel.

    rF2 then added this to the controller.JSON files:
    Code:
        "Steering torque capability":2.5,
        "Steering torque capability#":"The maximum torque capability of the wheel (in Nm, obviously)",
    This is how you tell the game what your wheel is capable of.

    Now with most wheels, like this example which is for the Logitech wheels, the wheel's capability is lower than basically any of the cars in game. So that same scaling happens as before.

    Set that value to 100, however, and now the game sees that the indycar peaks (basically) at 25% of what your wheel is capable of. So rather than scale its output to your full wheel range, it uses a mult of 0.25. So the car produces 25Nm, your wheel produces 25Nm. Jump in the skippy, same thing - the game multiplies by 0.09, you get 9Nm when the skippy does 9Nm. Happily, this allows a lot of extra room, so when you get some forces above that "nominal max" defined in the car, your wheel can produce those forces instead of clipping them.

    As I said earlier, generally the cars included with the game have some clipping (FFB reaching 100% output for periods) with the Mult on 1.0. So if you decide to avoid most of that clipping by setting the mult to 0.75, you should end up with about the same level of clipping on all cars by using that same value - but this assumes they're all set with output clipping at about the same level.

    Since each car (or mod as I tend to call them... nomenclature being of little importance unless you're trying to score points, evidently) has its own physics and is often made by a different person, there's no guarantee they are consistent in this way. That being the case (and assuming the wheel is set correctly in the JSON as above, or this perceived difference may not be factual) I can see why adjusting for each car - in the absence of the game doing it automatically, which is absolutely possible because it has access to all the physics and could conceivably generate an actual max force each time you go to get in - is necessary.

    The question is whether their level is set wrong, or reflects their relative actual strength. The former will come through when using a weaker wheel, while the latter will happen with a properly set DD wheel - and wouldn't be incorrect in that case.

    I find it funny that people have this thought process of "I can't think of anything, so there isn't anything". If the game allows you to adjust FFB live, a program can do it live too. Mid corner it could adjust FFB in an unrealistic fashion to help signal to the driver - or even partially do the driving itself - based on very accurate analysis of what the car is doing. A less direct version of something like manipulating engine modes in a fashion that a driver wouldn't be possible of, to give just one similar example.

    But I'm not making this any bigger than it is - was just a passing comment. The game could limit such input, much as it should limit other inputs like engine modes, preferably in line with series rules. Now I'm moving into other areas rF2 is lacking in though.

    @SuperMonaco_GP one point I should make, is that I haven't really said (exploit idea aside) that live adjustment shouldn't be possible. I didn't reply to your post in this thread initially, I didn't actually reply to any particular post but there was a discussion that seemed to be based on something other than what the game does, so I thought I'd try to help clarify. But I don't see how a manual adjustment is the best idea here - you either then need an FFB meter that you look at while driving in order to judge how your FFB level is, or use telemetry as I said to quite accurately set it (with the proviso that you need to lower it first, to avoid clipping and losing information for your calculation), or have the game help - either by providing some information that you can then use to adjust the value (in the menu, or live), or just use that same information and do it itself. I think that's the best option, with some configuration available to the user in terms of a saturation level (some might prefer more clipping, others less).

    @Nieubermesch I haven't looked into exactly what the saturation extrapolation setting that you pointed out does, I have seen it before, but it's not quite the same thing. I suspect it's more about lowering FFB away from 100% even though the raw force should still be clipped, based on the internal physics lowering. Maybe it also stops you quite getting to 100% output to allow a little room for reaction on peaks. One or both isn't as good a solution as linear response scaled correctly, anyway.
     
  4. Nieubermesch

    Nieubermesch Registered

    Joined:
    May 18, 2019
    Messages:
    571
    Likes Received:
    243
    Good stuff there Lazza ;)
     
  5. SuperMonaco_GP

    SuperMonaco_GP Registered

    Joined:
    Jun 11, 2020
    Messages:
    46
    Likes Received:
    50
    I don't care about the clipping level or the optimal ffb level provided by telemetry, I am asking for a way to set an adequate gain level while driving, a level that I find comfortable to drive with, without having to quit the session, go back to menu and restarting from the pits. any other sim does it, ac, acc, ams2, r3e, iracing. also, it has nothing to do with manipulating the level of physics-driven ffb : this and the multiplier assigned to each car are two completely different things. each sim's ffb is generated by the physics, rf2 is not the only one. another thing, I am not asking for a way to equate ffb gain among all cars : a live ffb multiplier command is useful to lower certain cars gain live, as I said many cars of the same class have a great variation of gain - and like I said I am talking about official s397 content, not mods.
     
    RaceNut and Nieubermesch like this.
  6. RaceNut

    RaceNut Registered

    Joined:
    May 21, 2013
    Messages:
    421
    Likes Received:
    371
    AC ffb-Gain adjustment has always been a reasonably convenient way to adjust strength on the fly but, AMS2's way of allowing assignment of buttons / dials is ideal imo. In AMS2's case, changing other ffb settings may affect the overall ffb strength, so the update for on-the-fly adjustments is even more appreciated.

    Personally speaking, such ease of adjustment is very useful as I suffer from shoulder injuries that can flare up from time to time. Sometimes, the pain may increase over the course of a session. If I drive a car with high down-force, there's a much greater chance that I'll need to lower the ffb gain setting at some point. Having to exit the session to change the gain and then test gets quite tedious and even frustrating when time is limited.

    Most other titles have added this feature over time, so dev's seem to recognize it having sufficient value.
     
    SuperMonaco_GP likes this.

Share This Page