rF2 FFB system and philosophy

Discussion in 'General Discussion' started by DrivingFast, Nov 4, 2020.

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  1. mesfigas

    mesfigas Registered

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    @pilAUTO well still ACC has weird FFB and hitting a curb with Gt3 car feels even more weird......
    bliah
    well ACC is good but still our old RF2 friend is doing amazing by giving good racing feel and a more engaging experience
     
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  2. Lazza

    Lazza Registered

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    @doddynco that's a good rundown of actual real things and their known implementation, very nice addition to the discussion.

    One thing I think not included in your post is abrasion (physical wear), obviously being uneven because of the other factors. As a complete guess I imagine such wear would affect grip in several ways - less depth producing less heat, conformity, and different layers of rubber having different properties (potentially grip).

    In rF2 we know wear is modelled at a fine level (because flatspots), can probably assume per-node, and abrasion leads to lower grip. Unfortunately all we can see in-game or via telemetry is an overall wear percentage.

    They can't instantly revert, or they'll instantly be in contact again (at least for a while). Interesting though. I wonder if a tyre could be constructed to test this? Maybe you've done some tests already, sounds like you've looked into this a little. One of the more recent additions to the model (adhesion?) might also mask this.
     
  3. doddynco

    doddynco Registered

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    <Is exactly the issue. The contact patch is effectively extended as nodes which should still be in a 'compressed' state and not in contact with the ground still form the contact patch. So what this means then, is that even if the tyre moves away from the ground at a very high speed, the air, carcass, and rubber will rebound at an infinite rate and keep in contact with the ground to match it, until the tyre has reached its uncompressed 'maximum diameter'.

    A way to test for this would be to build an tyre with unrealistically high damping characteristics, low structural integrity and run it around 1bar. There must be a parameter (or combination of parameters) in realtime) but so far I have not found it. Vertical damping maybe, but didn't work for me in the way I expected. A close up view on the tyres from the side, in slow motion, would reveal an instantly reverting 'impossible' material. If i'm wrong, you should see a slow rebounding rubber, like a memory foam matress, once the tyre has left the contact patch.

    Your point about the new adhesion feature is something which I overlooked when testing, however it still wouldn't explain some of the behaviour I could see.

    What we need is either;
    a) S397 to extend the tyre model to calculate a node spring/damping/position regardless of whether it is in contact with the ground.
    2)dev to tell me that i'm wrong
    iii)lazza makes memory foam tyres
     
    Last edited: Nov 20, 2020
  4. Andregee

    Andregee Registered

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    It´s not a bug, it´s a disabled function, caused by early tyres not working correctly with different temperatures and no it´s not acceptable for future.The whole UI thing takes to much resources i think
     
  5. David O'Reilly

    David O'Reilly Registered

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    No offense taken, but if we can't compare real life steering wheel forces (where most cars have power steering) to this sim then things suddenly get a bit boring.

    Regarding Pressures; One issue that seems to have evaded discussion is the impact of pressures on creating contact across the whole of the tyre. Higher pressures will push the middle of the tread (or contact area) onto the road reducing the patch, lower pressures will not allow that and edges run hotter. So if pressures are too low the middle of the contact area will not get to do its job. This is where tyre pyrometers are used in racing, to check temps across the tyre and ensure the whole tyre is being worked. Middle temp too low = pressures too low. In our series we have established which is the most effective hot pressure and check hot tyres for that when testing.

    In the wet its common practice in real life to run higher pressures to actually reduce the size of the contact patch and therefore reduce aquaplaning. I got this back-to-front in a wet race and went for low pressures to increase contact patch size, it did not end well!
    I was interested to see the wear pattern on Lewis Hamiltons intermediate tyres at Turkey which did indicate that approach.
     
    Last edited: Nov 21, 2020
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  6. Pawel44

    Pawel44 Registered

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    I'm not sure if you're trolling or not, but let me explain. ACC has everything in place (or at least nearly everything) like track temperature affecting tires, more realistic pressure levels etc. rF2 has much better FFB feeling (more realistic or not, doesn't matter for now), mesh modeled tires, but suffers from incomplete physics model. The coherency in my post is completely fine, because you can't go higher with incomplete model. ACC: 100% complete, but few things worse. rF2 80% complete (because few things ARE NOT IMPLEMENTED AT ALL), but few things better. In even more simple words: old, but fully functional steel bike vs newer aluminum one without a saddle.
    I prefer rF2 feel and it gives me more satisfaction, but I want its physics to be fully implemented. If you want some childish talk which is better I'm not interested. I'm only saying which one is more complete when comes to driving model.
     
    Last edited: Nov 21, 2020
  7. Pawel44

    Pawel44 Registered

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    I'm not a physics expert, but I know physicists who have shown errors and contradictions in einstein theories. He was a plagiarist after all and he didn't know much about mathematics. However, I don't care about him and I don't want to spoil this thread with that thieve.
     
  8. Comante

    Comante Registered

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    Bwaawawawawaw you made my day with that.
     
  9. UGM 133A

    UGM 133A Registered

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    You can still compare vehicle behavior, but if you're talking purely about steering feedback, then it's obviously not going to be the same due to the power steering. Just because something is boring doesn't mean reality can be changed to make it more interesting, it is what it is.

    People say Einstein wasn't great at math only because he wasn't a mathematician, meaning he didn't go too far into pure math since it's mostly irrelevant for HEP theory. Compared to anyone who isn't in academia, his mathematical knowledge would be pretty vast, he also learned all of it at a very young age. You wouldn't even be able to get a PhD in physics without learning a lot of mathematical logic, things like set theory and abstract algebra would pretty much be required to even read, let alone, write physics papers properly. Saying he doesn't know anything about math shows that you don't know anything about math or physics.
     
    Last edited: Nov 21, 2020
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  10. Pawel44

    Pawel44 Registered

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    I said he didn't know much about math. That's a difference. Maybe if he knew he wouldn't make such holes in his theories. He succeeded thanks to lobby that was behind him.

    Ps. It's my last post about einstein in this thread, because I don't want to trash this thread with this POS.
     
    Last edited: Nov 21, 2020
  11. Rastas

    Rastas Registered

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    Oh,another keyboard warrior,you whish be 0,00000001% of Einstein was pal.
     
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  12. nolive721

    nolive721 Registered

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    I am still relatively new to RF2, what kind of bothers me is the relatively vague wheel center feel for some cars (yes sorry again AMG GT3 I am looking at you) and also open wheelers like Brabham and Cos. I do understand that physics and car set-up do explain somehow this but I feel the deadzone to be really over pronounced for these cars. Is there any way for me to "tighten" the wheel center like its possible by modifying the FFB custom file in other Sims like AMS2 or PC2?
     
  13. doddynco

    doddynco Registered

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    Firstly make sure you have the multiplier set right for the car - if it's too weak it's not going to do much of anything. Use an FFB meter - this helps alot.

    A combination of factors related to steering geometry contribute to the self-centering force of the steering wheel. In RF2, the force is 'built in' to the suspension by whoever made the virtual car (hopefully based on real geometric data from the real car). However, if the car has adjustable caster angle, you could crank that up, as one of the things it changes is the self-centering force.

    You can post-process the RF2 FFB output by adding more center spring saturation in your controller.json, though I would strongly recommend against it because it is a 'fake' effect. There's not really any reason you should use this, but there's nothing stopping you.
     
  14. nolive721

    nolive721 Registered

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    thanks for the quick reply

    you are talking about this one here right?

    "Steering spring coefficient#":"Static spring effect rate (-1.0 to 1.0)",
    "Steering spring saturation":0.1,
    "Steering spring saturation#":"Static spring effect peak force (0.0 to 1.0)",
    "Steering torque capability":2.5,
    "Steering torque capability#":"The maximum torque capability of the wheel (in Nm, obviously)",
     
  15. Comante

    Comante Registered

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    What kind of wheel do you have? This is quite important because product like G27 and subsequent are inherently weak in the straight line because one 1 motor work in this instance (they have two) . I have a G27 an minimum torque does not solve but make this effect less bothersome.
    I would advise to modify .json file unless you have a very special FFB wheel. More easy than not you are going to mess up.
    (I'm into rf2 since the beginning and coming from rf1, messing with files was standard procedure, but in the end defaults were always better).
     
  16. nolive721

    nolive721 Registered

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    Thanks

    silly me I forgot that , I should have mentioned this obviously. its a TSPC Racer so if not Top End, pretty superior to the Logitechs in terms of Motors quality and torque(+belt)

    will do some test later tonight and report back
     
  17. nolive721

    nolive721 Registered

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    @doddynco

    thanks for your guidance, it has improved the center feel indeed and make the cars I was mentioning more enjoyable to drive.Good thing is that it didn't affect negatively the good feeling I have with my main daily drivers (GTEs&GT3s)

    thanks again
     
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