Any plans for tire thermal simulation?

Discussion in 'Ideas and Suggestions' started by Charlie24, Mar 1, 2021.

  1. Charlie24

    Charlie24
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    Im not sure if this already happens under the hood, and there just isn't a UI graphic for it, or its just not simulated at all yet. I would like to see a difference in tire handling with temperature. Also, a tire could pop it it gets too hot. Something I've been thinking about playing the game.
     
  2. Sithhy™

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    This.
    There has been many threads regarding this & all of them have the devs say that it won't come anytime soon due to how complicated it is to get all tire mechanics working realistically
     
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  3. atv_123

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    Yep, agreed... there are some mods out there that do add this functionality on a basic level... but they are nothing close to what the devs are actually aiming at. I am not a dev, but knowing how they do things, I guarantee that they are trying to add heat/rubber/friction/wear simulation on a node by node basis so that each individual node have its own independent values for temperature/mass/friction all on the fly while also changing the air pressure of the beam calculations in the tire along with it. I'm not 100% sure how the mods I have seen work, but my guess is that they are just doing a blanket statement per tire and adjusting friction biased either on driven distance, or some other calculation, for all the nodes in that one tire.
     
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  4. IonicOwl

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    Adding accurate tyre wear that takes camber and wheel mis-alignment into consideration, or flat spots from handbrake turns would be next-level.
     
  5. Diamondback

    Diamondback
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    Vehicle Systems Lead
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    Plans....certainly... But yea, it's a very delicate matter that needs very very careful calibration and affects a ton of other systems, so we can't really promise anything...
     
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  6. Dr. Death

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    >Inb4 you literally hire the Live For Speed devs to do tire grip simulations for beamng.
     
  7. Diamondback

    Diamondback
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    Why would we do that?
     
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  8. default0.0player

    default0.0player
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    This is a soft-body physics vehicle simulation game, not a professional racing/trucking/locomotivating game with tire wear, brake wear, battery wear, retarder overheating, KERS, spring brake, carb icing, pit stop, high idle at low temp, field weakening, automatic emergency braking, dynamic braking
     
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  9. atv_123

    atv_123
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    Agreed... LFS uses a completely different physics system. More than likely, the tire model that LFS uses is so incredibly different that you couldn't even pretend to adapt it to beam even if you wanted to.

    Remember, LFS simulates the tire as a whole while Beam simulates each piece of the tire and then combines them to make a whole. I know most people would look at that and think, "what's the difference?", but trust me... there is a MASSIVE difference. There are equations on equations on equations that most games use to simulate tires and all their physical properties that Beam has naturally emerge as a result of just physically simulating everything. Thus, to get the tire models correct in both instances, you have to come at the problem from completely different directions with the ultimate same goal.... to simulate a tire.
     
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  10. Krishty

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    I think LFS handles tires as 32 individual patches and not “as a whole”. You are, however, correct in that they compute the tire forces a bit different from BeamNG – in a top-down approach where tire forces are computed from the vehicle’s properties (velocity, orientation, suspension, torque …), form a contact patch, and then feed back into the vehicle simulation as grip, sideload, temperature, etc.
    BeamNG may be more of a bottom-up approach, where the contact patch is based on jbeam simulation, but that’s just me guessing.
     
  11. atv_123

    atv_123
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    Yes, you are correct. They do calculate calculate it in patches... but what I meant by that is that those equations feed back into other equations which feed back into other equations... yada yada yada... to basically make a singular contact point "act" as if it is a full fledged tire. If you actually were to take a LFS tire and try and give it more than 2 contact patches... it will freak out and basically default to the one with the most pressure (that might not be the rule, but its the best I can guess)

    I can even show you it happening in real time too.



    Right at around 52 seconds, he starts driving over some speed bumps. Look at the contact patch on any of the tires as he goes over those speed bumps. The deformation (which is linked to the model equations) will just bounce about adjusting as quickly as they can to the normal of the contact patch. This is because it just can't handle having more than one point be its defined contact patch. It has to have only one... and thus, this odd behavior is created.

    Beam on the other hand... while they will have to take a very similar approach in the terms of simulating multiple patches of rubber... That's really where the similarity's end. Now, while technically Beams tires are also equations fed back into equations fed back into equations... Beam is different because you can't point at any single equation and say, "that there... that's is the equation that defines the tire model"

    What they do have... they have Nodes that properly simulate the frictional effects of rubber on varied surfaces and in varied fluids. These basically make up their "contact patch" but no single node is defined as "THE" contact patch... they are all the contact patch... whenever they touch something... wherever they touch something. They also don't have an equation for sidewall stiffness... not really anyways... same with the belts... what they do have are some beams that are a set stiffness and damping in roughly the right geometry to correctly construct these areas with the proper physical properties so that it will act correctly. Same goes for the air pressure in the tire... no singular equation again, its a bunch of different beams all working together to simulate an air pocket.

    None of these elements separated really amount to much of anything but some fancy math... but when you put them together in the engine? All of a sudden, they manifest themselves to become a functioning, realistic, believable tire.

    What's even more fun though? The fact that since they aren't directly simulating tires and more or less simulating all the different components of a tire, you can actually use these properties in game to actually, manually, build your own tires... and I am not talking about using the in game code to literally set some parameter to generate a tire for you... no no no... I am talking about placing all the nodes and beams manually. Setting up all the parameters manually. If you, for some reason, decide to physically "build" a tire... from the ground up, and define all the parameters correctly. It will act just like any of the other in game tires... because again... there is no "one" equation or parameter that you can point to that defines a tire as a tire in Beam. Its just really really REALLY good at acting like it ;)
     
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  12. Krishty

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    Great footage of LFS’ contact mechanism, thanks!

    I guess “roughly” is the point here. BeamNG’s contact resolution is limited as well (seems like 20–30 nodes?), and I can’t believe this would be enough to construct a proper contact patch. I don’t even mean the profile, I mean the rough size and shape – if it’s a 5×5 cm disk, you need at least 2.5 cm resolution (Niquist-Shannon), and that means more than 100 nodes along the wheel circumference alone.

    I still suspect that both LFS and BeamNG are relatively similar in their tire models, with BeamNG providing better input to the tire physics on non-planar ground. I’d think that most of the difference comes from fine-tuning internal parameters, not from jbeam vs. plane collision.

    (As far as I know, you need two tire models because the well-researched ones become instable below 50 km/h. The low-speed tire models may differ more, but I believe neither are “completely different physics systems”.)

    Being relatively new to BeamNG, could you elaborate on PressureWheels’ role in BeamNG for me? From your quote I’d interpret it as just generating jbeams to represent a tire, but according to the Wiki it seems to contain “special” features like air pressure simulation?
     
    #12 Krishty, Mar 19, 2021
    Last edited: Mar 19, 2021
  13. P_enta

    P_enta
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    I mean, does it need to be THAT detailed?
     
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  14. Ascendancy

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    I would personally like to see some sort of tire degradation myself, but I understand that the physics behind them is fairly complex. I appreciate having the other thermals in the game as it is, so asking for this, in my opinion, is like asking for extra icing on a cake that does not necessarily need any more.
     
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  15. Agent_Y

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    Air pressure simulation is nothing special, anything can have it. The special features are things like detecting on the UI when the tire is broken, or the new handling system that hasn't been explained yet.
     
  16. Dr. Death

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    It was a joke related to how much effort the LFS devs put into that game.
    Wow that's really cool and informative. Guess after all LFS is still a product of its time and limitations.
    And that VW still reminds me im waiting for the scirocco!
     
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  17. atv_123

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    Yeah, basically the Pressure wheels make use of the Pressured Beams. The older tires just used a spring constant to simulate an air filled rubber tire... luckily the devs realized there was a better way of doing that.
     
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  18. SKB

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    Yeah I remember the older mods for beam that still had hubwheels, those things were terrible in handling, the wheels felt... Well.. springy lol.. you could see that while turning hard too.. the entire wheel flexing. Which isn't realistic.. the new pressure wheel I think separates the actual wheel rim and the tire/tyre I presume? I'm not that well versed in that side of the game..
     
  19. atv_123

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    Um... well the rim and the tire are generated in roughly the same manner... it's just the type of beams that are used in both that are different. Plus the rims and tires in the old ones did have different spring rates, it's just, that's all they were were spring rates. In the new tires, while the rims are still spring rates, the tires use the Pressure beams which really helps to push the simulation to the next level. That along with all the beams for anti inversion, sidewalls, tread belts... and all that fun stuff.
     
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  20. SKB

    SKB
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    Oooh interesting!
     
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