Rfactor2 Chassis flex?

Discussion in 'General Discussion' started by Skynet, Sep 13, 2012.

  1. Skynet

    Skynet Registered

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    I remember seeing a go kart in some of the photos released by ISI a while back, i cant imagine a kart being developed in house unless it was being modelled properly with chassis flex which has always been the stumbling block for kart mods in the past. It's got me curious does RF2 simulate Chassis flex?. I've asked around and searched the forums but found no info on this. Hope somebody can shed some light on it

    regards


    =)
     
    Last edited by a moderator: Sep 13, 2012
  2. dandar

    dandar Registered

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    Currently a way to enjoy the chassis flex effect, is to disable invulnerability and hitting a concrete wall.
    But I'm sure that you mean another kind of flex effect :D that is not currently implemented.
     
  3. coops

    coops Banned

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    dander ROFLMFAO sry skynet but thats 1 of the funniest answers for awhile. humor great isn't it.
     
  4. jtbo

    jtbo Registered

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    I don't think that even such would provide any chassis flex at the moment, maybe some suspension changes and some part may fell off, but I think that chassis is 100% rigid without any flex still.

    In future things are probably different, but of course it might take some time.
     
  5. Dhurara

    Dhurara Registered

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    +1

    For amateur modder, designing chassis with considering effects of components flex is too complicated to deal with.
     
  6. dandar

    dandar Registered

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    Totally agree ! The implications to conceive a working visual flex on chassis are enormous.
     
  7. jtbo

    jtbo Registered

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    Have you tested rigs of rods?



    In there one could do Kart with working body flex, but it would not drive too well because their engine model is bit limited, it does not work too well with small low inertia engines. Also tires are far from rF level, but you can get flex done by making correct underlying structure, at least that is my understanding.

    To get it 100% right would of course be quite a challenge and one would certainly need a kart to copy structure from, but it might not be as much impossible as first one would think.
     
  8. K Szczech

    K Szczech Registered

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    As far as I can tell, car body in rF2 is made of two connected rigid bodies - front and rear:

    [​IMG]

    So it seems like certain flexibility is simulated, but not as detailed as flexible wings or so.


    Body flexibility we see in Rigs of Rods is nice and gives a good feeling, but it's also very inaccurate. Good car simulation requires very high accuracy - otherwise all work done on tyre model and suspension would be ruined.
     
  9. jtbo

    jtbo Registered

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    Hmm, just how exactly did you get that wireframe view? I demand to have such too as I got very envy now all of sudden :p ;)

    I just wonder if inaccurate is better than none and how big inaccuracy there is as it looks to be right direction at least. Of course with some vehicles it is quite excessive.

    It is improvement then that we have already some bodyflex. I wonder if truck trailer will soon be possible...
     
  10. K Szczech

    K Szczech Registered

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    This is a screen from technology page: LINK

    It's a complex topic. I have implemented basic flexible bodies a long, long time ago, but it was just for fun. I would never use that for serious simulation.
     
  11. jtbo

    jtbo Registered

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    Interesting, I had never sawn that page before, I wonder if at some point they can make light version of that to evaluate suspension so that it would be easier to spot bugs from .pm geometry.

    I also spot that ISI has test track quite near them :p
     
  12. blakboks

    blakboks Registered

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    That reminds me of the old riddle I heard years and years ago:

    Q: Which (analog) clock is more accurate, one that is 1 seconds off every 24 hours, or one that doesn't work at all?

    A: (Spoiler alert!) In absolute (true or fals) terms, the one that doesn't work at all. It is correct 2 times a day, whereas the one that is off by 1 seconds every 24 hours is only right once every 118 years.
     
  13. Rich Goodwin

    Rich Goodwin Registered

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    Just to add something here (Or maybe not). I am currently starting a project to create a track for a reputable Motorsports simulator company (they have current F1 & BTCC drivers as clients). They use rFactor Pro in their simulator. In our discussions about what project I could do for them, they approached the subject of chassis flex. Their simulator does not model chassis flex. As far as they are aware no simulator in the WORLD accurately models chassis flex in a reliable, repeatable way. We came to an agreement that I would use my BSc year to research it and maybe find a solution.

    I have not researched it in any way at all, I only know what these guys have told me. Like I said, they are a reputable company and you guys could tell me I'm wrong. Hell, rF pro could include it, I just don't know.

    My point is that to expect or ask for chassis flex appears to be a HUGE undertaking no matter what team or sim will attempt it. It's not just a "oh let's add that" type thing.

    Again, please correct me if I am wrong. I'd like to know if my assumption is wrong in fact.
     
  14. Gearjammer

    Gearjammer Registered

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    Let me start off by saying I am no engineer, but I do have an opinion on the subject. Knowing what I do know about metal, car frames, unibody construction and such due to about 35 years as a mechanic, I would imagine that the math would be very difficult and seeing as most of the physics can't be done in real time due to limited power of desktop pc's adding chassis flex would only cause more work on the computer and thus would make it less accurate if you still want to have decent frame rates.

    As is mentioned in other threads here, most physics is likely to be put into a table and the data extrapolated to cover areas that the table doesn't have specific information for. I am sure you could probably do the same for the flex, but you will lose some accuracy doing so.

    For that reason I don't see anyone producing chassis flex that is accurate any time in the very near future.
     
  15. jtbo

    jtbo Registered

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    Cars have rubber bushings, rfactor does not, I think that could be already one thing before chassis flex that could be good to have?
     
  16. Gearjammer

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    Hate to say it jtbo, but most purpose built race cars do not use rubber for bushings anymore. The 60's formula's did, but the modern race cars, no. What is used most now is polyurethane which is a lot stiffer limiting the amount of geometry change of the suspension due to compression of the rubber that used to happen.
     
  17. 1959nikos

    1959nikos Registered

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    You just made me take the battery off my alarm clock and that doesnt help me at all !! :mad:
     
  18. jtbo

    jtbo Registered

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    But I don't want to make purpose build race cars BWAAAAAA :( (missing crying emoticon)
     
  19. JJStrack

    JJStrack Registered

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    could the chassi flex not just be simulated as two spring-damper systems between the front and rear - as a first approximation at least!? One torsion-spring and one bending spring...
    View attachment 3977
    this table made me think that could be close enough. it shows the torsion and bending eigenfrequenzy of different BMW 3-Series models. and as far as i know, the eigenfrequenzy is directly related to spring-stiffness. and isn't that spring stiffness one of the key design parameters when new chassis' are designed!?
    hope this all makes sense, it's 2 a.m. here and i'm a little drunk ;)
     
  20. Gearjammer

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    Heheh, sorry jtbo, forgot what you are working on :)
     

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