What's this understeer gradient you've mentioned? Does this come from raw slip angles? I'm just curious if it's anything I can add to my analyser, but I'm ignoring slip angles completely atm (from a simplicity point of view).
Do you claim that all current good simulators have such a basic flaw? It's very hard to believe.
I don't, clearly that issue is with almost any sim, I think LFS is somewhere between other sims and perfectly done model, only one that I have played that seems to have lot of basics right, I'm hoping that these small issues will be addressed in future and what I have read they are going to be addressed indeed.
Wtf, that F1 car is like a rally car, seems like the car is turning around a pivot point in the center and has unbelievable slip angles. Why o why did i thought LFS was so true to life.
The problem with tyre models seems to be that there isn't a lot of correct info available. Car 'dynamics' is all pretty straightforward, Suspensions are tricky but its all forces, angles, distances..
Tyres? Most you can find is very 'basic' info on this, plus of course many of the publicly available grip vs slip curves that show lots of grip drop off. It is quite understandable that a guy making a sim physics engine will use these dubious models and data as a base.
It seems like most of the time they are copied to sims, because programmers assume the data is correct and the models accurate. In fact it just seems to be a case where books have basically copied eachother from lack of good sources instead of really delving deeply into the matter.
I'm sure pro companies like Bosch or Siemens etc have long since developed way better and complex models but they probably like to keep that to themselves, plus for 'sim use' you need a 'simple and effective' model. Industry models tend to be overcomplex, like a ~60 parameter Pacejka model, where you basically can (and will at least a few times
go badly wrong with the input unless you have the $ to actually properly test the tyres.
So I would say it is anything BUT hard to believe that most of today's racing sims have considerable flaws in them, especially when it comes to tyres. Its just a 'grey area' as far as freely available data goes.
The extend of the error is subjective. I would say any sim that can have even a hint of POWERoversteer produced by a front wheel drive 'normal' car (i.e. with tyres at the back and some weight on them) is not a small flaw. Its quite fundamental tyre behaviour.
This is where it becomes subjective. Todd said he reckoned the last LFS physics patch (quite a while a go that was) to be a huge improvement. I would say it was a small step in the right direction; I was and am still left with the general impression that some fairly fundamental things are not good enough yet. I do think that of the currently available sims, LFS does the best job, but the room for improvement is huge.
Scawen does seem aware of the shortcommings, hopefully to the extend that somewhere before S3 final we'll have a much better tyre model. That is also good compared to the ISI competition where the developers just don't really seem to care what reality is.
Currently though, I'd say all sims go wrong somewhere pretty fundamentally when held to the 'realism light'.
Tyres? Most you can find is very 'basic' info on this, plus of course many of the publicly available grip vs slip curves that show lots of grip drop off. It is quite understandable that a guy making a sim physics engine will use these dubious models and data as a base.
It seems like most of the time they are copied to sims, because programmers assume the data is correct and the models accurate. In fact it just seems to be a case where books have basically copied eachother from lack of good sources instead of really delving deeply into the matter.
I'm sure pro companies like Bosch or Siemens etc have long since developed way better and complex models but they probably like to keep that to themselves, plus for 'sim use' you need a 'simple and effective' model. Industry models tend to be overcomplex, like a ~60 parameter Pacejka model, where you basically can (and will at least a few times
go badly wrong with the input unless you have the $ to actually properly test the tyres.So I would say it is anything BUT hard to believe that most of today's racing sims have considerable flaws in them, especially when it comes to tyres. Its just a 'grey area' as far as freely available data goes.
The extend of the error is subjective. I would say any sim that can have even a hint of POWERoversteer produced by a front wheel drive 'normal' car (i.e. with tyres at the back and some weight on them) is not a small flaw. Its quite fundamental tyre behaviour.
This is where it becomes subjective. Todd said he reckoned the last LFS physics patch (quite a while a go that was) to be a huge improvement. I would say it was a small step in the right direction; I was and am still left with the general impression that some fairly fundamental things are not good enough yet. I do think that of the currently available sims, LFS does the best job, but the room for improvement is huge.
Scawen does seem aware of the shortcommings, hopefully to the extend that somewhere before S3 final we'll have a much better tyre model. That is also good compared to the ISI competition where the developers just don't really seem to care what reality is.
Currently though, I'd say all sims go wrong somewhere pretty fundamentally when held to the 'realism light'.
The low speed behavior of the F1 car is tricky to model with the current physics. Very low weight, with limited mechanical grip make it behave inaccurately in situations. Better to have limitations in a true realtime physics model than to have completely predetermined outcomes for set speed/turn angle situations.
Put 10 other types of cars into an F1 sim and i doubt you'll get the solid experience across the board that LFS delivers. Is it perfect, not by a long shot. Is it the best all-round online racing sim out there, I would say undoubtably.
the bit i dont get about this is ... what the hell happened to info sharing within the scientific community ? there should be an abundance of papers on tyres and tyre models readily available via google but there just arent
ISI does not.
Even the ones that do are not designed to handle the many forms of racing that LFS does.
Kind of makes you wonder doesn't it 
The ones that say they do, but only target one type of car on one surface.... I wonder how "universal" they really could be, since we can't drive a variety of vehicle types.
The ones that say they do, but only target one type of car on one surface.... I wonder how "universal" they really could be, since we can't drive a variety of vehicle types.
I'm not sure what some people want? But I am sure no matter how hard I search, that I'm not going to find a PERFECT racing sim, and people whinge about this and that, well if you believe you can do it better, by all means, go ahead 
I just go and actually drive IRL if I want realism, but as far as sims go LFS is leading the way imo
I just go and actually drive IRL if I want realism, but as far as sims go LFS is leading the way imo Yes, but only because they have been around from times of SCGT and when you compare F1 2001 and rFactor there is quite little improvement actually over all those years, they have 10 people team working and they development speed seem to be still slower than for example what it is in LFS.
I'm almost suspecting that guy who had made physics engine originally is no more in ISI and they can't make big changes, but surely that must be just my imagination
But also they do have realtime force simulation running indeed, hopefully there would be lot of improvements done in next version of engine so it would actually be capable of handling something else than ~1000kg cars well and they really should make their own tires that actually work like tires, that would create some interesting competition to markets
Gameplay. LFS has a great gameplay.
Games that last long are games with a great gameplay such as Counter Strike, Unreal Tournament (the first one), Wolfenstein Enemy Territory, Falcon 4, Grand Prix Legends...
Not necessarily because a formula is just as predetermined.
Take the function f(x) = 3x^2
No matter how many times you find f(5), it will always return the same value, but say you have something along the lines of:
f(x) = e^3x + cos x/3pi + ln (x^2) + ... + 3tanh 10x etc.
Your CPU is going to go insane if you tell it to do that 500 times a second among other things. so just compile a table of values, load it into RAM and voila! Suddenly it runs fine and it's not much less accurate either if the steps between your values aren't big. The reason why ISI's engine is rubbish is because most of the things thrown in there aren't real quantities and on top of that, the things that are are rubbish data anyway. (Yes, I can say this for a fact, no, I can't show you how I know this stuff or what it's meant to be)
On the other hand, if you go and do a CFD model (stuff that runs no-where near real time) for aerodynamics and chuck all the data from that into tables of values and then use that in real time from your sim, you'd get some really good results.
Also in ISI engine there are some limitations in variables or something, try to make truck that weights 5000kg and have big tires as they have, engine is not capable of that, also larger tire size results less weight is possible as some forces become too large for engine and it will just go berserk.
Around 1000kg works best, less is causing trouble and more is causing trouble.
Around 1000kg works best, less is causing trouble and more is causing trouble.
My best explanation for the "bad low speed BF1 behaviour" is all related to the aero modelling. The current aero modelling allows you to make a very oversteery (mechanically) setup, which is still drivable at speed due to the seemingly never ceasing downforce when sliding. This however would mean when driving the BF1 at low speeds (when aero has little or no effect), the car has an awful amount of oversteer.
Edit: Stupid internet died while I was correcting a spelling error and missed the following out:
I think when the aero physics are completed / improved, poeple will be forced to make understeery (mechanically) setup's, because of the lack of downforce which would be inevitable during a high speed slide / yaw angle, and the BF1 would behave much more stable at slower speeds.
Does anyone else agree?
Edit: Stupid internet died while I was correcting a spelling error and missed the following out:
I think when the aero physics are completed / improved, poeple will be forced to make understeery (mechanically) setup's, because of the lack of downforce which would be inevitable during a high speed slide / yaw angle, and the BF1 would behave much more stable at slower speeds.
Does anyone else agree?
I find the low speed behavior great, and it is absolutely realistic. Some other here was flaming about "the car is to easy to catch". I don´t believe thats to easy to catch.
That's basically what Dave was saying. But he was also saying that the highspeed behavior is not due to unfinished aero modeling. Or did I get it wrong?
Don't underestimate the tyres, though that clip of the BF1 didn't look incredibly bad to me.. The issues raised in this thread regarding the rubber is a physics model thing which is very likely applying to all the tyres in LFS, slicks or road.
But what would the fun be if there was no room for improvement?
But what would the fun be if there was no room for improvement?
I've re-edited my post.
Yes, that was basically what I was saying. Highspeed behaviour IS due to unfinished aero modelling (because you basically have just as much downforce / grip when sliding). If there were no downforce at all, people would make much less mechanically oversteery setup's, as they would if the aero model was more realistic (I would think). So the mechanical grip / handling at low speed is fine in the BF1, but the aero means at high speeds the rear is more planted then it needs to be (so people make oversteer biased setup's)?
But, this is only a theory it could be all down to tyre physics.
I can't really rate LFS as a game or simulation, because I don't consider it in those terms. I don't review the physics system when I'm driving, or marvel at the graphics. LFS to me is simply a way into Open Wheel Racing League, R4R Stock Cup, OLFSL etc. All I think about is the league meetings, setups and strategies.
In a way, LFS has become completely transparent for me, if you see what I mean, which is probably the biggest compliment you can pay to it.
In a way, LFS has become completely transparent for me, if you see what I mean, which is probably the biggest compliment you can pay to it.
I'd say that's a pretty big compliment, frankly. I totally understand that perception, and the implications of it.. and I share it. Earlier, I raced with a few people in MRTs at Aston. My recollection, to all intents and purposes, is that I DID race there. Just, for some reason, I don't remember driving to Aston or driving home.. but I remember the weather was nice
Well, just looking around a bit there was a huge startup crash in MoE which is a professional endurance event with best pre-selected teams and yet they managed to crash on 1st laps (or first straight .
Driver errors are part of the game, just when the driver doesn't understand it you have a problem
.Driver errors are part of the game, just when the driver doesn't understand it you have a problem
I don't know if this would be of any value, but this link has some interesting books available for those of you who really want to get into the details of tire modeling.
http://www.millikenresearch.com/rcvdpae.html
http://www.millikenresearch.com/rcvdpae.html
Why Is LFS So Much Better Than Anything Else?
(315 posts, started )
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