Does GSC suffer from low speed grip loss?

[Msportdan]

Rf1 modeled sims have always suffered with low speed grip issues. I was wondering have reiza done anything to fix this?

I did the fextremes, and on the start i cant get any grip down no matter how hard i try. Especially compared to the AI. Also the chicane at kansai, trying to get power down there at exit, you just loose to much time compared to the ai, you can even see them squirm for grip too. This is also very noticeable in the MR18 and the karts, and most other f1 cars.

Rf2 feels different now especially with CPM, but rf1 engined sims, does make driving them harder than the real thing imo especially at low speeds, and very frustrating, as you get moments of wtf from the physics.

 

[xnorb]

Reiza posted that they are working on the tire model.
No further informations known to me, tho.

 

[Renato Simioni]

Wheelspin / breaking traction under power, specially with cars with high power-to-weight ratio and/or low end torque such as the ones you refer to is not necessarily a low speed grip loss issue, or even a physics "issue" per se. Controlling traction should definetly be a factor in these cars.

Of course there is always room for improvement (and such are constantly being made or pursued), but generally I wouldnt consider our tires to have a low speed grip issue or the engine to have some major inherent limitation in this regard. I actually feel latitudinal / longitudinal force combining is something they do very well, both in terms of breaking traction when it should, as well as allowing the driver to control it and regain grip by modulating traction. Reducing that threshold to the point you barely get any wheelpin past 1st gear with these types of cars might make driving them easier / more accessible (and thus more fun to some), but it´s definetly not what we consider to be realistic.

There are other factors at play, such as the absence of proper turbo modelling (it´s currently emulated directly on the torque curve for the F-Extreme, MR18, Mini & F-Classic) or the lack of option to adjust throttle maps in the case of modern formula cars like the F-Extreme - these are the areas where improvements are still due, which could help make power delivery more manageable.

Likewise, the fact that the AI has an advantage over the players in such circunstances is another issue altogether, and also something that we would like to improve as we move foward.

In sum there is certainly room for improvement in several areas which could help minimize the issues you refer to, but these are not necessarily tire physics issues

 

[Msportdan]

thank you very interesting.

 

[Jan Mikuž]

Thx for the insight, Reiza. Interesting read.

 

[David Wright]

Rf1 modeled sims have always suffered with low speed grip issues.

One of the key differences between the tyre physics of ISIs F1C and rFactor was the introduction of grip variation with speed. So while F1C physics was criticised for low speed grip issues these were fixed for rFactor (and Simbin's gMotor2 titles).

 

[Spinelli]

The ISI engine is overall the best engine in simracing for me , having said that, it does some bad things at times. It doesn't matter how brilliant the numbers "plugged-in" by modders are. No matter what numbers the genius and brilliance of a guy like Niels H does, once you approach the limits and/or get over the limits, the car does some bad RF1 stuff. It's like this on every single car from the amazing SCE cars to RF1 mods from 2006.

I believe the following to be a list of issues that plague the ISI physics engine as a whole (going back to even before RF1 but also - and slightly continually improved ever since - all the way up to and including rFactor 2).

The following is a copy of part of a post of mine from the RF2 forums.

"1. More of the vehicle's momentum/inertia should continue forward in the original direction of travel while the rear-end swings out, rather than so much of the vehicle's direction of travel changing so drastically as if you had a ton of grip and literally turned the car sharply left or right.

It's like the front-end just turns-in sharper and sharper with too much of the vehicle's original direction of travel changing to, and therefore following, the direction that the front-end is pointing towards. You can even easily see it when watching from a 3rd person, or trackside/TV cam; the car hardly looks like it's drifting, but rather just following the nose. Because of this, many times at the end of a slide you'll find yourself halfway, or completely, on the other side of the track because too much of the vehicle's original direction of travel was lost so you therefore find yourself just turning-in sharply and driving almost perpendicular relative to the track's direction and therefore heading towards the wall/side of the track nose-first.

The other sims do this too, but I feel ISI's engine may do this the most. The sim that did this, by far, the best and closest to real-life was the alpha/beta of an AMAZING driving game called Driver's Republic which sadly never came to fruition (the driving dynamics potential of that engine was mind-blowing). LFS is probably 2nd best (in this very specific area).

Is it strictly an issue with the core tyre physics, or something deeper in the overall physics engine? I don't know, but it's been here in every ISI-engine-based sim since F1 2002 and maybe even before (maybe SCGT? - Never played it).


2. At very slow speeds, when you crank the steering wheel very hard left-and-right (I like to call this, Fernando Alonso-style warm-up driving, lol) the vehicle will start to loose too much rear-lateral grip and start sliding even if you are applying neutral-throttle, and only a little amount of throttle at that. Again, this seems to happen with way too many cars and may be more of a core-thing rather than specific car-modelling.


3. On many cars - even at just 25%, or so throttle - once the rears start slipping just the most minute amount, the slippage, almost instantly, becomes WAY over-exaggerated. What do I mean by "over-exaggerated"? Well, for eg. the split-second you get just a bit of rear-slip - even at, let's say, 25% throttle - the car's engine/tyres want to increase their RPMs/speed WAY too quickly as if the car just gained 6000 lb/ft of torque, or as if you suddenly smashed the throttle to 100%. The RPMs / tyre-rotational-speeds just spike up insanely quickly - WAY too much and WAY too suddenly.

This last issue isn't experienced so much with less powerful cars like, for eg. The Skippy - I guess, due to it's engine (motor) modeling behaving as if it has a heavier flywheel and just generally more inertia in the entire drivetrain - however, the seeming flaw exposes itself more and more the more "hardcore" the car is. A perfect example this is the FR3.5 which is ABSOLUTELY ATROCIOUS in this specific area.

source --> http://isiforums.net/f/showthread.php/23533-RFactor-2-Best-overall-physics-in-simracing-FR3-5-ATM-one-of-the-worst-sim-cars (first 3 points)

 

[Msportdan]

i cant say ive noticed point 1 much.

but 2-3 are killers for me especially in rf2. The F2 is also ridiculous, ive driven a similar car and its hard to spin out on optimal temp slicks, at slow speeds.

 

[Spinelli]

I notice point 1 all the time in every single car (original content, mod, doesn't matter) no matter how bad or good, light or heavy, big or small, grippy or slippery, downforce or no downforce, fast or slow, etc. going all the back to F1-2002, lol. Heck, I just has it happen a bunch of times when I had a friend over playing the super slow rental karts. Sometimes my friend hardly tried correcting the slide because it's as if someone magically turned the vehicle sharply with the steering wheel rather than rear-end actually trying to swing around. Sometimes he even didn't need to apply much steering lock, again, because of that same issue. There were even a couple times where he'd hardly correct the slide, instead, we'd just watch as the vehicle turned sharply laterally across the track on the front-end as if someone decided to suddenly turn the vehicle's steering wheel sharply, then the rear would eventually regrip, and he'd continue on albeit on the opposite side of the track since the weird front-end darty turning issue made the car steer there to the other side of the track.



Anyways, GSC is one of my favorite sims ATM and ever. It is on, in my opinion, the best physics engine in simracing (ISI engine). Nothing is perfect, and the overall physics of SCE are gosh-darn amazing and better than any other sim on the entire market (except RF2, but comparing to that is unfair to Rieza since RF2's further developed engine is most likely not even available to other devs yet).

All that, as well as just about everything, has been slowly improving with RF2 thanks in large part to ISI continuing to update and improve the core engine (unlike previous versions where there hardly were any updates - physics wise - after release), having said that, they're still there, but having said that, the ISI vehicle dynamics modeling - overall - are still the best in the industry in my opinion (especially with RF2 but SCE is just so darn good. I really do love SCE and FT

 

[roby13]

I never had any of the three in sce
Ps: chronus, please com back

 

[Spinelli]

Happens all the time, I'm sure you've had it unless you've never gotten the rear-end of any car out. It's inevetible, down to physics engine, not the modder / content creator. I don't want to go about it too much as the ISI engine is still far-and-away the best racing sim engine, and because it's not Rieza's doing, but ISI's.

In ISI's defense, they have, and continue to improve in all sorts of physics areas (including those specific areas mentioned above) but unfortunately for some (non-RF2 owners), the physics work/updates/improvements are in the rFactor 2 engine.

 

[roby13]

Honestly, not in sce if we're talking about anything related to isimotor2 engine, default, mod or whatever, yes all points are common experience

 

[Spinelli]

Not in SCE? SCE is gmotor physics engine. I was just online with the V8 stockcars and then the 95 Ferrari, happens frequently. You can even see it happening a ton of times to other cars around you. It's been happening for almost 15 years (the points I alluded to in post #7).

 

[Renato Simioni]

For most of these 15 years though developers were sticking to a certain range in physics values, which we now know are unrealistic, or at least not net the most realistic results. Our physics bare little resemblance to preceeding titles, even if the physics engine is (for the most part) similar. As it´s often said, the physics engine is only as good as the values input to it..

I dont see points 1 & 2 you raise as common issues to be perceptible flaws in our cars, subjective as they are anyway. Point 3 could be down to tire lat-long force combining in a given car - it´s a super delicate balance to reach and it´s something we´re always working on. I´d say all cars in their current form are the best they´ve ever been in that regard, but that´s not to say there is no room for improvement... There always is

 

[Spinelli]

It's not at all a perceptible flaw in your cars, it's just a vehicle dynamics/behavior trait that, at one point or another, affects, to whatever extent, any and every car I've raced since at-least F1 2002. From the worst mods to the most absolutely amazing mods.

Your cars are darn amazing I'm alluding to a vehicle behavior trait that seemingly affects any and every car regardless of the particular numbers/data used for that mod.

Also - https://www.youtube.com/watch?v=o8AblngEFus
- 16:23 - 16:58 (Alonso)
- 1:14:32 - 1:14:36 (Raikonnen)
https://www.youtube.com/watch?v=rVmzgITat5k
- 0:18-0:21 (Schumi 97 Spa)
https://www.youtube.com/watch?v=xZlS-AB4-ik
- 1:10-1:13 (Schumi 99 Suzuka)
https://www.youtube.com/watch?v=B2Kmz1wmedg
- 51:50 - 51:53 (Schumi 2000 Canada)


- It is quite visibly obvious in the above videos that, during and after the slide, the car is still continuing to travel along the same original direction of travel that the vehicle was travelling before the slide began. That hardly ever happens in-game. In-game, the car's direction of travel would change and follow wherever the front of the car is pointing to. You don't have to drive/play the game to notice; you can easily just watch someone (or a replay, or follow them on track) and see it from the cockpit view as well as external view. In-game it's sort-of as if the driver suddenly decided to turn sharply rather than the rear rotating while continuing - for the most part - in the original direction of travel from before the slide occurred. Basically, if the above video happened in-game, the car would end-up at, or tried to travel towards, either the middle of the track, all the way out to the left-hand side of the track, or worse-yet, completely off-track on the left side, but in the video, the vehicle is almost, if not fully, still traveling along the same original path of travel before the slide occurred (straight down the track while not turning or moving across the track laterally).


Also, In-game, many of the corrections are limited to very small snap-correct corrections. If you look at the amount of steering correction required in-game relative to the angle of slide, it often seems very little and unnatural. If you do try to apply a more natural amount of steering lock then the car will suddenly grip in the middle of the correction and snap the other way most-likely (but not always) causing you to snap the other way and shoot you off track into a wall or something.

P.S. This is not about me personally or comparing us to F1 drivers and their skills or anything like that, but rather, observing the very similar and consistent way a vehicle behaves in real-life VS in-game.

I haven't provided videos of in-game because it happens in any and every car regardless of car type, car characteristics, quality of car-mod, etc. since at least F1 2002. I see it, and experience it every single time I play. It's quite obvious.

 

[Renato Simioni]

I would not disagree with the fundamentals of your argument - which seems to be there´s still too narrow a margin to catch a slide without it turning into a tankslapper, specifically on the modern f1-type cars. There is a whole lot in the physics which play a role into how manageable that "edge" is, many of which are not absolute measurable values, and it´s all incredibly sensitive (we´re down to tweaking the 15th decimal in some of those values).. Hence why I say there is still room for improvement, and why we´re still finding ways to improve some of these cars despite having worked on some of them for years. We will improve them further, both by introducing new variables as well as polishing the existing ones.

Having said all this, the Alonso video you linked is with intermediate tyres on a damp track, and most of the others are grooved tyres, so different properties to what we have in the sim. I disagree it´s not possible to reproduce some of these small corrections & power slides at such relatively small angles with the right equipment, the right settings and the right driving; I also believe we currently do a better job in reproducing that "manouverability" on the edge of the tires without compromising the precision they ought to provide than most if not all other sims.

In sum, agree there is room for improvement, but think your overstate the issue somewhat. Do welcome the well-reasoned debate in any case

 

[Spinelli]

Believe me, I love your guys' work. My friend finally bought a wheel and I convinced him to get Stock Car Extreme along with Formula Truck, thanks to your two wonderful products (and RF2) he doesn't even care to purchase any of the other sims (and he's had a lot of time with all of them at my place). We have spent the past week or two playing absolutely nothing but Stock Car Extreme

It's just so weird how - at some point or another - every car since at-least F1 2002 displays the exact same vehicle behavior trait (sharply turning and travelling adjacent to the original direction of travel rather than, for the most part, continuing in the original direction of travel like can be seen in any real-life slide regardless of type of car or type of tyres). That's 100s, if not 1000s of cars. How can 100s, if not 1000s of cars over an almost 15 year period display the exact same, very specific, vehicle behavior (which is so, different than in real-life)? This is what leads me to believe that it's something rooted deep down in the base/core physics engine itself which, if indeed true, would mean it wouldn't be able to be rectified regardless of how good of data/numbers are entered into that physics engine. If it's just down to the data entered, then how could it just be coincidence that every car over so many years displays the same trait? I just don't see how that could be coincidence.

Me and my friend were driving the 95 Ferrari for about 6 hours today and we absolutely love it, but again, almost anytime the rear-end get's some slip, the car's direction of travel turns as if we are trying to turn the car. It's as if you are driving straight and then you decide to turn left or right very suddenly, whereas in reality, the car hardly displays this trait but instead the car's original direction of travel - for the most part - continues on in the same direction. Therefore from the very moment the slide starts, until the moment the slide finishes, the car is still on the original path/trajectory as before but, -in-game, the car does a very, very, very sharp turn to the left or to the right.

I feel this is something that can only be rectified by adjusting code/parameters/systems in the "base/core" physics engine itself, the actual "root" physics engine running, rather than the "front-end" which content creators (developers, mod-makers, etc.) have the ability to work with. Again, I think this is the case because how could it just be a coincidence that every car displays this particular trait going back so many years, so many cars, so many devs, etc.? How could it be a coincidence that all those 1000s of cars have had the same type of data used which leads to the same very specific trait in physics? The odds or