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To Reiza: What physics do you actually want?

Discussion in 'Automobilista 2 - General Discussion' started by Richard Wilks, Jan 3, 2023.

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  1. Kuku

    Kuku Flying Kiwi AMS2 Club Member

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    Maybe it would be a lot better to describe the LSD Diff as closed instead of locked for the sake of this argument.

    So the diff is either closed or open.
    The strength of how closed or open depending on the clutches used and preload and other adjustable features.
     
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  2. steelreserv

    steelreserv Well-Known Member Staff Member AMS2 Club Member

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    Never said clutch lsds were always locked. Never once. Not ever.

    I never said clutch LSDs were always slipping and never locked either. You did and its wrong.

    And that quote was in response to YOU bring up the detroit locker out of the blue the first time.

    The detroit locker is irrelevant in this discussion, both times you brought it up.
     
  3. Richard Wilks

    Richard Wilks Active Member

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    Fine. A bit more and i will find out you opened this thread, not me...

    So i have a better question, who calls the shots physics wise? Who has the final say? Who decides if something is good and not good? How is the process done?

    In games which have consistent physics accross the board, and accross builds (kunos, sector3, etc) there is ONE person whose vision is the one that is put into the cars.

    Who is doing that here? Nobody? You guys divide the cars in parts? Or divide the cars amongst yourselves? Who inputed the values for the lotus 98 for example? I suppose you copied the tires from all Gen etc cars. Who did those? Who was researching the data for the cars?

    I think if we would know this, at least we would know a bit more of how this process happens, and how these cars come to be.
     
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  4. steelreserv

    steelreserv Well-Known Member Staff Member AMS2 Club Member

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    If the cars have a problem that can be objectively confirmed, they are subject to review.

    If YOU feel something is wrong and start pointing at random stars in the sky as the culprit, looking for likes, its a different story.

    What bugs me is your constant mis-quotes, mis-interpretations, bringing up unrelated items like detroit lockers or other random factoids to show how smart you are in order to prove your points some of which are clearly wrong. Like how the natural characteristics of a car don’t matter, how lat g as a reflection of lat grip at low speed and high speed as a reflection of grip and performace don’t matter, how a car with a clutch plate lsd and preload can be pushed in a garage without resistance, how a locking clutch lsd is a figment of sim racing “laws”, how I am not a dev and don’t have the credentials to work for reiza or discuss these topics, and that the clutch plate lsd is never in a static position

    Im trying to explain that the sim is in development and explain why people may experience traction loss with cars with over 1000 unrestricted bhp.
     
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  5. Richard Wilks

    Richard Wilks Active Member

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    Now now, dont get upset. I didnt attack you on that post, did i? No need to attack me.

    If people liked my posts, it's because people agree with me that there is a problem. If the fact that there are people who agree with me on that irritates you, thats well, not my problem, pun intended :)

    As for your considerations about my person, or skills, or knowledge, i have nothing to prove. Nor do i feel like i do. All my points were presented clearly.

    But as it seems, you seem too personally affected by this. Maybe you should yourself take a step back. After all, there are more people involved in the physics, no? I guess someone else can come here and tell us about it.
     
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  6. steelreserv

    steelreserv Well-Known Member Staff Member AMS2 Club Member

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    ...claiming i said the sim was perfect, that I said the same in the GM video that I posted a year+ back, suggesting I don't know how to analyze a telem slip graph chart, that setup changes in game are unresponsive, that if you setup a car for understeer its a "drift machine by default"...the list goes on and on and on.

    and this is just in a matter of a couple of days. my mind boggles about the sheer amount of misinformation you have potentially managed to spread on discords or other forums over the course of years. yikes.

    But don't worry, i'm not upset, this isn't an attack. if you deem that me paraphrasing you're words in a post as an attack, perhaps that speaks more about you're state of mind and intentions than mine.

    As an experienced modder I presume that you have spend countless hours working on tire behavior. As someone who has worked on over 30 different tire carcass structures in SETA myself, spanning the breadth and scope of motorsports and countless variations on each of them, from radials to bias plys, street tires to high performance racing slicks, i would have hoped to have perhaps met a kindred spirit in this regard. But alas, I've been met with condescension and dismissiveness ("is there anyone else on the physics team we can talk to").

    Nevertheless, I surmise from your body of statements that as a modder, you pride yourself on your technical knowledge, but have the opinion that the cars should feel natural first and foremost, practically under any circumstance. I suggested changing the gearing and you almost scoffed at the idea like gearing doesn't matter when it has a massive impact on how progressive torque can be, in light of the cars we are discussing and in light of the pressure spike on the turbo as it spools, this is highly relevant for overall feel! The engine, driveline and torque/power curves in AMS2 are highly complex. The differential behaviors as well. What separates AMS2 from practically all other sim racing titles is that we physically simulate the driveline, down to driveshaft inertias.

    My mind wonders how you managed to implement your technical knowledge about the cars with hard facts like boost pressures up to 1200bhp. Yet you dismissed the concept of weight distribution and polar moment of inertia having an impact on the cars. You talk about nice smooth progressive power and wheel slip suggesting that your cars express nary a hint of uncontrolled traction loss, under any circumstance. In other words a nice, natural driving feel well within the limits of the tires. Gearing doesn't matter the natural characteristics of the cars doesn't matter.

    Even I am squeamish about the thought of making any official post for a car in game where I would say the raw nature of a car like a high performance CART, Group C or F1 representation comes second to a drivers natural sit-and-drive feel. Despite people agreeing with what you have posted about traction loss and your discomfort with it, I still don't think the majority of sim racers would agree that a dev team should produce cars where feel is more important than what the car is truly capable of.

    For anyone who may have agreed with you about how the cars feels when rear traction is lost on throttle, or for any future reader of this thread who don't quite get on with cars or AMS2 itself, I am sincerely sorry to hear that.

    For a small passionate team such as Reiza, this project is more than just game. We are sim racers here. When I'm not actually working on AMS2 i'm actually racing/driving in AMS2 for fun when time permits. Our goal is to develop the most engaging and immersive driving experience as we possibly can. If you're inclined to check our history with the ME over the past few years, I hope you'll see we've consistently overcome barrier after barrier, ones SMS simply left for the playerbase to accept, ones you know about and many you don't. And we'll continue to do so. With any luck, perhaps you're main grievances, if its wheelslip characteristics or something else may be addressed at some point in the future.
     
    Last edited: Jan 7, 2023
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  7. steelreserv

    steelreserv Well-Known Member Staff Member AMS2 Club Member

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    Hi kuku, Locked is the proper terminology.

    The reason we say the diff is locked is to describe the state where the clutch plates are fully compressed in their housing, and are in a static state. (preload + ramp angle determines compression of the clutch pack. The # of clutches simply increase the total clutch surface area).

    Its the clutch housing that is locked to the axle. Therefore when the clutch plates are sufficiently compressed via preload and any pressure on the plates via the pressure ring (ramps), they drive the housing, which drives the axle. For all intents and purposes the differential is "locked" to the axle at that point and power is even distributed between the drive wheels.

    When the torque from traction differences on throttle or off throttle exceed the static friction of the clutches, the clutches change from static friction to kinetic friction where the clutches grind against the internal elements of the clutch housing, which acts to resist the differential from becoming fully open, but also not fully locked either.

    "Locking" is the the term for progressive compression of the clutch packs, which typically occurs as you apply more power. "Unlocking" is the the term for when the clutches change from static to kinetic, this can occur on throttle or off throttle.

    The torques for on throttle and off throttle are different as well, and thats why in the typical clutch LSD the power ramp is angled in a way that is more difficult for the pinion to expand the pressure ring and lock the clutches to the housing compared to when the car is off throttle.
     
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  8. Avoletta1977

    Avoletta1977 Well-Known Member AMS2 Club Member

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    After several walls of text I still can’t see a single graph with individual tire forces…

    @steelreserv can you output vertical, longitudinal and lateral force of each tire from the sim engine?

    Yes or no (simple question with simple answer).

    If yes, please provide graphs with decent resolution.

    This would explain MUCH more than any discussion.

    Thanks.
     
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  9. F1Aussie

    F1Aussie Well-Known Member AMS2 Club Member

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    I think steelreserv has already shared much more information than he needed to or is obliged to in this thread. He has taken a lot of time out to explain his lot. Richard also sounds like he knows his stuff, you both do, it is all way above my head.

    I am glad we have both a passionate team working on this title and passionate end users as well. We all want the same outcome, a feature rich and realistic racing simulator. And I am sure that that is what we will end up with once Reiza have finished polishing it.

    Reiza have previously said something along the lines of the main physics are sorted but fine tuning will continue to go on and that if there are any major breakthroughs that show physics flaws they will be addressed.

    I am more than happy to say that AMS2 is my number 1 sim and the one that I have the most hours on ever.

    I cannot see that changing, keep up the good work Reiza, a majority of us have faith in you and appreciate the time, effort, dedication and variety you are giving us.
     
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  10. steelreserv

    steelreserv Well-Known Member Staff Member AMS2 Club Member

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    Much appreciated sir. I do rather enjoy discussing such things. Its a blessing and sometimes a curse.

    @Avoletta1977



    This graph was posted earlier and is from the BT49 through the spoon at kansai circuit. I hope the resolution is satisfactory.

    The first data bar represents the axle load front and rear, and combines mechanical and aero. The darker green line is the rear, and lighter green line is the front.

    The second data bar is the lateral g forces which we can interpret as the lateral g the tires treads + carcass are willing to accept given the axle load.

    The third data bar is the long g force which is a representation of what the drive wheels are producing in forward momentum giving the load and throttle inputs.

    Here you can see at reference point 3700 to 3800, the BT49 tires are willing to tolerate acceleration forces of roughly 0.75g at the same time they are providing 1.0 to 2.0g in lateral grip.

    Unfortunately I cannot post screen captures of the development tools as it would be an NDA breach.
     
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  11. oez

    oez Mayor of Long Beach AMS2 Club Member

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    Of all the things I wanted to address I chose this. This is not a universal truth, because I have personally disagreed with him many times. And it’s not limited to me. To be fair it’s easier to accept criticism from a team mate since you’ve already decided to trust them earlier and gotten to know them a bit. Is it always easy to take in criticism? Of course not.

    Even so whenever you can prove something and/or build a case he’ll review it and rethink it with time. Like everyone else. When you have a million moving parts based on what you think is the truth after research and analysis, you can’t do anything with shallow feedback. It has to be specific and come with evidence/proof. This is also a requirement in team work in general, because you can’t just be stubborn and dominant about your position until your team mate simply gives in.

    For example what steelreserv has done with car physics in AMS2 was effectively a big criticism of tires and setups. That’s making it sound more dramatic than it was at the time, but for it to happen did require Renato to accept criticism.

    This really has nothing to do with the rest of the discussion so carry on.
     
    Last edited: Jan 7, 2023
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  12. Avoletta1977

    Avoletta1977 Well-Known Member AMS2 Club Member

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    Axle load and lateral accelerations are a small part of the picture.

    I would like to see single tire forces as we can in most of the other sims (and can’t understand how a picture of a graph would break any NDA).
     
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  13. Dicra

    Dicra Local Gamepad Ambassador AMS2 Club Member

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    I'm not so sure it's the traction control that's "wrong". It might also be a case of the rear being too eager to lose grip when turning under acceleration: In this situation, the weight should be more towards the back of the car, and the tires that actually do the turning are the front tires, so you would expect the rears to "overpower" them, leading to understeer. In AMS2, more often than not, the opposite happens: The rears begin to slip while the front keeps turning, leading to spins you wouldn't expect.

    Maybe it's not so much a case of the rear losing lateral grip too early, but of the fronts having too much of an iron grip into the track when turning.

    Anyway, I now had a chance to access my PC and made a comparison video around Hockenheim. I set the car up for more understeer than default and lowered traction control a bit, but still it activated at the quick T6 (despite the fact that the bump that was there in 2002 is gone). I hope the video shows what I mean: It's not a "large" issue in that it seems very excessive when looking on it from the outside, but it's noticeable especially on the exit of T8, that the car is a bit too prone to spinning the rears up when turning. As you see at the hairpin, it's comparatively tame when having a straight exit.

    You should also note that my car is set up for understeer (!) compared to the default, and Michael's car obviously isn't, which you can see at the entrance of the Motodrom. But still, it's my car that keeps spinning up the rear tires on curved exits.

    The real life lap time was a 15.0, mine was a 14.9, but my lap was driven from an absolutely cold start, with no practice whatsoever, so maybe you could make a case that I had a little too much front bite in the quick corners, too (but the time difference really is very good in this case in general).

    The original lap by Michael Schumacher is put first for every corner, because the sim is trying to replicate real life, so it's to show the benchmark and then compare.

    Video should be ready in 5 minutes.

     
    Last edited: Jan 7, 2023
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  14. Racinglegend1234

    Racinglegend1234 AMS2 wiki founder AMS2 Club Member

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    He can’t show a video from the development because they have certain tools which can’t be shown
     
  15. Maser V6

    Maser V6 Assume nothing._ Verify everything._Have fun AMS2 Club Member

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    This is what has yielded results in the past, graphs and video as before with respect to diff, transmission, holes in throttle response, lack of straightline wheelspin, retro drivability, all the dougnout diff stuff /ai examples, list is endless.
    No question people are having problems, demonstration in detail is lacking here, esp video of snap's weaving v8 'cant touch throttle on corners' etc.
     
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  16. WhippyWhip

    WhippyWhip Active Member AMS2 Club Member

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    i noted this type of behaviour a long time ago when i tried ams2 for the first time since early access, i made a thread back then, maybe the title is a little click baity but it's similar to what you mention the one thing that would fix every car in ams2
     
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  17. Racinglegend1234

    Racinglegend1234 AMS2 wiki founder AMS2 Club Member

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    I don’t know if this helps, but I noticed the same thing you describe, but with the Nissan GT3. I made a video reviewing the car and I noticed this very well. I used the defualt setup
     
    Last edited: Jan 7, 2023
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  18. Kuku

    Kuku Flying Kiwi AMS2 Club Member

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    The Nissan responds well to reducing the amount of clutches and small increase in power lock, as do a lot of cars , what you lose in ultimate traction, you gain in confidence and being able to get on the power early and carrying that momentum down the the straights .
     
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  19. WhippyWhip

    WhippyWhip Active Member AMS2 Club Member

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    one thing i noticed which may be just me but the FFB in this games give you a good feeling for what the rear of the car is doing but the front tyres you have zero feel, it feels like the front is just sliding over the tarmac, surely the fronts should feel a connection to the road as they are the ones connected to the steering wheel, i feel raceroom has this nailed when comparing to my real track day time
     
  20. Racinglegend1234

    Racinglegend1234 AMS2 wiki founder AMS2 Club Member

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    Believe if you read a little before this page in the thread that question has been answered. Believe Renato thought the FFB is to front end dependent
     

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