Grip Bug Thread v2

Discussion in 'Gran Turismo Sport' started by GT_Alex74, Jan 13, 2018.

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  1. GT_Alex74

    GT_Alex74

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    Solved as of 1.11, there's no need to panic anymore ;)


    IMPORTANT NOTE : this thread has been recreated following a suggestion from @Famine, as the original discussion drifted towards naming people, unproductive speculation and paranoïa. As such, it is asked you don't mention directly the name or PSN id of anyone you suspect of having the bug in this topic; instead, you should rather contact someone who was involved in the investigations privately so that can be reviewed by people knowing precisely what to look for - I think the best is that you send me a private message here or on PSN (GT-Alex74), so I can either have a look on it or forward it to a competent person. In the meantime, what you can do is send the link to this topic to the person (don't forget to refrain from any accusations, keep it as short and as polite as possible). Also, many thanks to @Tassie_tiger and @kilesa4568 for helping getting this to reach Polyphony Digital.

    EDIT : Polyphony Digital has contacted us directly, RA1784 has provided them the bugged save files, so everything is between good hands now.


    This thread is there to gather all the informations forum members found on a bug which can potentially have a huge impact on the game in the same place and in an organized way, in a hope Polyphony Digital can use this to identify and solve this issue in the best possible conditions. I will ask you to refrain from posting rants about the game or devs as that won't help in any manner and I'd like this topic to remain as clean as possible to allow further discussion if needed. I myself didn't do much except watching and asking a few questions, credits goes to those who did the research and RA1784 for taking his time to do all the tests.



    - What is this bug ?

    Basically, it is a bug which seem to change the physics of the game, allowing people who benefit from this lap times around 3 seconds or more faster than what they would achieve in regular conditions. It allows to brake much later and accelerate sooner than normal, while giving superior stability, as if the car was on rails. All the data suggests this bug is binary (there is only a single level of bug) and is only increasing grip, not decreasing it. Please note this isn't a cheat triggered by players themselves, those who are infected by this don't even realize something is wrong with their game.

    - How was it discovered ?

    Courtesy of some fellow GT Planet members and regular top 10 scorers for years. These guys noticed new people putting up abnormally fast laps above regular world records, so they started watching closely the replays and noticed something was wrong. It was publicly called out by Spurgy on GT Planet (link), and after some exchanges on the bug report thread, RA1784 invited people who showed interest in the investigation into a PSN chat (part 1/part 2/part 3/part 4) to clear things out. RA1784 was asked to perform various tests until we found where it came from.

    - What we know :

    * it is directly related with the game progress save file (deleting it and not loading it back removes the glitch)
    * it is not related to the game settings save file (deleting it doesn't change anything)
    * uninstalling and reinstalling GT Sport doesn't remove the glitch
    * it is not related to console hardware
    * it is not related to a specific controller (DS4 or any wheel)
    * it is not related to the temporary files cache
    * it is not a tyre swap bug (even on super soft tyres there is still an advantage with the bug)
    * tyre deformation is still there
    * no tyre screech is heard on bugged laps
    * it is not caused by a set of driving assists
    * it is not linked with liveries (including custom wheels) or gifted cars
    * it is not caused by internet connexion or network issues
    * it works both online (lobbies and sport mode) and offline
    * it works with all cars
    * it might be connected to another bug (driving preferences such as ABS, FFB and transmission always resetting, as well as the view) - If you experience this bug, please contact me by sending a PM here.
    * at least 4 different users were spotted driving with this glitch thanks to suspect lap times in the top 10 leaderboard replays, but there might be naturally slower drivers outside of top 10 infected with this bug as well
    * it effects lap times by around 3 or 4 seconds per lap
    * it is not connected to the debug menu glitch
    * it feels very close to how the boost feature ups the handling (details below)

    - What we don't know :

    * what triggers the bug
    * what exactly it does to the physics
    * if using a T100 wheel had any effect (most probably not but that wasn't thoroughly tested)
    * if an update can corrupt a savefile
    * how many people exactly are touched by this



    As regular players, I think we did pretty much everything we could do with the tools we have access to and the much appreciated cooperation of RA1784. It is now in the hands of Sony and Polyphony Digital to identify precisely what's wrong in the saves, figure out the technical details and work to solve this issue.

    @Spurgy 777 You may want to put your videos and other stuff directly in this thread, I'll edit this post to add them here if necessary.
    @RA1784 If you could upload your save file backup there as well, that would be ideal (EDIT : we discussed this and thought it would be better to keep it offline until someone from PD asks for it to prevent any hacking possibility)
    @MINKIHL @zzz_pt @Shottah072 @Rick23 GT @kubstar @nissman @Tidgney @Iceman If you have anything to add in there, don't be afraid to do so as well.
    @Jordan if you have any way of contacting Kaz or someone at Polyphony Digital directly, the community would appreciate if you pointed them to this thread.

    If I missed something or wrote something wrong in there, please correct me, but I think for now that's pretty much all what has been said and done.

    EDIT : MINKIHL sent me the pictures comparing his braking points with RA1784's braking points in better quality than what you can see in the PSN chat screenshot, so here they are (and RW stands for soft tyres in German, they're not wet ones). From his own words : "Its the frame where we both hit first time full brake."

    [​IMG]
    [​IMG]

    Also, here's a post from Spurgy with a few videos showing laps done with the bug :


    And here are some useful posts that have been post in the original discussion :


    UPDATE : new tests brought up something interesting related to the boost feature. Read the quoted posts below, which can be found on page 2.


     
    Last edited: Jan 26, 2018
  2. XtremePhoto

    XtremePhoto

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    Somebody beat me, so they must have this grippy bug /s
     
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  3. wingman1659

    wingman1659 Premium

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    I think it would be best to just not post sarcasm as a joke or not. Keep this strictly informational or post ideas about how to test it.
     
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  4. Shottah072

    Shottah072

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    I think this quote was interesting as well. Posted by someone i cannot name and i am not sure how to quote him cause the topic is closed. He said:

    'I can explain plenty about this but on were it works and were it don't because I have tested it everywhere

    This grip bug doesn't work on the cup races nor manufacturing series fact'

    Especially that last bit about cup and manufacturer races. We suspected it to not work, but not sure it was confirmed yet. @RA1784 didnt test it as far as i know.
     
    BigDawg_1281 likes this.
  5. Highlandor

    Highlandor

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    What about creating a standardised checklist or questionnaire for people who have had this bug to fill out - to compare against the people who haven't experienced it (who also can also fill it out?). This way, it could potentially highlight something?

    ie questions like (these are just examples):

    Their region
    When did they get their copy of GT Sport
    What version was it - Disc or download
    What was the first update they did
    Controller / wheel
    Preferred driving options: driving aids, view etc
    Cars affected
    Details of race(s) affected

    and so forth...

    They can be completely anonymous - who it is doesn't really matter in the long run, but by having some kind of standardised checklist it'll be easier to see any similarities / differences...
     
  6. GT_Alex74

    GT_Alex74

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    All the things mentionned in your checklist has already been adressed. Plus, we still have to see the replays, so it's better to have a private chat with them anyway.

    @Shottah072 yeah giving his overall attitude, I'm taking this with a grain of salt. I'll be waiting to have someone willing to provide actual data.
     
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  7. Nando deBem

    Nando deBem

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    I think I know a way of consistently testing the bug.
    Bluemoon Bay.
    Stay in the inside, accelerating all the way.
    Check where you hit the wall.
    Different grip levels should hit the wall in different places.
     
  8. andryush

    andryush

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    I think @RA1784 should load his backup of bugged save state back to his console for more testing. Actually we know nothing about this bug.

    Things that need to be tested imo:

    - various assist combination
    - aftermarket/stock wheels
    - driving wheel vs controller
    - various game modes, as @Shottah072 mentioned above
     
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  9. Shottah072

    Shottah072

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    Fair point, probably not the best resource. However it is the only usefull information he gave us and i dont think we have seen effected laps so far in the FIA events. He also mentioned he was roughly a second of FIA qualy times. I think it holds some truth, but maybe wait till we can confirm it.
     
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  10. GT_Alex74

    GT_Alex74

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    - Different bugged laps from different people show various combinations of assists. That's why it is mentionned in OP it is not related.
    - Same for aftermarket wheels, we've seen some laps with both stock and custom liveries.
    - It has also been ruled out the bug was controller dependent.
    - FIA races could be tested, but I really don't believe they'll be free from that bug. Besides, I think most of the top drivers put more effort into the FIA races than they do in the dailies (if they ever do more than one of them for several days tbh), so just stating he's one second off the top time in FIA races doesn't strike me as sufficient proof without an actual comparison of laps done with two different accounts.

    Right now, one of the priorities is to know if everyone affected also encountered the preferences resetting bug since RA1874 had this in conjunction, but nobody replied to us about that.
     
  11. Highlandor

    Highlandor

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    All those things mentioned were just purely examples, not definitive questions, try reading posts before dismissing them..

    It's not better to keep this private because anyone wanting to check for themselves have no definitive demographics to compare against.

    Seeing how the last attempt at gaining info on this turned into a public witch hunt - that's hardly condusive for making recipients of this bug come forward to give details.

    So how can anonymous, detailed demographics be worse????????????????????

    But, you obviously know best, so you carry on... :rolleyes:

    Bye
     
  12. Shottah072

    Shottah072

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    894
    Yes also a fair point, we need to confirm before we can be sure.
     
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  13. Tidgney

    Tidgney Premium

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    I would say hold off on this point as I believe there is some affect in these races. I've saved a lap that I want to look at more as I couldn't get close to it (Was earlier in the week), even in a race with slipstream nobody could get close to it. I'm not naming names, and also not on a witch hunt but I'd like to think I know what is possible in terms of times and sectors and it just felt not possible, especially as the apex speeds where way higher than what I could manage (3mph at least on every corner). It could be an amazing lap and I could certainly be wrong but I want to have a closer look at it.
     
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  14. Voodoovaj

    Voodoovaj

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    I think it would be good to encourage people to make a second account (doesn't need a psn account or anything) to test themselves for the bug, or to test if they have created a bug.

    It's pretty simple: Go to circuit experience and set a time on on of the road courses (I suggest Lago Maggiore or Suzuka, but I am open to other suggestions). Set a time with your regular account. If you cannot, with a decent effort, come close to that time on the new account, then you may indeed have the bug.

    I have tested myself using Bathhurst and I can do 2:06's on both accounts. I didn't notice a significant difference in grip.
     
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  15. GT_Alex74

    GT_Alex74

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    I understood that, but that may not be the case of everyone coming accross this topic, since some people seem to hover over large amounts of text quickly, so that's why I reminded that.

    Better or not, the admins don't want names being associated with the bug on this forum, unless they're coming there on their behalf. So that's how it will be : people contacting us to have their replays reviewed. Then if you really want demographic datas (which IMHO aren't that interesting), we can just ask people with a confirmed bug all of that and report them anonymously.

    Again, private conversations are mainly to separate false and genuine concerns. If those people want to contribute here then, they're free to do it but we won't call them out in this thread.

    Because we have no way to verify anonymous data. Giving how the previous thread turned out, I'd expect people thinking they have the bug while they don't, and people filling the form in the name of someone they suspect because "he overtook me and went away so fast" and that would just mess things up and make people even more paranoïd.
     
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  16. Turbo Racer 48

    Turbo Racer 48

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    One other question if I may related to previous thread.

    Did the few identified so far who have the bug compete in the beta as well. @RA1784 did you ?

    Saw your response that you think you might have had it from the start too......

    p.s assume ok to discuss with @RA1784 as he's been involved before ?
     
  17. andryush

    andryush

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    So, RA has this bug even when playing on Dual Shock 4 instead of his G29?

    Also I'm very curious whether this bug will give one advantage in races with "additiona power" (boost?) feature on? Will it allow to go even faster, or will it nullify bug effect in favor of non bugged users?

    Some of those bugged racers replays looking like RedBull X2010 laps, especially second replay on this video:



    And overall it looks like "boost" is "on" all the time for affected players.
     
    Last edited: Jan 13, 2018
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  18. Voodoovaj

    Voodoovaj

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    I still suspect SRF because it's a setting that was individual in previous GT titles. If that is true, it would give you the result that is seen in the video. More corner speed, and therefore more exit speed, which leads to more straight line speed.
     
  19. Spurgy 777

    Spurgy 777

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    More corner speed alone wouldn't explain what we see, no. Plus people with the bug don't maintain their mph advantage that they get out of corners and are usually doing exactly the same by the end of the straight.
     
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  20. RA1784

    RA1784

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    All questions that i can 100% confirm are already answered. I will keep you up to date if something strange appears.
     
  21. dabz343

    dabz343

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    Gentlemen, let's respect the OP's request to keep the driver names off this thread. It tends to invite a fog.

    If you wish to explore this bug out of curiosity, which is only natural, may I suggest a separate thread?
     
  22. XtremePhoto

    XtremePhoto

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    By then we will have a 4th thread and you will be on your 3rd account.
     
  23. DriftMethod

    DriftMethod

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    In two or three months, I expect something like this to be PD's official response. "An update has been implemented for Gran Turismo Sport.
    This update fixes minor issues and the physics of some players . Please continue to enjoy Gran Turismo Sport."
     
  24. user3392345

    user3392345 (Banned)

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    What if this bug isnt a bug and this is the normal way the tyres should work? :D:D:D
     
  25. andyparks

    andyparks

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    I can definitely say I've not got it

    Might be bad language

     
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  26. Sharpie

    Sharpie

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    Endless spinning in straight line with RSS tires is this also grip bug?
     
  27. VanessaMagick

    VanessaMagick

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    Is your TCS set on 0?

    If you're slowed down enough, especially if you've taken damage or are on a banked section, your tyres may spin endlessly instead of getting grip onto track. If you have your TCS on 0, there's a good chance you won't ever actually get going again without manually babysitting the throttle.
     
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  28. Sharpie

    Sharpie

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    Yes tcs is 0.
     
  29. VanessaMagick

    VanessaMagick

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    Bump it up to 1-3 as you're getting used to controlling the throttle on exits.

    If you get spun out or punted completely off track, I would suggest even bumping it up to 4 or 5 until your tyres get a grip again.
     
    NoFinClue likes this.
  30. kjeldsen

    kjeldsen

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    Spring Cleaning
     
    Last edited: Feb 1, 2018
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