Dear AI Programmer....

Discussion in 'General Discussion' started by salvasirignano, Jul 15, 2016.

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  1. salvasirignano

    salvasirignano Registered

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    Please could you fix the AI's behaviour when they are in a position to overtake other cars?

    May I just say first and foremost that I love rFactor 2, it is a joy to drive, this isn't a thread to bash it.

    However ever since the days of F1C, even before RF1, GTR2, AMS, RF2.. the AI in ISI based sims has suffered the same problem, when they get into the slipstream of the car ahead, they lift off the throttle instead of staying flat and using the speed advantage gained by being in the slipstream to pull out and overtake.
    For me it's an immersion killer, if I get a bad exit, I know that if I stay on line they won't pass me, unless they try a late divebomb into the following corner.

    For demonstration purposes I made some videos showing the problem, I chose a recently updated ISI made track which should have more recent AI lines - Indianapolis, with high aggression and 120% difficulty.
    Then please compare it to the behaviour in Grand Prix 4, where they slipstream, keep 100% on the throttle and then pull out to overtake, as in real life.

    As it has been over a decade that ISI sims have had this problem I fear it's unfixable.




     
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  2. Associat0r

    Associat0r Registered

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    Those 60s F1 cars have much longer braking distances due to worse brakes and tire grip and different slipstream effects, so of course they take different risks when passing. Btw what is your AI aggression set to?

    That said, a better comparison would be a modern F1 car.
     
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  3. Lazza

    Lazza Registered

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    I don't think the AI has the sophistication to work out when to slipstream or not based on the car, so the OPs observation is probably valid. But, a specialised game like GP4 can more easily make F1 behaviour realistic. Doesn't mean rF2 can't do it, so seems a fair wish.
     
  4. salvasirignano

    salvasirignano Registered

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    I think 60 in the first, 100 in the other...

    I have played ISI Sims and rFactor2 for years with all types of car, with all manner of aggression settings and on many many tracks, and the result is always the same. However for a more equal comparison I will make a video of the Marussia at a different track, but showing the same problem...
     
  5. Associat0r

    Associat0r Registered

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    Better would be to use the F-ISI cars since they are more up to date.
     
  6. Christopher Elliott

    Christopher Elliott Administrator Staff Member

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    Thank you for taking the time to report this and provide details.
     
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  7. Euskotracks

    Euskotracks Registered

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    I haven't checked the videos but certainly it is not difficult to imagine what the OP is talking about.
    As he says, this behaviour is an immersion killer if you wanna watch the AI racing.

    When something is unchanged for so much time, people trend to accept it as if it didn't have remedy and do not even care to report it. Fortunately, from time to time someone has the bright idea to report it. +1 for the OP.

    A constructive and objective community would support and confirm what OP is exposing. It shouldn't be the community role to provide excuses or reasons for something clearly not working as expected.

    That should be ISI's job. Tuttle, for example, recently explained omni lights limitations regarding shadows in a the night shadows thread. That's what IMO is to be expected in this cases.

    Back to topic. I think the issue is somehow related to the bad AI behaviour in some tracks where they brake constantly when trying to follow a specific line. It seems that the line is not smooth enough for AI to properly follow it. I really do not think a fast line concept is the way to go in the future. A wider corridor to stay within its limits concept seems a more human concept. In the straights this could be widened so that AI can abandon fast line in a natural way.

    For each segment of the corridor, one of both side limits would be the preferred path. Normally outside-inside-outside when taking a turn. The AI learning would be how far from the fast sides to stay but following their natural line and not strictly following a determined path. Specially if that path has not been defined by that car and at the same conditions the track creator used when making the AIW.

    Enviado desde mi ONE A2001 mediante Tapatalk
     
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  8. Associat0r

    Associat0r Registered

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    I just tried it out myself too on this track with the DW12 with different AI limiter (lower should in theory reduce the issue) and aggression settings and noticed the same issue. Though I don't remember it being this severe before. The F-ISI fared a little better, but still not good.
    Anyway, I wasn't making excuses and I'm very happy this has been reported and noticed. I always rated Crammond GPx AI highly, so would be great to see this fixed.

    I also remember that Crammond GPx tracks use only one path, and the AI dynamically adapts, reducing the burden for track creators, but I'm not sure how well this would work in a more universal car sim like rF2, as GPx AI physics are even more simplified rF1's. I also remember the GPx AI having trouble with mod cars other than F1 spec.
     
    Last edited by a moderator: Jul 16, 2016
  9. toebee

    toebee Member

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    Great post op. I would just like to add that this would improve oval ai behavior greatly. I am sure most of you know there is a big difference between road course and oval racing, and how most passes are made. While road course racing passes are usually made under braking on corner entry, oval racing is the opposite. Most passes on ovals are setup on corner exit and continue down the straight. Currently the ai race ovals like road courses. That combined with the behavior the op mentioned makes for unrealistic driving. I am glad to see ISI is still open to developing the ai further!
     
  10. shiet

    shiet Registered

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    I thought this has been discussed before, this is an issue for sure with every car.
    Just take a ride at Le Mans, the AI won't overtake you with the slipstream just taps the break every few seconds.
     
  11. Slamfunk3

    Slamfunk3 Registered

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    There's a setting in the tracks .aiw file called "draft stickiness", it controls how long the cars stay in the draft before they swing out to pass. For road courses from ISI it's historically been set to 4. Although I haven't tried any oval stuff recently I recall one of the new ISI ovals having it set to 0.
    I've been using the ASR formula 1 cars and a setting of 3 seems to be the sweet spot for those cars. Depending on the type of car being used different settings should suffice. I believe the 0 setting on ovals is meant to simulate pack racing i.e. Daytona and Taladega.
    P.s. Also from reading MB's development blog posts there are new aero setting in the vehicle .hdv that are more realistic then the fudged work around numbers from RF1. Depending on the mod that could also influence how the cars draft and pass.
    TK

    Sent from my SAMSUNG-SM-G800A using Tapatalk
     
  12. stonec

    stonec Member

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    Yep, that's probably it. This is the problem of rF2, there is a myriad of buried parameters that no one except ISI seems to understand how to tweak. I bet 99% of modders never touched this value.

    I'd say it would be better to not leave things like this for modders' control, even if it means loss of customizability. If it was just a hardcoded value, ISI could tweak it and reach an acceptable compromise, instead of now having almost every track using the wrong value. Now we are stuck with faulty AI overtake behavior until every modded track gets updated, which won't happen.
     
  13. Euskotracks

    Euskotracks Registered

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    It should be quite easy for most league admins to update a track adding a line to the AIW. The update can be included in the vmod as an incremental update in order to be transparent to the drivers who wouldnt need to download a new version.

    I'll give it a try since I am already fiddling with AIW.

    Enviado desde mi ONE A2001 mediante Tapatalk
     
  14. Slamfunk3

    Slamfunk3 Registered

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    I don't think it's as easy as a "right" value. As a track maker you have to take into account the different type of cars that will be used to race on your track. And the different ways they all race. Admittedly i haven't tested it enough to know for sure.
    TK
     
  15. mschreiner

    mschreiner Registered

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    Although Draft stickiness can help the AI somewhat at a particular track it is just a crutch to the real problem. The AI just needs more development. ISI has also stated that they are aware the AI needs developed more. This was stated when they released the Stock Cars the first time. Since then they have improved some but hopefully it gets a lot more attention in the near future. I think it will attract more users if they can race realistically with the AI and then feel like they can take a gander to online racing.

    Just my 2 cents:)
     
  16. Seven Smiles

    Seven Smiles Registered

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    I've always wondered why the AI isn't a plugin, then the community could take on the load of developing it, something akin to TORCS. It's not the core of any sim and it seems it's treated that way by developers like ISI, a bit of an afterthought given low priority.
     
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  17. Juergen-BY

    Juergen-BY Registered

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    I did some investigations around the slipstream behavior. What i found is, when the ai`s sticking behind a car, they (often) simple are running into the limiter and cant overtake therefore. As it`s in rl too, cars from the same class, depending on the used track, cant overtake very easy, they`re on the the same speed, same weight etc.. Mostly a mistake from the car in front is needed...

    However, i did some test with the rMegane and Oulton Park NC. I edited the rMegane draft related parameter from hdv file as good as i can, wich isn`t very easy, because of lack of information. For Oulton i used very different values for AIDraftstickiness, at least 0.1000 was the best working value for me. I made a short video. To keep the file size as small as possible, the quality isnt that good, but you w`ll get the point...



    Just to add: the AI from rF2 are the best AI i have ever seen from a racing game. Every complaints should be meant on a very high level ;)
     
    Last edited by a moderator: Jul 21, 2016
  18. hexagramme

    hexagramme Member

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    From my experience, draft stickiness does indeed affect ai behavior on road courses too.

    I did some tests a while back which indicated that 0.1 does indeed work very well and increases the number of ai overtakes.

    Also I agree about the point made regarding ai hitting the limiter on the straights, this is more often than not the reason why the ai isn't able to overtake. So more of a setup issue than an actual ai issue.
     
  19. ECAR_Tracks

    ECAR_Tracks Registered

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    Excellent thread and contained information.

    I'd add that AIW lines left and right affects this behavior as well. If you let AIW editor create left and right lines and don't perform a final check, sometimes those can be created out of valid corridors (e.g. too close of walls or grass), so it seems AI car get more afraid to overtake.

    I did a extremely permissive AIW version of my track by opening the valid corridors as much as I can, including a small portion of grass. The AI cars stop to lift pedals and try to overtake all the time, but it causes an excessive number of accidents and spins.
     
  20. TheGrunt

    TheGrunt Registered

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    I agree that AI is generally very good, but there are still odd things here and there which I'd like to see resolved. Most annoying aspect is the AI break checking/pumping. This is usually evident at the race starts and soon after that when the pack is still together and cars are going to tight turns. It just doesn't look silly, but it is not rare for me to ram to a car in front of you, because AI dude suddenly decides to go full on brakes when you expect him to go smoothly through the turn. Besides this general behaviour, it also seems that the effect varies depending on the car, some cars are worse than others, but for example ISI Formula Renault 2014 is atrocius and AI is constantly locking the brakes even on faster turns and outside the heavy traffic. Looking at AI driving the Renault, you'd think their tires are one flat spot after another after one lap.

    Another area of improvement would be the oval AI, as AI on ovals is also constantly break checking on turns and fails to overtake on draft and generally uses poorly different lines on turns.

    By the way, I'm pleasantly surprised how smoothly oval AI works on Automobilista with CART mod: cars drive smoothly on turns, don't do sudden braking and keep their driving lines through the turn. There are pracically two properly done oval tracks for the mod, the official in-game Jacarepagu√° and then the recently released Fontana mod and both work quite well. AI still struggles with lapped cars and fails to overtake on draft on too many occasions, but in general ovals and AI work already quite decently and when it is at its best, you can have terrific multi lap battles with AI on AMS. I hope ISI can improve the oval AI, because IMO it currently works quite badly and is definitely worse than it is currently in AMS.
     
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