AI cars driving through pits

[The Iron Wolf]

Hi,
I am running DTM 2018 v1.3 mod (I know v2.0 is out but I have some private changes that I have no time to port) and I noticed that several cars are entering the pits, but not stopping in the pit stall. Then they do it the next lap again, and again.

It happens on 2 tracks I tested so far and seems to affect only some teams/cars, which makes me think it is something with cars. I found some old posts about engine ignition etc and will look into that, but in my case are not even stopping and other cars with same engine do work. I also see enough pit stalls in .aiw etc.

Any suggestions? Thanks!

 

[GTR233]

I think it is a pit box reservation issue : in many modded tracks we can see pitgroups with gtr2 original teams so these boxes are reserved and not opened to other teams.
You have 2 ends to fix this issue :

- on track end
Open track GDB go to bottom and delete

PitOrder
{
PitGroup=xxxx
PitGroup=yyyy
...
}

but DO NOT DELETE NumberSharingPit


- on car end
set PitGroup=""

 

[The Iron Wolf]

I think it is a pit box reservation issue : in many modded tracks we can see pitgroups with gtr2 original teams so these boxes are reserved and not opened to other teams.
You have 2 ends to fix this issue :

- on track end
Open track GDB go to bottom and delete

PitOrder
{
PitGroup=xxxx
PitGroup=yyyy
...
}

but DO NOT DELETE NumberSharingPit


- on car end
set PitGroup=""

Thanks Paul. I tried that, because I am simulating mandatory pit stop using PitStopStrategy. Somehow several teams have issues and I do not see a typo anywhere, but it is good to know that this may have something to do with it.

What does NumberSharingPit mean? Does 2 mean 2 driver names are allowed to use this pit stall? Not simultaneously though, right?

 

[GTR233]

That is what it says : you set the number of cars per pit box (2 or 3 in general) but it must match the pits locations in aiw so it is not a good idea to modify this value if you have no idea of how pit locations are made in aiw.

 

[The Iron Wolf]

So, if number of cars sharing a PitGroup does not match NumberSharingPit this could confuse the game logic, right?

 

[jgf]

AI will drive through the pits and back onto the track if their assigned pit space is occupied, they will try to pit again on the next lap ...or the next.

Pits are assigned in vehicle.scn once the track and series/mod(s) are selected; the game notes the number of pits available and scans the .car files for team slots required and number of unassigned cars, so a team with 4 cars will have a space to itself while several one car teams may share a space. This worked fine in the original game (with specific cars/teams/tracks), but once mods are added this doesn't always work, you may have teams with eight cars, you may have unassigned cars, the game's pit priority goes by the wayside as it tries to make certain every car gets a pit, large teams (3+ cars) seem to get priority, then smaller teams, then unassigned cars such that each pit will have the same number of cars assigned to it. Now I've been told the problem here is the game to a degree controls teams pitting so no two team cars will try to pit at the same time, but with, for example, a three car team and two solo cars assigned to one pit this balancing act gets screwed and it's a "first come, first served" situation (that three car team does not recognize the two solo cars so will try to pit if no other team car is in the pit).

I have read that dumping the entire team concept from pitting (pit reference in car files is left blank) the game now gives every car equal priority as a one car team so pitting works better; though more than four cars per pit is still problematic (like four people sharing one bathroom).

(BTW, normally you will never see vehicle.scn, it is created when you go to a track and deleted when you return to the main menu ...but not always. If you get a CTD and the trace shows vehicle.scn or Slot000, that's the reason.)

 

[The Iron Wolf]

@jgf - thanks for your inputs - every bit helps. However, pit stall is empty in my case, and I even see pit crew out waiting. But AI just drives by.

Actually this is interesting idea (drop PitGroup from .car). PitStopStrategy seems to be working reliably, so it can help avoiding the conflicts by spreading pit stops out. A lot to investigate.

 

[jgf]

...However, pit stall is empty in my case, and I even see pit crew out waiting. But AI just drives by.
...

Probably waiting for another car assigned to that pit, car that drove through came in after other car had "called" for pit.

 

[The Iron Wolf]

A bit of an update - you both were right it had to do with pit assignment. With so many moving parts it is easy to get confused, but at the moment it looks to me like drive through was caused by some PitGroups containing fewer cars than NumberSharingPits. Also, first stall is too close to xpitin, so first group was missing its pits (fixed by making first two groups not used).

But now another issue popped up - on another track, same exact cars fail to return on track after refueling. I saw some posts that it might have to do with engine idling RPMs (Perhaps, pitlane is slightly up the hill or something?), so will be looking into that next, but hints are welcome Learning a lot, and my DTM events will get much better with all of this. For example, after pitgroup fix (plus fuel estimate change in .aiw) not a single car retired!

 

[jgf]

If the problem is just a couple of cars it is probably the engine file (use Tom's Engine Shop, it makes this very easy), the torque just above idle is often too low to get the car moving, especially with some tracks where the pit lane and/or pit spots have issues (car actually sits slightly above or below ground level, not visibly but enough to affect physics). Boost the torque in the 1000-2000rpm range just a little, and smooth the transition to the rest of the torque curve. This will not materially affect the performance of the car but should get them out of the pits.

In the engine file there is also a "LaunchRPMLogic=(6000, 7500)", this controls how much the AI will rev the engine from a standstill. You could try raising this slightly, but be careful - too high and at the start of a race they will take off and leave you in the dust.

Pitlanes on a hill can be problematic, but I'm convinced this is not a power issue but involves how the game interprets the pit spots not being level. The Clermont full circuit is a prime example; some series/mods have no trouble, some need a minor torque boost, some won't leave unless given ridiculous torque boost. The straight in front of the pits and the pits themselves are on the crest of a very slight hill, cars at the very ends of the pit area will leave, cars at the center (crest of the hill) barely move, cars in between may or may not move; they will move back and forth a foot or so, then disappear, only to reappear a couple of minutes later and repeat. I can maneuver behind them and give a slight push, once their front wheels are actually on pit road they will take off; except the cars at the crest of the hill, which I can hardly move, and will not leave even if pushed nearly onto the track. I was told to adjust "GarageDepth=" in the AIW file; default was 3.000 (if i remember correctly, most tracks seem to have this around 2.000 to 3.000), I tried increments of 0.30 from 0.1000 all the way to 6.000 with no appreciable results (there did seem to be a "sweet spot" around 2.000, the cars were easier to push).

 

[GTR233]

edit: deleted as jgf already answered

 

[The Iron Wolf]

Thank you guys. Spent an hour tonight raising torque in 1000-2000RPM range and tried raising LaunchRMPLogic without success. I copied track over to latest HQ Anniversary and NAP HQ 03/04 left pits correctly, so it is something about cars. I am not sure it is .eng file, as I even tried using one of the HQ car's file with no success. It could be something like cars being too low etc.

I am not giving up and I am determined to figure it out as DTM is my favorite tin top class - basically F1 in a stock car shell. But if this thread gets no update it means I found no solution.

 

[The Iron Wolf]

Figured it out! It was caused by "Pit Crew Detail: Full", had to change it to player only. Since DTM grid is small, I had it at Full as framerate is good with small grids, turns out that could cause the problem above. Strange, but all in all "Pit Crew Detail: Full" is pretty broken feature. Enabling it consumes a lot of memory on big grids.

 

[jgf]

Good to know. I usually disable pit crews for all but player in any sim, all the way back to N2k3 it's been a resource hog. But never knew it could cause this problem (maybe all the crews are standing in front of each others' cars, blocking them, lol).

 

[The Iron Wolf]

GTR2 keeps surprising us But when those things are worked out it is so rewarding - I just simulated 2 DTM races on different tracks. After all those fixes, not a single out of fuel or DNF and all pitted during the pit window per regulations (mandatory pit stop), looking forward to actually race those events.

 

[roby13]

Hey @The Iron Wolf ! First of all a big thank you for not abandoning gtr2! You, @GTR233 , @Shovas and all the guys still working on improving this game deserve some big credits for your hard efforts. Now that you're digging deeper into AI mechanics there's something I'd like to ask and that would be AI throttle application. Something very common in replays or when you're surrounded by many AI cars is that short before, during and exiting a corner or when they try to overtake a slower car, they sound like they're hesitating or constantly adapting their throttle input in an inconstant manner. As a result engine sound from AI cars in many cases is like "vroom, vroom, vroom, vroom" until they decide it's safe to apply full throttle. Maybe it's something worth looking at it!

 

[The Iron Wolf]

Hey @The Iron Wolf ! First of all a big thank you for not abandoning gtr2! You, @GTR233 , @Shovas and all the guys still working on improving this game deserve some big credits for your hard efforts. Now that you're digging deeper into AI mechanics there's something I'd like to ask and that would be AI throttle application. Something very common in replays or when you're surrounded by many AI cars is that short before, during and exiting a corner or when they try to overtake a slower car, they sound like they're hesitating or constantly adapting their throttle input in an inconstant manner. As a result engine sound from AI cars in many cases is like "vroom, vroom, vroom, vroom" until they decide it's safe to apply full throttle. Maybe it's something worth looking at it!

Hi Roby13,

AI improvements is something that I will attempt, but currently I have 0 insight into their behavior and controlling them, and there's no guarantee I will ever get to that - this is very, very, very difficult to do. Honestly, AI work is years away, because I have at least a year of work I want to do before I get to AI, and you may not like it, but general philosophy in my plugin is that AI is just a dummy to help with immersion. Which mean that serious features apply to player car only. Also, none of the new features will make it into replays, I never watch them.

However, I just started to port my rF2 shared memory monitor to GTR2, which will be useful in my AI efforts and might be handy in setting up events.

Did you join my project Discord? I noticed that we share some common interests, notably, passion for realism. I would really appreciate your help testing the new/early features, and AI work will not be possible at all without a group of dedicated testers.

And it is not just testing. This work involves collecting SimHub graphs, Motec data etc - all a lot for one person to do.

Cheers!

Couple of monitor screenshots: