AI drivers become massively off the pace when racing on a big distance (1 hour or longer). Any ideas how to fix it?

[monzaq3]

Hello everyone! I noticed some strange behaviour from AI drivers when I race on a long distance. At some point their pace becomes 10-20 seconds slower than their own personal best times. I tested it on three different tracks (all 3 are mods), raced for 60-120 minutes on each. During the first 40-50 minutes AI drive more or less competetively. But after that point they just slow down massively. It happens regardless of whether they pitted for new tyres or not: even after a pit stop they drive in a good pace for a couple of laps and then slow down again. Maybe there are some parameters to change in .CAR files or talent files to fix that? Who can help?

 

[Speednut357]

I remember something about this. I think the Ai get damaged aero and will slow down over long races. You can just turn damage off, but there is a better solution by adjusting damage in a file. I'm not at home so can't look to refresh my memory.

 

[jgf]

Every little contact between AI causes slight damage, in short races this is negligible, but the longer the race the more this accumulates until it is a factor in their lap times.

In the .dmg file-
"The key line for reducing the aerodynamic damage issue is this: AeroMin=1100.0. I have raised this line in the mod to anywhere from 5850.0 to 6250.0 depending on the car." (From vonDutch AI Tutorial)
You will need to do this for every car installed (TextCrawler simplifies this).

 

[The Iron Wolf]

Every little contact between AI causes slight damage, in short races this is negligible, but the longer the race the more this accumulates until it is a factor in their lap times.

In the .dmg file-
"The key line for reducing the aerodynamic damage issue is this: AeroMin=1100.0. I have raised this line in the mod to anywhere from 5850.0 to 6250.0 depending on the car." (From vonDutch AI Tutorial)
You will need to do this for every car installed (TextCrawler simplifies this).

Does this mean AI never repairs aero damage? Thanks!

 

[monzaq3]

Every little contact between AI causes slight damage, in short races this is negligible, but the longer the race the more this accumulates until it is a factor in their lap times.

In the .dmg file-
"The key line for reducing the aerodynamic damage issue is this: AeroMin=1100.0. I have raised this line in the mod to anywhere from 5850.0 to 6250.0 depending on the car." (From vonDutch AI Tutorial)
You will need to do this for every car installed (TextCrawler simplifies this).

Thank you! I'll test this within a couple of days and will leave some feedback in this thread. So simply saying, this parameter makes AI cars less sensitive to damage, but the damage itself would be still visible, right?

 

[monzaq3]

Does this mean AI never repairs aero damage? Thanks!

Good question, I thought about it too. Obviously, AI cars always pit for repair if they have a splitter torn down. But do they repair damage if it's less crucial (but still affects the lap times)?

 

[jgf]

Does this mean AI never repairs aero damage? Thanks!

They will repair such damage if it exceeds a certain amount, but what happens is they get a number of small "dings" that individually are not worth repairing but collectively affect performance.

 

[The Iron Wolf]

They will repair such damage if it exceeds a certain amount, but what happens is they get a number of small "dings" that individually are not worth repairing but collectively affect performance.

Thanks. Is the threshold configurable?

Edit: ah, one way is to make it bigger to cause AI to repair it, right?

 

[jgf]

Thank you! I'll test this within a couple of days and will leave some feedback in this thread. So simply saying, this parameter makes AI cars less sensitive to damage, but the damage itself would be still visible, right?

Yes, it will take more impact to cause damage. So when there is damage it will be greater, thus more likely to get repaired.

 

[jgf]

Thanks. Is the threshold configurable?

Not to my knowledge. Beyond that this adjustment means the cars will not take damage from all the little bumps, so when there is a bump large enough to cause damage it may cause enough to trigger repairs.

 

[monzaq3]

Every little contact between AI causes slight damage, in short races this is negligible, but the longer the race the more this accumulates until it is a factor in their lap times.

In the .dmg file-
"The key line for reducing the aerodynamic damage issue is this: AeroMin=1100.0. I have raised this line in the mod to anywhere from 5850.0 to 6250.0 depending on the car." (From vonDutch AI Tutorial)
You will need to do this for every car installed (TextCrawler simplifies this).

And what if there is no .dmg file in a team folder?

 

[jgf]

And what if there is no .dmg file in a team folder?

I have never encountered that; as it is one of the files called when the car is loaded I would assume its absence would throw a CTD.

 

[MJQT]

For future reference, the community isiMotor AI documentation website has a section on the "AI slowdown" issue due to damage:

Car files - isiMotor2 Community AI Documentation

A community-made isiMotor2 AI documentation website

sim-racing.gitlab.io

Does this mean AI never repairs aero damage? Thanks!

I have read that in Reiza's isiMotor2 optimizations for Automobilista 1, there were changes made so that the AI has better pitting logic around damage fixes. Certainly the behaviour I've seen in AI races in AMS1 suggests they made improvements. Don't know what those changes were, specifically. Possibly isiMotor2 source code changes? Means I'm not sure if or how this could be adapted to GTR2. But however Reiza did it, it may well have been to configure the threshold at which the AI choose to pit when damaged and when they decide to repair that damage.

 

[jgf]

The current system would work fine if damage were cumulative, but it apparently isn't. Just pulling figures from a hat let's say it takes a damage factor of 5 to trigger repairs, the car can take a dozen hits of 4.9 and will get no repairs, but a single hit of 5 or greater will get that repair done at the next scheduled pit stop (but not all the smaller dings). So with the aeromin parameter you seek the "sweet spot" (different for each type car) where the only damage taken will be above the repair trigger.

I also believe there is a higher damage level that will trigger an immediate pit stop (if the car can make it to the pits).