AI Discussion (dev branch)

[klamacz 448]

Hi, there

When it's possible/useful, we will try to post brief descriptions of recent AI changes done on the development branch. We hope this will help demonstrate the tweaks that we're making and generate useful feedback to help us validate and polish our work.

We'd like to use the news thread to keep track of the information, as feedback about AI has a history of generating a modestly apocalyptic number of replies. This thread can be used to discuss the changes we track.

Just a quick note. It really helps us in this thread when you provide considered feedback to the changes in progress, or clean repros missions that highlight some repeatable AI behaviour.

Our programmers tend to get lost when the discussions trail off into other areas, like headless client, etc. This thread can't both function as a place for feature requests and discussion and as a place to discuss the active development. It's one or the other, gents, and I'd like to be able to pass as much useful info to our guys as possible! :)

For now, the first batch of notes to kick things off:

Fixed: AI turn limitation while aiming

It wasn't supposed to fix rotation speed of AI soldiers, but is letting them use "aiming deadzone" as specified in the unit config (minGunTurnAI, maxGunTurnAI) which is typically 60 degrees cone.

Therefore currently AI should be able to follow targets better without moving whole body.

AI shouldn't take unguided missiles as guided

RPG and NLAW are supposed to be unguided, but AI was still able to use them as guided weapons. This was corrected.

FIX: AI ballistic calculation fixed.

Quite big change, now AI is able to calculate and predict accurate ballistic of bullet, therefore is able to aim and engage targets on all ranges, both static and moving. Also, this improves AI ability to hit moving targets by more precise time of leading calculation. Good way to check this change is try to fight AI sniper on 1km+ range. Of course it still depends on his skill.

FIX: AI now can shoot over animals.

AI was considering animals as friendly, therefore denied to shot in theirs direction. Example: put yours character, enemy soldier and snake animal between you. After this fix AI won't bother with friendly fire against animals.

Edited August 4, 2013 by RoyaltyinExile

[dale0404 5]

I am really liking where this is (hopefully) going.

[froggyluv 2135]

A Dev sponsored thread on AI..... *has heartattack*

It seems enemy AI can turn/spin on a dime a full 180 degrees when shot at from 100m+ but has a hard time with very close proximity targets at times -can/will this be addressed?

[instagoat 133]

Oh Supr, totes gonna keep on eye on this here thread.

I´ve noticed they are still very accurate over long distances and like to fire from standing up, rather than kneeling or prone positions. High processor load and low fps also leads to them occupying identical grid nodes and sometimes even clipping through doors/walls: I am going to finally flesh out my documentation and post what I´ve found here. Unfortunately I deleted the stuff I found during alpha because the changes were so rapid and non-transparent, and I also didn´t use default settings most of the time, which made quite a lot of things I found useless.

I´m gonna report back once I´ve managed to assemble something. If life doesn´t get too busy, I´ll hopefully be able to contribute. Knock on wood.

[bad benson 1733]

It seems enemy AI can turn/spin on a dime a full 180 degrees when shot at from 100m+ but has a hard time with very close proximity targets at times -can/will this be addressed?

yup. this is still the main problem with turning. i noticed some subtle improvements in urban areas. they seem more competent. but the infamous prone turning around trying to follow me while i mockingly vault over their body is still there. as i said somewhere before. the behaviour froggyluv described needs to be switched. those instant (almost) lock ons are needed for very close range (only if they see you ofc) and need to removed from long range engagements.

i realize that might be angle related but maybe add a distance coef value that controls all other settings so they can be tweaked for different distances. seems impossible otherwise. there can't be a setting that works good for all distances.

one question. can AI use the deadzone in the prone position?

[-Coulum- 35]

Nice one BIS. I am hoping this means ai is going to get more love even if its just a bit. Also love to see the descriptions of what changes actually do.

Quite big change, now AI is able to calculate and predict accurate ballistic of bullet, therefore is able to aim and engage targets on all ranges, both static and moving. Also, this improves AI ability to hit moving targets by more precise time of leading calculation. Good way to check this change is try to fight AI sniper on 1km+ range. Of course it still depends on his skill.

Has anyone seen the results of this? Does it fix the issue where ai are unable to hit you if you strafe across their LOS? I haven't been able to test myself.

[twisted 128]

fantastic thread! any news on suppression effect on ai?

[papanowel 120]

Good move from the devs, it's taking the right direction!

[NeMeSiS 11]

Has anyone seen the results of this? Does it fix the issue where ai are unable to hit you if you strafe across their LOS? I haven't been able to test myself.

I thought that was the change they made so sniper bullets wouldnt have to have unrealistic ballistics.

[Stlkrash1 1]

Here is an idea... Actually get things done... We are two years late as it is... Plenty of time to get this done. Shows terrible business management.

[instagoat 133]

Nice one BIS. I am hoping this means ai is going to get more love even if its just a bit. Also love to see the descriptions of what changes actually do.

Has anyone seen the results of this? Does it fix the issue where ai are unable to hit you if you strafe across their LOS? I haven't been able to test myself.

I´ve re-started my tests, and at least when firing at jogging enemies at a distance of about 25 meters, they were able to reliably hit them when prone or kneeling. Problem is that when kneeling or standing up, oftentimes they will even miss targets that are right in front of them because they fire over the enemies heads (veteran difficulty, no alterations to config), and then kill with the 1st bullet after reloading. If they hit, it is usually not like players who hit with one of the later rounds in a long burst, but rather with the very first and then throw the rest away into the sky.

Edit: Mind, I have done 3 tests so far, so this is not at all a statistically relevant result.

[Tyl3r99 41]

cant wait for more details on AI improvements :) keep up the good work

[Tonci87 163]

Very good idea BIS!

Are we supposed to tak about all kinds of AI here? Eg Diving, driving, flying etc?

[klamacz 448]

one question. can AI use the deadzone in the prone position?

Yes, it's supposed to.

I´ve re-started my tests, and at least when firing at jogging enemies at a distance of about 25 meters, they were able to reliably hit them when prone or kneeling. Problem is that when kneeling or standing up, oftentimes they will even miss targets that are right in front of them because they fire over the enemies heads (veteran difficulty, no alterations to config), and then kill with the 1st bullet after reloading. If they hit, it is usually not like players who hit with one of the later rounds in a long burst, but rather with the very first and then throw the rest away into the sky.

Edit: Mind, I have done 3 tests so far, so this is not at all a statistically relevant result.

This is still right, due to the recoil.

Very good idea BIS!

Are we supposed to tak about all kinds of AI here? Eg Diving, driving, flying etc?

For us, it would be best to keep the discussion and feedback about actual changes done. This way we can actually confirm the effect of changes done in many test-cases.

We have enough sources for bug-reports and suggestions already.

[frostwyrm333 1]

Also I noticed some new behaviour like switching to pistols in extreme CQB and picking up launchers from dead soldiers.

[chortles 263]

How do you define "extreme CQB"?

[instagoat 133]

Also I noticed some new behaviour like switching to pistols in extreme CQB and picking up launchers from dead soldiers.

Never observed either of those. Sure you´re not running mods?

[metalcraze 290]

Has anyone seen the results of this? Does it fix the issue where ai are unable to hit you if you strafe across their LOS? I haven't been able to test myself.

Heavily tied to AI turn speed limitation (at least acknowledge this ticket, BIS). They hit you at 200m and up alright, but the closer you strafe - the worse it gets

[chortles 263]

Lately BI acknowledgement of a ticket hasn't proven an effective indicator of visible progress. :p However, at least the OP was clear (well, clearer than the changelog was, admittedly an issue with the changelogs if you ask me) about just what the "turning" fix meant in this case.

[f2k sel 164]

I´ve re-started my tests, and at least when firing at jogging enemies at a distance of about 25 meters, they were able to reliably hit them when prone or kneeling. Problem is that when kneeling or standing up, oftentimes they will even miss targets that are right in front of them because they fire over the enemies heads (veteran difficulty, no alterations to config), and then kill with the 1st bullet after reloading. If they hit, it is usually not like players who hit with one of the later rounds in a long burst, but rather with the very first and then throw the rest away into the sky.

Edit: Mind, I have done 3 tests so far, so this is not at all a statistically relevant result.

That sounds about right, I do 20-30 tests.

I placed two OPFOR 25-30m from me with their backs towards me.

I fire a single shot.

The units start to turn after a 2-3 second delay.

If they hit me with the first shot they will usually finish the job.

If they miss then they will just fire shot after shot with only the first after reload finding the target.

Normally though only one unit seems to be able to find the target.

Testing in normal mode with default skill settings.

[Champy_UK 1]

I have seen a soldier kneeling and what seemed to be cycling through his weapons whilst testing today after the Dev update, then get up then repeating :)

[Tyl3r99 41]

im going to test this now

[instagoat 133]

https://docs.google.com/document/d/1gfUZBAvqugrveCmFZ-O84gieJQ6dFsdIw-pxAkqJQKw/edit?usp=sharing

I have uploaded my first 8 test reports here. I think you can notify me on the google docs thing and post comments, I would also be happy about feedback here or by PM.

Note that none of this is statistically relevant. Around 50 tests would begin to show a pointer towards average AI behavior, but since I and many others have played this game series for so long, I have allowed myself to draw some very light conclusions. Also, I will try to optimize my methodology further. I hope that this will be helpful to the developers in some way.

[Champy_UK 1]

I have seen a soldier kneeling and what seemed to be cycling through his weapons whilst testing today after the Dev update, then get up then repeating :)

Seems its linked to one type Opfor 'rifleman' (O_Soldier_F), has appeared for my friend also who has been testing a script, he removed the rifleman and added a different type and it was fine after that... any ideas?

[dslyecxi 23]

Quite big change, now AI is able to calculate and predict accurate ballistic of bullet, therefore is able to aim and engage targets on all ranges, both static and moving. Also, this improves AI ability to hit moving targets by more precise time of leading calculation. Good way to check this change is try to fight AI sniper on 1km+ range. Of course it still depends on his skill.

Shooting at moving targets at range in reality is a very difficult skill to develop - even well-trained shooters have difficulty with it. I hope that this has been kept in mind with these changes, and that we aren't going from a world in which AI are often pinpoint precise on static targets, to one in which AI are pinpoint precise on both static and moving targets at close and long ranges.