[Bug] AI Spots targets that are not visible

[welcome to hell 23]

Known bug, still present in build 60141

Tested as a squad member led by AI and as a lonewolf fighting against a group.

When under command SL would constantly order me to engage targets that are behind buildings, over the hill, or not visible due to foliage.

Ai squad members would lead (lock on) the targets when they are not visible and as soon as they would run across the field of view they would engage.

Fighting against a squad i was engaged when i was hiding behind a wooden fence (Not moving or exposing myself) not visible to the AI but they still engaged me seeing right through the obstacle.

Also they seem not to see the grass layer, they engage me when i think i am unseen and i have no idea where the fire is coming from.

[nomdeplume 0]

The grass layer is definitely approximated, but only insomuch as the grass you're actually in, not that which lies between you and them. It only reduces their likelihood of detecting you, AFAIK, so I think it still is more of a hindrance to humans than to the AI.

Can you upload a simple mission showing the problem of AI detecting targets that aren't visible to it so it's easy to reproduce? I haven't noticed this behaviour for some time, although I haven't been looking for it so it may have simply not noticed.

Edited November 24, 2009 by some kind of guy
Clarified the "problem" I was referring to.

[maddogx 13]

I remember this was a big problem in early versions but apparently it was fixed, around patch 1.03 I believe. Since then I haven't experienced the problem as you describe it.

An example mission where this behaviour is constantly reproducable would be really helpful.

[Potatomasher 0]

In my user made mission Ghosts Of Namalsk my team reports everytime at certain point that enemy static defence seen even though i don't have any static defences used in my mission. I don't understand that and it's even more strange than reporting non visible targets.

[b00ce 160]

I remember this was a big problem in early versions but apparently it was fixed, around patch 1.03 I believe. Since then I haven't experienced the problem as you describe it.

An example mission where this behaviour is constantly reproducable would be really helpful.

Earlier today (In the standard 1.04 build) I was engaging a squad, I had shot and killed the leader with a suppressed weapon in the black of night. Somehow they managed to see me through the 7-8 foot high brick wall and started shooting. The part that puzzled me the most was when there was a guy standing in front of me in the open looking at me, that somehow didn't see me. :confused:

[Alex72 1]

Silent weapons doesnt work in ARMA unfortunatelly. Not very good anyway.

Being able to sneak must be made better in ARMA2 like working silencers, dark hours and no NVG should make it hard to see for AI PLUS ofcourse that objects should not be transparent.

Mission design should make it harder like having some patrols that can stumble on to you or having alarms that can be triggered. That way there is no need to balance the game, and leave it hard for the AI to notice you in dark with silencer.

Will test this particular problem with seeing through obstacles. I have never seen that myself.

[Blechreiz 0]

Exact same problems here. They can see through corners of buildings, buildings, fences, vegetation and complete hills. Its really feaky if they report things that are not visible and sucks like hell when you get shot at even if there is hard cover between you and the enemy. I think its not necessary to talk about AI shoting through trees, bushes, grass or other vegetation. In one case AI ran into the water of a retaining dam and shot my coop mate right through the water. I mean WTF?!

You cant go stealth like in OFP, AI will detect you instant in 90% of the cases (since 1.0 Version) - even if you behave like chucknorris1337snipz0r in teh best cover where no human (WHO IS NOT TO FAR AWAY AND DOESNT SEE THE GRASS) would ever find you... and it makes me sick. There were so many great sneak 'blackop' missions for OFP. Unbelievable to see such a mission for ArmA2.

Edited November 29, 2009 by Blechreiz

[neokika 62]

Exact same problems here. They can see through corners of buildings, buildings, fences, vegetation and complete hills. Its really feaky if they report things that are not visible and sucks like hell when you get shot at even if there is hard cover between you and the enemy. I think its not necessary to talk about AI shoting through trees, bushes, grass or other vegetation. In one case AI ran into the water of a retaining dam and shot my coop mate right through the water. I mean WTF?!

You cant go stealth like in OFP, AI will detect you instant in 90% of the cases (since 1.0 Version) - even if you behave like chucknorris1337snipz0r in teh best cover where no human (WHO IS NOT TO FAR AWAY AND DOESNT SEE THE GRASS) would ever find you... and it makes me sick. There were so many great sneak 'blackop' missions for OFP. Unbelievable to see such a mission for ArmA2.

I play a lot of stealthy missions at night, and with silenced weapons, and sometimes I can get <20/30 metres from enemy, without being spotted, sometimes one or two enemies survive first bullet atack and go "danger" mode and still dont see me. So I dont have this problem.

Edited November 29, 2009 by neokika

[ARM505 0]

People tend to over rate the effectiveness of suppressors too. Having fired several suppressed weapons (9mm, .45 ACP, .22LR, 7.62X51) they are normally easily reconisable as having been fired when you are reasonably close by (a couple of hundred metres), and the bullet is VERY easily heard when rushing through the air, especially for somebody near the target, even subsonic ammo. Suppressors are legal, and require no licence at all where I come from. The .22LR subsonic is the quietest of the bunch, so that's the stealthiest, maybe this doesn't totally apply to that. The 7.62X51 makes quite a rushing noise as it flies through the air though, it's clearly recognisable as a bullet. The sound of the weapons action (if semi or full auto) is also actually quite loud, although obviously not as loud as a gunshot. The hollywood idea that you can fire something bigger than a .22 in a crowded room and nobody will notice is wrong (to be expected I suppose). The only people who won't notice, are people very far away, who would normally hear a loud gunshot. The lack of muzzle flash is however a huge bonus when using a suppressor. So I'm not surprised that suppressed CQB weapons at close range still get the AI to notice, that's realistic. Suppressed sniper rifles, at long range, should still cause the AI to get all worked up (they'd be morons not to notice a bullet swishing by), but they should perhaps have less idea where you are.

[welcome to hell 23]

An example mission where this behaviour is constantly reproducable would be really helpful.

The mission i played was one of ArmA 2 standard Single missions. Where a huey drops off a squad in a village infested by insurgents.

[nouty 10]

What really needs to be fixed is every AI in a squad seeing what one AI, or the player sees. Try it like this, put a squad at the NE airstrip for example, play one of the subordinates, leaving the squad leader and the rest standing on the strip, and hop onto a plane. Put enemy forces, armor and such some 5km away from the strip and go fly over them, your squad leader will spot targets and give you targets to engage even tho he's 5km away. He'll also probably tell other troops in the squad to engage them as well.

EDIT: And yeah, easiest way to reproduce AI spotting hidden targets is to play in a squad lead by an AI. When you get into combat, the AI squadmates are constantly reporting targets, even tho you don't see anything, and the leader is constantly giving you targets that are behind buildings or even behind hills. It doesn't work if they haven't seen any enemies, but once in active combat mode, they seem to spot everything from everywhere. Somehow the AI can keep track of everyone they've ever seen during a fight.

Once we were in an engagement with the AI, and had to retreat behind a hill. We circled the hill to flank the enemy position but as soon as we popped our heads from behind the hill, we were met with gunfire. We did this many times, circled to another position and every time we popped our heads up, there was a hail of gunfire raining down on us. I think you can see why this might be. When an AI leader gives you a target, and that target runs behind on obstacle, you can still see the icon move behind that obstacle. I think you only see it for so long, or it represents an expected position where the target is, but it still sucks. When an AI leader gives a target to another AI, that AI can track that target, at least momentarily even behind obstacles and thus know exactly where you are.

Edited November 30, 2009 by Nouty
adding stuff

[fabrizio_t 58]

Please somebody make a repro demonstrating this.

[jw custom 56]

Please somebody make a repro demonstrating this.

It happens in every mission you play just not always at same location.

When you walk a long your AI team mates report non visible enemies, behind houses, hills etc. So i suppose the enemy does the same as they are AI aswell.

If your playing with extended map info you can take a look at the spotted enemies positions which often is need to actually see them from your current position.

[Heatseeker 0]

Beta 60588... its nice that supressive fire is finally working but other than that i think 1.4 a.i. is better balanced and behaves more naturally, now a.i. are all seeing, uber aimbots again.. this time half sunk in the terrain due to the distant grass layer too.

edit:

The a.i. can also see thru the grass now better than before.

Adjusting skill level under dificulty options or individually (in editor) doesnt seem to decrease a.i. "skill" either.

I hope 1.4 a.i. isnt going to be replaced by.. this.

Edited December 1, 2009 by Heatseeker

[maturin 12]

What are you guys talking about? I have unloaded half a clip of a suppressed M4 and they ignore me. Hell, I'm pretty sure that I've hit them and they still remain oblivious.

[fabrizio_t 58]

It happens in every mission you play just not always at same location.

When you walk a long your AI team mates report non visible enemies, behind houses, hills etc. So i suppose the enemy does the same as they are AI aswell.

If your playing with extended map info you can take a look at the spotted enemies positions which often is need to actually see them from your current position.

Personally i haven't seen this recently.

Are you sure that those enemies are really not visible nor audible ?

For example engines are heard by AI way before vehicles being seen.

Also markers on map do not necessarily show the exact threat position, but rather the perceived approximate position (you can check that through the nearTargets function).

Finally the fact you can't see a unit does not mean one of your squaddies can't as well, since moving into formation each units have different angle of view on surroundings.

Latest patch 60588 has "sensitivity" raised to pre-1.02 levels, so AI has way better spotting capabilities. Sometimes they just see to well (eg. units concealed in grass / woods), but i have not seen it spotting units hidden behind houses or hills.

Try putting a unit behind a house into the editor and see if other units are able to see it through?

---------- Post added at 09:30 AM ---------- Previous post was at 09:17 AM ----------

What are you guys talking about? I have unloaded half a clip of a suppressed M4 and they ignore me. Hell, I'm pretty sure that I've hit them and they still remain oblivious.

A few bullets from a suppressed M4 just kill a unit in vanilla ArmA2.

Either you missed him or you are using some mods?

Edited December 1, 2009 by fabrizio_T

[jw custom 56]

Are you sure that those enemies are really not visible nor audible ?

I'm sure, and i believe it's the same problem as when AI shoot's you point blank from behind heavy vegitaion where there's no visibility at all, some objects doesn't seem to hinder detection.

Often when i get shot at i can of course i can hear the shot but pin pointing the exact location is not easy and often takes quite a few shots, so if AI team mates can hear other AI 100m+ away where they ain't visible and pin point them then there's something wrong with that.

[nomdeplume 0]

What really needs to be fixed is every AI in a squad seeing what one AI, or the player sees.

I don't think this will ever be "fixed", it's a fundamental part of how AI groups work. If they didn't share target information with each other, the forums would be full of people complaining how the AI is so stupid and doesn't communicate with itself. Personally, I wish it went a bit further and shared information with other groups -- or at least that there was a nice easy way to enable this.

Ideally there'd be a delay between one group member seeing a target and the rest of the group knowing about it, but in practice it's a minor issue now that dead people can't tell their buddies about their killer.

Once we were in an engagement with the AI, and had to retreat behind a hill. We circled the hill to flank the enemy position but as soon as we popped our heads from behind the hill, we were met with gunfire.

Sorry, but I think you must have circled very poorly - either remaining visible or making enough noise that they could track you. I've done similar things many times and there's many experiments people have done that show the AI really does just go off what it thinks the enemy location is.

When an AI leader gives you a target, and that target runs behind on obstacle, you can still see the icon move behind that obstacle. I think you only see it for so long, or it represents an expected position where the target is, but it still sucks. When an AI leader gives a target to another AI, that AI can track that target, at least momentarily even behind obstacles and thus know exactly where you are.

Again, this is by design, and precisely so the AI isn't so stupid as to never provide a challenge. As you theorise, the icon showing where the target is is the best guess, and assumes the target has continued to move how it was moving when it was last seen. This is just basic common sense, and if the AI didn't do it people would be complaining madly. But it's not magical -- if they can't see or hear you, they have to guess where you are. A lot of times you'll see that icon tracking through a heavily wooded area or behind a hill or whatever, then suddenly it'll jump somewhere else because the target has become visible to one of the team members -- at a different location.

In previous releases the AI had extremely sensitive ears; this was toned down a while back, but in the recent betas BIS have upped the sensitivity again so possibly that problem has returned, and may explain recent reports of the AI "seeing" targets that are behind walls etc. I also think they're a bit quick at identifying you based on gunfire -- but that might just be because I'm not very good at locating enemies based on sound and I resent people that can. ;)

[fabrizio_t 58]

I'm sure, and i believe it's the same problem as when AI shoot's you point blank from behind heavy vegitaion where there's no visibility at all, some objects doesn't seem to hinder detection.

Often when i get shot at i can of course i can hear the shot but pin pointing the exact location is not easy and often takes quite a few shots, so if AI team mates can hear other AI 100m+ away where they ain't visible and pin point them then there's something wrong with that.

I don't think it's the same kind of problem.

AI seeing through hills and houses is one thing, AI shooting through grass and vegetation is another.

I've not seen the former problem, but that's just my experience.

About the latter problem: i see no reason AI should NOT fire through vegetation, that has nothing to do with the ability of seeing through.

It may fire through because it has seen you before and tracked your movement. It may fire on your target or do area fire (suppressive fire).

Time ago, when ArmA2 was released, i took my time to check whether AI can really see through bushes. Did many tests and also put result on youtube.

The AI was not able to see through, as long as the hidden unit was not moving.

I agree there are still problems with AI spotting capabilities, it can spot you easily sometimes, but i don't think it's related to the dreaded myth AI-can-see-through-all-things, i think AI supposed "clairvoyancy" it's maybe related to 3 params that have to be tweaked:

1) AI movement perception (AI see moving things way easier than you)

2) AI sound perception (probably AI will hear your footesteps even in a hail of gunfire)

3) AI "hit" behaviour (units being hit/wounded automatically gain too much "knowledge" about shooter)

Just my 3 cents :).

Edited December 1, 2009 by fabrizio_T
orthography :(

[nomdeplume 0]

Some more cents from me... I just did my favourite test, plonking down an enemy at the corner of a hanger, and me on the other side, and then popping out and back in watching the AI's reaction. Making yourself invulnerable aids in this kind of testing...

The results were what I saw ages ago, so the current beta doesn't seem to have messed things up too badly. The initial placement of the guy happened to have his back to me, so I also tested his hearing -- at a sprint he didn't notice me until I was 20 metres away, so it didn't seem excessively acute.

It's also interesting to move out so they see you, then move back behind cover and stop. If you watch them closely, you'll see them slowly turning to keep aim at your supposed position for a while.

I also tried out the effect of a bush on an enemy that had clearly seen me - walked out to the bush only a few metres from the enemy, and he happily blasted me the whole way. Once I was behind the bush he stopped firing, so he definitely couldn't see me. This is actually a proper bush (i.e. one with collision geometry, not ground clutter you can walk through).

Ground clutter didn't help, but I wouldn't expect it to -- it only reduces the chances of an enemy spotting you, but if you're already seen it's not much help.

As others have said, a reproducible test case showing them detecting things they shouldn't be able to detect would be good. Just saying "it happens in missions" isn't all that helpful, since missions are complicated and you can't be certain that there's no AI in the group who does have eyes on, or that the mission maker hasn't scripted some additional awareness.

Nor can you be sure that they didn't just get lucky; if you pop out from behind a hill, you'll usually have a moment before they'll lock on to you and start firing. But sometimes an alert enemy just happens to be looking in that precise direction, and its combat logic causes it to immediately fire rather than think for a bit and then go prone and then ponder the meaning of life and then finally get around to shooting, as often happens.

[jw custom 56]

I don't think it's the same kind of problem.

AI seeing through hills and houses is one thing, AI shooting through grass and vegetation is another.

I'm not talking about the shooting itself, i'm aware that leaves and grass doesn't stop a bullet. What i'm talking about is having no visibility and still pin point targets!

[mr.g-c 6]

The issue is of course still there.... i'm playing always with the latest beta-version.

Here is a Mission and its Progress explained in 2 Screenshots. Please Read the markers like they are numbered, eg 1. then 2., 3. and so on.

To Note:

1. I used a group-marker script to know everytime where all groups were!

2. I made every unit controllable so i could switch during mission if i was suspecting they already know where i am ;)

3. Enemy-Squad 1 and 2 had the waypoint "Guard" at their current position. Squad3 had normal move cammands with "Attack/Engange at will"

Mission Setup and early Progress after i opened fire with a M4 (me playing a Force-Recon guy):

Roughly 15 minutes later...

I just opened fire with my M4 at the Enemy Squad 1 and then immediately run into a small house, closed all doors and layed down on the ground:

Enemy Squad2 could IMPOSSIBLE saw me from their current position at that point ( i back-tested it, only with XRay eye it would be possible for a player). However still they knew exactly where i am!!!! :eek:

As Enemy Squad2 passed the marker "3." i first switched player into one of the Enemy-Squad2 guys and i was getting instantly a red- "attack-marker" pointing DIRECTLY at the house "I" was hiding in :eek:

How was it possible they saw me there? They knew i was in there, laying themselves prone around that little house a few minutes later.... Then after another 10 minutes even Enemy-Squad 3 was coming to the house and observed it......

Edited December 1, 2009 by mr.g-c

[nomdeplume 0]

3. Enemy-Squad 1 and 2 had the waypoint "Guard" at their current position. Squad3 had normal move commands with "Attack/Engange at will"

I'm not sure about enemy squad 3, though it doesn't look like you're all that far from the village where they're located when you start shooting... isn't it reasonable they'd be able to hear you? I need to experiment to see how far they're willing to go to track down enemies when set to engage at will.

Enemy Squad2 could IMPOSSIBLE saw me from their current position at that point ( i back-tested it, only with XRay eye it would be possible for a player). However still they knew exactly where i am!!!! :eek:

Well you gave them a GUARD waypoint, so their behaviour is exactly what is expected: "guarding groups are also ordered to destroy any enemy units which are known to any group of the same side." See notes here.

If you don't know what the GUARD waypoint type actually does, well, you might be for in a bit of a surprise. I certainly was when I first read about it. :)

[mr.g-c 6]

I'm not sure about enemy squad 3, though it doesn't look like you're all that far from the village where they're located when you start shooting... isn't it reasonable they'd be able to hear you? I need to experiment to see how far they're willing to go to track down enemies when set to engage at will.

Well you gave them a GUARD waypoint, so their behaviour is exactly what is expected: "guarding groups are also ordered to destroy any enemy units which are known to any group of the same side." See notes here.

If you don't know what the GUARD waypoint type actually does, well, you might be for in a bit of a surprise. I certainly was when I first read about it. :)

Thats not at all the issue here, lol :rolleyes: Trust me, after 9 years BI-Games i am well aware of what guard waypoint does and what not... i like it quite much how far they go, they react like that since OFP1.

The issue here is, that they could PINPOINT me/my location in that little house, even though Squad2 NEVER saw me getting in there.

Thats the issue.... And the attack spot their commander gave Squad2's Subordinates, was not "somewhere near" my location, no it was EXACTLY pointed at me. :cool::D

EDIT: Even if they share enemy location between groups on same side (this is new to me, when i don't place any guarded-by triggers), none of the groups saw me getting in there.... As i openend fire on Squad1, i actually ran 100m south so i could be even able to have a clear LOS towards them, then after emptying one magazine, i ran back into the house.

EDIT2: But it made me very curious and will remove guard waypoints, will check it with normal move-waypoint in conjunction with "Engange at will" setting, hopefully they'll chase me that far too.

Edited December 2, 2009 by mr.g-c

[suma 8]

Here is a Mission and its Progress explained in 2 Screenshots. Please Read the markers like they are numbered, eg 1. then 2., 3. and so on.

I would like to try to debug the AI in your mission, however I am unable to run screenshots (or even videos for that matter). :)

Can you please attach the mission itself?

Also, it would be very helpfull if you could try to find the smallest mission that can be created to observe the behaviour. Can you still see the problem if you remove X? If you can, remove X. Can you see the problem on Utes instead of Chernarus? If you can, place your repro on Utes.