A hooray for the AI

[h - 169]

This is not true. ArmA2's AI squads are using an actual "buddy system" during combat movement. One unit moves, while his buddy provides cover. It's quite a big step up from OFP, where Engage orders would indeed be executed by single units. And as shown on the previous page, they also take kill zones into consideration a whole lot more. Have a good look at a squad's movement patterns when they make contact. A good giveaway is the "Go, I'll cover!" messages you're probably quite familiar with :p

Have you guys ever considered writing some sort of article in the Biki about how the AI works?

I don't mean posting actual code or anything but providing an in-depth article about what goes into the AI's workings; what it actually does, why it does it, how and what it "sees" and so on.

It would be much easier to command the AI, design missions with effective AI use, and even spot bugs or whatnot if one knows the logic the AI works with.

[Cyteless 10]

I don't know if you guys have noticed this, but what I've been doing when given orders by fellow AI is to actually respond.

eg.

Squad Leader calls out: "Go, I'll cover."

I would then "respond" by saying: "Copy."

When I reach a particular location, and I don't want to go any further, I would say:

"Ready."

The next man would then move.

I'm not sure if this actually works, or if it's pure coincidence, but the AI seem to react more when I respond using the Space Bar.

[Guest]

I love the AI very much, they make the entire game as we know it. Online co-op, single player, mission editor, the AI are superb.

@CMB Unit 01, that is a very interesting find, but it seems very logical! I will have to give it a test!

Edited March 30, 2010 by Guest

[Bulldogs 10]

Hmm.. I don't see why that wouldn't work. Theoretically (and I say this as I have no idea of the actual AI coding), the AI could respond to the "go, I'm covering" by moving then the other unit could react to the "Ready" as the variable that tells them the operation is complete and to continue the next operation... gotta test myself now.

[no use for a name 0]

When the AI is working as it should it can definitely be a formidable opponent; but sometimes there's a "glitch in the matrix" or something because I've also seen them act flat out dumb.

Even if BIS kept it like it is, but made them more consistent then I'd call that a big +

I think in most cases it's probably a faulty trigger and somehow their algorithms get 'stuck' and they turn dumb...but that's a total guess as I have very little idea how AI works.

Edited March 31, 2010 by No Use For A Name

[CarlGustaffa 4]

I love the AI too, despite its problems. Biggest gripes for me are these:

* When I'm commanding, it's extremely hard to actually get out of a problem. There are no commands to break contact, or setup something that gets us out of there efficiently.

* AI walking into water (probably to stay in formation and perform a movement order, remember ponds doesn't show up well on the map), which results in them dropping their equipment.

* AIs disability to navigate bridges.

* AIs blindness to editor placed objects. An AI controlled HMMWV would try to ram a road block object than find an alternative route. At least in the setup I tried a while back.

* Convoy behavior after contact is made. Oh my oh my what a mess...

But I have to agree. I don't think I have seen anything better as long as path noding isn't used, and in many cases they behave better than what I've seen by (unorganized) humans.

[^Th0mas^ 10]

Hope they will fix this in 1.06. Hope they dont release a broken expension pack.

[Alex72 1]

Fix what? All of the above written by CG?

Im glad if BIS reverts back to the user activated danger mode. That will give us the power back. If you think all of the above will be fixed and that OA wont have a single bug your dreaming. That doesnt bother my personally however as i dont see the oh so many bugs some of you see. They are there if you look (like most games) but they are avoided through mission design. I feel good just knowing BIS checks DH A2CIT and i feel good knowing problems have been fixed thanks to it.

And yes i agree with OP. Havent seen this level of AI in other games. Despite the quirks. If one uses his mind logically its pretty clear AI in this massive world cant be flawless at the degree we want them to be (human like decisions). That is further into the future.

ARMA ownz. :D

[SteveJA 12]

I couldnt agree more with Alex72

I cant think of any other games that make me have to think so hard to guess the AI's next move, and 50% of the time being wrong and end up geting mowed down by fire on our flank.

For just one example try shooting at an AI group and then sit and wait behind a building. The ai will (sometimes takes a while because the Ai goes so damn far away) flank to your left, right or both, while some hold their position and cover the area you were just at, and or move forward slowly. Ive had Fun just trying to kill 2 groups of AI in a town and it took me over an hour. Sure sometimes the AI made mistakes like deciding that the main road is safe to walk down but half the time there's a chap behind sitting there as if using him as bait lol

[NeMeSiS 11]

Im glad if BIS reverts back to the user activated danger mode.

Combat mode was already automatically actived when combat started since OFP. It was never fully player controlled AFAIK.

BI just changed it being actived by prone/crouch or not a while back. The AI not wanting to retreat from combat has always been a problem, but for some reason it just got worse in the last patch, though i doubt its related to whatever that line said in the changelog.

[galzohar 31]

Them not wanting to retreat is the smaller issue, the bigger issue being that they don't really want to move *anywhere*.

[maturin 12]

Combat mode was already automatically actived when combat started since OFP. It was never fully player controlled AFAIK.

BI just changed it being actived by prone/crouch or not a while back. The AI not wanting to retreat from combat has always been a problem, but for some reason it just got worse in the last patch, though i doubt its related to whatever that line said in the changelog.

Until the beta patches and 1.05, AI would stay in tight formation while under fire. If you didn't put them in Danger mode manually, they would line up like baby ducklings and get shot to pieces.

There is a massive difference inbetween the two patches. You no longer have any control at all. It can take a rifleman up to a minute to board a humvee because there is an enemy tank on the other side of a ridge 1000m away.

[Heatseeker 0]

This is not true. ArmA2's AI squads are using an actual "buddy system" during combat movement. One unit moves, while his buddy provides cover. It's quite a big step up from OFP, where Engage orders would indeed be executed by single units. And as shown on the previous page, they also take kill zones into consideration a whole lot more. Have a good look at a squad's movement patterns when they make contact. A good giveaway is the "Go, I'll cover!" messages you're probably quite familiar with :p

Indeed but they still end up running all over the place.. instead of sending 2 guys after the enemy why not send 4?

There is an old feature from OFP days that allows us to assign teams within a group (team white, blue, red..), it could be developed into something usefull ;) .

[Binkowski 25]

you know, amidst all of the "hatred for bis ai" going on around here, i have to thank myke for making this thread. it is true, i mean. how massive chernarus and most of the landscapes are i give them some credit for whats going on (not saying its perfect) but imagine throwing COD's ai on here, lulwhut.

[THEBLITZ6794 10]

Hi all

The AI in ArmA still regularly hands our asses to us at Zeus; to add to the near Mythical Forest of Death in the old OFP mission on Nogova, we now have a new bet noire, the Wall of Death where whole squads have disappeared into the meat grinder.

ArmA AI kicks ass.

Kind Regards walker

wuts the forest of death in nogova?

[lecholas 2]

In my opinion the two following sentences are true:

Although the Arma2's AI often don't seem too smart it is in fact based on a piece of very sophisticated programming.

Although the Arma2's AI is in fact based on a piece of very sophsticated programming it ofthen don't seem too smart.

I suppose that the AI is sophisticated. But there is a big difference in what the AI does and what it shows it does. Maybe it considers the dead zones of fire, maybe it takes complicated tactical decisions but it doesn't show that much to a player. All the player sees is that it runs here and there without knowing why it does so and if some actions the AI takes are totally random or 'intended'. This could be improved (and in Arma2 in fact is a bit improved when compared to Ofp of Arma) by factors like communication (look at e.g. DSAI addon) or animations (gestures, more than one animations for one action, facial expressions, animations for human-like actions as panic, or taking cover) - visual or audial ways of comunication with the player. There is a big room for improvements in the areas.

And another thing is one of the biggest (IMHO) mistakes in the design which is the lack of ability to use cover by the AI. By the ability to use cover I mean the basic actions: hidding from the fire and popping out from the cover to fire. I know that it is not that easy to make AI use cover. I (and many other much more skilled script makers) did a lot of scripting tests since OFP. But the fact is that without it we will never have a simulation of the real combat. It is one of the most basic infantry combat actions.

Look at this, the most of real life battles are not win-or-perish situations. In BIS games (not to say that it is only in BIS games, but BIS games are supposed to be more simulators than the other arcadish games) almost every battle ends in the totall anihilation of one of the sides. And no, it is almost imposible to change it by the mission design (if you don't agree, please show me a mission with the realistic design and realistic outcome; I would be the most grateful). And the using of cover function is a base for other more complex combat tactics or behaviours. How a suppressing fire can be used if the AI can't take cover? How a defense or ambush scenarios can be done properly? Also, the main goal of flanking maneuvers is out when the enemy is not using cover. How a panic or a fear-for-your-life effect can be moddeled? As consequence, the Arma2's AI is a greate ilustration of the rule: "A maneuver without a fire is fatal."

That said, I'm still a big fan of BIS games but that doesn't mean that I can't disagree with the program for development of newer games. I suppose that at this stage of the engine it can be very hard if not impossible to modify the very basic routines of the AI, and I don't know how closely is the AI connected to the other modules of the engine.

I, of course, don't have an insight in how the AI is done but I can see the effects. And the effects are what the players see, and by what they usually judge the game.

[node_runner 0]

Just a couple of random thoughts as a result of reading this thread:

-Without having a good view of why an AI is behaving a certain way, it is difficult to judge whether the AI is being stupid or smart. If there is some bit of information which is known to the AI, but is not known to you as a human observer, then sometimes AI behavior can appear to be dumb when in fact there is good reason for the behavior. For example, watching a BLUFOR squad retreat from a firefight that they are clearly winning may seem dumb if you don't know that the squad is running very low on ammo. A good exercise is to imagine yourself as an alien observing human behavior on Earth from your spaceship, without knowing anything about human society.

-The only valid way to judge the quality of AI is by how well it achieves the goals that the developer intends to achieve, not by how effective it is at defeating you.

-Here is a cool site to learn about gaming AI and some of the techniques and challenges: http://www.aiwisdom.com/

-While I agree that ArmA2 is a much more ambitious game as far as AI requirements go than most other games, I wouldn't put it in my top 5 list of most impressive AI. Consider the following games as a comparison of ambitious AI that pull off their intended goals with impressive execution: Elder Scrolls 4: Oblivion, FEAR, The Sims 2/3, Fallout 3, Thief: The Dark Project, Left 4 Dead, GTA IV. They aren't apples to apples comparisons, but when I think of AI that made me feel like I was in a living world, I think these are better examples.

-I think the AI in ArmA2 would greatly benefit from two additional AI "systems". I've been thinking about trying to do this myself in a mod, but I don't know how feasible it is or whether or not I'd be up to the task. The two features would be:

1) Overall Strategic Planning w/ Strategic Waypoints

The AI does not navigate the terrain with any military strategy. If you set a waypoint down, they simply route to that point in a straight line, working around obstacles as they are encountered with basic pathfinding routines. It would be ideal to use the mission editor and define higher level objectives, but allow the AI to plan on its own how to go about navigating the terrain to complete that objective. For example, giving an AI squad a "Seek & Destroy" objective instead of a waypoint, the AI would plan a more strategic route across the terrain towards that objective and plan that route keeping things like the following in mind:

-Avoid skyline routes

-Scout unknown terrain *before* crossing it

-Determine a good attack vector for the objective, keeping in mind cover, concealment, height advantage, and range.

-Scout the target area in stealth mode and designate important targets before engaging.

-Modify formations and behavior modes (danger, safe, stealth, etc.) dynamically as appropriate.

2) When commanding your AI, it would be nice to specify the "firmness" of your commands. Just having a "firm" or "soft" version of most commands would be best. Firm, meaning "follow my orders literally and do not deviate as you see fit", soft meaning "follow my orders as a guide, but modify as you think you need to". I would imagine just using a modifier like the SHIFT key to each command in the command menu. By default, each command would be "soft", but if I held the SHIFT key while giving the command, it would be "firm".

So, for an example situation, sometimes when I tell an AI to engage a target, I want to specify one of two different styles:

Soft: Engage the target as you see fit, breaking formation if need be, navigating to different terrain as you see fit, and planning on how to take down the target on your own. If the enemy moves behind cover, figure out a way to flank him.

Firm: Start shooting at the target but don't break formation or move around on your own. If the enemy finds cover, stay put.

[maturin 12]

Okay, but Oblivion's AI was terrible. It could pick up weapons and follow scripted instructions (walk in a slow circle here at 4:00 until 7:00) but not much else.

Soft: Engage the target as you see fit, breaking formation if need be, navigating to different terrain as you see fit, and planning on how to take down the target on your own. If the enemy moves behind cover, figure out a way to flank him.

Firm: Start shooting at the target but don't break formation or move around on your own. If the enemy finds cover, stay put.

The AI has that capability via Engage At Will, Disengage, etc, it's just not implemented so it noticeably works. And other things interfere with it. Really, 90% of developing Arma style AI seems to be beta testing. It's too complex to predict.

As for not sky-lining yourself and other advanced spacial observations, that is probably a generation off unless you tag every square meter of terrain. Cover Here, Defilade Here, Crossfire Here, which makes modding near impossible. There's a reason CoD maps are fifty feet across and socked in by fog.

[node_runner 0]

Okay, but Oblivion's AI was terrible. It could pick up weapons and follow scripted instructions (walk in a slow circle here at 4:00 until 7:00) but not much else.

The AI has that capability via Engage At Will, Disengage, etc, it's just not implemented so it noticeably works. And other things interfere with it. Really, 90% of developing Arma style AI seems to be beta testing. It's too complex to predict.

As for not sky-lining yourself and other advanced spacial observations, that is probably a generation off unless you tag every square meter of terrain. Cover Here, Defilade Here, Crossfire Here, which makes modding near impossible. There's a reason CoD maps are fifty feet across and socked in by fog.

RE Oblivion: I'm sure others will agree with you, but everybody tends to have different variations of what constitutes "AI" in a game. This is why I was careful to clarify the standard by which I was judging the AI, which was in terms of how well it accomplishes design goals, not based on how many tricks it can do. I would consider the design goals of Oblivion characters as ambitious and well executed for various reasons. They were capable of a lot more than just the things you list. But, whatever. I don't want to argue about it because I just don't think that would be very productive.

RE Strategic route planning: There is a MUCH more efficient and easier way to accomplish things than that. I've sketched up some pseudo-code of how it would work, I just haven't looked through all of the A2 API to see if all the functions I would need are there. But it would essentially be a two-stage process that could probably be implemented as an FSM.

Stage one would be to break up the terrain into squares, then use very simple rules to eliminate terrain that would be undesirable to cross through. This would be fairly easy and light on the CPU.

The second stage would simply have to pick the most efficient path that crosses through the terrain that IS desirable to cross through. The AI would then re-evaluate the "plan" along the route if certain conditions are met, such as detecting enemies that were previously unknown and things like that.

[CameronMcDonald 146]

* When I'm commanding, it's extremely hard to actually get out of a problem. There are no commands to break contact, or setup something that gets us out of there efficiently.

Try this - it's saved my squad's bacon a few times (and worked quite well), most recently in W0lle's port of Operation Lojack.

Set units to aware, formation file. Get running in the direction you want to retreat. The close formation puts the virtual boot up the AI's backside to get moving.

I used this to disengage beautifully many times in the past. The AI will even stop, fire off a few rounds at close enemies, and then continue tabbing.

[Alex72 1]

Combat mode was already automatically actived when combat started since OFP. It was never fully player controlled AFAIK.

Your right ofcourse. However you could tell them to go AWARE and then get the **** outta there - wich they did. It was 500% (or some like that) easier to control the AI in battle.

[ScorpionGuard 10]

Going back to the question of the calculation of the AI and the CPU processing of it.

1) Exactly what is the drain on the CPU per AI?

2) And due to the 6 core series of CPU coming on to the market. Will the improvement of the technology give the AI the ability to calculated at a higher rate if any?

3) Will BI ever have ArmA series access the technology of the RAM beyond the 1.5? I have a motherboard that accept RAM up to 24 GB RAM.

Edited April 3, 2010 by ScorpionGuard

[galzohar 31]

Not with the current way it is made. AI currently cannot use more than 1 core, but it can use an entire core for itself. Once you have 3 or more cores (2 or more for dedicated server which doesn't need graphics), the only thing that will help performance is faster clock speed.

The exact drain depends on a lot of things. Not just the number of AI, but also how "active" they are and what environment they are in (some environments make each AI unit require a lot more calculations, probably for path finding).

Hopefully Operation Arrowhead will improve things, but I wouldn't hold my horses.....

[Alex72 1]

With my AMD X2 6000+ i even experienced severe lag when 4 BMD's plus an A-10 started battling. That was on Thirsk among a lot of trees, water, rocks and tons of other debris. Usually it doesnt go that bad so i guess its true in what environment they are in matters. High time throwing that CPU out the window.

However a bit OT.

[ScorpionGuard 10]

Chould you mod the engine to boost the core count? Are would that be a copy right issue? Are does the engine has to be change or rebuilded all togather?