Quote:Original post by Metahawk
I am writing a dissertation on games AI and am interested in frequent gamers opinions on the current state of game AI.

Very cool! Will I be able to read it when you're done?

I think that most people are in agreement here. Graphics have indeed seen amazing advancement in recent years. A lot of focus is on the graphical aspect of a game, more so than AI. So, yes, AI has been neglected in a lot of games.

I've played alot of RPG games, and the AI in that genre is mostly concerned with NPC interaction. I recall specifically two games which I played, the one being Morrowind, the other being Gothic 2. Morrowind had stunning graphics, and was enjoyable to play... for a little while. Gothic 2, at first, was disappointing when comparing the visuals with Morrowind. However, at length, Gothic 2 was much more enjoyable, (this is likely a matter of taste, though), and really served to will the suspension of disbelief. This was all because of the NPCs interacted in a much more believable way.
Let me give you a simple example: In Gothic 2, while walking around in the city, you would notice people mingling in groups, actually having conversations with each other. In morrowind, there is absolutely no interaction between NPCs, whatsoever. The environment in Gothic 2 is much more believable.

Does anyone else have any good examples?

Quote:Original post by Zodiak
Well, I just think that when one DOES create an awsome AI, the gaming industry will get that boost like with physics. What I mean, is if you haven't heard of a certain game, and then it comes out with average graphics etc. but with some awsome AI system, it will immediately be noticed... It's just a matter of making an excellent AI system, that's all. Because above all, people tend to admire AI the most when it's there. So the game will be a huge success, with millions of people going like 'Oh, Joe, check it out... Yesterday that <beep> had actually outsmarted me... it's so fun! I created a line of defence in the north, but that <beep> anticipated it and attacked me from the rear..." something like that.

Well, this is debatable. I get the shit kicked out of me if I play against anything other than an 'easy' computer opponent in Warcraft 3. Does that mean the game has good AI? I think RTS games generally are not the games which are in need of improvement in their AI.

Quote:
(unless we are talking about multiplayer).

That's a very good point. I can't imagine that a lot of MMORPGs, for instance, would require the same kind of AI as would a single player game. I suppose the other players make up for it, and give you all the 'intelligence' you need.

"Well, I just think that when one DOES create an awsome AI, the gaming industry will get that boost like with physics "

I definitly agree with you, in my opinion A.I. is, better ,should be more important than phisics.
The point is,it it just a matter a good will ?

"I created a line of defence in the north, but that <beep> anticipated it and attacked me from the rear..." something like that."

Cool, but is possible to do something like that?
If you can not distinguish a real opponent from a virtual one you have passed the Turing test.
Do not forget that no machines passed the Turing test, yet

Quote:They don't change the AI, they just make it harder for you to fight your enemies.

This is frequently intentional. Game companies have a limited amount of time to create behaviors/assets/sounds for games. Any time you design content only a subset of the audience will see, a strong argument can be made that you are wasting time that could better be spent on content everyone will see.

Quote:The ultimate goal is to make a challenging AI, such AI that a player won't 'know' that he is playing with AI rather than real-human

Minor detail, but those are really two very different goals. A challenging AI is much different than a human-like AI.

Quote:while I know that the enemy WILL NEVER in *that* window... Something like that, you know...

This is a great example of a game design decision/game tech limitation than an AI limitation though. There are a lot of very valid issues people here have with gameplay; I think many come down to game design more than AI tech limitations.

Guys, yes, graphics have made massive advances, but so has AI. Graphic advances are simply easier to see. Does anyone remember when Quake2 AI was marketed as advanced because the AI was capable of ducking? Constrast that with Halo 2 for instance. There is a massive AI tech improvement there. The fact that graphics improvements are easier to see is a strong argument for continued work in that area.

Many game companies have just as many AI programmers as graphics programmers (1 or 2 people working for 1 to 4 years). It isn't a lack of focus, its a lack of low hanging fruit. AI improvements take a lot of time, are higher risk, and are typically higher risk to game design.

I also don't believe it is a lack of peoples knowledge about AI technologies. Technologies are just tools. In first person games for instance, the bigger issue is how the AI interacts with 'external' systems such as animation, sound, etc. We can't do completely procedural content generation, so we are restricted to use of assets built by artists, animators, sound designers, and level designers. These define the boundaries of what the AI is capable of, which rapidly becomes a buisness issue.

Take a look at: http://stuffo.howstuffworks.com/halo2-ai.htm This is a pretty article about where game AI is at right now, particularly how it relates to buisness decisions and game design.

My opinion, as an experienced gfx/physics progammer and as a less-experienced AI programmer, is that AI is more hard to program. It really requires your "own thought" based on the exact game you're programming - there are no "cookbook recipes" as there are for gfx/physics things.

Therefore, it might be that it's easier for developers to concentrate on graphics. Want outstanding, state-of-the art graphics? Just buy the GPU gems book and start implementing the recipes! Want believable, intelligent and creative AI behavior? "It's up to you."

-- Mikko

P.S. Yes, I know certain algorithms such as ANNs, GAs and such, are fairly established, but in the end they are just tools - applying them to your exact problem requires more thought.

I'm not sure if AI is being neglected because of graphics, but I feel that a lot of work could be put into AI to make games better. Here are my observations and ideas:

I agree with Steadtler that graphics sells the game, but the AI is what makes it great. Game boxes has pictures of the graphics on the back, and in features it's listed "Advanced AI". What do people see? IMO the pictures. It's when they play the game they see how the AI is. If a game has good graphics (sub-HL2/Doom3), but a very realistic and life-like AI that retreats and calls for backup and such if faced with overwhelming odds, then I would like that better than a game with photorealistic graphics, but enemies that just swarms me.

I also agree with James Trotter, in that the non-enemy NPCs in Gothic 2 looks more realistic than those in Morrowind. I'm not saying the AI is better, as I can't remember them walking around and actually doing stuff, but they stand and talk with each other which makes them more life like than those in Morrowind who just stand in a spot or patrols an area all day long.

A FPS where the enemy's AI analyses a "render" of what he sees and identifies the player (or his team-mates) visually would be great. AFAIK in most games just let's the AI know where the player is even if he's perfectly camoflagued and standing still and otherwise made no action to reveal his position. Their advantage can be compared to the enemies being rendered with a pure red color and a pointing arrow on the player's screen. Some games, most notably the Thief games, Splinter Cell games and some of the Delta Force games is taking cover and concealment into concideration, but more often than not it's too black and white. If the player stands still in the shadow in front of a white, lit wall the enemies still won't see him, even though he should have a very distinct silhouette. I doubt making "AI-sight" would be easy, but it's certainly something that would add realism. Even in a simplified form that takes into account camoflague, silhouette, light, movement and other things like that would be better than what is in most games. Sound is also a thing the enemy should be aware of, but not necesserily be enough to pin-point the player's position (it might at higher difficulties).

Enemy cooperation and needs:
In all genres the enemy should be able to retreat and look for cover or assistance if he feels threathened. I don't think it would be hard to implement (at least calling for help), and would add realism to games where they today mostly just runs heedlessly towards the player, guns blazing. Again, there are games that are better than others, but in most cases the only need the enemy has is to kill the player. If he at the same time tried to stay alive then there wouldn't have to be an overwhelming and sometimes respawning number of enemies to make the game challenging. Team tactics with cover fire and advancing to cover would make it more challenging to hold a position. Most games make this act a shooting gallery where the only thing the player needs to to is to avoid running out of ammo. Adding realism could be as easy as placing the enemy behind corners and having them pop out and fire a burst once in a while. Then the player needs to aquire the targets and shoot, and at the same time avoid being shot from one of the other corners. Keeping the crosshairs in a single spot and hope to catch the enemy as he pops out is simple, while doing the same when the enemy has the player pinned from multiple spots is foolhardy.
Speaking of ammo, it seems that enemies in FPS games has an infinite amount of it. They hardly ever fire bursts or single shot, even though in real life that would increase accuracy and lower ammo consumption. Most games penealies the player by increasing spread if he keeps the trigger depressed, but I'm not sure if it's the same with the AI enemies. IMO it should, and the AI should compensate by making every shot count (of course there are times for full auto as well). If the AI has to find more ammo if he runs out would also increase realism. This would be easy enough by setting waypoint and a path to the armory or a stockpile (which doesn't have to be accessible to the player if it should be hard for the player to find ammo).

AI in RPGs:
For the most part cities in RPGs tend to be populated by a lot of people just standing around having nothing to do. In Gothic they stand around talking all the time, but they don't stop talking after a while and go to do some work or running errands. In Morrowind they stand around and waits for someone to walk up to them and talk, or in the case of guards patrol an area. They don't ever walk up to another NPC and talk to them, or walk from a building to another. Most other RPGs are like this as well. Giving the people a list of places to go, and letting them stop and talk about rumors to people they meet wouldn't be very hard to do, and would add a lot of realism. It doesn't have to be extensive, just enough to give impression that they are real people. Farmers would get up at sunrise and go milk the cows, eat breakfast, tend the fields, eat dinner, go to bed, etc. People in cities would get up, go to their store and open it up, go to the market, go and eat, go home and go to bed etc. Guards could get out of bed, have an inspection, guard change (perhaps exchange some words), tend their equipment, go to a tavern, go to bed etc. Townspeople could wander around to various stores and chat with the store-keeper and perhaps buy stuff, to the market etc.
In most cases it could be a simple list of what to do at what time. They could have a list of people they know, and rumors they know about, and stop for a chat if they meet. In most cases the player wouldn't notice it if everything is the same each day, but if they do nothing at all each day, then it would be noticable.
For even more realism, the shopkeepers could walk around in their store and arrange their goods and other things like that until the player walks up to the counter. Of course this depends on the type of store. Pharmacists or Alchemists could be working in their labs, armorers and smiths could work in their smithy, scholars and mages could read books etc.
At night the thieves could go out of the thief guild and sneak around in the town. At day pickpockets could be roaming the streets and target passers by. If the player notices them and follows them to the thieves guild it would be a lot more realistic than if he just asks a person on the street where the hidden guild is located.

Monsters in RPGs tend to be incridibly stupid. They mindlessly attack the player who walk in on them and never try to flee if they're wounded. In some cases it's ok, but in some cases it would be more realistic if they decide to run if they're out of their league, and just fight if escape isn't an option. Even if they're initially aggressive, they might want to flee if the player is more powerful. I'm sure you agree that fighting a pesky Lvl 1 rat worth 10 XP isn't interesting if you're level 20 and need 10000XP to reach next level. Undead creatures and mindless or extremely hostile enemies would fight to the death.

AI in RTS:
I'm not into RTS, but a friend of mine mentioned the Close Combat series in regards to AI. In his opinion the AI in CC1: A bridge too far is about as great as it gets, but in the newer games of the series the AI has been lacking. Even so far as that if he destroys a column in an ambush on an open field, the enemy keep sending more units in the same way just to be destroyed as well (more or less swarming). In the first game they learned where ambushes was placed so that a single tactic couldn't be used all the time. In real life this would be done by using radio, or in lower tech scenarios, with observers following the column that returned to warn the rest of the force.
Also, in the first game (not sure about the others), the player controlled units had a morale meter that controlled how they reacted to the player's orders. If their morale was very poor they would refuse to enter dangerous areas or even try to desert. In complete panicked frenzy they could do weird things like running towards a machine gun nest to destroy it or other such things. One of his soldiers once destroyed 3 nests inside some buildings without the player's command because he panicked and acted on "instinct". CC1 is a pretty "old" game and it's graphics can't measure up the the graphics of modern RTS games, but because he feels the AI was so spectacular he considers it one of the best strategy game he's ever played. A great example of Steadtler's comment.

Lol...when I saw the thread I had to say something....

The way I see it is that AI is still truly an after-thought in the industry. Why do I say that? Well, for starters, most of the games out there that have some sort of "AI" is based on just a fixed heuristic algorithm. That's probably like the stuff you see in the first 3 or 4 chapters when you take a college AI course. A* pathfinding has been around for like...forever and its still being used to death, and sometimes not because its useful or good or required, just because everyone else seems to use it and implementations can be easily found. Some "smarter" games, from what I hear, do user modelling, but that still takes time and still quite prone to exploits, etc. In general, most AI in games out there are nothing more than plug-ins. They are just plug-in methods, classes, or even scripts that are on the outer ring of an engine.

For true AI, AI must not be just a plug-in, it must be a pivotal and fundamental piece in the engine design. Then you move beyond plug-in and heuristic based AI and can move into agent-based AI. From there, you can acquire and build emergent behavior. Let's say for example the power of building some sort of memory into a monster entity on the engine level. Then you can write a simple set of behavior based on this "memory" that it poses. It can then manipulate and alter behavior based on experience. In short "Evolutionary Programming" or "Genetic Programming" where each monster/NPC, over time, evolves its own behavior defining finite state machine. That would create some interesting results. Imagine an RPG where you don't randomly encounter monsters and when you do, they will try to run away when they feel they are about to lose. Then later on, they'll come back at you again and try to take you on with a different strategy. Or even specifically ambush you when he knows that your party's hp and mp are lower and more vulnerable. Then we will have a different game altogether where you have a fixed number of monsters and xp is earned truly through "experience" fighting them.

The point is, AI must move from the outter ring of game development down towards the inner ring.

One of my ideas is to set up an NPC server. Kind of like a boot camp server for all NPCs in RTS games. Every so often, they come back to the server and their deaths and kills are tallied and they either get killed permanently or have their strategies combined with other well performing NPC, then sent off into your games agains. In that scenario, even your boring single player game can constantly evolve and change as the NPCs start learning new strategies and behaviors that they've learned from you, other players, or just other NPCs.