AI 101

AI(Artificial Intelligence)... The final frontier... In gaming at least. I mean Graphics can't get that much better. We have near Pixar quality graphics in games. Movement(Waggle) games. Stories that rival books, comics or movies. Games that could take you some serious amounts of time to see everything like World of Warcraft. Even games we can build ourselves with valve modding systems or even simpler games like LBP. Downloadable games straight from the internet and even games on phones and facebook. Serious characters that intrigue us and bring us in. It has become more than an arcade hobby. More then just a fighting game or a racing sim. It is ingrained in us as gamers to want the best and feel we deserve the best. So what do we still need to make these games "Real"?

My blog/soapbox here goes out to AI. I feel like it is the final step in gaming. What prompted me to write this blog? Well really I was watching gameplay for the new Mafia 2 game coming out here soon and was watching very intently and the story looks good(Not godfather but good) the characters were good, Graphics were good, Cars unique, World intense and everything fit... Except the AI... What do I mean by that? Well I got to thinking. There was an enemy who was standing behind boxes and crates and you could always see a knee or hand or top of a head stinking out and I thought "I know some people are stupid enough to do that but really?" I mean if I was getting shot at (And I have in my army service) I wouldn't be sticking my hand around a corner for you to shoot. If my hand did get shot I wouldn't stumble out so you could shoot me elsewhere... It was every enemy too. This kind of disappointed me.

This got me thinking of all the times I have seen people hype the AI in games like Halo 3 or Killzone 2 or Left 4 Dead or otherwise. I did some research and learned about different ways programmers use AI (Wikipedia is useful sometimes). Then I started thinking about AI itself and the idea of it. Deep blue was an IBM Program I heard about a long time ago. A computer specifically designed by engineers and chess grandmasters. The computer can supposedly see hundreds of moves ahead and was accused of cheating... This was a big step into what we now know as AI. If you think about it a human could never really win agains't AI. Especially if the AI knows whats next. Think about Tetris. You can see 2 blocks ahead and plan that much but in a 'Cheating" AI, which happens often, The game might now the next 20,000 blocks and plan accordingly. You could never win especially because their reflexes are better then yours due to speed. How does it all get managed and made into something playable. Even if it doesn't chest it still has the same opportunities as you but is faster by nature. You have to see it, Translate the movement from brain to hand, move with your hand, adjust properly and hit the button then wait for it to register and all that. The computer can skip most of this process... So how do we balance it. Give the computer a "Humanish" brain so it has to take that time to register? Do we use a cheating AI that knows where you are to make it harder?

Back to the more modern games. Looking at Killzone 2 as an example. I really do feel on harder difficulties the enemy works as a team better. Flanking and moving like I would and you, as the player, die a lot as a result and need to adapt. Especially once you up the difficulty and it's not because they have perfect aim or know where you are. It's because they seem to act smartly. I honestly didn't much care for the game but I do appreciate what I saw in the AI department. Where as (I know I will get flamed) I felt halo 3's AI was a big let down. I just felt like the enemies aim got more accurate as opposed to using some kind of tactics or otherwise. It felt like they knew where you were the harder you upped the settings and that was it. They had faster trigger fingers and more head shots as opposed to working as a unit.

I remember when I first played Hitman on my PC. The enemy AI seemed top notch as it adapted to your every action. Similar to how AI works in Batman AA. There seems to be a very very large graph that represents your choices 1-XXX and depending on your choice enemies will react in a certain way. This gives a lot of opportunities for variance and strategy and learning. I really like this way of doing AI. It's not incredibly smart or OP. It's reactive and you can learn and have a pretty good idea how the AI will act but it wont be the same every time. Every choice opens up many more and this creates a very creative way of playing.

What games do you think have good AI? What makes good AI? I have been hearing a lot about AI and I really do think it's one of the hardest things to do right. I hear a lot of people here talking about "ZOMG TEH AI IS SOOOO GOOD" But really it looks like they have no clue what they are talking about. I think good AI is what a normal human would do or a trained soldier or whatever your teamed agains't. Does Street Fighter learn your patterns? Does slippy ever learn to fly worth a damn? Will more dynamic story telling and actions be learned by the AI in the future? How has AI improved over the years and influenced the way you game? What games would not benifit from better AI and which would? I have many questions but want your opinions on what you think makes AI good or bad. I may be totally off with my assessment and would love to hear your opinion on it. Please don't take it as me flaming I'm just talking from my point of view and this is not about console wars its seriously about what you think and hope for.

[thor]

AI is about giving the impression that your opponents are real. Not real as in other players controlling the enemy, but real people/aliens. I think a lot of people get confused between AI and difficulty. Having good AI doesn't mean your game is difficult, because the player might have a lot of health.

Things like having mocapped animations, voice acting and scripted or semi-scripted events (such as rolling out of the way when you throw a grenade) will add to the impression of good AI without actually adding any "intelligence" to the enemies.

Another thing I have noticed in games with "good AI" such as Uncharted and Killzone 2 is that the enemies will pop their head up for a very short amount of time, then pop up again in a slightly different place. Again, no intelligence really, just scripted behaviour, but it gives the impression of intelligence.

Then there's the slightly more intelligent parts such as being able to find cover. But once you have that in place, it's simple to say "push forward" - more clever scripting like throwing grenades and then pushing forward, or firing a volley of shots and falling back can give the impression of intelligence.

One thing that really annoys me with AI and game scripting is when the AI knows where you are even though they haven't seen you, or some kind of event is triggered (like the enemies stop spawning) when you pass a certain invisible line. The latter means that many games are a lot easier if you first run to the end, avoiding enemy fire, then run back to a safe postion and take out the enemies who will now not respawn.

[Jinxstar]

I hear you on that. I do feel like uncharted had some decent AI. The enemies weren't on set paths and they would try to flush you out with grenades and such but I understand what you mean. Thanks for reading though.