IA on AI

Posts Tagged ‘Far Cry’

Far Cry 2 – a little deeper look

Monday, March 24th, 2008

Back in January, I posted a snippet of a review regarding Ubisoft’s claim that the AI in Far Cry 2 was going to be seriously cutting edge. Well, apparently, Far Cry 2 was apparently a hit at the recent Play.com LIVE event at Wembley Stadium. According to this review at 411mania.com the AI was at impressive. Of course, many things can be made to be impressive in a tightly controlled demo, but I would like to at least give them the benefit of the doubt. Here’s some comments from the review:

Different factions and gangs are spread across the 50 square km environment, and it’s up to you who you befriend and who you turn into mortal enemies. Walking around the wasteland area, the guards patrolling the area didn’t seem very phased by the player’s presence, carrying on with their everyday duties, and it was at this point that the specifics of the AI became obvious. It’s evidently a very sophisticated system, as we were assured that the AI is totally non-scripted. Redding joked that the enemy AI is like “The Sims with guns,” and it was clear where he was coming from. In the small preview we were shown, guards stopped to chat amongst themselves, went off for smoke breaks, and generally busied themselves about the area. They didn’t look too happy when the player tried to steal one of their cars though! One guard in plain sight of the truck shouted out, and his comrades came running, forcing the player to hightail it out of there. Interestingly, the vehicles in the game have a detailed damage system, and you’ll have to physically get out and repair them if they take too many hits. In the demo we saw, the player tried to hijack an abandoned vehicle, which was plainly kaput, so the player had to open the bonnet and use a wrench to fix various parts. We couldn’t see LJ physically controlling this part, so I don’t know exactly how interactive this portion will be, but it’s a novel idea.

Just observing a few things here. It sounds like they are using a similar sort of A-life approach that may have been used in the game S.T.A.L.K.E.R. Although much maligned for some poor behavior, Crysis also had a lot of the very engaging “idle behaviors” that are mentioned here. They mentioned The Sims in there and I’m sure that’s a nod to the “smart objects” model that was pioneered to such great effect by that franchise.

The idea of multiple factions also lends a lot of potential depth to the character behaviors. It will be interesting to see how this is handled. One question that I would have is how the alliance system is implemented. That is, if you make an enemy of one person in a faction, do they now ALL hate you immediately? If you quietly kill one guy, do they all know or can you continue to deal with them all happy-smiley-like?

Going back to the matter of the AI, the intense gunfight around the straw huts revealed some interesting snippets about how enemies react to being shot. Location-specific damage is nothing new, but Far Cry 2 takes it one step further, as the goals and objectives of enemy AI may change according to where they’ve been hit. Shoot them in the foot, and sure, they’ll hop around in pain, but they’ll still be in good enough condition to keep plugging you with hot lead. But we were shown a scenario whereby an enemy had taken a bullet in the upper thigh/groin region and was obviously in a bad condition. His primary objective therefore changed to finding safety, and he could be seen limping off to hide in a building. Naturally, the player finished him off for good measure, but it’s refreshing to see enemies that don’t act like mere moving targets, rooted to the spot until either you die or they do. FPS fans often have to deal with this kind of AI logic, so it’s good to see enemies acting more like actual humans with real thought processes and the like.

It looks like they have hooked up not only the animations to the agent damage models, but also made a point to have the behaviors change as a result. I have seen a lot of the location damage animations lately, and occasionally we see behaviors change as a result of being under fire, but it is nice to see that people are trying to blend them both in. It is perfectly natural to expect an injured warrior to go off and try to lick his wounds to “fight another day”. How does this affect the overall gameplay, however? Will they give up if injured? Are they a factor still or do you still need to clean up all the riff-raff that is hiding around? That makes for an interesting dynamic if you now have to root out all the cowering wounded people.

Whether or not Far Cry 2 will be plagued by the same overachievment strain issues that it’s predecessor and cousin (Crysis) did remains to be seen. Prima fascia, they both looked pretty good at first only to be exposed later on. I, for one, would like to see these boundary-pushing experiments work. The AI world needs some successes in new stuff in order to open up people’s minds to even more experimentation in the future.

Good luck, Ubisoft.

Far Cry 2 and AI promises

Sunday, January 20th, 2008

I happened upon this blog entry by a reviewer of the new Far Cry 2 by Ubisoft (note, not Crytek). I include this paragraph here but please visit the blog for more information.

Ubisoft also makes some very grandiose claims about Far Cry 2’s AI, which makes me far more leery than any promises of beautiful graphics or realistic physics. Every game I’ve seen that promises realistic artificial intelligence has fallen short. It’s not about bad AI, but more about developers making promises they can’t back up. According to Ubisoft, Far Cry 2 will sport complex, nonscripted artificial intelligence that has enemies and NPCs reacting to personal needs. I’ve heard that enemy soldiers will seek shade when it’s hot, take breaks then they’re tired, and seek out food when they’re hungry. Combine these claims with a sprawling world and I find myself having flashbacks of the buildup to The Elder Scrolls IV: Oblivion. Bethesda Softworks promised some amazingly realistic behavior in its NPCs, but it didn’t quite make it. The game was still very good and its characters occasionally showed glimpses of intelligence, but it didn’t live up to the hype. I saw an enemy medic pick up a wounded soldier to carry him to safety in Far Cry 2 and was impressed by the action, but until I play the final game myself and see that sort of behavior manifest consistently, I’ll take the promises of AI with a generous spoonful of salt.

I seriously agree with the skepticism. One thing that Far Cry 2 has going for its AI is that Crytek is not doing it. Far Cry had gaping holes in it and Crysis continues that trend (see my observations on Crysis at Post-Play’em.). That being said, I would seriously like to see the claims come true, of course. Anything that advances the technology of autonomous agent-based AI is cool with me.