How would I program AI on the DS for a Sim game?

I am curious as to whether or not you realize how completely open-ended that question is. You may as well ask "how do I build a house?" or "what should I eat?". The answer to all such vague questions is... "it depends on what you want." Do you want to narrow down what you are saying when you say "sim game"?

Usually, you program AI to solve a specific problem... that is, "I need my character to do X." Solve that single issue and then move on to the next one. If you continue to solve those individual issues one at a time, eventually you have a comprehensive AI.

Well, by sims game, I mean literaly, The Sims, as in The Sims 2, The Sims 2 Pets, etc..... does that help any?

Quote: Original post by YoungOne
Well, by sims game, I mean literaly, The Sims, as in The Sims 2, The Sims 2 Pets, etc..... does that help any?

Short answer: it's extremely complicated.

Long answer: Don't try to build a skyscraper if you don't know how to build a shed. Start small with basic AI projects/simulations. The AI in the Sims games is probably the most complex example you could choose, and therefore describing in any useful detail "how to do it" would take an extremely long time and also assume a lot of knowledge on your part about all fields of artificial intelligence and computer programming.

Hi,

I would advise that you go with the most simple that would do something sensible on screen.

For the low level stuff you can have tile system and make your guy move naively according to that. I think you can find a lot of example implementation of A* on internet if the level starts being complicated at a point where the agents act stupid.

For the actual behavior, I guess you can maintain a list of the stuff yours guys want to do the most, and a global list of what the object in the area allows your guy to do, and match the first of the list sorted by `on how much the guy want to do it divided by how easy it is' or something.

It looks like the easies thing to have something running AI wise. Now I am not sure if you just meant AI AI or like the animation and stuff ?

how come you are working on the DS ? is it a professional thing or indie ?

Other than that for the previous answer : the guy asked how to do it, not how not to do it.

Quote: Original post by germain
Other than that for the previous answer : the guy asked how to do it, not how not to do it.

Well you didn't tell him how to implement 'The Sims' AI either, you just scratched the surface of the initial steps necessary to implement it, proving my point. All I was saying was that in order to implement "The Sims AI" you'll need to do a lot of background work and research and work your way up to that point. Asking such an open question leads me to believe he does not have said background experience to implement the system he wants to...and that he's making a classic mistake of trying to make a MMORPG as the first game, or implement the most complex AI imaginable as a first go [ ya know, the whole simulating human interaction and life thing that the Sims pulled off].

Start by picking up a book on AI game programming and look through it, implementing each of the examples and understanding how they work.

I am curious why you want to implement it on the DS though, and how the platform is even relevent...unless you want to know not only how to implement complex AI, but how to implement it in a memory/resource limited environment?

Anyways I'd recommend "AI Game Programming Wisdom" by Charles River Media.

- Danny

Hi,

I see what you are saying. I hope I didn't looked like I was underestimating the work on the sim, I don't think the underlying concept needs that much theory.

Look at those two links from that thread: http://www.gamedev.net/community/forums/topic.asp?topic_id=318452

http://www.cs.northwestern.edu/~forbus/c95-gd/2001/Programming%20Objects%20in%20The%20Sims.pdf
http://www.cs.northwestern.edu/~forbus/c95-gd/lectures/The_Sims_Under_the_Hood_files/v3_document.htm

of course there is more than the two lines I put in my message, but that s what it seems to come down to me.

I am curious about the ds thing too :)

Germain

Heh, I don't think he wants the theory, which is indeed basic. I think he wants to know how to "program" it for the "DS"...

Those are interesting slides in your links that do focus on the theory, and on an object editor it appears. The 2nd link had some interesting information.

Anyways, it still doesn't scratch the surface of the actual code-wise implementation, which I think is what he's lookin' for based on his one sentence OP.

I believe he'll only find that information in detailed books/courses on the various AI topics that, when combined, produce the AI experience in "The Sims".

I'm assuming by "Sim game" you mean a game like the Sims. Anyway, the Sims had a rather clever way of implementing AI using "smart terrain". rather than have characters keep huge lists of what they could do and massively complex state machines to determine which action to perform, each object in the world would broadcast what it was capable of to nearby characters. Your character would have basic needs, like hunger, social interaction, boredom, etc. So, a refrigerator might broadcast "I have food in me, which reduces hunger." If your character was more hungry than anything else, it would go to the fridge and get food. The food might then tell the character "I need to be cooked" and a microwave would broadcast "I can cook food". So, the player microwaves the food, eats it, and reduces his or her hunger.

If you want the quick redux...

Living with The Sims’ AI: 21 Tricks to Adopt for Your Game
http://aigamedev.com/reviews/the-sims-ai