Im doing a theses on how to improve the level of AI in Digital Games using specific Machine Learning Techniques namely ANNs, Genetic Algorithms and Decision Trees. I know there a lot more but my time scale is very limited. The 8 of March is the final deadline. In order to do this I have to first document previous classic games or any game really I can find a lot of AI info about. Two of the games I am currently looking at are Half Life and Emipre Earth, if anyone can find useful AI info about these games you would be saving my ass, cause it is so hard to find info when developers generally keep their ideas secret. Thanks in advance. Brien Crean

Most of the AI code in Half-Life is freely available (it''s in the modder''s SDK, rather than in the engine itself). Such code is mostly comprised of state machine stuff, though there''s some threat triage and pathfinding as well (though a large part of pathfinding is in the engine).

Thanks superpig. I had an idea that the Half life AI code was availible but its in C++. I did java in my course unforunately! What i am looking for is a top level view of the AI in half life. I have already described the technologies of pathfinding, FSMs, FuSMs, and scripting for my Non Machine Learning Techniques Section. Now Im looking for detailed examples to link with the technologies.

Brien Crean

Perhaps this can help:

http://www.extremetech.com/print_article/0,3998,a=25462,00.asp

It''s not half-life specific, but might give you a hand

The "AI Wisdom" book has articles in it from the AI programmers at Stainless Steel. They mention about a few of the techniques they used. Also, Bob Scott of Stainless Steel pops his head in here regularly.

Dave Mark - President and Lead Designer
Intrinsic Algorithm - "Reducing the world to mathematical equations!"

Thanks Wolverine that game engine article was really helpful it pointed out a few things that I was missing and some more things I might use in the future

Also thanks to InnocuousFox I now have AI Wisdom its a great book but there is a few things I would like to know more about the architecture of an RTS game although.

Would you guys reckon its right to say that the AI for the Adventure game genre is similar to the AI for the FPS genre apart from the large amount of ''friendly'' interaction with NPC''s and more detailed storyline

Brien Crean

Here I am - ask away!

Seriously - the articles in AI Wisdom cover a large part of the design of the AI in Empire Earth. Afraid you won''t find much info on the use of GAs or ANNs - we didn''t use ''em. Most of our AI work was decision trees and expert systems, coupled with much randomness and anything else we could do to enable emergent behavior.

Bob Scott

Thanks Bob. Ive actually been reading the AI wisdom book recently (I havent finished reading "Architecting an RTS AI" in detail as I write this so forgive me if i ask something thats covered in the article) and its great it has almost every thing I need, except exactly how the combat componet works when engaging an enemy. Does it work similarily to an FPS with different tactical manoueveres?

I wasnt looking for how ANNs or GAs were implemented in EE cause I figured they werent as all RTS games I know of have little Machine Learning In them and its generally statistical. My theses is about trying to find places where they might be useful in an RTS. I didnt know Decision trees were used in EE though, thats interesting. If you could point me in the direction of some good online info i would be very grateful. Thanks again

Brien Crean

Brien,

The combat component was actually written by the other AI guy here at SSSI - Dan Higgins. He had a couple of articles in the book as well, but they dealt with pathfinding optimizations.

Combat in EE was very much a micromanaged thing. Units were grouped and subgrouped, usually by ability (ranged, melee, special) and individual units were given orders to engage individual enemies based on how well they would fare against them. Of course much randomness was thrown in, especially at lower difficulty levels.

We did code a handful of particular tactical situations, but a lot of what you see in the game that might look like it are actually just random behaviors. It''s quite fun listening to someone describe the AI doing something that you know wasn''t actually programmed...

As far as web sites with decision tree information, you''d do as well as I could with google - I don''t have any favorites for that...

Bob

quote:

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It''s quite fun listening to someone describe the AI doing something that you know wasn''t actually programmed...

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Damnit Bob! Stop bringing that up in public! Oh... uh... never mind. Uh... he was talking about... uh... my brother! Yeah, my brother just makes a fool of himself! After all... I''m an AI designer/programmer. I know random behavior when I see it, right? Yeah... it was my brother who said the stupid stuff... yeah... moron. Heh...



Dave Mark - President and Lead Designer
Intrinsic Algorithm - "Reducing the world to mathematical equations!"