A.i. Q & A

[encomium]

I'm hoping the coding team could answer a few questions about your intended A.I. setup. If this has been posted elsewhere, could you please link me?

 

Keeping in mind I am coming from the artist / gamer side of things, and have no knowledge of the doom3 engine, or it's capabilities code wise:

 

1) on a scale of 1 to 10, where is TDS's A.I., and where will your's be?

 

2) do you plan on using Thief's A.I. as a foundation, and building on it, or will you pretty much have a uniqe A.I. of your own? The A.I. in Theif is fairly lame, but i can appreciate the fact it takes a lot of resources to use hardcore A.I.

 

3) if you have night/day cycles, will the NPC characters have 'schedules'? (ie. at certain times, will they do different chores, and/or carry out differnt tasks, missions?)

 

 

 

...these are just a few, but if you don't mind answering the likes of these questions, I have many more for you.

[Springheel]

I'm not on the coding team, but I can give you some answers:

 

1) on a scale of 1 to 10, where is TDS's A.I., and where will your's be?

 

That's very subjective. TDS's AI were actually pretty smart by computer game standards, though some bugs kept that from being obvious. We do aim to make our AI more versatile and more believable, however. Our AI are going to search intelligently, heading for good hiding spots first. They'll poke deep shadows with their weapons to see if anything is lurking there. They'll look over their shoulder once in a while.

 

3) if you have night/day cycles, will the NPC characters have 'schedules'? (ie. at certain times, will they do different chores, and/or carry out differnt tasks, missions?)

 

We aren't specifically supporting day/night cycles, though it is possible to do that with the D3 engine. We have talked about a time-based schedule for AI in a few of our campaign missions though. It is certainly possible.

[encomium]

Very nice...

a new batch:

 

1) if u are on a higher level (say a balcony or roof), will the cpu look for u there?

 

2) will the cpu set traps for you, or call a massive search (forcing you to flee the area), if they are aware of your presense? if they actually spot you for 100%

 

3) will cpu go and find a torch if there is one nearby, and bring it to search for you? that element of gameplay from TDS always gave me a rush, cuz i knew i hadda to get the funk outta dodge when i saw the torch light coming...

 

4) will the cpu have any trained animals to aid them at all? ( like the big ass grey dogs in Robin Hood PRince of Theives, haha or how about the hell hounds in Willow??)

 

5) i think it would be nice if you created additional elements which might draw a guards attention to you, such as a few birds that flutter off when u approach them, or a dog that barks, and/or follows you.

 

 

ALso, while we are discussing A.I., would it be at ALL possible to integrate NPC characters that might become involved in either helping you or fighting for you on certain missions? One thing that always slightly bothered me is that there are so many people in the game, but you dont' ever really get a chance to know any of them well enuff. I realize it makes things a little more complicated storyline wise, and technically, but would be a pretty cool addition to keep things interesting.

[Ishtvan]

I'm not sure about AI fighting for you. We are definitely planning to have AI able to fight eachother though.

[Ishtvan]

1)  if u are on a higher level (say a balcony or roof), will the cpu look for u there?

 

That's actually an intersting question, because in reality, people's field of vision (in degrees) is narrower in the vertical direction than the horizontal direction. Plus, people naturally look from side to side, but do not often look up at the ceiling.

 

vanilla Doom3 uses a cone field of view, you specify the cone angle and it spreads equally in all directions. So to implemented the fact that people have a narrow vertical view, we would have to do a slightly different field of view calculation.

 

2)  will the cpu set traps for you, or call a massive search (forcing you to flee the area),  if they are aware of your presense?  if they actually spot you for 100%

 

5) i think it would be nice if you created additional elements which might draw a guards attention to you, such as a few birds that flutter off when u approach them,  or a dog that barks, and/or follows you.

nt

 

Both of these things can be done with scripting. Doom3 scripting is pretty powerful. Scripters will be able to call a function like AlertAI( amount ), in addition to AI being automatically alerted by sight, sound and touch. So for the example with the birds, you would just call AlertAI() in the script if the player walked near enough to the birds to trigger them.

Edited April 4, 2005 by Ishtvan

[Springheel]

2) will the cpu set traps for you, or call a massive search (forcing you to flee the area), if they are aware of your presense? if they actually spot you for 100%

 

One thing we're looking at is having "emergency" points that the AI go to if a thief is spotted but not caught. Like some guards may run to cover the exits rather than search the immediate area where you were seen.

 

3) will cpu go and find a torch if there is one nearby, and bring it to search for you? that element of gameplay from TDS always gave me a rush, cuz i knew i hadda to get the funk outta dodge when i saw the torch light coming...

 

Yep, I just posted this a few days ago, a system for AI who start searching for you to actually pick up a torch or candle as they pass it (although they won't specifically go looking for it unless you tell them to). Of course AI can be given a torch or lantern to hold all the time as well.

 

 

4) will the cpu have any trained animals to aid them at all? ( like the big ass grey dogs in Robin Hood PRince of Theives, haha or how about the hell hounds in Willow??)

 

Dogs are on the back-burner right now, as they are very difficult to animate believably. We already have plans for fluttering birds, rats, and possibly scripted cats to give away your presence, however.

[encomium]

Well, I could get some really nice looking dog animations together for you if you ever wanted to use them. That sparks another area of production I'm interested in knowing more about.... Animation.

[encomium]

Ishtvan, (LOL @ vanilla) you've semi-confused me with your talk of perspective. The only thing I can relate to what your are talking about was my ability to change my persepective view in Quake 3 Arena. I increased my degree of perspective so i could see more fragging opportunes on my screen at once.

 

Will the guards look for you while you prowl about on the rooftops or nah? heh heh.

 

I think having the guards somewhat intelligent in regards to running towards exits, and/or important treasure items is a really good idea. Again, it adds to the realism, and leaves the player with nuthin to carp or laff to themselves about. Why do we play video games? A challenge yeah? Or do we play them for entertainment? Personally I'd watch a movie if I wanted to be entertained. A good movie is WAYYYYY more entertaining than some dumb video game. I dont care what u say, it's true.

 

Gaming is the perfect mix of both a challenge, and entertainment. Does a greater challenge within the realm of possibility add to a game, or make you all the more frusterated?

 

( ie ) How do you feel about having to reload your saved game from about 10 minutes or possibly 20 minutes prior to your current state because u funked up?

 

What do you think?

 

my answer is that I hate the fact I can save so often in the "Theif" Series. There is absolutely no penalty for your carelessness. You should be able to "buy" saves. That'd make finding loot all the more glorious.

[Renzatic]

My answer is that I hate the fact I can save so often in the "Theif" Series. There is absolutely no penalty for your carelessness. You should be able to "buy" saves. That'd make finding loot all the more glorious.

You know, that's not too terrible of an idea. I wouldn't want it to be used as the savegame standard, but it could be something we throw in for Oddity Mode.

[Vadrosaul]

my answer is that I hate the fact I can save so often in the "Theif" Series. There is absolutely no penalty for your carelessness. You should be able to "buy" saves. That'd make finding loot all the more glorious.

 

A limited number of saves on the higher difficulties worked in AvP as I recall. I think each difficulty level that FM authors produce should be truly different and change even core elements like saving, carrying capacity, AI auditory and visual identification, more AI opponents (and not just randomly/arbitrarily spawned), AI alerted to more out of the ordinary events(moss patch not there before), etc..

[Domarius]

( ie ) How do you feel about having to reload your saved game from about 10 minutes or possibly 20 minutes prior to your current state because u funked up?

 

What do you think?

 

my answer is that I hate the fact I can save so often in the "Theif" Series. There is absolutely no penalty for your carelessness. You should be able to "buy" saves. That'd make finding loot all the more glorious.

Sir, I salute you! Up until now it was only me and oDDity, and also Darkness_Falls (to varying degrees) who actually acknowledged this problem and were thinking of ways around it. People like us seem to be far and few between. People who play a game for a challenge. Saving anytime you want means you will complete it with much greater ease, because by dying and reloading from a few seconds earlier, you will get by out of sheer luck eventually.

[sparhawk]

There was never a doubt that limited saves were more challengin. That was not the issue. And we agreed to have this as a option anyway.

[Domarius]

Yes but only a few of us appreciate it.

 

BTW I don't see limited saves as more challenging, I see unlimited saves as CHEATING.

[oDDity]

I see unlimited saves AND using health power-ups as cheating - both things are used to fool yourself into thinking you completed the level successfully.

You're only fooling yourself.

[Ishtvan]

  ... AI auditory and visual identification, more AI opponents (and not just randomly/arbitrarily spawned), AI alerted to more out of the ordinary events(moss patch not there before), etc..

Read the frontpage and you may be pleasantly surprised

Edited April 5, 2005 by Ishtvan

[encomium]

Bahaha, aww man. You guys should not of mentioned the whole belief that saving every 5 footsteps is cheating. Now i'm gonna feel really bad when I do it. I must confess that I tend to use the quicksave key pretty often, but that's only because it's available to me. If i were forced to (or at least given the option to, at the start of the game) vaule my save points, I'd feel much better about completing the level. This is important, especially in a 1 plyr game. At the same time, you don't want it to become annoying. Balance is everything yeah?

 

Another thing I'm wondering is how hard do you think it would be to integrate an option for co-op missions into your editor? Is that adding a whole new element of difficulty, or is it fairly straight forward?

Edited April 5, 2005 by encomium

[Fingernail]

I suppose in technical terms, it'll be the same as making a D3 coop map for any of those coop mods there are...I'm sure a hack is possible, but eventually we may actually provide proper support for Co-op games.

[Ishtvan]

We have made a design decision that we are not coding it to support multiplayer initially. That would require a lot of extra coding and workarounds that would slow down our progress as we try to get the base elements down.

 

When we release, it will be open sourced, so anyone who wants to try to get it to work with multiplayer is welcome to try.

[Domarius]

You guys should not of mentioned the whole belief that saving every 5 footsteps is cheating.

If you were able to play back the final game as a movie (with no loading interruptions) you'd have this Matrix type video of this guy dodging everything perfectly and using everything at the perfect time, not wasting a single bit of anything.

[Ishtvan]

AI "Dev journal" hilite

 

Bringing the topic back to AI Q&A, I thought I'd give the forum visitors an insight into the AI coding process, which sometimes yields hilarious results, such as this:

 

I set up AI so that if a D3 physical object collides into them, they get a tactile alert and pretty much go to the highest alert state. This was so that, like in T1-3, if the player throws an object and it hits an AI, the AI will spin around to face the direction it hit them from and go to full alert.

 

Now, this worked well and good when you throw objects at AI, but there was one thing I didn't think about: Since D3 has a physics engine, objects behave physically. If you are walking around, and bump into say, a box, you upset the balance of that box, and that box may wobble back, then forward, and bump into you. D3 also considers this to be the box colliding with you.

 

So, when I put some boxes on the floor and had AI patrol around the room, they sometimes kicked the box, and in rsponse, the box wobbled back and then wobbled forward, nudging the AI. At this point, the AI believed that it had just been hit by an object out of the blue, so it went to a full alert and started freaking out and running in circles (this is my placeholder behavior for full alert )

 

As he ran around, he kicked more boxes, and with more force because he was running, and the boxes wobble around and knocked into him again, and he received full tactile alert again, resetting the de-alert timer. So the result is he runs around indefinitely, kicking boxes and then freaking out when they bump him back.

[sparhawk]

:lol:

 

This means, no more nudging in TDM.

[Ishtvan]

Yes, there will be no nudging up in here. You'll just have to find a better way to ghost

Edited April 6, 2005 by Ishtvan

[Pyrian]

Interesting. Perhaps you could simply give the guard (and probably nearby ones as well) an "amnesty" period when they collide with a stationary object. Thus, the AI could kick a box and have a bunch of stuff fall on him and his buddy as a result without going nuts.

[Ishtvan]

That's a pretty good idea, I'll look into it. I was also thinking about adding a flag to idMoveables when they're picked up and thrown by the player, so that AI only respond to objects thrown by the player, but your idea seems more general.

 

The only failure case I guess would be if you threw an object at an AI the instnant after they kicked a box or something in their path. At that moment in time , the "amnesty period" would still be going and they wouldn't notice the item you threw at them.

[sxotty]

On the topic of saving forcing too few saves is always a bad idea. Think about games that have done this and then been patched to allow more saves. The reason is obvious, it isn't that much fun to play the exact scenario over and over, thus if part of the level is difficult replaying the first part 10 times to get there sucks...