Secret identities in Dwarf Fortress (2017)(ojs.aaai.org)
ojs.aaai.org
Secret identities in Dwarf Fortress (2017)
https://ojs.aaai.org/index.php/AIIDE/article/view/12963
36 comments
I don't know if this is this specific system in DF, but there is a recent video by Game Makers toolkit explaining The Sims AI which is kinda similar regarding objetcs and needs, pretty interesting https://youtu.be/9gf2MT-IOsg
This video is a nice introduction to “Utility AI” systems and includes examples from games like The Sims and Total War. (The Sims section starts around time 6:50.)
https://youtu.be/p3Jbp2cZg3Q
A utility system is basically a codification of Maslow’s hierarchy: the system continuously re-evaluates possible behaviors’ utility functions and then chooses the top-scoring behavior.
https://en.m.wikipedia.org/wiki/Utility_system
https://youtu.be/p3Jbp2cZg3Q
A utility system is basically a codification of Maslow’s hierarchy: the system continuously re-evaluates possible behaviors’ utility functions and then chooses the top-scoring behavior.
https://en.m.wikipedia.org/wiki/Utility_system
Thank you! This makes me wonder why there is no open source implementation of/framework for such a mechanic (or why i haven't heard of one) yet - it seems to be the (potential) basis of many games - one other popular game using it is Rimworld.
Also, why games like Minecraft have not long implemented such smart and interesting NPCs yet!
Also, why games like Minecraft have not long implemented such smart and interesting NPCs yet!
Games experiences are carefully crafted. Minecraft is not a world simulator, or an RPG (I mean, without mods), if you added such features in the base game, it would change the experience dramatically. I'd say that the reason they didn't implement it yet, is simply because it's not the experience they want to give.
Never underestimate how hard it is to create the game experience you want. There's a reason why a lot of NPC AI in videogames are dead simple: it's easy to implement, players easily interact with it, without being confused, it follows rules carefully crafted for the game experience, it's easy to debug and test etc. etc.
Also, how many games like rimworld, DF exist in 3D ? That's right, none that I know of. Making this kind of AI in a free 3D space becomes a whole other story. I think it works well with 2D minimalistic games, because the player uses its imagination a lot. In 3D you can't really leverage this. Anyways that's my 2 cents on why not every game implements it.
Never underestimate how hard it is to create the game experience you want. There's a reason why a lot of NPC AI in videogames are dead simple: it's easy to implement, players easily interact with it, without being confused, it follows rules carefully crafted for the game experience, it's easy to debug and test etc. etc.
Also, how many games like rimworld, DF exist in 3D ? That's right, none that I know of. Making this kind of AI in a free 3D space becomes a whole other story. I think it works well with 2D minimalistic games, because the player uses its imagination a lot. In 3D you can't really leverage this. Anyways that's my 2 cents on why not every game implements it.
Not really relevant to this since it is ultimately a 2D game, but Prison Architect has a "hidden" 3d mode for some reason: https://www.youtube.com/watch?v=D9MhCZSgc_0
>Thank you! This makes me wonder why there is no open source implementation of/framework for such a mechanic
Most likely because actually implementing it is dead-simple, which is a major selling point of this technique. Short of adding it as a building block for non-coders in game engines such as Unreal, there is really no point in trying to prefab it. Most projects will be better served by just coding it in a way that is uniquely tailored to their needs and integrated with their game.
Most likely because actually implementing it is dead-simple, which is a major selling point of this technique. Short of adding it as a building block for non-coders in game engines such as Unreal, there is really no point in trying to prefab it. Most projects will be better served by just coding it in a way that is uniquely tailored to their needs and integrated with their game.
Very, very, few people would notice the Minecraft NPCs having a semi-realistic day to day life.
Noticing that an NPC has a work schedule requires that you stalk random NPCs all day. It works with the Sims, and similar games, because the game essentially forces you to watch them, and to be the stalker.
It's so hard to get players to notice the AI is doing anything that one technique is to make NPCs yell their decisions at the player. That's why enemies exclaim things like "grenade!" or "flank him!" in FPS games. They are trying to force you to notice the AI is doing something.
Noticing that an NPC has a work schedule requires that you stalk random NPCs all day. It works with the Sims, and similar games, because the game essentially forces you to watch them, and to be the stalker.
It's so hard to get players to notice the AI is doing anything that one technique is to make NPCs yell their decisions at the player. That's why enemies exclaim things like "grenade!" or "flank him!" in FPS games. They are trying to force you to notice the AI is doing something.
My favourite anecdote is what in F.E.A.R it's the grenade itself which triggers the "grenade!" sequence. Of course it's enemy who is shouting and taking cover but the action itself is triggered by the protagonists's grenade, not by NPC
Although Microsoft/ Mojang does still actively work on Minecraft, a large fraction of real input to Minecraft's evolution is driven by the independent (Java) modding community. Today vanilla Minecraft has bees, but for many years modded Minecraft had bees, and in fact it had so many bees that people would routinely "nope out" of bee stuff because "Oh MY GOD. No more fucking bees". Jaded Cat's original Agrarian Skies has custom bees, which I think were pink or purple - and within a year or two everybody was sick enough of bees that they didn't want even the normal ones.
As with other creative communities there are some distinct threads, like some people are into very heavily survival focused, up-against-it packs, where e.g. gravity works properly, mobs understand the game rules and will climb up to get you, or set fires, they will upgrade their gear, etc. while people like me prefer ascend-to-godhood type gameplay where you quickly dispense with monsters and become untouchable not far into play.
In the latter style there's not a desire for "smart and interesting NPCs", in fact it's often played alone or in small groups, intentionally. In the former style the NPCs are somewhat smart, but they're a threat so if you make them too clever they'll just always kill the players which isn't much fun after a while.
I think NPCs with the type of independence of a Dwarf Fortress dwarf wouldn't be attractive to either of the sorts of player I mentioned, it may be that such people just don't play Minecraft. But it's also possible somebody has implemented it and I've never run into it. There are a lot of Minecraft mods. Curseforge lists literally thousands of them, there could be hundred like you describe and I wouldn't have noticed.
Packs might typically have a few hundred of those thousands, I might play four or five packs per year, but often the same mods recur because they're so useful or well-liked, like Just Enough Items gets used a lot, so does Refined Storage, but some weird dwarf intelligence mod could easily go under the radar not because people don't like it but because they didn't know it existed.
I reckon a lot of people had never really used Compact Machines for example until Compact Claustrophobia took off, and in that the machines are absolutely mandatory and you use them from the first minutes so you have to get very familiar with them.
As with other creative communities there are some distinct threads, like some people are into very heavily survival focused, up-against-it packs, where e.g. gravity works properly, mobs understand the game rules and will climb up to get you, or set fires, they will upgrade their gear, etc. while people like me prefer ascend-to-godhood type gameplay where you quickly dispense with monsters and become untouchable not far into play.
In the latter style there's not a desire for "smart and interesting NPCs", in fact it's often played alone or in small groups, intentionally. In the former style the NPCs are somewhat smart, but they're a threat so if you make them too clever they'll just always kill the players which isn't much fun after a while.
I think NPCs with the type of independence of a Dwarf Fortress dwarf wouldn't be attractive to either of the sorts of player I mentioned, it may be that such people just don't play Minecraft. But it's also possible somebody has implemented it and I've never run into it. There are a lot of Minecraft mods. Curseforge lists literally thousands of them, there could be hundred like you describe and I wouldn't have noticed.
Packs might typically have a few hundred of those thousands, I might play four or five packs per year, but often the same mods recur because they're so useful or well-liked, like Just Enough Items gets used a lot, so does Refined Storage, but some weird dwarf intelligence mod could easily go under the radar not because people don't like it but because they didn't know it existed.
I reckon a lot of people had never really used Compact Machines for example until Compact Claustrophobia took off, and in that the machines are absolutely mandatory and you use them from the first minutes so you have to get very familiar with them.
Honestly it really was too much fuss about bees, in already very dense modpacks! I'm trying to get this space program off the ground so I can get back to my moonbase damnit. The reactor is melting down, I haven't got time for bees!
Most of the space mods can fuck off. So crashy and yet so bland. I did like the one where you can build arbitrary space stations, except its oxygen sealing mechanics are too sketchy so all I ever do is build an open air space station and spend as little time there as possible, wearing a space suit, until I'm immortal and don't need to breathe anyway. Advanced Rocketry maybe?
Whereas I rather liked some bee stuff. Maybe not over and over again, but I played Valdan's Sky Bees a while back and I really enjoyed that again, with modern huge bees and so on.
Whereas I rather liked some bee stuff. Maybe not over and over again, but I played Valdan's Sky Bees a while back and I really enjoyed that again, with modern huge bees and so on.
The short answer is that Mojang doesn't care about implementing actual, innovative features.
The long answer is that the game is in a managed decline. The target audience is small children so anything not targeted to them doesn't get implemented. "Smart NPCs" isn't a feature like that, so there is zero chance of that being included into the game.
The long answer is that the game is in a managed decline. The target audience is small children so anything not targeted to them doesn't get implemented. "Smart NPCs" isn't a feature like that, so there is zero chance of that being included into the game.
This playlist[0] from TangoTek shows him developing a mod to improve villagers in minecraft. Definitely nothing compared to DF, but still much more interesting than vanilla. Spoiler is that development is paused, not sure if anyone has continued to develop it.
[0] four videos here https://www.youtube.com/watch?v=GK6Vr9mcgjM&list=PL8t707flkq... and playing through the mod/ tweaking as he went here https://www.youtube.com/playlist?list=PL8t707flkqpcAWeVeAUSh...
[0] four videos here https://www.youtube.com/watch?v=GK6Vr9mcgjM&list=PL8t707flkq... and playing through the mod/ tweaking as he went here https://www.youtube.com/playlist?list=PL8t707flkqpcAWeVeAUSh...
During my brief participation in game development I watched an attempt to make game out of needs and actions. This was done because state machines in previous game have failed in unpredictable ways, like dead bodies started to walk while continuing laying on their side and even went into fight.
The end result? AI programmer resorted to state machines, because it was difficult to control character's behavior. For example, there were oscillating behaviors without any advancement on character's part. Team lead had to agree because there aas no budget to tune each character needs and actions to make game playable.
I think this anecdote can explain why objects, needs and actions are seldom used.
The end result? AI programmer resorted to state machines, because it was difficult to control character's behavior. For example, there were oscillating behaviors without any advancement on character's part. Team lead had to agree because there aas no budget to tune each character needs and actions to make game playable.
I think this anecdote can explain why objects, needs and actions are seldom used.
Because successful games aren't about copy and pasting as many pre-made assets and code together and shipping it. You can certainly do that nowadays for the Unreal and Unity engines but eh.
They are all tailored experiences to form what is known as the game.
They are all tailored experiences to form what is known as the game.
There's nothing wrong with using pre-made assets. Not every developer has a studio with in-house artists and designers.
Have you heard of Goal-Oriented Action Planning (GOAP)?
I've tried implementing it from scratch and it's really easy to get interesting, emergent behaviour. It can also be difficult to debug however, or reason about why things are happening -- or how to make things you want actually happen. I have a feeling commercial products would have much better tooling to ease some of those pains.
I've seen this great video about it! https://www.youtube.com/watch?v=PaOLBOuyswI
for more behind the scenes stuff on Dwarf Fortress I recommend listening to the occasional 'bay12 talks' podcast episodes hosted by BlindIRL (long time dwarf fortress streamer) he periodically talks with Tarn, and more recently Putnam (longtime modder and first external programmer on DF) about the state of the game and asks them player questions.
https://youtu.be/BY4jwUuvy4E
https://youtu.be/BY4jwUuvy4E
Unfortunately these interviews tend to be full with fun anecdotes, but tend to lack technical details
now that putnam is here you can glean some details because they talk about working on the code more and about the stuff putnam is optimizing
Basically when you make a task in dwarf fortress that requires a character in the game to do something, it gets added to a global jobs list.
Dwarves will, assuming they don't have other jobs at the time, pick a job from that list as long as they're allowed to do so by their labor selections + workshop availability (if that is possible). Do note that this doesn't actually account for pathfinding or if the job is even possible. The game will gladly tell you over and over that a job is being cancelled if for whatever reason the items needed for it are inaccessible/don't exist. Just a small note.
If the dwarf in question has no current jobs, the first priority will be for them to check their needs and try to fulfill them. Needs more or less are in two categories - "essential" and "non-essential". Non-essential needs used to be more obvious - it was the On Break part of a dwarfs schedule. Basically every once in a while, a dwarf goes "On Break", effectively making them unable to do anything except take care of their essential needs. Nowadays it's a set of activities derived from the unique identity of the dwarf (On Break doesn't exist anymore) - religious dwarves will want to play, while dwarves that seek musical entertainment will try to do so with a musical instrument.
Essential needs on the other hand are things like drinking/eating and sleeping. These pretty much come in two degrees, "want" to do and "need" to do. Want to do means the dwarf will immediately get a job to fulfill the need once the criteria are hit - if a dwarf gets hungry while hauling a rock, they'll grab a bite to eat after. When a need progresses to "need to do", it just will straight up interrupt any non-need job they're currently doing[0] (the game even tells you this) and create a new job to do it. Its how a dwarf will fall asleep on the spot if they're extremely tired.
Mental breakdown and tantrums are similarly "essential" needs, just with their own triggers that can't be interrupted by the player.
[0]: With the notable exception of military duties, which is one of the reasons militias in Dwarf Fortress have to be on a rotating schedule - dwarves will not eat or drink if they're on active duty, no matter what. They will sleep in a barracks though.
Dwarves will, assuming they don't have other jobs at the time, pick a job from that list as long as they're allowed to do so by their labor selections + workshop availability (if that is possible). Do note that this doesn't actually account for pathfinding or if the job is even possible. The game will gladly tell you over and over that a job is being cancelled if for whatever reason the items needed for it are inaccessible/don't exist. Just a small note.
If the dwarf in question has no current jobs, the first priority will be for them to check their needs and try to fulfill them. Needs more or less are in two categories - "essential" and "non-essential". Non-essential needs used to be more obvious - it was the On Break part of a dwarfs schedule. Basically every once in a while, a dwarf goes "On Break", effectively making them unable to do anything except take care of their essential needs. Nowadays it's a set of activities derived from the unique identity of the dwarf (On Break doesn't exist anymore) - religious dwarves will want to play, while dwarves that seek musical entertainment will try to do so with a musical instrument.
Essential needs on the other hand are things like drinking/eating and sleeping. These pretty much come in two degrees, "want" to do and "need" to do. Want to do means the dwarf will immediately get a job to fulfill the need once the criteria are hit - if a dwarf gets hungry while hauling a rock, they'll grab a bite to eat after. When a need progresses to "need to do", it just will straight up interrupt any non-need job they're currently doing[0] (the game even tells you this) and create a new job to do it. Its how a dwarf will fall asleep on the spot if they're extremely tired.
Mental breakdown and tantrums are similarly "essential" needs, just with their own triggers that can't be interrupted by the player.
[0]: With the notable exception of military duties, which is one of the reasons militias in Dwarf Fortress have to be on a rotating schedule - dwarves will not eat or drink if they're on active duty, no matter what. They will sleep in a barracks though.
lol, bladder/bowels right up there.
...and the physiological needs are broken down further and slightly differently:
Bladder 9
Bowels 9
Sleep 8
Food 8
Safety 7
Hygiene 7
Exercise 6
Family 6
...
...and the physiological needs are broken down further and slightly differently:
Physiological needs include:
Air
Water
Food
Heat
Clothes
Urination
Excretion
Shelter[2]
Sleep
> Instead of giving NPCs task lists, tasks are assigned to objects - say, a door that is not installed yet.
I believe that’s how Will Wright designed The Sims too
I believe that’s how Will Wright designed The Sims too
At this point I think some transparency would be good. One of the complaints about the game is how as time goes on the simulation gets more and more detailed and eventually the game just grinds to a halt.
A little more visibility into how all of this stuff works, and someone might be able to suggest that there's an algorithm that does this or that bit with a much lower order of complexity. A few of those and you can let a game run maybe twice as long.
A little more visibility into how all of this stuff works, and someone might be able to suggest that there's an algorithm that does this or that bit with a much lower order of complexity. A few of those and you can let a game run maybe twice as long.
If it's any consolation, a big CPU suck is friend-or-foe checks being done by characters on everyone in sight, in every tick. That came out last year-ish and making smaller taverns can (slightly) improve processing.
Might be more fun to only check so often ir somewhat random ally. Human nature often it takes a moment to realize something is off.
Bear walks into tavern. Some panic, others are slower to react / notice. A very drunk dwarf might never notice, or offer a beer to the bear.
Bear walks into tavern. Some panic, others are slower to react / notice. A very drunk dwarf might never notice, or offer a beer to the bear.
[deleted]
there is a menu in the game where you can see all the tasks that are scheduled in the queue including stuff like "wash self" and "replace clothing", with targets and who is currently assigned. I believe personal tasks like "have a mental breakdown" are spawned already assigned and locked in to the dwarf they are relevant to. iirc its the (j)obs manager, the same place you assign automated orders like making more beds/beer if the stockpile ever has less than 4 etc
Based on your description, you could describe “need fulfillment” as a task associated with the NPC object. Then you just maintain your original operations while adding NPCs to your object list.
>But how to combine this with needs is unclear to me, I would love to see a good explanation of this.
some inefficient ways off the top of my head: create a threshold filter on the object with logic something like "only agents with need > X allowed", or iterate through the agents until you find one with the greatest need score that is pertinent to the object, or a combination of the two to reduce the list size that must be iterated. sprinkle in agent range from object and specific traits preferably before the list generation to further reduce iterations needed.
i've thought about all of this a lot because i'm addicted to games with agency and emergent behavior. rimworld is a lot of fun in that regard because it's easy to jump into modding it, which makes agency experimentation a lot of fun.
some inefficient ways off the top of my head: create a threshold filter on the object with logic something like "only agents with need > X allowed", or iterate through the agents until you find one with the greatest need score that is pertinent to the object, or a combination of the two to reduce the list size that must be iterated. sprinkle in agent range from object and specific traits preferably before the list generation to further reduce iterations needed.
i've thought about all of this a lot because i'm addicted to games with agency and emergent behavior. rimworld is a lot of fun in that regard because it's easy to jump into modding it, which makes agency experimentation a lot of fun.
The early-access game Shadows of Doubt also has extensive secret-knowledge mechanics which must be carefully managed, with the additional complication that it ideally wants to keep in sync the knowledge of the player and the player character.
I had an opportunity to play it for a few hours. It's not perfect - it didn't always keep up with my deductions, and on one instance it leaked unknown info via the UI - but on the whole it succeeded at a convincing mechanic.
I had an opportunity to play it for a few hours. It's not perfect - it didn't always keep up with my deductions, and on one instance it leaked unknown info via the UI - but on the whole it succeeded at a convincing mechanic.
It's a very good immersive-sim on top of that.
It has some tempo management to work through I think, sometimes crimes are too obvious to solve and others are essentially dead ends unless you brute force your way to the info you need (which means talking to every NPC randomly or fingerprinting the whole city). And as you said, sometimes you have made a deduction, like who someone is thus linking their other details, but it's not relfected in the UI.
It has some tempo management to work through I think, sometimes crimes are too obvious to solve and others are essentially dead ends unless you brute force your way to the info you need (which means talking to every NPC randomly or fingerprinting the whole city). And as you said, sometimes you have made a deduction, like who someone is thus linking their other details, but it's not relfected in the UI.
Somewhere I saw a blog post about Prison Architect, a game inspired by and with similar mechanics to Dwarf Fortress, that described one aspect of the task system:
Instead of giving NPCs task lists, tasks are assigned to objects - say, a door that is not installed yet. The door would contain the instructions: "(1) move me to location [x,y] (2) install me at my current location", and idle NPCs would lookup objects with fitting tasks to their abilities/priorities and then execute the instructions.
But how to combine this with needs is unclear to me, I would love to see a good explanation of this. Here is the insane list of needs a Prison Architect NPC has: https://github.com/originalfoo/Prison-Architect-API/blob/mas..., and Prison Architect, while already displaying emergent behavior, seems to still only have a fraction of the detail and complexity and emergence that Dwarf Fortress has.
All the hype is about neural networks now, but these don't display this kind of emergent, social and constructive behavior, resource awareness and https://en.wikipedia.org/wiki/Homeostasis that these NPCs can.