[HN Gopher] Imitating Human Behaviour with Diffusion Models
___________________________________________________________________
Imitating Human Behaviour with Diffusion Models
Author : belter
Score : 97 points
Date : 2023-01-26 09:07 UTC (13 hours ago)
(HTM) web link (arxiv.org)
(TXT) w3m dump (arxiv.org)
| FeepingCreature wrote:
| Will this mean better AI in computer games? "Better" here in the
| sense of "more realistic", not necessarily "higher scoring"?
| Because I'd love that.
| dkersten wrote:
| Maybe, but most games use simpler tools like behaviour trees or
| utility systems not just over machine learning based AI, but
| also over fancier game AI techniques like GOAP, MCTS or even
| HTN's simply because:
|
| 1) they are easier for the designer to understand and easy to
| understand why an NPC made the decision it did
|
| 2) they are easier for the designer to tweak and update to get
| the behaviour they want
|
| 3) they're computationally expensive. Most games only give a
| few milliseconds at most per frame to AI. The model would have
| to run very quickly. GOAP and MCTS are known to work well but
| the search space can explode too large, eg the total war games
| use MCTS and can only look a few turns into the future because
| the search space is too large.
|
| The problem with machine learning based game AI is that it is
| difficult to understand why the NPC is doing what it's doing
| and if you need to tweak or update it, you have to retrain the
| model which could be costly or time consuming. It may also be
| difficult to train in the first place because you need to
| create example data that has the desired behaviour.
|
| A big part of game AI is designers authoring an experience that
| they wish to convey on the player and machine learning takes a
| lot of control away and puts it in an opaque black box.
|
| GOAP = goal oriented action planning, a graph-search based
| planner
|
| MCTS = Monte Carlo Tree Search, a heuristic search based
| decision making algorithm. Some of the Total War games use it.
|
| HTN = hierarchical task network, a hierarchical planning system
| that solves some of the issues GOAP has: it can prune the
| search space more aggressively and it gives designers more
| control over the resulting behaviours. It's lesser known and
| has less talks/articles/sample code compared to GOAP
| kossTKR wrote:
| Interesting. It's honestly quite disappointing that progress
| has been so slow in this space, but in this time dependent
| context it makes sense.
|
| I remember AI NPC behaviour being a discussed and promoted
| all the way back to the late 90's, but it's like there's been
| a standstill and characters still run around i zig zaggy
| pathway patterns, switch between pre-made states and get
| stuck and never really surprise you with anything really
| "outside the box".
|
| So much that it's not even really a topic anymore as far as i
| am concerned? Maybe because of multiplayer.
| actionfromafar wrote:
| Which is sad, because even multiplayer would be very
| interesting with Alien style NPCs who were actually clever
| and cooperated and had memories stretching over the
| timespan of the games existance. (Years.)
| dkersten wrote:
| Another thing worth noting is that "smart" game AI is as
| much about presentation as it is about actual intelligence.
| That is, if your NPC's are super smart, but doesn't
| communicate their smart decisions to the player, they will
| often still be perceived as dumb. That's why "barks" are
| such a big thing in games: NPC's tell each other what they
| saw or what they're doing to communicate to the player that
| they made a potentially smart decision. This communication
| may not be so simple with a machine learning based AI where
| the intent of the NPC isn't known.
|
| Similarly, often super intelligent AI doesn't look very
| intelligent, doesn't feel very intelligent or is just not
| very fun to play against.
|
| It also depends on the type of game. If the player spends a
| lot of time observing NPC's (eg in a stealth game), then
| intelligent AI is more important than if the expected
| lifetime of the NPC before the player slaughters them is
| only a few seconds (eg in a shooter).
|
| I don't think its necessarily time constraints. Its also
| understanding the AI: why did the NPC make the decision it
| did? Exlpainable machine learning is still very much a
| research topic. Its about giving the designer the ability
| to control and author the interactions that the player will
| get. Its about controlling what situations are actually
| desired (there was a story about the AI in The Elder
| Scrolls: Oblivion's "Radient AI" system where they had to
| tone the NPC's autonomy down because they found that NPC's
| would tend to do unfun things like murder everyone in
| town). In terms of training machine learning models, for
| many games you may simply have no way of gathering
| sufficient quantities of data to train it to do the
| behaviours you want for the scenarios where you want them.
| Time may not necessarily solve these, or at least you'd
| need a decade to do everything.
|
| Personally, I like sandbox RPG's, so I personally want to
| see better NPC AI and deeper NPC simulations. I want to see
| NPC's go about their lives independently of the players
| interactions and have their own agency in the world. So I'm
| very much interested in seeing better decision making,
| planning and simulation of characters in games. But machine
| learning based techniques aren't necessarily the answer, if
| you want the game to still be a game and be fun for the
| player.
|
| In fact, in my own opinion, if NPC's have true autonomy and
| agency, then you likely also need a storyteller/director
| system that manages the NPC's so that they 1) don't go too
| far off script, 2) don't go too crazy in undesirable ways
| (like the Oblivion murder spree), and 3) that their
| interesting interactions tend to occur when the player
| might actually notice them (otherwise you may simply "miss"
| all the intelligent behaviour because it always happens
| when you're not around or in places you don't visit in time
| to notice the consequences)
| delusional wrote:
| I think there's more to it than time constraints. Of course
| the efficiency of the method is a big concern, but we also
| have to remember that games are primarily experiences. In a
| lot of the games I play, stuff like stealth games, rougue-
| lites, and DotA, the simple and predictable behavior the
| current models is required for the game to work. The models
| HAVE to be stupid to make the game work.
| f_devd wrote:
| Certainly is a possible outcome although there are a few
| problems with the current paper as I see it:
|
| * Quite slow to execute (somewhat inherit to diffusion models)
|
| * Requires a lot of human data which increases dev time, since
| it needs to be done near the end of gamedev to get a consistent
| enviroment
|
| * The current paper doesn't consider previous observations (I
| can't find the reference so I could be wrong)
|
| I believe issue 1 & 3 can be overcome quite easily with changes
| in model architecture, and 2 can probably be overcome with RLHF
| to pretrain on self-play and fine-tune on human input.
| naillo wrote:
| We're definitely like 5 years from being able to have really
| realistic NPCs in games. But then probably another 10 until
| they're actually widespread (RL AI have been able to be
| incorperated into games for years now but these things are
| surprisingly slow to be adapted).
| asdff wrote:
| If the game uses voiced npcs that might be trickier. People
| expect to hear a voice actor not Microsoft Sam.
| [deleted]
| dustbitying wrote:
| I've been waiting for civilization franchize to do this.
|
| by this point anything less than free form chat with the other
| 'leaders' won't cut it
| PedroBatista wrote:
| Is this realistically useful outside of games?
|
| The moment we need to express all this AI in the real world all
| we have is some clunky pieces of metal joined together with
| electric motors like a 50s Sci-Fi movie that costs multiple
| thousands of dollars.
|
| Right now the "brain" looks like the Star-Trek age but the body
| is stuck in the 19th century.
|
| Having said that, I would probably freak out if I saw some bot
| casually strolling down the street.
| fudged71 wrote:
| Simulating human behavior is useful in a ton of areas, think of
| economic and sociology research as a first step before real
| world studies
| actionfromafar wrote:
| The "brain" is good enough for a Star-Trek _sound stage_ but
| not enough for a Star-Trek _real life_. It 's a big phrase
| book.
| sys32768 wrote:
| Imagine characters as well written as those in Mass Effect 2, but
| who actually connect with you, who remember your adventures
| together and your conversations, who listen and respond more
| thoughtfully than many real world friends.
|
| To the human brain, they will be real, as will the suffering from
| losing them, or the passion of falling in love with them.
|
| Thankfully, resurrections will be an option for a fee, and
| virtual marriages will be sought but I think the mental health
| and legal issues will put the brakes on some of that.
|
| Sex workers with VR headsets will allow for hook-ups with your AI
| lover.
| sillysaurusx wrote:
| > Who remember your adventures together
|
| Hah.
|
| (GPT and I have a long history of me pointing out that it can't
| remember a darn thing, and it never remembering anything.
| https://news.ycombinator.com/item?id=23346972)
|
| You can prompt it with context, but that's still only a few
| pages, not chapters. It'll be hard to turn in game actions into
| a coherent prompt, then parse the output to take in-game
| actions. Both directions are difficult, but I suspect it'll be
| _much_ harder to get it to do things in the game in a unique
| way -- i.e. you'll run into the classic problem of all NPC's
| feeling "kinda same-y" without being able to put your finger on
| why they don't feel like unique human characters.
|
| On the other hand, it does seem like I'll be proven wrong
| within a decade, and I really look forward to it. :)
| pineaux wrote:
| This is bad. This feels like something that could be used as a
| pumped up Cambridge analytics scheme.
| visarga wrote:
| It is for robotics, no relation to social media.
|
| > On a complex control task, diffusion models achieved a task
| completion rate of 89%, exceeding recent state-of-the-art of
| 44%.
| belter wrote:
| https://arxiv.org/pdf/2301.10677.pdf
| g8oz wrote:
| Romance scams are definitely going to benefit from this.
| mullingitover wrote:
| Open world RPGs are going to get really weird. I'm looking
| forward to the version of Grand Theft Auto where you can abandon
| the main quest chain, meet a nice quirky NPC with a really great
| sense of humor, and raise a family together. Maybe get involved
| in local government or do some volunteer work.
| asdff wrote:
| Sounds like modded skyrim
| dustbitying wrote:
| where the mods plug advanced (post-chatGPT) AIs into this.
|
| it happened already, but it's still "military grade and
| security cleared" away from plebs but I am a crazy person so
| feel free to disregard what I say if it makes you queasy. (q
| easy, cue ez)
|
| also, it's online.
| thedorkknight wrote:
| I'll bite, what are you referring to?
| nathanwh wrote:
| This sounds very similar to the game that was described in
| Ender's Game, with the giant and the two shot glasses. That's
| always been one of my wishlist games, excited to think that it
| is starting to become a possibility.
| sublinear wrote:
| I have a serious if not possibly ignorant question here, but
| shouldn't experimenting on human behavior without consent be just
| as illegal as any other human experimentation and shouldn't that
| be extended to imitating art or language?
| ShamelessC wrote:
| Certainly ignorant, since you mentioned it. Read the synopsis.
| Then, read the paper. Then evaluate based on merits, not some
| (frankly unrelated) prior agenda about copyright infringement.
|
| The title doesn't even really imply what you're suggesting.
| Quite a reach. At risk of breaking the rules, RTFM.
| BurningFrog wrote:
| Imitating someone is not experimenting on them.
| O__________O wrote:
| Curious, based on the research referenced, where do you are
| non-consensual methods of research utilized?
| [deleted]
| canjobear wrote:
| Why should it be illegal?
| anigbrowl wrote:
| 'without consent'
___________________________________________________________________
(page generated 2023-01-26 23:01 UTC)