gameplay-ai

[dense owl]

Afaik Lyra is more of a tech demo than an actual shipped game

[unborn sphinx]

so they will randomly shoot

if they spot some person they are not aiming at

[dense owl]

It’s for people to explore the engine’s capabilities

[tawdry zephyr]

Lyra is excellently made, it's designed to show devs how to build that kind of game as well as how to build a framework for any type of game

Who is "they"

[dense owl]

Them, the bastards

[unborn sphinx]

no hate I love lyra

[ivory rune]

Well, I think we should stop the topic since it doesn't help in any reasons for game dev though.

[dense owl]

I guess r/troll went private ?

[tawdry zephyr]

Well, I'd refer him elsewhere, but then that would just be mean for the people in that channel because it looks like cheems is here to complain instead of learn

This is a channel about #gameplay-ai

Maybe you can try #ue5-general or something

[dense owl]

#lounge is better for him

[tawdry zephyr]

Good point

I was hoping there was a channel related to unity build, called #unity

[dense owl]

They have their own discord server I heard

[crystal hatch]

If you're not a troll then you're obviously a noob. Start with 10 bots, and learn stuff. Hell, start with 1!

[tawdry zephyr]

Well, they're not mutually exclusive either

[dense owl]

Lag -> Optimize

[tawdry zephyr]

You don't optimize for 1,000 characters running client-side prediction 😐

Why is someone meant to make your game for you 😄

[crystal hatch]

you go and learn unreal by heart so that you can start messing with internals and be aware of all the cache misses and virtual call.

[tawdry zephyr]

Unreal engine does not offer a ready-made character that is exceptionally light-weight and single-player only. But it does offer this framework. APawn.

And it has #mass for ECS based approaches

As I said previously someone did a HISM approach for RTS type game

[ivory rune]

What is this?

[crystal hatch]

oh yeah, definitelly not a trol 😄

[tawdry zephyr]

But as new as you are, you need to learn the engine first, not go directly into making a game with 1,000 characters

[dense owl]

<@&213101288538374145>

[night hazel]

hi

[ivory rune]

How this is about AI?

[dense owl]

Hi, pls delete troll

[tawdry zephyr]

Whichever mod arrives, can you pin this while you're here so it doesn't get lost

[dense owl]

Thx 🙏

[night hazel]

zero tolerance for transphobia

[potent iris]

Well that ended well 😆

[tawdry zephyr]

I thought it was a good question if he had approached it from an actual learning perspective lol 🤣

(How to get 1000 ai in unreal)

[night hazel]

it's possible

very hard

but possible

you're going to have to fake a looooot to make it work

[ivory rune]

Any existing plugins doing this?

[dense owl]

I was thinking most of those games that have lots of pawns use smoke and mirrors to make it look like they’re all singular AIs

[tawdry zephyr]

I think glass beaver was the person who did a HISM approach

[night hazel]

the tech to make it work easily is relatively new

Mass is kind of the thing here

[ivory rune]

I hope to see some simple NPCs doing interaction like combat with Mass in the future.

[potent iris]

Yeah, it would have been a good question 😅

[tawdry zephyr]

Btw I heard SpatialOS died. Or at least changed gears completely. Are you still using it? You could technically have done 1,000 AI with that 😄

[potent iris]

The problem I have with mass is that it's stitched together around a framework that's really not meant for what mass is trying to do

[potent iris]

Oh god lol
We got rid of that thing ages ago luckily, needed some engine mods too because it saved some additional flags to every single asset and ended up needing mods to asset loading to get them to load in normal engine builds lol

[dense owl]

So if instanced meshes are just redrawn copies of the same mesh with diff transforms, you just have a few characters navigating the mesh and the rest of them pretending to navigate next to them? 😀

[tawdry zephyr]

I didn't think you'd keep using it. Building a game reliant on a service that could - and very much did - go away at any moment would be asinine 😄

Well my conclusion for the 1,000 AI question is ~~maybe you can do it with mass, but no matter what, it is going to be a phenomenal amount of work that most people can't do (maybe including me) 😄 ~~ come up with a better idea for a game that doesn't need 1,000 AI

[potent iris]

Yeah, definitely ain't worth it imo 😅

[dense owl]

Why would you need 1000 individual AI loaded at the same time in one spot tho

[tawdry zephyr]

High density RTS or something 😄

Homeworld?

[dense owl]

Well if you make ants it’s simple, they have a hive mind 😀

Still, they don’t all need to be individualized, just appear to be that way, players won’t sit there with a magnifying glass trying to discern if each unit has its own personality

If you’ve got 1000 units on the screen, it’s chaotic af to begin with

[radiant path]

One of the games with the most impressive amount of AI's that I can think of is They Are Billions. That one makes 1000 AI's feel like a small feat :P

[ivory rune]

How many AIs are supported in Ultimate Epic Battle Simulator?

I've checked some videos with that (I believe so, maybe wrong) like have 1 millions vs 100k, something like that...

[tawdry zephyr]

What's causing the AIController to have a FocalPoint when not doing anything? Causes my AI to stare off into space and I have no logic that sets the focus at all yet for them. I like the results I get when it focuses on the next waypoint (engine behaviour) but not sure why it does this.

[crystal hatch]

GetFocalPoint always returns a value, but it can be FAISystem::InvalidLocation. Not sure if it helps 😄

[tawdry zephyr]

Ah yup, they compare against inline static const FVector InvalidLocation = FVector(FLT_MAX);
Which I can handle with if (!FAISystem::IsValidLocation(FocalPoint))

Thanks 🙂

[crystal hatch]

no problem 🙂

[pallid mica]

Maybe there is something interesting you aren't aware of in the distance

[tawdry zephyr]

I haven't even put in the background birds yet 😉

Really looks quite nifty wandering around looking at the next waypoint. Really brings him to life 😄

[celest python]

looks cool

[celest python]

How do you handle climbing?

navlink -> montage?

[tawdry zephyr]

Well, I have a system that all my characters use, which uses both CMC and GAS and is properly net predicted. For the AI yeah its just a navlink, don't yet have a proper way to do those procedurally yet but I'm thinking on it.

[celest python]

I recall UT4 source code contains a system that lets you add navlinks without designer input

[tawdry zephyr]

Well, I have the path they character will take, so I could do some tests along the path to search for ledges that need a navlink spawned. I have bAllowPartialPaths as well, so if it reaches end of path without reaching goal, then I can do an additional search to catch edge-cases in whatever system I build

[celest python]

Yeah that's a good idea too

[tawdry zephyr]

I find with stuff like this it is better to dwell on it for a while, something often occurs to me if I give it enough time

[celest python]

I was brainstorming something similar earlier; navigation system lets you bind a different functions to FindPath methods

so I thought maybe I could do that edge searching method after the default FindPath method is executed

and my function would run exactly after it, and if any edge found, it would recursively build new path on top of the previous ones until it reaches the goal

and between each FindPath() it would add new path points from bottom to top

but issue was I needed to information of the current state of the path, so I had to extend path points etc so pathfollowingcomp could report if I am climbing, swimming etc otherwise only way to play climbing animation is trying to guess it by velocity

then gave up

[tawdry zephyr]

Do you have any example to show? I'm curious

[celest python]

Not at the moment, a while ago my computer is infected with a malware and I couldnt save some of the data

[tawdry zephyr]

Aw man that's a shame

The older I get in life the more vehement my backups are ;D I have a perforce server that I submit everything to religiously, and it runs backups itself - need to think about getting some external system as well for the backups but they could be huuuge

My perforce server is just an intel NUC that doubles as HTPC in living room

Well, since this project is going to have years of development, risk isn't really something acceptable anymore

[celest python]

Once I am free from what I'm working on currently I will continue my suffering with AI programming

I might redo it

It wasnt even working properly but at least was a nice start to execute the idea

[tawdry zephyr]

I'm having trouble finding the functions. FindPath is used everywhere for... finding asset paths 😄

[celest python]

but in my project all MoveTo tasks run async pathfinding and they wait to receive the result

it wasnt cheap to run

[celest python]

FindPathSynchoronously in AIModule

it makes call to a more abstract native class

and that class has a typedef for a func ptr

which findpath logic uses it instead of calling virtuals

[tawdry zephyr]

Would that imply that you're stuck with non-async pathfinding and take a performance hit?

[celest python]

No idea, I didnt test much

but I was dumb enough to premature optimize things way before I worked on that

with 50 AIs it was around 1.75x faster to find paths though

dropped from 0.5ms to ~0.3ms

so since its was already estabilished like that I went with async route

        // this awkward implementation avoids virtual call overhead - it's possible this function will be called a lot
        return (*FindPathImplementation)(AgentProperties, Query);

[tawdry zephyr]

Oh, I see, I can see why that comment is there

So basically I just need to grab the nav mesh and change it's FindPathImplementation to my own function

[celest python]

inherit from recast and change yeah

[celest python]

though dont forget the disclaimer

[tawdry zephyr]

Ah yep

Yeah, I'll be on my own for this 😄

[still crypt]

Does anyone know if EQS queries run concurrently? / What is the best way to handle a situation where one query depends on the results of a previous one?

[celest python]

EQS is timesliced

unless you explicitly run it sync

you need to write a system that builds a chain of EQS requests on your own if you have dependencies

[still crypt]

Right, but doesn't timesliced mean its allocated a budget per frame and will defer calculations to latter frames if its over budget? That doesn't mean its going to be executing concurrently necessarily

[celest python]

sync implies it will happen at the same frame (or at the same thread), since EQS extends it to next frames its not synced but not the concurrent in terms of multithreading

basically sync one ignores the budget and runs it directly

[still crypt]

I see, but, to clarify - I do not need the results of the first query to start the second, only that the first query is resolved at the time the second is run. The order of execution matters, the start and end times do not, so long as order is maintained

[tawdry zephyr]

Seems it was a moot question anyway, it only has sync method not async 😄

[celest python]

yep you can do that, just sort the EQS assets in order and run first one ,then bind the delegate of the eqs instance that gets called after EQS is finished

then pop from array, then execute the index 0 if it exists

[tawdry zephyr]

What is the advantage of basic vs hierarchical pathfinding

[celest python]

afaik hierarchical is more advantegous in complex paths

basic is more punishing but faster in simpler paths

not sure though

[celest python]

it has async too

[tawdry zephyr]

Oh you're right it does. Mine is using sync but I don't think I ever made a decision there

Suppose it needs to be specifically setup

[celest python]

by default all is using sync

[tawdry zephyr]

Probably best to just stick to sync then

[celest python]

doesnt matter really

if you have multiple AIs doing pathfinding at once async is better

I had a custom system each 1-2 seconds AIs was changing their paths so I was batching the requests and processing them all together

async one runs the sync code on another thread

[tawdry zephyr]

Does async actually call find path too?

[celest python]

iirc yes

it just a wrapper of sync on another thread

[tawdry zephyr]

Any idea why it's disabled by default? Maybe sync is actually faster unless doing many requests

Or maybe less simple to require waiting for the result for newer devs 😅

[celest python]

yes threading has an initial cost and it not always practically beneficial unless you batch requests at once

[celest python]

How do we change the default nav data?

I forgot

were we suppose to drag it to map

[tawdry zephyr]

Haven't done it yet, just about to get started so I'll find out soon 😄

[harsh storm]

Nah, GB is on another level. He wrote his own skeletal mesh renderer. He's doing instanced skeletal meshes.

He's done his own networking stack, his own navmesh tech, his own VFX I believe... he's just built different.

[tawdry zephyr]

Heh yep he sure is 😄

[harsh storm]

I want to say he's also doing his own physics as well.

But I can't remember at this point.

I think he's doing GPU physics.

[tawdry zephyr]

That's some dedication

[harsh storm]

Yeah, it's wild. I still wish Epic would give us an instanced skeletal mesh 😭

[tawdry zephyr]

Gotta make red alert in UE5? 😛

[harsh storm]

With animation sharing, you can already really lighten the load of a lot of AI

CMC still proves somewhat problematic though.

But you can use nav mode and that helps a bit as well

Then do some AI LOD and you can do quite a bit with that.

If skele mesh was a bit more lightweight, could probably get away with more skeletons

I do wonder what the most expensive part of CMC is to be honest 🤔

[tawdry zephyr]

It will be the client-side prediction

Possibly also the physics subticks

These things

    // Perform the move
    while ( (remainingTime >= MIN_TICK_TIME) && (Iterations < MaxSimulationIterations) && CharacterOwner && (CharacterOwner->Controller || bRunPhysicsWithNoController || HasAnimRootMotion() || CurrentRootMotion.HasOverrideVelocity() || (CharacterOwner->GetLocalRole() == ROLE_SimulatedProxy)) )
    {
        Iterations++;
        bJustTeleported = false;
        const float timeTick = GetSimulationTimeStep(remainingTime, Iterations);
        remainingTime -= timeTick;

[celest python]

its the FindFloor()

it also updates overlaps 3 times (via MoveComponentImpl, which is extra overhead)

calls something expensive two times based on FindFloor result

[tawdry zephyr]

The accessors are really making it hard for me to make this FindPath function. It has private the RecastNavMeshImpl and then protected it's accessor GetRecastNavMeshImpl but FindPath is static so it can't even access the mesh in any way whatsoever

[celest python]

then use pathfollowingcomp

[harsh storm]

Idk if this should be all that expensive to be honest.

[celest python]

override tick, bind to path ended delegate if exists

when path ends, do the search

then block the super::tick call until it climbs

but you will have to repath

after climbing is done

[tawdry zephyr]

So the theory is that if I use a partial path, it will get as close as it can, then it'll check if it should create a nav link?

[celest python]

yes

navlink is not necessary either i guess

just find the surface to climb

then execute climbing action

literally by updating transforms

treat the wall as a path

[tawdry zephyr]

That's problematic, if the black line is a valid path the red is significantly shorter especially with verticality, but it'll never test for the red path.

Off the top of my head, maybe I can simply search from actor location -> goal location and add navlinks along there instead of along the actual path, but there's probably some big flaw that hasn't occurred to me yet

[celest python]

what I did was when goal reached I did a box trace, divided into steps by distance, ran line traces

at point hit was not blocking i subtracted climbing root motion animation's height (how much Z it moves) from the last hit trace and after reacing to that Z played the animation to climb

[tawdry zephyr]

I think I will have to try doing it the Fortnite way instead

[celest python]

i dont know how fortnite does, but i'd guess its relying on static mesh data

[tawdry zephyr]

This one

[ivory rune]

I wonder why not releasing the fortnite built component out though. It sounds very useful for the case with non-continous navmesh

[tawdry zephyr]

Perhaps it isn't project independent in the sense that you have to build your level specifically for what it is built to handle

[celest python]

extra data
hm, how?

UUserAssetData or something

[tawdry zephyr]

Perhaps mesh sockets

[celest python]

I dont think so

[ivory rune]

I have no idea either.

[celest python]

desigers would die

[ivory rune]

How to make these extra datas

[tawdry zephyr]

Mm not sure

Maybe fortnite editor has code specific to it 😛

[celest python]

yeah seems like static meshes has UAssetUserData

they can bake vertex points to the UAssetUserData in editor

[tawdry zephyr]

All my problem would be solved if nav mesh could have huge step height 😄

[celest python]

some engines allow vertical navmeshes

[harsh storm]

I don't think I've seen UAssetUserData - how would you go about actually using it? 🤔

[celest python]

its exposed as UPROPERTYs on assets

its often instanced

so they get serialized with their owner data

[ivory rune]

After all, I think Unreal navmesh feature is very limited. If you want to do anything a little bit complicated, you have to do a lot of cusomization.

[harsh storm]

Yup 😅

[ivory rune]

Like Jumping AI, wall climbing, wall run, flying...you cannot solve any of this with just tweaking the settings which makes me frustrating.

[harsh storm]

To be fair - flying isn't something like any engine really solves for you

And jumping is pretty much solved for you

[celest python]

flying is someting UE could support without much trouble

both mercuna and kythera supports

and probably many other in house engines also follow similar methods

[harsh storm]

And those have more than like 3 people working on them

[crystal hatch]

one of these days we'll buy Mercuna out and we'll suddenly support flying 😄

[ivory rune]

Hooray🤣

[harsh storm]

Easy way to convince Tim - make next season of Fortnite be flying based.

[tawdry zephyr]

I think I'll deal with the navlink problem in the future when I'm actually designing my environment 😄

[celest python]

if we could insert splines (navlinks) into path point arrays it would be awesome

it would require OOP on navpoint classes though but it would make extending pathfinding and following very easy

hit an obstable? slap a spline and make path following comp follow it

wanna fly because player is floating in the air? run eqs around it and modify the current path with a spline

[celest python]

@ocean wren what do you think?

[harsh storm]

Found on Mercuna page

[celest python]

kythera also received megagrants

[harsh storm]

So looking at UAssetUserData - guessing, based on your theory Eren, they made their own that allowed them to just quickly draw on the static mesh

[celest python]

Mieszko has to confirm that, I am not sure what kind of extra "data" that is

[harsh storm]

That's why I was just talking about your theory

[tawdry zephyr]

Had no idea what Mercuna was so googled it. I thought this was tongue in cheek but nope its definitely there 😄 Lets make the joke about Epic buying it out into a reality

[harsh storm]

Keep tweeting Tim about wanting a flying focused Fortnite season.

[tawdry zephyr]

They have a habit of buying out stuff right after I pay for them, happened with Live++ (now integrated as live coding)

If I pay for it maybe they really will buy it out 😛

[celest python]

if CPU access for meshes is opt-in in editor yeah

[harsh storm]

Or another way - become a big UEFN creator and then tweet about how it would be so much cooler if you could have flying AI

[tawdry zephyr]

The prices aren't indie friendly, unless reasonably well funded, so I won't be buying a license for that 😄 my ape brain missed the indie licensing because its tiny by comparison, but still a hefty amount

[celest python]

there is no other standard way to add extra data to SM without subclassing SMComponent

[harsh storm]

I was with Vaei's idea that it's probably just sockets on the static mesh

[tawdry zephyr]

Yeah there would be a 00_l and 00_r socket, 01_l... etc

[celest python]

they dont need userassetdata for it

just blueprint utility class

that loops all SM assets in content folder and adds sockets

[tawdry zephyr]

I think they spawn at runtime but yeah

[celest python]

userassetdata is a container that'd keep the "data" in shipping build that you can serialize during editor

[tawdry zephyr]

My world is... enormous, so none of that at runtime for me

[celest python]

sockets get serialized into the mesh class directly, since you cant do the same for your non socket data without engine mods, userdata asset is the way to go

[harsh storm]

I mean - it was your idea about the asset data 😅

Don't need to explain to us about mesh sockets

[celest python]

I dont know what kind of data* Mieszko is talking about

[tawdry zephyr]

I'd love to know more too

[harsh storm]

I've got an idea

[celest python]

it could be a socket, or just raw FVectors representing relative transforms

[harsh storm]

@crystal hatch Can you expand a bit on how FN adds that extra data to generate the nav links?

[harsh storm]

I also thought about this as well.

[tawdry zephyr]

Maybe they have a secret way of performantly accessing all AssetUserData of a type from a world 😄

Definitely missing part of this picture

[celest python]

its public via an interface

Mesh->GetUserAssetData

[tawdry zephyr]

I know 😄

[celest python]

too much slackers for today

bye

[tawdry zephyr]

I literally wrote some code using that interface today 😛

[celest python]

i found my old code btw https://gist.github.com/intaxwashere/b915daa7c1f27475a55bb9f7990ca2ed

its bad, slow, probably wouldnt work either

but in case if you need it

its also intentionally written badly to achieve proof of concept only

[tawdry zephyr]

Thanks for that! I think it has the same issue I pointed out before though

[celest python]

which one?

[tawdry zephyr]

If there's a valid longer path it'll never reach the partial path because it'll never test for it

But again, I haven't tried the other idea, of simply searching towards the goal instead of searching along the path and potentially spawning some nav links there ahead of time just before the AI MoveTo is called

[celest python]

yeah naturally it wont cover that

[tawdry zephyr]

I think that idea could feasibly work though now that I think about it. You'd just do multiple traces based on how far the goal is and see if there are any navlinks to spawn. Not perfect but doesn't have to be

[celest python]

what kind of isekai is this anyway

the one pratagonist is an average loser in the real world and a hero in another? 😄

[tawdry zephyr]

Not a hero 😄 Think KonoSuba

[celest python]

its still on my watchlist

[tawdry zephyr]

It's the best Isekai on the planet

[celest python]

re:zero still exists

[tawdry zephyr]

Yeah re:zero is good

[celest python]

if you are into evil mode you can do that trace thing per path node

then if it succeeds run pathfinding from found location

recursively

and sacrifice around 2-3ms at worst case scenario

but it would be "perfect"

[tawdry zephyr]

Trying to run a big world on a small device so don't think I can afford that

[celest python]

you have up to 10 pathfindings if you have less than 10 AIs pathfinding at once

if you run on a seperate thread

[crystal hatch]

Super high level, because it's been like 10 years already 😄 :

• we have a dedicated asset to configure a collection of links, with nice visualization etc.
• every static mesh can have dedicated user data that points to one or more assets of that type
• at runtime we extract this data and based on it create navlinks, with some additional testing for applicability (in FN you need to care about "things in the way").

[celest python]

just something came to my mind btw, that specific situation seems to be guaranteeing if a valid path prevents you to execute climbing, there will be sharp turns in the path

you can filter the path nodes by calculating their direction to next one
and cut 90% of the operation

[harsh storm]

@tawdry zephyr 👆 He speakth!

[harsh storm]

https://tenor.com/wHOT.gif

So Eren was accurate - user data

[celest python]

i guess since FN runs on dedicated server it wouldnt matter but, is every static mesh create navlinks runtime? I didnt ever play Fortnite so I might be being a little bit naive here by missing the design of the game 😅

i was assuming they create the navlinks like how UT4 does, in editor time

[crystal hatch]

Every player buildable thing and all walkable building pieces have these links, and most of them are being built at runtime

[celest python]

Ah, I see, okay

thanks

[verbal violet]

Hello, is there any way to get current active task from BTS/BEhhaviorTreeComponent ? Name at least or any reference on that

[celest python]

const UBTNode* GetActiveNode() const;

[tawdry zephyr]

Do you have an editor tool that helps with generating/visualizing these for the designers then?

[celest python]

this will only provide "instanced" nodes

[crystal hatch]

yeah.

[harsh storm]

with nice visualization
I'd imagine so

[tawdry zephyr]

Makes sense. For my project I'm just going... to use sockets... and make something that bakes the socket to user data 😄 Some primitive error checking such as them exceeding the ledge height

Since I don't need to build walls/etc at runtime I can just bake in editor I suppose

[verbal violet]

tnx

[tawdry zephyr]

I could also look into doing something like a procedural foliage spawner? That spawns nav links

[harsh storm]

What a wonderful class 😅

Wonder what it was intended for

[crystal hatch]

for managing hot spots, duh! 😉

In the original FN:StW when AIs attack walls and other building pieces they distribute nicely along the wall, and projectile tossing ones stand at the back, all at the defined locations. Hot spots are essentially "attack locations" but the thing has been built with more uses in mind. There are bits of that in AIModule, but the actual implementation is in FN.

[harsh storm]

I only found out about it 'cause I was exploring the AI System section in the project settings.

Oh dang - and while looking at AISystem.cpp I have learned that there is a static delegate that gets called whenever a pawn is spawned 🤔

Errr - when begin play is called on the pawn that is.

[crystal hatch]

I always say that code is the best documentation 😉

[harsh storm]

Sure - but some C++ code is awfully weird and hard to follow lol

[tawdry zephyr]

Interesting. I'm doing something similar for AI attacking something - they circle the target

[tawdry zephyr]

Best
Only

[quartz trout]

Hi! I have a question about EQS generator dot test. I have set the EnvQuery context to the player and trying to obtain the rotation, but with no success. Anyone knows what could be the issue?

[pine steeple]

Is this done by predefined points on the walls ? or generated via the nav system?

[crystal hatch]

the points are actually defined similarly to the navlink approach I described - there are assets containing information in relation to the mesh, and at runtime the "slots" are created dynamically.

I mean that's the way it worked when I implemented it way back when 😄 FN:StW definitely shipped with that, not sure if it ever got changed.

[trim berry]

yo any good places to start making AI?

[crystal hatch]

would you mind elaborating?

[pine steeple]

Is there a way to load namesh data from an asset into a dynamic navmesh ?

Basically trying to optimize our map generation system. Each building set should have its own namesh data but I could never get it working using NsvMeshChunk

[crystal hatch]

NavMeshChunks is the only "load a piece of navmesh and stitch it to the rest" thing we have.

[quaint bramble]

Hey! How do I ensure that AI MoveTo always rotates the character in the same direction? Sometimes the character rotates around in a huge arc which isnt necessary when its already facing the direction of where it's moving to.

Basically when AI moving I want the character to always use the smallest rotation possible, how do I do that?

[dense owl]

There is a rotation rate setting in the CMC. You might need to disable use controller yaw in the pawn settings

[lyric flint]

Hi, may I ask how I can run EQS in a state tree?

For example right now the return value how can I select a position or actor depending on what I want?

[lyric flint]

And is there a way to switch an AI between Mass AI and either a State Tree or Behaviour Tree?

[lyric flint]

I also notice that adding a condition to a selector in a BT doesn't do anything. Even when it evaluates to false, the leaf nodes still run.

[spring inlet]

probably because its right after the root node

add another selector between root and yours

[brisk compass]

Hi

[lyric flint]

Thanks I'll try

[lyric flint]

Huh, that works. Thanks.

[spring inlet]

i think the BT jumps right into the first selector, without evaluating any decorators/conditions

[lyric flint]

I see

[dense owl]

You need a simple composite node right after the root afaik, so your tree doesn’t just get stuck on root

You can run services on it tho iirc

[crystal hatch]

The ROOT is just a dummy node, editor-time-only, just so that there's a convenient way to indicate which BB is being used. The first node after it is the actual runtime Root (that's why I always name it that) and the execution starts from there. No conditions are being checked on the real root node. Services do work (by design, if not let me know).

[elder perch]

If you want navigation at runtime over a map and you don't want it to lag hugely as that happens, aside from using navigation invokers, how can you do that?

[crystal hatch]

you can use static navmesh, or configure the dynamic navmesh so that it doesn't get discarded on map load (needs coding I believe). If your map is procedural then that will involve a lot more work.

[elder perch]

No they are static maps, it's just got items in it that can moved around (barrels etc) that are likely to affect the navigation

[crystal hatch]

depending on the nature of the movable things you might get away with "modifiers only". So it's that or use dynamic and look for "how not to discard dynamic navmesh at game start". It's been discussed a couple of times already IIRC

[elder perch]

iirc?

International Integrated Reporting Council?

[crystal hatch]

yeah, sure 😉
If I Recall Correctly

[ocean wren]

Hmm, doesn't sound enough. You'd need to sweep a capsule along the spline to really see if its traversable. That's how the Havok guys did it (Ben Sunshine-Hill did a great presentation on their capsule sweeping shenanigans).

[celest python]

why nothing is easy

[ocean wren]

If it was, everyone would be doing it 🙂

[celest python]

You're inspirational as always 😄

[ocean wren]

Maybe someday we'll make it easier.. but until then, at least you have a job 🙂

I mean, its not outside the realms of reason that behaviour specification might be automated in the near future

[celest python]

It came to a point nothing surprises anyone when it comes to automating stuff

[ocean wren]

There's a lot of potential for making game dev a lot easier

and creative work in general

I'm of the view that co-creative stuff will be pretty popular very soon as the tools become more capable

Been reviewing some papers for AIIDE and there's some very nice work going on

[celest python]

Copilot writes my 1/3 of the code these days and it already assimilated me

[ocean wren]

I've only used it for python 🙂

[celest python]

Hey at least you can get away writing code for something you dislike 😄

[ocean wren]

I'm writing a bid for some funding for some more voice-control data viz stuff for unreal right now

using large language models and having them control an API is pretty on point.. Unreal won't be able to avoid it 🙂

[harsh storm]

Probably just on vacation to be honest.

They come and go though.

[celest python]

I noticed absence of our lord and saviour too even though I was just here for a few hours since a few weeks

[harsh storm]

You already abandoned us Eren

https://tenor.com/FIPr.gif

[celest python]

I recommend taking a break from Slackers to every regular in here 😄

intoxicating

it actually makes you more productive, not saying to shitpost

[harsh storm]

To be fair - that's how I've always treated it. I'm mostly here during work hours when I'm waiting for stuff to compile or blocked by something. Or when I'm just chillin'.

Ever notice how I like never interact on the weekends?

[dense owl]

I learn a lot by interacting and I know SFA rn, so that’s why I’m around a lot 😅. Also dead-end job with no escape rn

[fading mortar]

Hey guys can you please recommend some good guides/books (except pins) about AI in UE (preferably c++ based) in particular, cause I have a Junior AI programmer interview scheduled soon and I have not worked with AI before.
And looking into AI-related engine classes it doesnt seem to me "big" enough to separate the topic to position. Is it really so different from "Gameplay programmer"?

[keen crow]

There's no easy way to make BTService listen for AI messages like BTTasks do is there? I mean I looked into the source code and it seems BTComponent has some special structs to hold BTTasks references and stuff but I believe that could also be used for any UBTNode

[harsh storm]

There really isn't much out there for C++ based. But there are a few resources pinned.

[foggy moth]

It's good to see someone is getting paid well to do some work @ Unreal.... I wish there were a thankyou emoji i could send :/

https://docs.unrealengine.com/4.26/en-US/API/Runtime/AIModule/Perception/IAISightTargetInterface/

[tawdry zephyr]

As far as I can tell it is just gameplay programming, but also likely includes knowledge of AI specific tools such as behaviour trees

@crystal hatch actually, if I PR this node itself into the engine, think it will be accepted (assuming I do it exact way they want, which I'm sure I will)?
Edit: Or better yet, maybe just change the AI MoveTo node itself because all I'm doing is exposing parameters that the move request takes that weren't available, maybe you know why it wasn't done by Epic?

Only thing I'm not sure is what to name the node, ideally the original should become AI MoveTo Simple but don't want to mess with that

[foggy moth]

what could they do in worse case scenario - reject it?

[tawdry zephyr]

Isn't about worse case scenarios, just wondering if its worth doing in the first place

[foggy moth]

i chimed in on the last second of you posting - didnt even read the log you have going..... I do know how LIMITED AI::MoveTo() is - you almost 100% have to make your own task.....

In my own experience in application development the choice to its "worth" is yours alone to make

[tawdry zephyr]

Maybe I don't need to add a new node, maybe I can just expose those parameters to theirs, I don't see any downside or reason they're missing to begin with, but maybe there is a reason I've missed

[foggy moth]

if its beneficial - which i'm sure anythign outside of UE's default implementation of that funct is... i'm certain its far better than the state its currently in

[tawdry zephyr]

The choice is, if there is a good chance it will be accepted, then its worth doing, which the person I @ will have a much better idea of, I'm not here to debate philosophy 😄

[foggy moth]

i'm not trying to hold a debate with you -t rust me i'm on your side in teh matter.

theres tons of things UE that i'd wish were different

[harsh storm]

I haven't had to code my own MoveTo node yet (not counting my side scroller!)

[tawdry zephyr]

Check the top-most pin, you can just fork my repo

[harsh storm]

No need. Built in works for me.

[tawdry zephyr]

If you do, I mean 🙂

[harsh storm]

I probably wouldn't even if I needed to, because if I needed to, I'd be doing something else entirely.

I'm fortunate enough that most of my games work within UE's framework quite well 😅

[tawdry zephyr]

Fair enough. All I did was expose parameters that aren't exposed, it doesn't really do anything different, just allowing the option, I'm still unsure why Epic didn't do it to begin with

The main one I wanted is bAllowPartialPaths and @gritty glen also needed FilterClass so I just exposed everything that the move request has a parameter for that wasn't exposed

Hopefully MieszkoZ knows why Epic didn't expose them in the first place, then I'll determine if I should PR the entire new node or only expose the extra parameters

[dense owl]

It is interesting, considering Move to Location has all of those

[sacred shale]

currently running into some issues with RVO Avoidance and Detour Crowd AI Controller. Right now my AI character has completely custom locomotion logic (separate from Character Movement) completely using Root Motion animations. In the avoidance example on the Unreal docs, they are using the Move To node in AI Controller along with RVO Avoidance and the Detour Crowd AI Controller. I am not using character movement, but rather creating a path to a location synchronously and using a direction vector pointing my character to go straight there.

Is there any information from RVO or the crowd following component I can use to affect my direction vector? Should I be using character movement using Move To if I want to do this? Any help would be appreciated

https://docs.unrealengine.com/4.27/en-US/InteractiveExperiences/ArtificialIntelligence/NavigationSystem/Avoidance/

for the record this is what I am referring to.

Are these irrespective to character movement? Will this add character movement sliding to my characters if I have these enabled?

[uneven cloud]

Haha

[uneven cloud]

There is a course on the learning site called AI with BP. That will go over most of the systems. Then you can dig through the code.

[uneven cloud]

You should not use detour with RVO. It's either one. Detour adjusts the path to avoid objects, so you'd need to override some functionality to use it without the movement component.

[tawdry zephyr]

How do you determine whether detour or RVO is more suitable? I'm new to avoidance in general. Is either of them better at handling the situation with two actors crossing paths both trying to move out of the other's way but because they don't communicate they endlessly move into each other's way? 😄

[fierce carbon]

Literally trying to work this out myself

[sacred shale]

as far as I can tell the Detour Crowd AI Controller is literally just the AI Controller but casting the Path Following Component to the Crowd Following Component, is there any information I can gather from that?

like how I can recalculate my direction vector to determine to move away from other enemies, since I'm not using the Move To node

which typically would do that for me

[uneven cloud]

You should use the move to node and override functionality in the crowd path following component. I don't remember which function it is, since it's different than the default path following component.

[sacred shale]

thank you!

[sacred shale]

I seriously dunno what I'm doing wrong. Using character movement still causes these guys to all bump into each other. Using pawn control rotation makes no difference. is there a typical simple algorithm I can use to recalculate my direction vector or something? One thing i was thinking of doing was doing a line trace to the location I want my AI to move to, then if it hits another enemy, just get the right of that vector and strafe around it until the line trace doesn't hit anything, but probably not the best solution

It looks like most of the crowd following component functions aren't meant to be used outside of the class despite the fact that they're publicly exposed, most of them have no comments or documentation (the Unreal documentation also has nothing) seriously at a loss lol. pullin my hair out over here

at the very least if it could give me all the overlapping agents that (probably) would help me but it looks like that's all handled by the Crowd manager

[uneven cloud]

Are you using the crowd following component? Why are you trying to use the functions outside of the class?

You need to give more information on what you are actually doing, instead of saying that it doesn't work. Have you tried debugging it with break points and/or the visual logger instead of guessing (control rotation has nothing to do with avoidance) or getting frustrated that you want to reinvent the functionality.

[sacred shale]

I am trying to incorporate the detour crowd AI controller onto my existing AI. the only problem is I'm not using standard character movement, I'm using purely root motion animations

I am creating a custom controller which casts the path following component to a crowd following component just like the detour crowd AI controller. My custom locomotion logic creates a direction vector from the main character's position to the location it is trying to move to and uses that to drive the movement. I am trying to extract any information I can out of the crowd following component to see if I can somehow influence my direction vector just like the way they're doing in their code. But ultimately this whole thing would probably be easier if I got rid of all that custom locomotion logic and just used the move to node like the example project on the unreal forum.

I am trying to use the move to nodes and they work but my character slides along the ground because it wasn't set up to respond to character movement. That's a separate thing to refactor for my animation blueprint

My characters spawn in on a random point inside of a circle. They walk to random points in the circle, stop, wait a few seconds, then move. Unfortunately using Move To at the moment doesn't solve this, they still just slide into each other. Is the main Detour AI controller set up differently? I'm seriously unsure as to why I can't derive from it, the only code I see is a constructor which casts the path following component to a crowd following component

Idk I'm prolly overcomplicatin this this is causing me more stress than it's worth and probably nowhere near as hard as I'm making out to be

[uneven cloud]

It doesn't cast to the crowd following component. It sets the class to be the crowd following component instead of the default.

You need to use the move to logic, because it MUST use the path following component to follow the path. What you need to override (in your own crowd following component) is sending the information to your locomotion functionality instead of the movement component.

[tawdry zephyr]

I will just make my AI detect "am I touching another AI", and then on update "well, I've been touching them for too long so I'm going to stop" which will put them back to "idle" before going to their next waypoint. I'll randomize what counts as "too long" on the initial detection so usually only one of them stops, and sometimes both stop 😄 That will work for patrolling and for combat, well, I'll wait until I have an issue then fix it a similar way. Maybe I'll just randomize a "priority" for each bot, if it happens to be == they can both re-randomize. Lower priority maintains their pathing, higher priority changes.

Such simple solutions don't work for a lot of games tho 😦

[lyric flint]

Is it possible to use EQS with StateTree?

[warped solstice]

not sure where to post it, we have a problem with rebuilding navmesh, really huge map, rebuilding crashes engine because not enough vram (24gb vram 4090), any ideads what can we do?

[ocean wren]

Buy A6000's for your build machine?

or I guess RTX 8000 or whatever the equivalent is

[tawdry zephyr]

Any reason you can't do dynamic navmesh with invokers instead? That's what I'm doing for my really huge map 🙂

I never had a crash in the first place but I also never tried to build a static one

[warped solstice]

it's still better for performence to build it rather than use invokers

[tawdry zephyr]

Ah yeah it would be. Sorry I can't be of any help 🙂

[warped solstice]

nah its okay, its still some advice, we are thinking about that but would like to find a solution to current problem if possible, if not then we will buy some quadro or go with invokers

[uneven cloud]

How are you building it and are you using world partition or world composition?

[lyric flint]

Anyone know best way to get the Nav Mesh to generate within this vent ?

Vent is using complex collision but as you see no generation of Nav mesh inside ?

[dense owl]

Might not be big enough

[lyric flint]

isn't there something in settings that you can change for it to accept it ? like allow AI to move in there ?

[dense owl]

Not sure

[lyric flint]

fair enough

[uneven cloud]

Can the AI fit in there? If you change the settings to fit in a small space like that will change it for the entire nav mesh. If the settings are smaller than your character, that will cause issues navigating around.

I'd recommend nav links instead, especially if they have to do special animation to fit in there.

[lyric flint]

?

well I was hoping that I could have certain AI only navigate through the vents, I was going to use a modifier to help with that

issue I'm getting is no matter how I chage the nav stuff to allow Navigation to gereate in their it just isn't wanting to generate I've made vent bigger and it still won't generate in there

[uneven cloud]

That doesn't change what I said.

[lyric flint]

Not sure what you mean can it fit in there, I would be making one that will fit ?

or am I not fully getting something here?

Looking at an AI Size of about 0.293794 m

[verbal violet]

Hello ppl, is there any way to simple enable/disable nav link component? I have nav link component as part of my Door blueprint and want on open to enable navlink, and on close to disable ?

[uneven cloud]

How are we supposed to know if you are going to have a really small AI that fits in there or if you are going to do something with animation to make them fit?

You can have multiple agent settings in the project settings. This creates multiple nav meshes, which can cause memory problems. But a few of them isn't a big problem from my experience.

Something that small might also be better as Niagara and using boids.

[uneven cloud]

Are you using smart link or point link? Point links you change the nav area. Smart links have a function to disable.

[lyric flint]

apologise thought with a vent and the picture a small AI would have been a given

[verbal violet]

Regular Nav Link Component, added in blueprint, there is no smart links. How to change nav area, that is first what I tried but can't access to anv area to se

[lyric flint]

also making the vents bigger in both height and width it's still not really wanting to generate in there but when moving the collision on the mesh it's building nav each time so must be doing something

just isn't show visiable green thing that nav mesh has generated there

[verbal violet]

I tried clear for links but nothing happend, maybe should call some nav mesh regen? but that also not optimal for performance

[lyric flint]

you have any links to where I could get more info on this ?

[uneven cloud]

Info on which part?

[lyric flint]

the multiple agents bit

[uneven cloud]

Go to the navigation settings in the project settings. You'll see an array called supported agents.

[lyric flint]

arr yes, I looked at that slightly weren't sure on it

So what would this allow me to do this adding a supported Agent ?

[uneven cloud]

If you are BP only, it might not be accessible. You can try to deactivate the component. If not, you could switch to a smart link that has more BP functionality.

[uneven cloud]

You set up the agent settings for your different AI sizes. I would highly recommend grouping them together into categories like small, medium and large. Then you set the settings to fit those AI sizes. It's really not that hard.

[verbal violet]

ok, tnx

[lyric flint]

arrr right okay

not working

Still does not like this venting, I'm starting to think it's not generating issue, but maybe something else

[lyric flint]

Now I'm just confused like why have i got pink showing when the vents close to floor of the where the green is

When I lower this to the floor it blocks navigation which i would expect

any ideas here cause I'm quite confused whats happening here

[tender chasm]

Pink means low height for your configured Agent. No color means it's too low for the Agent height (or the agent height is too high), so it won't allow the navigation mesh to be built below the Object

You should be able to change these settings on the recast navmesh actor if I remember correctly.. But you should also be able to completly remove the Actor from influencing the NavMeshGeneration.. Might be easier

[lyric flint]

so found how it was doing the pink thing, makes sense what you said

my major issue which is driving me round bend is the follow

The white vent is on for player to crouch through and literally just that height will about generate nav mesh

the silver is the vent which actually I want only small AI to go through but no matter what settings I change it simply won't generate nav mesh in there @tender chasm

[warped solstice]

world partition

and crash is durin using building paths

[uneven cloud]

How are you building paths?

[uneven cloud]

What is the size of the opening and what is the agent property settings?

[lyric flint]

so the white vent is

I've just made another vent which can fit a 1m object within

[uneven cloud]

Is that the entire size or the size of the opening?

[lyric flint]

thats the entire size

if I understand you correctl

*correctly

[uneven cloud]

That information is useless. I asked for the size of the opening and what the agent settings are.

[lyric flint]

That help

the opening is equal to the size I just mentioned it's open at both ends

[uneven cloud]

No. The supported agent settings in the navigation settings, not the nav mesh settings.

[lyric flint]

it wasn't working so I deleted the custom one

Just re-created a supporting agent

it's gonna be default settings obvs but what I changed was the radius and height and still wasn't wanting to work

unless I missed something

I need to go but will return later to hopefully getting it to work 🙂

[uneven cloud]

Your supported agent settings needs to be smaller than 1/2 the size of the opening plus a buffer. Keep reducing the agent settings.

If the size you gave is correct, the radius has to be < 50 and half height < 98. However with the pictures you showed, it looks a lot smaller than the dimensions you gave.

[lyric flint]

The silver vent or white one ?

White one is actually bigger them 1m, planning can stand up in it where as one I just made is just over 1 meter both width and height

Also, would I need another nav bounds volume for this other supported agent I've created ?

[uneven cloud]

No you don't need another bounds volume.

You are making it far more difficult by bouncing between different size of openings. Pick one and then find the settings that work.

[lyric flint]

That's what I tried to do with the vent

But it wouldn't accept anything I pit in to generate the nav mesh.

Hopefully with this new vent being just over 1m wide and high it will actually work

[dense owl]

Will the player actually see the AI travelling through the vents btw?

[lyric flint]

So I changed it to yeah as they can also be used by player

This is the new vent versions I'm making

In the previous version you would have seen the ai still just only at points where it goes over a opening

[warped solstice]

as i said, with button build paths

[uneven cloud]

Are you following the world partition navigation documentation? https://docs.unrealengine.com/5.2/en-US/world-partitioned-navigation-mesh/

[strange notch]

why does my ai move just fail

[lyric flint]

Is there a nav mesh ?

And can it get to were it's going

The ai move to won't bother moving AI if path failed

[dense owl]

Use the AI debugger and vislog to troubleshoot

If it wasn’t the missing navmesh

[strange notch]

Thanks ill try that rn

[nova raven]

why arent they allowed in there?

they are made out of static meshes btw

like just cubes

its fixed if i put them on "overlap all" but i need them to block the bullets

[dense owl]

Why isn’t what allowed where?

[nova raven]

sorry that was really vague

my enemies that have the code for ai arent allowed in the navmeshboundsvolume

but its because of their collision

is there any way to like

whitelist it? or anything?

[dense owl]

Are you talking about the holes in the navmesh ?

[nova raven]

yes

[dense owl]

Go to their mesh settings, turn off can ever affect navigation

Same for capsule or other components if needed

[nova raven]

ayy that works ty

but they.. arent moving

ill show my code

[nova raven]

and this part shouldnt affect it

[dense owl]

Troubleshoot. Is your AIMoveTo failing?

[nova raven]

the roam is working, but its not suceeding

and it only detects the player as soon as the game starts, so if i start the game behind them and move forward it doesnt detect me

[nova raven]

same thing wit the retriggarable delay

[dense owl]

Might be better to use EQS with the built-in perceived actors generator

[nova raven]

im gonna look that up hold on

[lyric flint]

This is driving me round bend Nav still won't generate inside the vent only on top of it

Vent opening, literally big enough to fit player croached easily so relly can't get why with the agent settings applied why nav can't generate inside of it

actually scratch that with a build all levels

it's working but I now have two nav mesh it seems

okay so another build all levels get rid of the double nav mesh green thing

[warped solstice]

Thanks, didint see that. Will check it!

[lyric flint]

awsome so I did this

two supported agents the default and another with altered radius and height, however in the world it's only showing the Nav Generated for the Defualt one and not the Low one as well, is there setting somewhere I have missed?

so it only seems to like one supported Agent if I include the other it just doesn't generate

Get rid of the defualt on supporting agent and it uses the other one there

now I can keep this but need a way to ensure the AI when it should uses the Vent to traverse and not the hallway, currently theres a modifier there making that area different cost etc to the purply one

[uneven cloud]

Does it not generate or does it not debug draw?

[lyric flint]

so without it drawing it I weren't able to actually see if it was generating it, I was taking the drawing as what it is generating

I could be wrong there though

[uneven cloud]

You are wrong. You need to enable drawing on the recast actor that is generated.

[lyric flint]

Now I have put the other supported agent back I lose the draw for the Low one and have neither one or other or both

I have two recast obvs and both are set for drawing etc so not 100% on this one

Apologies so with drawing back on all I see is the Low Recast and not the default one ?

Okay so fair enough ever knew it defaulted to off when drawing

[olive prism]

Is it possible to make a combat artificial intelligence that learns from combat and improves?

[dense owl]

Possible, yes. Should you do it? Probably not

[olive prism]

Why shouldn't I?

[dense owl]

Good AI is not smart, it just has the semblance of being smart. Players don’t have fun when they’re getting wrecked by an AI that’s learned all their tricks

The Last of Us had to dumb down their AI because it would just flank the player and absolutely destroy them, and people hated it

It’s ok to make it seem like it’s learning, but no one wants to sit there playing chess against Deep Blue in your game

[olive prism]

Thanks you!

[unborn sphinx]

Maybe "learns from combat and improves" could means "improves the fun of the player." You could make AI that adapts to the way the player fights to make it more engaging and fun. If they like doing a certain type of combat, the AI could pre-empt that and set up the scenario to be more fun for them.

The player likes using explosives? Cluster the AI near funny explosion points so they go flying in cool ways/interacting with interesting set pieces.

Or, line them up and run out into the line of fire of the player if they like CQB with automatic weapons.

Or, if the player likes being a sniper, prepare to engage them at a longer distance and give them a challenge but a fun scenario.

[dense owl]

Yeah, that would be fun for sure

[olive prism]

Thank you very much to all

[lyric flint]

So this doesn't seem to be working

when playing the AI never moves to the vector thats been passed out

even if I flip the + inputs AI still seems to not want to move

Keeps telling me this as well, NavMesh needs to be rebuilt which I've done

could this be something to do with I have two recast and it not knowing which to use

[tawdry zephyr]

Are you projecting that vector onto the navmesh?

[lyric flint]

I did try try to find that but couldn't find the function

I know is something like project ...

[tawdry zephyr]

I don't use blueprint for it but this is my C++

            if (NavSys->ProjectPointToNavigation(CurrentWaypoint.GetLocation(), ResultLocation, NAV_EXTENTS, NavData))
            {
                CurrentWaypoint.SetLocation(ResultLocation.Location);
            }
            else
            {
                // We have utterly failed to resolve this waypoint, or there is no valid nav mesh at all
                bLastWaypointWasUnreachable = true;
                bWaypointUnreachable = true;
            }

(The commented part might be a bit misleading since its part of much more elaborate logic so ignore that)

[lyric flint]

I've done that and it still don't move

So when I try grab a random point it fails

[tawdry zephyr]

Did you debug the values? Print if it fails, draw the debug location, etc

You'll want to step through the engine code with a debugger and see where its failing

[lyric flint]

I've done random point to debug if it's my code or something else which is must be

it should work with that though

it's the function UE gives you

[tawdry zephyr]

Yeah, it should do, unless there is no navmesh there

[lyric flint]

well I have Nav mesh there but because I am seperating my AI so one can go through a vent there is two recast

one for normal sized AI and another one for the smaller AI

do I need to pass in the recast it needs to use or ?

[tawdry zephyr]

You'll need to pass the nav data for that navmesh I suspect, but I haven't dealt with multiple so I'm not 100% that's it

If you give nullptr it does

    if (NavData == nullptr)
    {
        NavData = MainNavData;
    }

I'm suspecting its not the MainNavData that is responsible there

[lyric flint]

I'm trying to select it but it doesn't let me

[tawdry zephyr]

There are functions like this, not sure what BP equivalents are there (these functions are part of the UNavigationSystemV1 class)

This is how I get a reference to my navdata but I don't access a secondary navmesh

    UNavigationSystemV1* NavSys = FNavigationSystem::GetCurrent<UNavigationSystemV1>(GetWorld());
    ANavigationData* NavData = NavSys->GetDefaultNavDataInstance(FNavigationSystem::DontCreate);

So long as you have something to pass to the NavSys, you can get the NavSys that way and have it return the correct NavData

[lyric flint]

but I'm not doing any of this in C++

my AI stuff so balckboard are all BP

just because I'm not good enough yet to do C++ for this bit 🙂

[lyric flint]

Like it's got a random point but never sees it as succesful

[lyric flint]

it does keep telling me the NavMesh needs to be rebuilt

[lyric flint]

anyone help with this becuse it's driving me round the bend, I literally can't find whats wrong but this all started roughly after messing with adding another nav thing that only smaller AI can use

[lyric flint]

even doing default character based BP and AIC BP based on defualt AIC it simply just can't find valid vector on nav mesh

There is literally generated Nav mesh there like how is it failing to grab a location on it

So I have noticed this, Its getting the exact location of the actor every time which is why it's failing which leads me to believe it must be something with the Nav Mesh which is messed up, It does say NavMesh needs to be rebuilt as you'll see in video. I've rebuilt nav mesh multiple times but constatly says same think

[lyric flint]

is there anyone who can help cause this issue is really causing me pain

literally worked up to point of trying to implement another supported agent and now everythings broke

[uneven cloud]

Use the visual logger to debug. https://docs.unrealengine.com/4.27/en-US/TestingAndOptimization/VisualLogger/

[uneven cloud]

Shadow mode in Killer Instinct did this years ago. There's a GDC talk on it.

Metal Gear Solid 5 has adaptive AI, such as AIs spawn with helmets if the player does enough headshots.

Then you have left 4 dead's AI director that adjusts the game based on player behavior.

At the end of the day, we are creating player experiences and not real AI. Most advanced game AI topics are about balancing believable AI, difficulty and performance.

[lyric flint]

will do, I did get it working some how but then after going through some stuff it now don't want to work again haha

[dense owl]

Keep at it, that’s programming. You make something, it doesn’t work, you fix it, you change something else, it breaks.

[sudden citrus]

do overlapping nav area modifiers have any concept of priority?

I'm doing a quick test in the editor now and it looks like Null has advantage but I remember running into the issue a while ago where the last updated one would take precedence

[sudden citrus]

sure, just no need to think about it in terms of machine learning, but rather clearly understandable mechanisms for the player

[dawn schooner]

I am working with state trees and I was wondering if, when we're executing a task on a child state, the parent state is also active and therefore their tasks also execute 😄

[radiant path]

I think that is intended

They are more like scopes I suppose where every scope can still abort all children by succeeding or failing. Well that's how it seems to work anyway.

[dense halo]

hey, does anyone know how to set the initial values for blackboard?

are they always zero initialized?

[crystal hatch]

you can create your BB component before running the tree which will give you a chance to set valued before the first BT run. Call AIController.UseBlackboard (also available in BP) and after that call you can access the BB component

[trim berry]

Yo ai peeps how do you guys decide what type of framework you use for an ai e.g bt utility goap blah blah blah

[uneven cloud]

Figure out the pros and cons of each (I made a table for easy reference) then pick the best one based on the needs of the game and the team.

[trim berry]

is it cool to paste it in here? like a screenshot of it

[uneven cloud]

No. This talk is a good place to start:
https://www.gdcvault.com/play/1024224/Flame-Retardant-AI-Stopping-AI

[trim berry]

rah xD

why no

[uneven cloud]

I work at a studio and what I do on company time is owned by the studio.

Also you really need to understand the different architectures to make a decision.

[trim berry]

fair enough

thought you was just being a bit weird about it

[trim berry]

@uneven cloud fully appreciate the link , suuuuper helpful

[dense owl]

Great link, thanks, now I want to learn other AI tools 😀

[unborn sphinx]

There are a ton of good AI talks in the GDC vault and on the GDC yt page. The vault has more videos, but is harder to navigate IMO.

[crystal hatch]

99% of my theoretical AI knowledge comes from a combination of "AI Game Programming Wisdom" book series, "Game AI Pro" book series and GDC AI talks witch a dash of AI-related parts of "Game Programming Gems" book series.

[celest python]

TIL we can brute-force change the execution of the BTs

[ruby python]

Hey guys, the purple thing is my NavMesh, anyone knows why there's this path which I can't seem to include in the Navigation? Even the top of the tank has it but not the path

It seems to be only this specific landscape which has these weird paths

[celest python]

check show collision on console

see if anything is blocking it

[ruby python]

sorry where do I do that?

[celest python]

check which shortcut is assigned to open console from editor settings

in EN keyboard it should be tilde

[ruby python]

yeah I don't think it did anything

So im guessing im doing it wrong

[celest python]

is it not displaying any collision boxes in the map?

[ruby python]

shows me same as before, these collisions are blocking volumes

Oh here

So I see these unclear lines, do you know how to fix that?

[celest python]

yeah its the collision display

doesnt seem any collision blocking the path

I was betting on some weird collision setup since you said its happening on a specific landscape

[ruby python]

it might be

I searched online and people said to check ‘fill collision under landscape for navmesh’, do you know where that is?

[celest python]

its in the scene components that you put to actors

[ruby python]

doesn't that mean that the navmesh itself wont change?

[sudden citrus]

the navmesh will change, because you'll (hopefully) remove the collision

and then it will generate walkable polys on the path

[modest dune]

okay so kinda basic question, how do I move my ai to one specific place in the world, cus I thought that was what the world direction input was in the add movement input node

apparantely not

[tawdry zephyr]

AI doesn't use AddMovementInput because they don't have an input device. use the move to nodes

[spiral bone]

I've got a question related to BB and BT. I made a fairly complex but solid AI for my first enemy. It' a swordsman, which basically it'll just go to the player and try to hit him. Now, if the enemy isn't seeing the player, [they'll just patrol and do their stuff].
Right now, I want to make a new enemy, which is an archer. The blackboard should be fairly similar, but the behaviour tree will be similar in, let's say, just a 30%.

In this scenario, what would be the best way workflow? In my last project I've been duplicating the BB and the BT and that worked fine, but I would like to know if there's a more efficient way to work with multiple enemies.

Something to consider is that all enemies are going to be humanoid and all the AIControllers are going to be children from the same class.

[trim berry]

Just make a new one ?

I just have an ai controller class that has the BT and BB as an input exposed in blueprints

It isn’t worth tweaking your current one to fit the archer

[lyric flint]

If you have behaviour that is generic enough you can turn that into its own BT and call the Run Behavior node whenever you want to execute, for example, a Ranged Attack Behavior. All variables that can be used by all AI could then live in a parent BB, and then make children BBs that have AI specific variables.

[lyric flint]

I would counter that it isn’t worth writing the melee attack behavior multiple times for multiple AI. It also means if you update that behavior you only have to update it once. This is akin to turning repeated lines of code into a function.

[trim berry]

but you dont write it multiple times?

your just making a diff BT

[lyric flint]

If you have two independent BTs that would be my definition of writing it twice. Writing is probably a bad verb—I should have said creating.

[trim berry]

yeh id have to disagree.. dont think that rule extends here

[spring jetty]

Hey guys, any idea why EQS doesn't come outta beta mode ? it still says not recommended to ship projects with

[trim berry]

but yeh its w.e

[spring jetty]

then how would one implement an AI that reacts to surrounding sounds without eqs for example ?

[lyric flint]

It’s because the front end isn’t up to Epic’s quality bar yet. Functionally it has been used in many games so consider it effectively out of beta.

[spring jetty]

wdym the front end ?

[lyric flint]

The UI IIRC

[spring jetty]

on the doc it says not recommended though, by UI you mean the debug system they provide with it which you can see on screen ?

[lyric flint]

#gameplay-ai message

[spring jetty]

thx a bunch, kinda got it.

[lyric flint]

That’s from one of the developers. So feel safe in using it 😉

[spiral bone]

Thanks for your answers, @lyric flint and @trim berry.

I think I know how to proceed.

[harsh storm]

Not "one" of the developers. It is the developer 🤣

[lyric flint]

Long may he reign

[trim berry]

lool

[harsh storm]

Mieszko is the one we praise (and curse ✊) for the AI tools. BTs, EQS, AIController, debugger, Mass, etc...

He has help finally though 😅

[harsh storm]

https://tenor.com/ZomK.gif

[idle crystal]

Hello, I'd like to ask you for some help, I've been having some trouble with my AI in my Tower Defense project, it would be really simple, it's just supposed to follow a path created by target points, I followed a tutorial for this because I'm fairly new to unreal engine. The problem is that the character only turns left, but not right, I tried to check everything but I have absolutely any idea what the problem might be. I'll link the video I followed. I'd really appreciate some help.
https://www.youtube.com/watch?v=SfnvbzfGZnE&t=1s

[dense owl]

If you’re following a tutorial and it’s working for them but not for you, watch it again, you probably missed something.

[idle crystal]

Well, I already did, but I’ll give it another go tomorrow.

[olive prism]

Hello, I am copying a pathway system with splines for an AI to move, but I don't know why my AI doesn't recognize where it has to go, I've been trying to see for many hours but I have everything exactly the same as the other system that does work for it

Can someone tell me what could be causing this problem?

Thank you

[ivory rune]

Do you have more details? Like AI doesn't execute BT at all or something wrong within BTs?

[olive prism]

I'm forcing that part of the BT to run

Now I discovered another problem and that is that when I update the behavior it does not change the enum in the BT

[ivory rune]

You probably need to check if the location set to BB is right or not, then nail down the problem to your character movement or something.

[olive prism]

Oki

how i can check this?

[ivory rune]

Add break point in your BTs task nodes or watching the BB value for the location is the really one of your spline or not?

Basically, if you are not able to set the correct value for BB, it would be an invalid vector value at all.

[olive prism]

I just checked the coordinate that the spline gives me and it is correct

Positions it right at the beginning of the spline

[ivory rune]

So the problem is your character is not moving?

[olive prism]

sure, my character doesn't move towards the spline

The movement in general of the AI works, I have another state that is to follow my character, and that executes it correctly

Done, I was able to solve it, I was just missing a connection in Ai Move To

The pawn exec

[olive prism]

Sometimes talking about the problem makes me solve it faster, I realized very quickly where the problem was when you asked me this question

I don't know why that happens to me hahaha, sorry for the wasted time

[ivory rune]

Did you forget to hook the pawn pin to the AI MoveTo task?

[olive prism]

Yes

here

[ivory rune]

Even input the AI pawn, doesn't work?

[olive prism]

This works now

[ivory rune]

Still have any other issues now?😅

[olive prism]

hmm actually yes, but it's not a problem, it's a question

My AI when I quickly pass through a wall, it gets stuck with the wall since it can't go through it, I would like it to realize that it has a target in front of it and try to cross in another way, is there any way to do this? Maybe a tutorial or documentation can help me

I can record this if you dont understand me

My english is so bad

[ivory rune]

It's okay. I think I can understand it. Do you have any logic built in BTs that how it supposed to do if realized the target?

For how to set the target, I suggest using AI perception component.

[olive prism]

Sure, the target sets it right

[ivory rune]

So how could AI stuck? Did you make it chasing players?

[olive prism]

The problem is that the AI tries to break through the walls

[ivory rune]

Ok, I think the problem is why the wall object doesn't be exclusive from the navmesh.

Did you rebuild the navmesh though?

[olive prism]

How i can rebuild that?

In build?

Build paths?

[ivory rune]

Yeah, try it.

[olive prism]

Hmm same problem

[ivory rune]

But you can see the navmesh is not correct in your map. Some places has wholes but it has nothing there.

You may check your mesh collision settings that have "CanEvenAffactNavigation" checked.

[crystal hatch]

Just so we're clear, I'm the one to curse about the UE4-era AI tools (that we still use/maintain/develop) and Mass (mostly) 😉 . State Trees are Mikko, and I only kicked off Smart Objects that were taken over by another dev since.

[harsh storm]

Si

Isn't Mikko also working on a new pathfinding thing?

Not MassZone but something else

[crystal hatch]

not at the moment. But he did put together some awesome prototypes that we're sure to pick up at some point

[unborn sphinx]

What I like about the UE AI tools is that I watch a bunch of GDC talks about AI, over the course of months, then when I get to UE I find all the cool stuff already there it's like... u can just sit down and play with enterprise tools. So thanks.

I would get excited by some AI devs getting excited about like BT, or whatever... (yes, these are old GDC talks lmao)... and I see UE not only has these tools, but is building the next gen tools that people are rumblign about too at GDC.

[lyric flint]

hello all. ive noticed some of the default engine decorators do not have Observer Aborts options. (for example Gameplay Tag Condition). am i missing something here? must i recreate the decorator myself to add this functionality?

[tawdry zephyr]

That was a good watch. It did a good job of justifying my use of FSM over BT, not that it came from a place of experience 🤣

The chart is useful

[sudden citrus]

what are you talking about, Bulletstorm was awesome 🙂

[crystal hatch]

indeed it was!!!

[sudden citrus]

My big naive UE5 AI wishlist is:

• mobile navmesh (e.g. on a ship)
• a more "moddable" EQS
• automatic traversal navlink placement

[crystal hatch]

mobile navmesh (e.g. on a ship)
oh man, this has been on my todo list ever since 4.2 😄 We just never had an internal need for it so I wasn't able to spend time on it.

[harsh storm]

The strategy is the usual. Convince Tim to do a Season of Fortnite on a moving ship with waves of enemies.

[crystal hatch]

Crossover with Sea of Thieves 😄

[celest python]

<@&213101288538374145> this is a great source, can we please pin it?

[celest python]

[potent iris]

Np son

[sudden citrus]

just buy Kythera with fortnite money, easy

[celest python]

no

[crystal hatch]

nah, we just want more nav, we can handle everything else 🙂

(we have too much fun building it 😄 )

[sudden citrus]

lol I can relate, every time I see a well-built marketplace plugin my reactions are 1. wow neat 2. but what would I do?

[uneven cloud]

The navigation features are included in Havok, so I doubt there is a large push from bigger studios.

The EQS is very moddable in C++.

[sudden citrus]

Where should I look for modifications in terms of stuff that isn't obvious from the editor? Item types?

[uneven cloud]

It depends on what you are trying to do

[sudden citrus]

Maybe I'm approaching my problem badly but I would like contexts to be less static (right now it's a subclass of) - e.g. a context along the lines of "get <thing> with <gameplay tag> from my collection" where I can pass the gameplay tag in as a data binding

[celest python]

that was one of the nice features of kythera but their domain specific language was pita to work with

in UE I guess bindings happens through run EQS node in BT but its not extensive

[uneven cloud]

What is the problem that you are trying to solve?

[sudden citrus]

my targeting layer can reason about multiple types of targets at the same time and I don't want to have a duplicate context class and query for each case

[uneven cloud]

Why not make it a test instead of a context?

[sudden citrus]

Then I'd be hardcoding the target type per test? But I'm not asking for help, I am simply pointing out that EQS is not as data driven from the querier's side as much as I'd like, you said it's very moddable from the C++ side so I asked for some avenues that I might be missing.

[unborn sphinx]

So Havok+UE is a very popular combination? interesting

[celest python]

BTs would have to implement property extension module like how animation system and statetree does but it doesnt so you're not missing anything

its not scriptable/moddable easily

there are simple structurse to allow bindings but they dont go beyond simple data bindings from node to eqs instance

[pine steeple]

@crystal hatch is there any news on NavigationSystem V2? 😛

i mean they went and changed everything to V1 years ago

[crystal hatch]

I did that 😛 And I did have a V2 prototype ready! But then we hired more people, and more projects happened, and priorities shifted, and... you get the picture 🙂 I recently started again calling out a need for a nav system rewrite, and it's a consensus that indeed we do need that, but we don't have enough people to work on it (AI team is spread really thin right now).

[pine steeple]

ah yeah makes sense, what was the plan for V2?

just more optimized, cleaner code? or new features. One of the biggest issues i see with navmesh and the navigation system as a whole is the generation cost, not being able to easily implement navmesh chunks from a UNavMeshChunk (i could never get it working)

[crystal hatch]

in short, support for a "limitless" number of independent navigation data instances of different types (navmesh, nav grapshs, flowfield, etc) with a hierarchical graph of them supporting seamless pathfinding and transition between any of them.

it was to make us ready for huge open worlds. I guess I saw the future 😉

[pine steeple]

hah nice

see i tried to do chunking

with our prefab system

                {
                    PrefabAsset->SerializedNavmesh.Empty();
                    for( int32 Idx = 0; Idx < NavChuckActor->NavDataChunks.Num(); ++Idx )
                    {
                        FNavDataSerialized& Data = PrefabAsset->SerializedNavmesh.Emplace_GetRef();
                        FObjectWriter(NavChuckActor->NavDataChunks[Idx], Data.Bytes);
                        Data.NavName = NavChuckActor->NavDataChunks[Idx]->NavigationDataName;
                    }
                }```

            if (APrefabNavChuckActor* NavChuckActor = Cast<APrefabNavChuckActor>(ChildActor))
            {
                NavChuckActor->NavDataChunks.Empty();
                for( int32 Idx = 0; Idx < PrefabAsset->SerializedNavmesh.Num(); ++Idx )
                {
                    URecastNavMeshDataChunk* Chunk = NewObject<URecastNavMeshDataChunk>(ChildActor);
                    FObjectReader(Chunk, PrefabAsset->SerializedNavmesh[Idx].Bytes);
                    Chunk->NavigationDataName = PrefabAsset->SerializedNavmesh[Idx].NavName;
                    for (FRecastTileData& Data : Chunk->GetMutableTiles())
                    {
                        dtMeshHeader* Header = (dtMeshHeader*)Data.TileRawData->RawData;
                        Data.TileCacheDataSize = 0;
                        if (Data.TileCacheRawData.IsValid())
                        {
                            Data.TileCacheRawData->RawData = nullptr;
                        }
                    }
                    NavChuckActor->NavDataChunks.Add(Chunk);
                }
            }```

but i never could get it to work

[crystal hatch]

yeah, I never got navmesh chunks either 😄 Someone else worked on that 🙂

[pine steeple]

all i wanted to do was save the navmesh in our prefab level

and inject it into our generated level to save on calculation costs

cause i lock the navmesh, and only release once the level has been created

everything is in blocks and defined sizes, so it shouldn't have caused much issue

on older platforms (ps4/xbox one), this is one of our biggest costs 😦

the main issue i found with chunks is it only works for static, not even dynamic with modifiers

[crystal hatch]

sounds like it should work [edit: it being the code you posted]. One of the changes I did when FN started using AI was to not discard the serialized navmesh, block regen on load, and once load was done reset the accumulated "navigation dirty areas". And then made random POIs dirty navmesh, for good measure. Saved shitloads of time on load.

[pine steeple]

how do you stop it discarding the serialized navmesh?

cause i already block the generation, and flush the dirtyareacontroller

[crystal hatch]

that one I believe is based on a flag in nav data instance, or nav system. Give me a sec.

[pine steeple]

this is what i do

    *  setting bForceRebuildOnLoad to false can override this behavior */
    UPROPERTY(config, EditAnywhere, Category = Runtime)
    uint32 bForceRebuildOnLoad : 1;

    /** Should this instance auto-destroy when there's no navigation system on
     *    world when it gets created/loaded */
    UPROPERTY(config, EditAnywhere, Category = Runtime)
    uint32 bAutoDestroyWhenNoNavigation : 1;

    /** If set, navigation data can act as default one in navigation system's queries */
    UPROPERTY(config, EditAnywhere, Category = Runtime, AdvancedDisplay)
    uint32 bCanBeMainNavData : 1;

    /** If set, navigation data will be spawned in persistent level during rebuild if actor doesn't exist */
    UPROPERTY(config, VisibleAnywhere, Category = Runtime, AdvancedDisplay)
    uint32 bCanSpawnOnRebuild : 1;``` i see the flags

[crystal hatch]

I'm looking at the code right now and it starts getting back to me. In general your code should be enough - with caveats. The main one being that the navmesh will get scratched and rebuilt if the navigation bounds don't match. I suggest you made sure that's not the case in your, well, case 🙂

[pine steeple]

yeah, i will keep tinkering with it, i mean its def faster than what it used to be

i managed to reduce it by a good third of the generation by tweaking stuff

but just getting that last bit of performance would be nice, we do hide the navmesh loading behind a loading screen anyway

i did try using async building but that turned out to take super long to build the navmesh

sure it didn't freeze the gamethread

but the generation took in the order of around 50-60 seconds

[uneven cloud]

I'm not sure why you'd be hard coding it. You mentioned maybe approaching the problem badly.

Contexts can be data driven outside of the param functionality. Not directly in the EQS, but it can call functionality that is data driven.

[unborn sphinx]

lmao hey I recognize that name

https://www.gdcvault.com/play/1033898/AI-Arborist-Proper-Cultivation-and

[mossy yew]

Hi guys, I have a really simple MoveTo function on my Pet class, Basically when I press E as my Summoner Character, it'll spawn the pet and its default controller

void ABasePet::Tick(float DeltaTime)
{
    Super::Tick(DeltaTime);
    
    TObjectPtr<AAIController> PetController = Cast<AAIController>(Controller);
    if (PetController && GetWorld()) {
    PetController->MoveToActor(UGameplayStatics::GetPlayerCharacter(this, 0));
    }
}```

this works, but if I change it to my custom AI controller then my pet no longer follows me

    TObjectPtr<APetController> PetController = Cast<APetController>(Controller);

I've tried changing it to this, but still doesn't work

[dense owl]

Is your pet controller an extension/ child of the normal one?

[mossy yew]

If you mean APetController : public AAIController then yes

[dense owl]

K

[mossy yew]

then the BP controller is from APetController

[dense owl]

Can you show that declaration?

Or was that done in bp ?

[mossy yew]

c++, which declaration ? like spawning ?

// In my SummonerClass
void ASummonerClass::Summon(const FInputActionValue& Value)
{
    if (BasePet) {
    TObjectPtr<ABasePet> Pet = GetWorld()->SpawnActor<ABasePet>(BasePet, GetActorLocation(), GetActorRotation());
    Pet->SpawnDefaultController();
    }    
}

[dense owl]

What is your default AI controller in settings

[mossy yew]

this one ?

[dense owl]

Oh right, you did show that

Did you use the AI debugger and vis log to see if anything stands out?

[mossy yew]

😩 Didn't know that's a thing

The only thing in log is

LogPackageName: Warning: DoesPackageExist called on PackageName that will always return false. Reason: Input '' was empty.

[dense owl]

Not sure, but that looks like some different issue. And I meant the visual logger in Tools > Debug. Start with the debugger tho. At runtime, press ‘

If nothing is showing under AI, maybe use the main level window to manually select the pet instance from the outliner and see what AI is controlling it

[mossy yew]

this?

[dense owl]

Yes, that is the vis log

[mossy yew]

from what I see BP_Petcontroller is controlling

[dense owl]

Hover over the blue bars

Or just click on them

To see what happens step by step

should see something like this:

[dense owl]

is there more beyond the move accepted? or rather do they all show the same?

also expand the stuff on the left i.e. ai controller and path following

[mossy yew]

Is focus supposed to be null?

[mossy yew]

both pets show similar log, just with different number

[dense owl]

It's null on my end too

the main diff I see between mine and yours is that onPathFinished: Aborted

my vis log doesn't have that.

could be something else, but unfortunately this is where my extremely limited "expertise" ends. I'm sure someone else will be able to spot your issue, might just take a bit for them to come on

[dense owl]

Btw, this other error might be happening if you try to load a level by name. Safer to use refs. If that's not the case, it might be a common 5.2 bug which apparently gets fixed when clearing the Unreal Engine folder in AppData. See here for more info https://forums.unrealengine.com/t/doespackageexist-warning-flooding-output-log-in-pie/268002/12

[mossy yew]

Sorry for the wait, yea I tried this solution of deleting files in cache UE folder and it no longer shows that error

tried it with AIController this time, it seems to show very similar outputs

except it worked 😭

[dense owl]

Ok, fair enough. Then all I can think of is you're extending wrong somehow

[mossy yew]

Haha, just wondering, is my way of doing it correct? like we "can" use our own custom AIController right? Like in my case PetController is a AIController so it should work?

[dense owl]

yeah, you definitely can, I have it done in bp

but not sure about the cpp implementation, I'm trying to find an example now

[mossy yew]

thx, I'm experimenting rn

[dense owl]

here's a preview of what my custom AI bp would look like in C++

[mossy yew]

I tried doing it in bp and it works, but as soon as I change Pet's AI controller to my own PetController (BP or not) then it stops working lol

[dense owl]

how did you create it in Blueprint?

like this ?

[mossy yew]

yea, except my BP_PetController is from my c++ PetController, and PetController is from AIController

[dense owl]

do you have the BlueprintCallable flags on?

or Blueprintable w/e

[mossy yew]

probably not

[dense owl]

well copy this header

[mossy yew]

oh you thought I called my c++ function in bp?

[dense owl]

maybe not the blueprintType

[mossy yew]

I comment out my c++ ai code and just did it in bp

[dense owl]

I think you need to make it so your c++ class is exposed to BP

to test, you can try to make a new BP AI class directly from the AI Controller base

if that works, then it might be a missing flag issue on your custom one

[mossy yew]

without doing AGridPathAIController right? let me test it

[dense owl]

yeah, ignore the GridPath, that's just an experimental Epic AI I'm using for my project

[mossy yew]

oh god

BP_AIController works

[dense owl]

yep

so your c++ class is prly not exposed to BP properly

[mossy yew]

umm

[mossy yew]

Is that by default? or did I accidentally changed something so it's not exposed to BP?

[dense owl]

I think you normally have to set flags on C++ classes in order for them to be exposed to bp, but tbh idk enough about the #cpp side of things to tell you for sure, those guys might tho

[mossy yew]

I'll try to delete my current custom controller class and add it again, I may have changed some stuff about it because I was following UE behavior tree guide

👀

It works now

thanks Neo!

[mossy yew]

Trying to use my AIController to run Behavior tree, so the pet moves to x location, but pet isn't moving for some reason, any help is appreciated

// PetController.cpp
void APetController::BeginPlay()
{
    if (BehaviorTree) {
    RunBehaviorTree(BehaviorTree);
    }    
    GetBlackboardComponent()->SetValueAsVector(FName("EndLocation"), FVector{ -4290.000000,-1710.000000,0});    
}

The EndLocation value is indeed changed, but not sure why pets aren't moving

[ivory rune]

What is your pet pawn class?

[mossy yew]

ABasePet : public ACharacter this?

[ivory rune]

Ah, ok. So you have the movement component for your pet.

[mossy yew]

yea

[ivory rune]

Do you have the navmesh?

[mossy yew]

yea

oh god, even my c++ code stops working lol

[ivory rune]

Ok, try a humanoid pawn to see if moving or not. Then to nail down the problem with you AI BTs or your pawn class...

[mossy yew]

ah found the problem 😅

it's because I didn't call Super::BeginPlay()

[ivory rune]

These kinda simple logic code I usually called in Blueprint and it could avoid some issues like that😛

[mossy yew]

True lol, just tryna get some practice in C++

[mossy yew]

Hi guys, is there any reason why my pet follows me really smoothly using my c++ code, but my pet isn't smooth using behavior tree, it will stop for a very short time then continue moving

Is it because of Selector and Sequence?

void ABasePet::Tick(float DeltaTime)
{
    Super::Tick(DeltaTime);
    
    TObjectPtr<AAIController> PetController = Cast<AAIController>(Controller);
    if (PetController && GetWorld()) {
    PetController->MoveToActor(UGameplayStatics::GetPlayerCharacter(this, 0));
    }
}

vs

// in PetController.cpp
void APetController::Tick(float DeltaTime)
{
    GetBlackboardComponent()->SetValueAsVector(FName("EndLocation"), PlayerLocation);
    PlayerLocation = UGameplayStatics::GetPlayerPawn(this, 0)->GetActorLocation();
}

[ivory rune]

I think the main difference is the MoveTo in BTs is a task. It will stop the movement and the speed will be set to 0 immediately while the task is finished.

[mossy yew]

Does that mean Behavior tree is more suitable for like Enemy AI? Do people use BT for pets as well?

or it works, but I just don't want my pet to stutter every few seconds, is there anyway to change it?

[ivory rune]

You could do it but you might need to customize something for your pet AI.

Like you set the moveto target but you also doing a service that if it reaches the specific range close to the target, then you speed down your pawn.

Something like that.

[mossy yew]

I see, I think another reason is the MoveTo node means the Pet will need to reach that location, only then my Pet will move to another location, it becomes obvious when I increase my Summoner character speed

oh well, it may be because I set MoveTo's key to Location

[ivory rune]

Yeah, that's why I said it is a task. It needs to be finished unless you abort it by force.

[mossy yew]

oh I probably miss understood you haha

I was trying to set it to just chase my player object, not exactly sure how to do it lol

so far I've made a BB key and set it as my MoveTo key

[ivory rune]

Yeah, you can do that, but the pet will probably stop immediately too if it gets close enough to the master.

[mossy yew]

struggling with the second paramter that requires a UObject*

[ivory rune]

If you want it be smooth, still need to do more extra work😛

[mossy yew]

oh lol, was hoping it'd fix the problem

[ivory rune]

Basically Actor is a UObject

[mossy yew]

I tried it with UGameplayStatics::GetPlayerPawn(this, 0)

oh nvm it does work

thx

I think it is following very smoothly for some reason

[ivory rune]

Good to hear.

[mossy yew]

thx 😋

[uneven cloud]

You should not be calling move to on tick like that. Move to contains latent functionality.

[uneven cloud]

If you have the controller setting to spawned or placed in world (variable on the character) then you don't need to manually spawn the controller.

[uneven cloud]

Run behavior tree should happen in On Possess and not Begin Play.

[uneven cloud]

Set Use Acceleration For Paths to true in the character movement component. Then adjust the acceleration and deceleration.

[dense owl]

Is that in case it gets unpossessed and repoed at some point or is there another reason for it?

[crystal hatch]

There's usually no point in running BT if there's no Pawn - a number of task nodes will just fail without it. And there's no Pawn until Possess gets called which is always after begin play.

[dense owl]

Oh, that makes sense. I thought the AICon’s begin play only occurs when a pawn with an AI controller it spawned

[crystal hatch]

nope. It's perfectly fine to spawn an AIController without any pawn in sight and have it posses and unposses any number of pawns (in sequence, not at once).

[dense owl]

Oh that’s good to know, thx! Btw, I’ve noticed if I stop logic via bp while a tree is running, the tree’s runtime visual indicator (highlighted stream) keeps showing as if it’s still running but stuck in that task with no finish execute. Mind you, it still restarts the tree from the root when run BT is played again, so it might be just cosmetic, but I was wondering if I’m doing something wrong and keeping the tree loaded or something

Like I would expect it to just appear inactive

[crystal hatch]

sounds like a bug.

but yeah, it also sounds cosmetic.

[dense owl]

Ok, np, not a big deal

[ivory rune]

Hmmm, I've never consider about an AI controller without a pawn. Usually just think it is spawned along with the pawn. No idea what is the case that spawning an AI controller bug without the pawn though😅

[crystal hatch]

I've seen a number of people using AIController without a pawn just to use BTs (with game-specific BT nodes that don't need or want Pawns). For example as a squad-controller with BT driving the squad logic.

[ivory rune]

Okay, it makes sense in this case. By the way, since you are here, I'd like to ask a question confusing me for a long time. Let's say I have a parent tree for a certain AI pawn, and inside this parent tree have several child trees including attack tree. I put a cooldown decorator for a specific attack movement and this cooldown decorator will still stop the behavior tree task being triggered even get out of the attack child tree? Not sure you can totally understand my question, sorry for my poor expression.

[crystal hatch]

nope, I don't get it 🙂

[ivory rune]

Ok, for example. I've an AI can move or attack. For his attack, he has a melee and a ranged attack. I put the cooldown decorator on his ranged attack task for about 10 secs. So after his attack, he will get back to the main tree which has movement and attack sub trees. If he meets the condition for the ranged attack, does the cooldown still work to stop him doing ranged attack? Because he finished the attack tree in the last iteration.

[crystal hatch]

It depends on a number of implementation details. If it's a "static" subtree and the condition is on the root then it should work. In other cases it heavily depends on specifics of how you set up your subtree and where the data comes from.

[tawdry zephyr]

Easy example is to have an autopilot mechanic I think

It could unpossess when you disable autopilot

Or games that have AI take over when a player disconnects

[crystal hatch]

not to mention that if an AI driven pawn wants to drive a vehicle there's an unpossess and posses taking place (possessing the vehicle pawn) 🙂

[ivory rune]

I remember we did this before but not with AI controller (player controller probably), because the AI programmer implemented a lot of stuff himself without using behavior tree😅

[ivory rune]

Thank you for the answer. I'm still a bit confusing what means static subtree, since I don't remember any options for that😅

[tawdry zephyr]

In my game I have AI that basically control player characters anyway, since its combat based they need to do what players can, would be an easy hand-off 😄

[crystal hatch]

there's two "run BT" taks nodes in BT - onc "static" and the other "dynamic". The "dynamic" once lets you switch inject different subtrees at runtime.

[ivory rune]

Ah, thanks. So yeah, probably dynamic one won't work because it has different instances at all?

[crystal hatch]

Even the dynamic one could be made to work. If you store "ranged attack cooldown" in BB, and use timestamp for it instead of "time left", and you don't expect decorator checking it to "abort lower priority" then it would work. Or more precisely: it would abort lower priority but only within the limits of the given subtree.

[ivory rune]

That's pretty clear now. Thank you for the clarification.

[mossy yew]

thx for the explanation! I've changed run behavior tree to OnPosses!

[sacred shale]

which function sends the information to the movement component in the crowd following component?

I keep finding a variable in CrowdFollowingComponent called MovementComp but I'm never seeing any struct or packet of information it's specifically sending into it :/

are you talking about the MoveTo function sending information into the character movement component?

[sacred shale]

also does Detour Crowd basically make RVO obsolete? I remember someone saying you can't use both RVO avoidance and Detour Crowd AI Controller

If anyone knows, does anyone know how the information generated by MoveTo gets passed into Character Movement? I'm seriously confused since I cannot find any direct references to Character Movement specifically in the MoveTo node in AIController

essentially I need to pass in the information generated by MoveTo which typically gets passed into Character Movement into my custom locomotion logic