gameplay-ai

[sacred shale]

Is Detour Crowd AI Controller different from if I were to just initialize my path following component with the subclass Crowd Following Component? the logic seems very inconsistent, I created a new AI Controller which just derives from AIController but I cannot derive from DetourCrowdAIController

[harsh storm]

DetourCrowdAIController isn't exported from the AIModule. So you can't derive from it in C++. But if you look at it, it is literally just the AIController with a different component passed in the initializer

Really no additional code.

So you can just copy that.

[sacred shale]

but yeah thanks

I'm just trying to figure out where either the crowd following component or AI Controller recalculates the direction vector relative to the crowd following component's velocity, or some other thing. Looking at the AI controller's cpp tick it only updates the control rotation and not the direction vector if it's moving

[harsh storm]

¯_(ツ)_/¯

I haven't actually looked at the pathfinding stuff.

[sacred shale]

not a lot of this is commented or documented very well lol, making it a big pain in the ass 🙂

[sacred shale]

so as far as I can tell the Path Following Component's tick updates the pathfinding and the CrowdManager (which registers every Crowd Following Component on every character associated with a Crowd Following Component) updates each of the crowd following component's characters' crowd velocities to determine where to move

[celest python]

Its the detour framework itself

Pathfollowing is the wrapper around it

MoveTo:

• Makes a pathfinding request, if succeeds, it routes the found path to PathFollowingComponent
• PathFollowingComponents keeps its own state, checks if pawn reached the goal etc
• MoveTo listens to the state and other variables of the BT/BrainComponent to manipulate the behavior of the task (not the movement), so it can cancel itself or re-trigger path etc
  PathFollowingComponent:
• If there is a valid path to follow, it does bunch of vector math to follow the path along point A to point B, point A being current location of the pawn and point B is the next path point from the path array
• On FollowPathSegment, it moves the pawn by adding move input to its movement component, it also lets you manipulate the direction via a delegate but it does not exist in CrowdController

real crowd stuff happens at UCrowdManager

[sacred shale]

Is the crowd manager's tick dependent on the path following component / move to? I guess I'm trying to figure out how I can take my existing direction vector and manipulate it based on information from the crowd following component. But it looks like the crowd following component is only ever made to interact with the crowd manager and generally isn't used outside of that since the crowd manager keeps track of all of the information relative to each crowd following component

And if I'd want the information for how I should redirect my AI's direction vector it sounds like I would need to get information from the crowd manager for each crowd following component

This would be so much easier if I didn't have custom locomotion logic instead of using move to 🙂

[uneven cloud]

ApplyCrowdAgentVelocity is the function that you are looking for.

You need to build with the debug editor config to get breakpoints to work on editor files. If no breakpoints are getting hit, then your setup is wrong.

[celest python]

You probably cant with detour

At least not via PFC

I didnt read the Manager class' code so I dont know about it

[uneven cloud]

Like I told you before, use the move to and override the functionality that sends to force to the movement component and send it to your locomotion system.

[celest python]

Does move to do that though? Its Path Following Comp who sends the force/accel to movement component

[uneven cloud]

First rule of working with UE is don't fight the engine. There is usually an easy way to do what you want to do, you just need to find it.

[sacred shale]

Yeah I thought Move To only sends a location or actor to follow and is only called once, then the tick of the path following component handles the rest

On tick

[uneven cloud]

That's what I meant. Override the functionality in the crowd following component to send the force to their system instead of the movement component.

[sacred shale]

thanks, maybe I'll end up creating my own crowd following component and override ApplyCrowdAgentVelocity

[celest python]

What are you trying to achieve by the way?

[sacred shale]

I'm trying to achieve the same thing as the default Detour Crowd AI controller logic, except I have custom locomotion logic which isn't using Move To or character movement. I instead have a separate component for all that stuff that handles all that move input through curves and animations. Basically I'm trying to find a way to convert the existing detour functionality into my custom locomotion system

actually hm, I'm not sure if calling an overridden ApplyCrowdAgentVelocity would even work since it would still be dependent on the crowd manager to listen for all that, which would probably require Move To

I'll try anyways 🤷‍♂️ 🙂

[uneven cloud]

Like I said several times now you should be using move to.

[celest python]

Something is wrong somewhere but if your end goal is to manipulate the FVector direction that detour provides you just need to override ApplyCrowdAgentVelocity and use your own logic to call RequestPathMove or RequestDirectMove from movement component

you seem overthinking or overengineering something or both

[sacred shale]

I didn't end up creating this custom locomotion system, but right now my project's pretty tight and would require a lot of time to refactor my entire system into character movement using Move Tos

but honestly might be worth it given the amount of time I've spent banging my head against a wall over this specific problem

[dense owl]

You are currently on fire.

[celest python]

how come your system is not using MoveTo

its just a fancy wrapper to call MoveTo() in pathfollowing component (the BTTask)

are you not using pathfollowing component at all?

[sacred shale]

because my characters' movements aren't using character movement, so using Move To would just cause them to slide along the ground, the entire animation blueprint is set up with all this custom locomotion logic rather than using traditional character movement

[sacred shale]

nope lol

[celest python]

so you are just trying to register your own system to detour?

so you can make it provide you velocity

[sacred shale]

nah I'm trying to use the existing detour system in Unreal but it seems more trouble than its worth

I've spent a couple days on this and it's been drivin me nuts, so much of the actual movement re-calculation is dependent on stuff thats already built for me

I have this already working in the sample third person project on the official unreal docs which specifically tutorializes how to use all this stuff

[celest python]

this doesnt seem right either, PFC just provides a normalized FVector to make movement component post-process it by adding velocity

it doesnt matter which movement component you are using as long as PFC provides a valid value

(Detour <-> PFC) -> movement component

[uneven cloud]

It sounds like he didn't make a new movement component. Just made a new component and ignores the movement component. Which the movement component is likely still doing expensive checks.

[sacred shale]

I didn't make this specific locomotion logic lol

I would just use what's given to me if I could 😄

[celest python]

what do you have right now? from which base classes derive from?

[sacred shale]

just an actor component completely unrelated to character movement with a bunch of custom logic

[celest python]

literally an UActorComponent?

[sacred shale]

yea

I gtg figure this out tho I'm wasting more time complaining than actually making progress lol

but thanks for the help sorry that my problem seems pretty vague without specific examples and stuff

I can't show a lot of code specifically bc of NDA

[celest python]

detour is abstract so if you provide info to it, it will return you a FVector that represents current direction agent should follow
UCrowdFollowingComponent is responsible of registering its own agent data to crowd manager, and crowd manager calls UCrowdFollowingComponent's ApplyCrowdAgentVelocity
create a new manager class based on crowd manager, see how it registers agents, do the same for your own actor component

CrowdManager is specific to UCrowdFollowingComponent but actual detour is not

otherwise prefer the sane way, refactor to proper classes 😄

[uneven cloud]

It's not vague. You just are trying to rewrite far more than you need to. And fighting the engine.

[sacred shale]

I'm not trying to rewrite anything, just trying to learn how this all works for my specific application

[celest python]

problem is once you get rid of gameplayframework elements you end up rewrite a lot of stuff

you got rid of two core things to move something

pathfollowing comp and movementcomp

those are hundreds of lines in total

and each function serves a purpose

what worse is you're trying to interop something something specifically written to work with those which increases your burden

[sacred shale]

again I didn't write any of this custom locomotion logic lol

[celest python]

I know but just trying to make the fire you're in more obvious to you 😄

[sacred shale]

ye I know I'm on fire lol

[celest python]

dont solve the tech debt with more tech debt

[uneven cloud]

The movement component doesn't even need to be a character movement component. Just a nav movement component, which is really light weight.

[crystal hatch]

Amen!

[sacred shale]

thanks guys. sorry I made a bigger deal of this than I should. I guess I need to learn when to draw a line in the sand when it comes to overcomplicating problems that can just be solved by doing it the easy way

[dense owl]

The guy who made your custom locomotion is a bastard 😀

[uneven cloud]

It's so common, even in big studios, to rewrite large parts of the engine because of the "not built here" mentality. It always causes so many problems.

[crystal hatch]

[haven't read the whole conversation, so forgive me if I'm repeating something someone else said, but:] KIS! 😄 Complexity should come from composition of simple things rather than monolithic complex things. Howgh!

[harsh storm]

I've been meaning to actually dig into this so I can create my "Zombie Game Maker" framework inside of Unreal 😅

[crystal hatch]

Epic used to follow "not built here" policy for ages. It started going away with UE4, but we still have some of that. I'm actively fighting it!

[celest python]

My favorite two big studio things that I keep hearing from... friends:

• Rewriting stuff or doing things unity way
• Trying to add multiplayer after everything is written (😭)

[sacred shale]

lol

[harsh storm]

I have experience in other engines that seem to follow the same philosophy (NBH syndrome). Maybe it's just an engineering problem 😅

[dense owl]

More of an ego problem

[crystal hatch]

Trying to add multiplayer after everything is written (😭)
Oh man, this brings memories of me retrofitting bots into a "we'll never need AI to drive Hero characters" game (Paragon) 😄

[uneven cloud]

I worked at a studio where they tried to get everyone to write all systems outside of UE. It was an absolute shit show.

[harsh storm]

Rewriting stuff or doing things unity way
With the rise of using components for everything in Unreal (even coming from Epic apparently), I don't know if this is as big of a con these days 😅

I still like putting stuff in Actors!

[crystal hatch]

I guess you don't like to have a lot of stuff 😉

[harsh storm]

Mass is too volitile for me. I know that old is what makes games. Not new and shiney!

[celest python]

I enjoy mass but get lost in codebase a lot

Complexity should come from composition of simple things rather than monolithic complex things. Howgh!
this is the exact definition of mass

[dense owl]

Hehehe, I wonder who authored that 🙃

[harsh storm]

I'll let the masochists figure it all out, then come in and reap the benefits 😈

[crystal hatch]

The main thing Mass is missing is a good debugging toolset. We're working on it.

[harsh storm]

How's mass replication comin' along? And does it have any tie ins with Iris?

[crystal hatch]

I live to serve! 🫡

[harsh storm]

I don't know if it is said enough or not, but I do most certainly appreciate you Mieszko!

[sacred shale]

what a nice community lol

[crystal hatch]

we actually were dragging our feet on Mass replications because we were waiting for Iris. Now I'm working on an internal project that does need Mass replication, so it's going to get a lot better.

[crystal hatch]

why "lol", eh? 😉

[harsh storm]

Ah - so Iris will aid in its development. That's actually kind of exciting.

[sacred shale]

damn y'all must be canadian too with the "eh"s 👀

[celest python]

Same, especially for interacting with community ❤️

[celest python]

How it will work differently than regular network programming we used to with actors? For example will actor channels, RPC functions etc stay or will there be another workflow we need to get used to?

[harsh storm]

There isn't much actual concrete info on Iris yet. So I'd imagine it's still a bit in the design phase for Mass Replication

[celest python]

ECS allows tons of cool stuff like better rollbacking and maybe even slight possibility of implementing lockstep especially with reflection system but I guess it's mostly relying on Iris's internal architecture

[celest python]

Since it does not affect high-level systems workflow wise decisions might be up to Mieszko AI team 😅

[harsh storm]

I'm still excited to actually see Iris for just the high-level systems.

Let alone mass benefits 😅

[crystal hatch]

I'm actually staying away from replication, there's another dev working on it 🙂

[silent hamlet]

I struggle understanding what is mass built for. What are the use cases where I'd want/better make use of it?

[harsh storm]

Zombies. The answer is always zombies.

[crystal hatch]

Imagine you want to simulate a huge world, with a lot of things having internal logic like growin, or spreading fire, or flooding, or whatever natural large scale phenomena you want. Mass would be the right tool for that.

if you want regular FPS with 20-30 AI opponents you don't need Mass

[harsh storm]

Unless you want those 20-30 AI to go brrr

[silent hamlet]

Ok so it's definitely going in the direction of supporting big worlds.

[harsh storm]

You can check out flecs to get an idea. There is even a pretty simple integration for UE out there.

[silent hamlet]

I am a solo dev working on a small project. I'll keep looking at mass from the right distance 😁

[celest python]

Workflow wise difference TL;DR explanation:

• It's an ECS framework, an alternative to default Actor/Component system (but still interops with it). Actors and components rely on object oriented programming while Mass/ECS focuses on data oriented programming
• DoD has advantages of easier parallelism, better CPU cache coherency etc. which makes it naturally faster than OOP (you can watch Mike Acton's 2015 talk about data oriented programming)
• Entity is a collection of Components which are just structs with data only and Systems execute entities (runs the code)

[harsh storm]

No shame in that!

It would've been nice if Mass didn't change the lingo though 😭

[idle crystal]

Hey, I have ran into a problem, the problem is that my character cant move to the next targetpoint if its on the right side of the character. If its not it has no problem moving to it, a tried debugging (in my bp i still use the debugs) but i cant come to a conclusion. I tried to rotate it 180° so the target point is relatievely on the left but it doesnt work, even if it would would it wouldnt be my final solution. I would really appreciate some help. I used a yt video for this but it simply cant turn right. I did it over several times but it still doesnt work. https://www.youtube.com/watch?v=SfnvbzfGZnE

[harsh storm]

Now - if we could get the transform updates to go brrr 😅

[crystal hatch]

We had to, there's already too many components in Unreal, and (Sub)Systems.

[harsh storm]

Makes sense. I figured as much. But a boy can still dream!

[crystal hatch]

No he cannot! Don't be silly! :some-monty-python-emote:

[harsh storm]

While you're here Mieszko - what is one thing you wish was different about the BT in UE? 😈

[crystal hatch]

I wish the developer had time to work on it more before he was dragged away to other projects 😉

[harsh storm]

It's no longer the hotness 😭

[crystal hatch]

but seriously - local variables. It's something I even prototyped - a BT node could declare variables that could be utilized in child nodes, and the vars would get auto reset on node's "cease being relevant"

a kind of extention of BB

[celest python]

Wouldnt it replace the blackboards directly?

[crystal hatch]

no, a suplementation of BB

BBs store global state, but sometimes you just need something local to a given branch

[celest python]

Ah, I see, BT variables are for execution logic rather than AI state

[harsh storm]

I've seen some bring up that they don't like that the BB isn't shared between all the BT users - was there any particular reason for this design decision?

[crystal hatch]

the asset is shared. And if you want to share specific key values there's a way to do that.

[harsh storm]

I know the asset itself is shared, but the key values are unique to the agent.

[haughty coral]

there is a per key checkbox you can enable to make them shared

[harsh storm]

...

How did I miss that?

[haughty coral]

Instance Synced

[crystal hatch]

I'm so disappointed...

[silent hamlet]

BT included in engine is great but I find it way more comfortable programming ai with state trees at least for standard idle patrol chase cases. It feels just more natural to think of it as state machine

[harsh storm]

Don't be! I hardly need them to be synced 😛

[silent hamlet]

That was a great addition in UE 5 that nobody basically spoke about

[harsh storm]

Classic Unreal though. It's just a checkbox away 🤣

[crystal hatch]

all right then! 😄

[harsh storm]

Nah - ST's were talked about fairly often. Especially here.

[silent hamlet]

Oh here yes but I mean in official communication channels. Some brief mention is all

[harsh storm]

Well - because it isn't glamorous

Not like Nanite/Lumen

[silent hamlet]

I guess lumen and nanite had to steal the stage

Yea

[harsh storm]

Listen to the sales pitch

[celest python]

I'd like values in BB to be regular FProperty values instead of UBlackboardKey's and has property extension support instead of FBlackboardKeySelectors, would solve majority of my issues

[harsh storm]

"We have fully dynamic, real time global illumantion AND unlimited polycount"
vs
"We have a fancy state machine"

Which is going to garner more hype?

Let's be honest here.

[crystal hatch]

BB is older than FProperty 🙂

[harsh storm]

What is under the belly of ST is pretty neat though 😅

[celest python]

Wait.. isnt FProperty is from UE3

its even referred as "UnrealScript variable" in source code 😄

[haughty coral]

I guess you mean UProperty :P

[celest python]

yeah was UProperty back at the day

[silent hamlet]

I think it's been a good choice for the company

[crystal hatch]

that's what I meant. FProperties are a modern attempt to get rid of a lot of Unreal slack (one of the attempts, we have smart people working on getting rid of unnecessary stuff).

[harsh storm]

I'm mainly waiting on more bug fixes for ST before I pick 'em up again. Mostly surrounding the editor. Was having the states just randomly no longer be able to bind to stuff.

[celest python]

Did API also change with new FProperty system or was it same as UProperty?

[harsh storm]

Also found it kind of annoying on how you update data in the ST at runtime. Never even figured out if the way I was doing it was "correct" 😅

[celest python]

turns out it wasnt

[haughty coral]

How I see it is that in the beginning the engine was just growing, there were even no plugins and every team was inventing what they needed for their feature. Nowadays it is a bit different when we are getting more standardized reusable stuff like property binding, instanced structures, MVVM and in general a more consistent experience between all the systems. I am sure BTs could be significantly different if it was made from scratch nowadays.

[celest python]

because there isnt a correct way

[silent hamlet]

Yea sometimes they lose a binding but overall they are already quite neat

[celest python]

Yeah the modularism attempt coming with each new version is awesome

Mass was my favorite because it directly provides an alternative for gameplayframework itself

[harsh storm]

I still love the GameplayFramework

[celest python]

If I could have more than 3 brain cells maybe I could figure out how DOOM Eternal does that "no game thread" thing and I could not love gameplayframework again

but since I dont have any choice I love it too 😄

[harsh storm]

I don't love it out of necessity though. I love it 'cause it's generally pleasant to use for a majority of games that I like to make.

[celest python]

being too used to regular workflow of actors provide is a huge selling point for me

[celest python]

I actually sometimes hear designers prefer ECS over OOP in other studios, its not less pleasant to work with either

[harsh storm]

I know. I enjoy ECS as well to be honest.

But ECS is still quite young in Unreal. And I want to make games.

[celest python]

Cant say I used enough ECS to love it, I just know what I dont like in OOP

but I often find myself in a situation where I thank god virtuals and inheritance exists

I guess I'd prefer a scenario where low-level side of things go brr with ECS and scripting doesnt even care about yolo with OOP

[silent hamlet]

The gameplay framework is perfect for small projects. Having modular systems is great but I think they become more and more useful as projects start to scale. I have a background in backend web development where modular architecture has taken over but i feel like the complexity of managing these systems has increased tenfold. Sometimes the benefits justify the effort. Sometimes the don't. And I feel the same risk exists in game development

[celest python]

I dont think gameplayframework is going anywhere anyway 😄

[harsh storm]

GF is fine for bigger projects as well.

A lot of games these days don't actually have a lot of moving actors anyway.

[silent hamlet]

Pheeww 😛

[celest python]

MoveComponentImpl

[harsh storm]

Not to mention, they're also doin' work on multithreading animations. So anims go brrr

[celest python]

I finally found a way to both get immediate physics callbacks and run logic on another thread for MoveComponentImpl btw

and its not even hacky ( FSimCallbackOutput )

cant wait to shoot myself on the foot again while trying

[fossil wraith]

Does EQS based AI need nav mesh volume still?

[dense owl]

Yes

[uneven cloud]

Only for projection onto the nav mesh and using the pathfinding tests.

[uneven cloud]

Back in the early days, BB keys were set to shared by default and you had to manually turn them off.

[mossy yew]

Hi guys, does AIPerception have debug lines in editor similar to pawnsensing?

the only thing I found is to press ' at runtime

[dense owl]

yes, press Num 4 after you hit the '

Also, not sure you should be using both PawnSensing and AIPerception at the same time

[mossy yew]

oh ye that's what I meant

[mossy yew]

oh dw, I was just using it for screenshot haha

was wondering if it's possible to see those debug lines when editing

though now I run into a problem, the detail panel of AI Perception is gone

[dense owl]

window -> details

[mossy yew]

usually when this happens, restarting or renaming the name works

yea it's checked

I can see other component's detail

ah

had to comment it out then compile then uncomment it then compile

thx

[dense owl]

I haven't played with PawnSensing, but if you use EQS, it can draw pathing and hits for you at runtime

I’m def using wrong terminology here, but if you watch the first pinned video you’ll understand

[mossy yew]

since you mentioned EQS, I'd like to ask do we usually use EQS or AI Perception with BehaviorTree? or both?

is it this one ? https://www.youtube.com/watch?v=6Po7YGGvl_g&list=PLbRBWFaQHaW__LcCtV-KnqqgIFOyyFhr5&index=1

[dense owl]

Perception with EQS. And I meant 3rd pinned link, from Eren

[rigid portal]

Hiya! How would I go about having my AI robot climb a wall? is there a nav mesh way, or do I have to basically play an animation ?

[celest python]

there are multiple ways but easiest one is putting a nav link to the edge of the wall and once AI reached to the navpoint play climbing animation or drive the movement until it climbed

[spring inlet]

what would be a good approach to run a (dynamic picked) task (executed from BP) on top of a running BT?

[celest python]

if I understood correctly thats not the ideal way to execute BT (you shouldnt make BT to jump arbitrary nodes externally)

can you elaborate more

[tawdry zephyr]

Hi guys, I'm testing collision with AI in multiplayer with ~200ms latency because this is a non-competitive co-op game when played in multiplayer so would like to support that much. For this I made a third person template and duplicated the character, made it walk 100cm/s, and added AIMoveTo random point in radius. Not much else besides debug stuff (ping widget & p.netshowcorrections 1). The second video shows with 425cm/s speed which is more realistic for a game to use, notice how it becomes truly egregious, even more so with larger capsule radius.

First off I work with Character/CMC and prediction all day every day so I understand how/why this happens. But it did seem quite extreme so I'm wondering if there is actually anything I can do to assist or improve it. Basically, when the player character moves into the path of an AI controlled character the desync can become truly extreme and will thoroughly desync.

As an oceanic gamer (NZ) I'm used to the uphill battle of playing games with this amount of latency and I don't think it ever becomes this extreme even in competitive games when involving other players, but I do suppose I never had the opportunity to test with AI. I don't have a secondary player to test with at the moment but I'll get my sister to help when she visits on Sat.

[tawdry zephyr]

<@&213101288538374145>

Probably not quite what they had in mind...

[pallid mica]

Yop

Ban them manually

They spammed it everywhere.

[celest python]

I think some games either steer away from player or wait player to pass and stop NPC

and you shouldnt support beyond like 150ms or something even for co op, maybe 200ms at max

its too high to recover

from what I can see problem occurs because AI is pushing the player and since this hapens in server, client is not aware of its new position yet

so server ends up correcting

You might consider making AIs not push the player

[tawdry zephyr]

This is actually what I just arrived at. I made the player character affect dynamic navmesh - actually attached it under my blob shadow component because it sticks to the floor so it still works when jumping (reserving their landing space, effectively). Combining that with disabling collisions between the two is a good start. I have a dither effect already for characters (AA faking transparency for hiding meshes without the cost), so if two players overlap their characters I can just dither the non-local character partially.

[celest python]

player character affect dynamic navmes
thats generally discouraged

[tawdry zephyr]

Without that the player can walk inside AI - I still plan to have AI collide with player while idle

[patent hornet]

if you're using GAS, have the AI give the player gameplay ability that pushes the player back

rather then doing it by force

[tawdry zephyr]

Ooh that's a good one

[patent hornet]

it should avoid corrections

[pine steeple]

i just stopped the ai from colliding with the player pawns

🤷

[tawdry zephyr]

In my case I do need enemy AI to body-block players from just walking through them

So I will disable collisions for non-enemy AI and then try the GAS solution for hostile AI

Well, I can disable collisions for hostile AI too, and the GAS solution will mimic it

[tawdry zephyr]

Why

[celest python]

prone to bugs for AI movement and relatively expensive

[spring inlet]

i have a drone, where the usual BT is for stuff such as following actors, etc. but the drone also has the function to lift off/land where for the later the motor should turn off when it landed

so i would like to execute some task, which runs until it's landed and shuts the motor off

but i don't want to clutter up the BT with small things like this

[tawdry zephyr]

In that case maybe Zlo's solution is best, just have AI push player away, I could make it opposite of assassin's creed where they shove you instead 😄

[celest python]

deactivate braincomponent

run the task

when its finished activate again

[spring inlet]

but what kind of task should i make?

i've seen AITask in cpp, would still like something which can be implemented in BP

[celest python]

so its a complex thing and should be decided properly based on your design

issue comes from you cant jump to random nodes in BT

you can only prioritize behaviors with BB values and selectors

so you have multiple options

[spring inlet]

and i don't really want it in the BT aswell

[crystal hatch]

this is by design and makes debugging things and predicting a lot easier.
StateTrees let you jump around.

[spring inlet]

yea there's an article which also says to not try to implement a state machine in BT

so i try to avoid it 😄

[celest python]

I have a "stack" (TArray .pop/.push) BTs in my own braincomponent, I treat BTs as tasks but sometimes they are GAS abilities or raw UObjects
if there is any other BT/task/ability in the stack BrainComponent runs it instead

and after they're finished they are popped from stack

and default behavior is running

This is a generic way I thought a while ago

a simpler thing would be just locking the braincomponent in somewhere

and running the logic whereever you want until its finished

[celest python]

https://tenor.com/view/columbo-clublumbo-double-exposure-thats-me-hey-gif-23120730

[spring inlet]

so just something like a latent action / coroutine for the task?

https://dev.epicgames.com/community/learning/tutorials/L9vK/unreal-engine-common-issues-with-behavior-trees-and-things-you-should-competely-avoid

that's the article 😄

[celest python]

(I'm so ashamed of how terribly I wrote that)

[spring inlet]

wait you really did?

[celest python]

it doesnt really matter tbh, key point here is keeping the "main" behavior deciding BT alive and locked until you finished secondary tasks

yes

I'll remove it later and re-write in my blog one day though

[spring inlet]

nice, thanks for that overview 👍

well it's a good overview to not run into a bad design pattern

[celest python]

Yep but my 3 brain cells junior brain misunderstood some things about AIModule's design choices back then and quite shitposted about it 😅

[celest python]

Here's what I did

• FBehaviorTask with virtual function Execute()
• TArray<FBehaviorTask> for LIFO stack logic
• UBrainComponent derivative class, whenever a new FBehaviorTask is added, it runs it, newly added tasks can decide if current ones should be cancelled or not
• UBrainComponent derivative also listens for end/start events of FBehaviorTasks, if any is ended pops the LIFO array and if nothing left in the array continues executing the BT, otherwise switches to next prior task and ticks it

Execute either runs a BT or triggers a GAS ability, each task type has its own derivative of FBehaviorTask

[spring inlet]

could this also be extended with a 2nd array where i can push tasks which are allowed to run in parallel to the BT?

or is deactivating the BrainComponent necessary to run other tasks?

[celest python]

nope thats also a good idea, you can also lock the execution of secondary parallel task (which will run the main behavior BT) with a decorator from the other parallel

so you can prevent conflicts of tasks

UBrainComponent derivative here means UBehaviorTreeComponent btw

BTComp is a brain component

[spring inlet]

guess the FBehaviorTask is a custom struct!?

[celest python]

yep

everything in the list is custom

if you want to reference them in editor use a uobject though not struct

BTs doesnt support instanced structs too yet

[spring inlet]

i'm thinking of just using the existing "system" of UBTTask_BlueprintBase

that way the tasks could be implemented in BP and i could use them for BT and my custom execution thing

[celest python]

i think they are meant to run on BTs, though, prefer UAITask instead

and see how MoveTo node is exposed to BPs*

[spring inlet]

thing is that UAITask isn't Blueprintable

so i would have to write every little task in cpp

[celest python]

then I'd say create a new UObject, UBTTask_BlueprintBase is BT dependant

[spring inlet]

well it runs on the BrainComponent after all?!

i don't think that it's much aware of the outer flow tree

[celest python]

UBTTask_BlueprintBase is the UBTTask itself

you wont be able to execute it outside of BT

BrainComponent is something different, its a generic AI thingy that runs AI logic for AIController

StateTree also runs on it

you're looking for something to lock/disable BrainComponent and run your external logic until its done or do it with parallel nodes in BT

if you're okay with having your secondary/blocking tasks as BTs you can prefer Run Behavior Dynamic too, but if you want to queue secondary tasks, want them to execute different things etc. create a new object class and poll them on parallel

[tawdry zephyr]

Any info on how you implemented this? The idea in my head ends up similar to the way lyra did their interaction ability/task - an ability & task that scans using a sphere trace, and when overlapping something that implements the interface, it gives the ability

[spring inlet]

so digging a bit through the source... UAITask seems to be supposed to be used with UGameplayTasksComponent

i can't believe that there's no engine feature for something like this

this seems to be quite common requirement for AI stuff, or not?

[verbal violet]

Hello ppl, is there any easy way to check is my character on some specific nav area? I have characters whom is forbidden to use some nav areas, so I need check if they accidentally drop on forbidden area and than do something

[twilit folio]

Hello everyone, simple questiom, how can I make this character walk through the middle of the nav mesh instead of the side?

[radiant path]

If the navmesh only exists in the center it would walk in the center. Or if you use Nav mesh modifier volumes you could make the cost of the center lower. That would be the easiest solutions.

[ocean wren]

Don't do the string pulling? If I recall there's an offset value somewhere for the string pulling.. you'll have to look at the code

[celest python]

or interpolate the path direction from path following component

FMath::CubicInterpCR

[twilit folio]

I'm using Blueprints for this.

[celest python]

then you're very limited with options, none of two is exposed to BPs

[harsh storm]

Is this how you'd go about making them actually round the corners as well? That was something on my todo list and wouldn't mind some resources covering this

(as opposed to just snapping around)

[celest python]

yes

wouldn't mind some resources covering this
sadly there arent much

but I think GPT4 can help

GPT3.5 can partially implement the math part

4 would kill it

TL;DR get Path from path following comp, bind the PostProcessMove delegate, calculate new interpolated direction with FMath::CubicInterpCR

T1, T2, T3, T4 are path point FVectors

Exponent can be around 0.5 and 1.5 i guess, depending on path lenght you can lerp

[still crypt]

🤔 If you just interpolate the direction how do you avoid errors compounding over a few turns getting you off path?

[celest python]

i dont know how it works but it magically never went out of the path for me

generated "spline-ish" path was always inside of the navmesh

[still crypt]

Hm, fair enough

[celest python]

my 3 brain cells are not enough to explain nor understand why it works

math scares me

but i guess its about tangents being calculated properly

[ocean wren]

Yeah, its about the continuity of the spline.. it depends on which spline you use, there's a nice article about it by Natalie Taterchunk from AMD or NVIDIA If I recall

Basically, look at the spline maths implementation and you'll find one where you give it the same tangents and it maintains continuous values at each spline point

Typically, I'd look at the string pulling, figure out where its doing the pulling (funnel algorithm) and find the pre-pulled points and do a spline between those through the pulled point (i.e. only pull the corner point and use a spline position relative to that with some clearance offset)

Hard to explain without a whiteboard

You can also watch Freya Holmer? videos about splines for info

On an off-topic note.. I really shouldn't watch korean street food cooking videos 🙂 hahaha

I don't know what any of it is, but I want its deep fried goodness! 🙂

[fossil wraith]

The first point in the map works but the others dont

the move too is being triggered but character doesnt move

NEVER MIND I FIXED IT

[still crypt]

I want to increase the cost of nodes close to nav-mesh edges, what is a reasonable way to go about this without having to rip out too much engine code?

[hard obsidian]

I have Enemy AI which can detect players and Can attack when close to the player but when I play attack anim montage it rotates the player in a different direction. But If I set the anim montage to none it works fine no rotation happens.

[celest python]

There is a way to get edges from navmesh but I dont know how

You can generate a spline along the edges in editor time and build nav modifier

but you also have to ensure modifier's radius wont block whole path

if nav corridor is too narrow

[still crypt]

Hm, well the idea is to make the cost higher, not impassable so blocking seems okay. Nav modifier volumes are always boxes though arent they? How would one generate one around a spline?

[celest python]

More spline points and smaller boxes 😄

[still crypt]

Not sure if that would be a very scalable solution 😓

[celest python]

navmesh is baked

once its generated

[celest python]

as long as edge is straight line it doesnt matter anyway

either box or not

its actually a rectangle not directly a box

[still crypt]

True, I suppose, but not if you want dynamic generation to handle stuff like breakables or whatever. Not sure if anything is cached if your modifiers are static but it still feels like a pretty awkward approach

[celest python]

On yeah that would definitely explode your cpu

[harsh horizon]

not sure if this belongs here but I'm trying to get my enemy class to move from A to B (for now just a straight line, later I want to change it to a spline) but for some reason they're just refusing to move. I have a nav mesh volume over my scene and I have an AI MoveTo node but it just refuses to move there

I also have this set so I know it's not that

[uneven cloud]

Use the visual logger to debug.

[harsh horizon]

I'm assuming this is what I want to see? Or rather, don't

[uneven cloud]

Hit P to view the nav mesh. Is there anything blocking the path from your AI to the goal?

[harsh horizon]

Nope.

[ocean wren]

You can alter the cost by subclassing one of the Get... Cost functions. Can't remember the exact name. GetNavPolyCost or something similar. Basically, it gives you a navpoly which you can then query the nav system to get the edges of the poly and each edge has two navpoly id's if its an internal edge and only one if it hasn't. So you can just increase the cost of the navpoly traversal by the number of edges with only one connected navpoly. I think the starting point is GetPathCost or something.. follow the flow of that.

[uneven cloud]

When are you calling move to? Is there any other logging? Turn off all categories other than the navigation ones to make it easier to read.

[still crypt]

Ah, that sounds like what I'm looking for, thank you

[finite gyro]

Can anyone please explain to me why when I spawn in a character (which has auto possess by AI when spawned) and immediately possess it by the player controller, there is still its original AI controller hanging around? Now there are two controllers (AI and player) but only one character, i dont understand this

[dense owl]

Did you unpossess it before possessing it with the player controller?

[finite gyro]

i did this

doesnt work

even destroying it doesnt work

[dense owl]

Iirc I had a similar situation, and I was advised against trying to switch the character’s controller at runtime. Rather just spawn it with the right controller to begin with. I’ll check to see what I ended up doing

[finite gyro]

but the nature of the game requires changing the controller at runtime. I was making a similar project back in 4.27 and i had no issue with this, i could just switch between characters seamlessly and the ones i didnt control were automatically taken over by ai

the difference here though is that im using AI perception, and like this the unused AI controller keeps sensing everything even though its not controlling anything

[dense owl]

Then maybe destroy the perception component ?

[finite gyro]

doesnt work

im not sure if im dumb or if this is UE5 being UE5 lol

[harsh storm]

Controller is an actor. It still exists in the world. If you have the perception stuff on the controller, this makes sense to me.

Also - I don't think unpossessing destroys the controller. So it sticking around after unpossession, also makes sense.

[finite gyro]

i have to have it on the controller because damage perception sense doesnt work on a pawn for some reason

i just need to get rid of it somehow after i unpossess it

[harsh storm]

Just destroy it

[dense owl]

yeah, makes sense, since it looks like I ended up spawning the AICon, spawning the actor, and then possessing the actor with it, in my case

[finite gyro]

ah so you dont have auto possess then

[harsh storm]

Don't have auto possess if you're just going to unpossess right after spawning

[finite gyro]

but im gonna have multiple characters, im just gonna possess one with the player

i tried this and its still there

[dense owl]

how are you getting that player controller reference, where is this code located?

[finite gyro]

im testing this in gamemodebase now

this is before it

[harsh storm]

That Get PC is going to be bad once you have more than one player.

[finite gyro]

like the player possession works fine, its just that the AI controller is still there

[finite gyro]

its a single player no worries :D

[harsh storm]

Are you sure the AI Controller is valid

[finite gyro]

ah yeah, its not

but idk why

because if i dont possess it by the player controller, it runs around with the AI controller

okay im really lost now lol

like this its valid, but it still doesnt get destroyed

even this doesnt work on the pawn

[finite gyro]

Well it just didnt work with the auto possess, so I did it like you said, turned it off and spawning each controller manually and then possessing it, this seems to work for now, thanks for the tip c:

[uneven cloud]

Whomever told you that was wrong. I've shipped multiple games that swapped controllers just fine. Either call detach controller pending destroy if you want it destroyed or unpossess and disable the AI controller.

[dense owl]

oh, that's good to know, thanks! 🙂

[ebon apex]

Hey guys! Is it somehow possible to use Launch Actor or set velocity of actor who is possessed by AI without stopping brain?

In my current setup I have to call Stop Logic in On Launched event handler, and give attack command in On Landed but I would really like to get rid of this

Without this, launch actor or setting velocity just do nothing

[crystal hatch]

it's not a bad approach, unless you do want AI to do something while in the air, like shooting a gun. In that case instead of stopping the brain you can pause movement request at the pathfollowing component. But I feel it can cause some strange behaviors. Then again, those should be solvable.

[harsh storm]

@crystal hatch Hey Mieszko, two questions if you don't mind:

1. What's up with removing the class export in the AI module? What's the plan? 😅 https://github.com/EpicGames/UnrealEngine/commit/5db685f9
2. I heard a rumor that we may be getting namespace support for UHT stuff. Have you heard anything about this?

[crystal hatch]

re 1 - someone made it his life's goal to export only functions rather than everything. That's not just AIModule. This can actually improve compilation time and binaries size

re 2 - that's true, but I don't have an ETA for that

[harsh storm]

@terse star 👆

Just that it's being worked on is good enough for me! 🥳

It's like my #2 requested feature 😅

[harsh horizon]

On begin play, weird thing is I know it works because it worked when I was testing it on the older version of the level (which was just cubes) but now I've made a bigger version it doesn't work. Here's my nav mesh and there's nothing blocking

Although doing some more visual logging I did just find this

[uneven cloud]

That means that the AI is not on the nav mesh.

[harsh horizon]

What determines if it is or not? I've tried googling and a few posts saying to uncheck can effect navigation but I've unchecked it on all my components and it's not changing

[uneven cloud]

It projects down onto the nav mesh. You can hit f8 while you are playing in editor to see the nav mesh.

[dense halo]

Hey, does anyone know how to set a sub behaviour tree's blackboard values from the parent behaviour tree?

Or better yet, share the parent behaviour tree's blackboard values with the sub behaviour tree?

[fierce carbon]

What is the best way to create navmesh for ai when the ground is created upon begin play?

[tawdry zephyr]

Dynamic navmesh with invokers

[celest python]

I hope Epic will use a linter to not forget exposing functions or I'm pretty sure some people will end up having to wait next version to be released to just call a function because its not exposed 😄

[tawdry zephyr]

@patent hornet Since your suggestion for resolving AI collisions by having them give you an ability that pushes you back, I actually played FFXVI, they have an interesting system that forces you to sidestep AI.

And just now, I duplicated and rewrote Lyra's interaction tasks, because it does exactly what you suggested - provides an ability (for interaction). See screenshots.

This is my most minimal implementation to get a result for testing, but it actually produced an interesting result - if I really try I can breach the 500cm Strength on the Apply Root Motion Constant Force which makes it feel like there is a collider that instead of being a solid object is more of a suggestion - in real life you can get that close to a person and really invade their personal space if you are feeling stupid too 🤣 It actually feels quite nice. I prefer it.

And I could absolutely couple this with an animation like FFXVI does, where it sidesteps, of course having actual root motion on an animation could feel super disruptive depending on gameplay.

I'm going to make the AI play a "shove" animation 😄 It will look so rude, I can even make them say "move it!" if they're a gruff looking soldier

[ocean wren]

I used the DetourCrowdController and added a seperation force that took into account other agents and a push force scalar value.. so a human player could "push" through the seperation of another agent.. otherwise they'd be equal in terms of the seperation steering force.

[dense halo]

Anyone know a solution? Or am I not using the sub run behaviour tree node incorrectly?

[harsh horizon]

@uneven cloud I fixed it!

[boreal tundra]

Can someone help me? My AI during a chase gets glitched and starts snapping continuously. Also, how can I avoid my AI to walk towards walls when pathing? Thank you

[dense owl]

Use the visual logger to see what is making your AI receive multiple different instructions instead of just the one

[dense owl]

show your current code

[boreal tundra]

https://tenor.com/view/homelander-the-boys-season3-exhale-homelander-exhale-disappointed-gif-26166811

[dense owl]

use words

or screenshots of the visual log

[hearty niche]

how would you recommend previewing my navmesh if my navmesh only generates around invokers (only way to do it in world partition as of now afaik)

[zinc cape]

Im new. Can anyone help me call this weapon pickup vector in my ai task for getting the vector? Or what can I plug into the actor location? I just need the ai to go to the pickup. ty!

[boreal tundra]

I don't understand. The glitch is because of the Behaviour tree you think?

[dense owl]

Maybe. The snapping effect you described sounds like your AI is receiving multiple instructions on tick or something. Maybe show some code

[boreal tundra]

Okay how can I do that?

[boreal tundra]

Or maybe navmesh?

[dense owl]

How can you show code? Screenshots or snapshots (win+shift+s). Would need to see what you’re doing if anyone’s going to be able to assist

[boreal tundra]

Basically the killer get stuck and start shaking

and if you go behind him he'll get unstuck and chase you again

[dense owl]

did you look at the tree at runtime to see what happens?

[boreal tundra]

How? don't remember the button

[dense owl]

also that decorator on the first selector of the right branch is prly unnecessary. Because if the left side branch fails, the right side branch will execute. same with the next set of decorators

look at your tree, alt+P to start the game and observe the flow of code in the branches

you can also pause the tree at anytime and rewind so you can see what is failing

[boreal tundra]

I'm getting chased by one hour but the fucker doesn't get glitched

[dense owl]

aren't you setting the nearest gun's location vector with the service already?

[dense owl]

ugh well, you need to replicate the issue to see what's causing it

[boreal tundra]

Lol I will in the future. Do you know why I can't package the game if I disable SteamVR?

I don't use it and I don't want to keep it

but the packaging gets error

[dense owl]

not sure, #packaging might

[boreal tundra]

Thx

[zinc cape]

Yes but I'm not sure how to 'get' that vector for the other task(so that it can 'move to'. Im not sure the setup makes sense but that's how I made it lol

or should I set a reference to the gun?

[dense owl]

Not sure why you need a task to get it again, just feed it to the MoveTo node.

You also need to give your tree a fail condition

Right now you have a selector that has nowhere to go but down that branch

So move your branch to the left and put like a wait node or something on the right, so it has somewhere to go if the branch fails

[zinc cape]

like this?

[dense owl]

yeah. Do you need that simple parallel or would a sequence work instead?

[zinc cape]

I think a sequence will work from what i understand

[dense owl]

Does your tree go past your first decorator? I could be wrong, but I think that check will run before your service has had a chance to run and set the values.
I'd also maybe add a Gunlocation1 is set decorator further down, just to avoid it trying to move to 0,0,0, but might not be necessary

[zinc cape]

the black board is saying failed even though there is a gun in range:(

[dense owl]

Try moving either the service up the tree or the decorator down the tree. My guess is your decorator runs the check before the service had a chance to set a value, so it fails instantly

And I would move that whole branch left more, for visibility's sake, because in BTs, the left-to-right order is very important (it determines execution path), so it's important that you can see that distinction at first glance

i.e.:

[zinc cape]

Ah ok makes sense yeah the reason is cause i have the other stuff on stand by basically

He moved to it!!

last question is what do i set it to so that it prioritizes picking up the gun over attacking the player?

[hearty niche]

tun a common service which checks what values are true and then prioritize accordingly?

[dense owl]

if your gun pickup is on the right of the player attack, the player attack will run first. If you want the gun pickup to occur before that, you need to move the branch to the left of the attack. If that's what you meant

hover over the number at the top right of a tree node to highlight the execution order

[zinc cape]

Ah ok that does work Thank you so much for the help! Now I just need to get him to pick shouldn't be too difficult lol

[dense halo]

the second screenshot is from the blackboard, I set the parent to be main behaviour tree's blackboard

[dense owl]

show the inside of your BT_SoldierCombat tree, namely the Details panel

[dense halo]

so I'm guessing I'm going to add all the new blackboard keys that I want in the sub blackboard to the parent one, and have it shared?

[dense owl]

ok I think I figured it out

for that run behavior tree to not give you a bb not compatible message, it looks like both BTs need to run off the same blackboard. Note that if you change the BB on your 2nd tree to match the first one, the change won't register until you save that 2nd tree

[dense halo]

yeah unfortunately I'll have to include all my variables in a single blackboard

also, does anyone know if it's possible to set a filter on a Blackboard Key Selector in blueprint?

i.e have an expose Blackboard Key Select variable, but only allow keys that are object types or int etc

[uneven cloud]

No. It's C++ only.

[left crest]

Hey everyone, I'm using a BT for my ai and using an EQS query to pick spots to wander around the player. My issue is that when the EQS query gives the ai a spot behind the character to wander to, it tries to walk straight through the player. Does anyone have any advice to get the ai to avoid the player while navigating to the point? I have started looking into nav query filters, but I felt there was an easier option

[dense owl]

RVO or DetourAI

And make sure the 2 can collide

[left crest]

I tried both of those but it didn't seem to work. I had been messing with the collision, so I may just have to switch those around and try again

Do they just have to block?

[dense owl]

Yeah

Try either of the two not both ^^^^

[winter moon]

right now my project is purely c++. are behavior trees worth using in this scenario? my ai will be relatively simple, as in a generic enemy with a few states

[tawdry zephyr]

If there is any interest in this solution; I'm going to turn it into a plugin now. Tested and working without desync at >200ms latency. It will be MIT license and free once done. Seems like a pretty basic necessity having AI characters that can collide without desyncing 🙂

[uneven cloud]

The Behavior Tree is just a fancy data asset. You can have all the functionality in C++.

Not enough information to determine which architecture is best.

[tawdry zephyr]

PushPawn plugin released under MIT License.

Provides a net predicted solution for Pawns to Push each other. Uses GAS to prevent desyncs that often occur when colliding with AI.

https://github.com/Vaei/PushPawn

Not bad for a night's work.

If anyone wants to use it, you absolutely will need to go through that Readme

But its a solid system, both these examples are >200ms latency with p.netshowcorrections 1

Hopefully someone gets some use out of it, its pretty niche I think

[winter moon]

Is it bad practice to have one monolithic behavior tree?

[tawdry zephyr]

I use FSM instead of BT for my game but I mostly do this for my AI. I can't see why it would be bad so long as its not running unnecessary checks or any logic that isn't needed, and so long as it doesn't become messy or difficult to work with

[dense owl]

may want to watch that first video Luthage has pinned. It's important to know if the tool you are using is the right one for your use case, i.e. are you fighting the engine, are you fighting the tool's intended purpose, etc.

[uneven cloud]

It entirely depends on what you are doing. If it's really big and difficult to follow, it might be better to break it up into subtrees. If you have different AI types that have minor BT differences, it might also be better to break up into subtrees to share functionality easier.

[celest python]

Thanks

[north tide]

Is there any good docs/tutorials for setting up a simple chase AI with C++?

[uneven cloud]

Watch the AI with Blueprints course on the unreal learning library. That will go over all the AI systems. You can then find the corresponding C++ function by right clicking on any BP mode and going to the C++ definition.

[north tide]

Ah okay, I'll give that a go. thank you

[still crypt]

If I want to use a delegate in a BTDecorator the underlying node has to be instanced right?

[olive prism]

how to make an AI grab a player when touches it?

What I did was create a collision (in the AI) and in the ActorBeginOverlap event I wanted to do an attach actor to actor, but I don't know if this is the right thing to do

My idea is to do like the AI in Pacify or Devour that when they touch you they take you to a random point on the map

[signal island]

You dont need to use overlap. theres a perception called Touch and you can use for that

[fluid cedar]

Are behavior trees right option when I need performance?

[celest python]

BTs are right option when you need to have a behavior decision tool that you design by prioritization of the behaviors rather than states

Performance is not a concern for BTs

[olive prism]

Thanks, i did not know this!

[fading field]

Hello, is there a way I can control where the ai looks while it's walking around?

Is that something I can set up in the behaviour tree or do I do that in the enemy blueprint itself?

[celest python]

AIController's "focus"

and AIController::FaceRotation function (only available in C++)

If you set focus AI will rotate there

[fading field]

oooooh I see, thank you so much!

[dense halo]

Do you have to call this every tick?

[uneven cloud]

There is setting focus, which will rotate the entire body or look at which is just the head. Look at is entirely animation driven and there are lots of tutorials. Focus is available on the AI controller and there's a BT service for it.

[lyric flint]

I have two functions in my Character called Sit() and Stand(). I also have two Behavior Tree Tasks called BTT_Sit and BTT_Stand which set the state of the Character with an Enum.

My animation blueprint then checks that state and selects one of four animations (see picture). This all works well, however...

When I want the character to move, I call BTT_Stand and then the Move To task. The character stands and starts moving, but they move while they are still transitioning from sitting to standing. I imagine I have to delay the Finish Execute node in my BTT_Stand until the character has finished standing. What's a common way to be notified of when the ABP finishes its current node? Or is this entirely a backwards way of approaching this?

[uneven cloud]

I would recommend not using the anim BP for anything the AI needs to wait for. Instead you can use the built-in play animation (single player) or GAS (multiplayer).

[fierce carbon]

What is the best practice when create navlinks attached to spawned actors? I want to achieve the following:

[dense owl]

uh... I guess you can't place bp comments inside EQS Querries? 😅

[lyric flint]

Thanks! I haven't had a chance to try this yet, but I'll try moving the more discrete actions whose finish I am concerned about into my BT Tasks.

[hazy oracle]

Hey guys, I'm working on animal ai, and want different animals to be able to walk up different slope angles, what would be the optimal method to set that up? Generating paths seems so ignore character movement settings, is there a way to have settings for multiple agent types?

One thing to mention: map is very big, so what I really want is a way to do it without placing navmesh modifiers everywhere

[winter moon]

Currently playing around with behavior trees, it seems that this type of framework is best used in editor rather than c++. I was thinking of doing the blackboard and behavior tree in the editor, and the tasks in c++. I don’t know if this is a good approach

[marble pilot]

Hey, can someone tell how I can get context as actor or location in C++ EnvQueryTest?

[orchid meadow]

hello there,
I am working with EQS but need some help.
I actually want to use EQS with player controller character Not with AI.
Anyone could guide me with this to use EQS with Player Controlled character not With AI there are a lot of YouTube videos on EQS with AI but no video on EQS using with player controlled character.

[dense owl]

That’s prly because EQS is an AI tool… what are you trying to accomplish, exactly ?

[orchid meadow]

I want to use motion warping with EQS to detect the points to check for sync points.

[harsh storm]

Yes

[dense owl]

I c. Don't know much about motion warping, but I imagine you could attach an AI actor to your player controlled one that runs the EQS and feeds the desired points to your character

[orchid meadow]

Ok try this thing.
Hope workes well
thanks

[uneven cloud]

You can use the EQS with any actor. How you use it depends on BP or C++.

[uneven cloud]

You create a child class of env query context and then override the appropriate function. https://docs.unrealengine.com/4.27/en-US/InteractiveExperiences/ArtificialIntelligence/EQS/EQSNodeReference/EQSNodeReferenceContexts/

[marble pilot]

I can create context and give it value, I don't understand how to use it in RunTest function.

[uneven cloud]

The movement component settings only determine if the character can move there, not navigation. Navigation is based on the agent settings in the project settings. You can have multiple agent settings, but it costs memory. Having a few is fine, but it can get costly depending on your game.

[uneven cloud]

There is a prepare context function that you either send an array of locations or actors.

[harsh storm]

What's your favorite thing you've used EQS for Luthage?

Like, "wow, I can't believe this worked"

@ocean wren See the new AI stuff with Unity?

[marble pilot]

You mean provide actors/locations/array function?

[uneven cloud]

Abilities. My combat branch on the BT is 6 nodes. Then design can add whatever ability they want and the AI just picks them.

[harsh storm]

I'm too noob with EQS to conceptualize doing that 😅

[uneven cloud]

I mean that there is a helper function to fill an array with the context actor or locations. If you have source (which you really should if using C++) you can look at the built-in tests.

[harsh storm]

I still just use it to find a potential "investigate" spot. So go to the last seen location, then pick random X spots on where the player could've potentally have gone 😅

[uneven cloud]

There's a lot of boilerplate code you need to write, but it's actually not that difficult. I think I added 3 custom EQS item types for this project.

[uneven cloud]

I use it to find smart objects, abilities, targets and nearly all move to locations.

[harsh storm]

I still just use the random point in navigable radius - or w/e the function is called

At least for standard wander behavior

[uneven cloud]

I prefer a less random wander. Especially one that they don't turn 180 degrees to go to the next point.

[harsh storm]

Yeah, I can see how that'd give a more controlled wander actually.

Then probably do a test to see if you need to make any turns. IE - if you end up facing a wall

[marble pilot]

Yes, it looks like I will have to set the source, it is strange that getting the location of an item in the item iterator is quite simple, but there is simply no information on how to get the location of the context in the same iterator. Well thanks anyway.

[uneven cloud]

You appear to misunderstand. There is a helper function to get the actors or locations FROM THE CONTEXT. It's called prepare context. You don't get it from the iterator.

[marble pilot]

Prepare, now I get it, thanks for the heads-up.

[uneven cloud]

I haven't ever needed that. I tend to have a fallback query if it can't find a point in front of the NPC, so they recover well.

[sand kettle]

Why doesn't the Run Behavior subtree abort after failing once? Is this a bug? When using the Sub BT content inside the main tree without Run Behavior, everything works fine.

In my case, when I'm in patrol mode and LastSoundLocation is set, the nested tree aborts and runs successfully for the first time. However, if the nested tree fails (because MoveTo can not get to location) it wont be able to run/abort again until it gets re-evaluated again after patrol finishes.

Also if the abort decorator is not on the top level node, it wont abort at all

[orchid meadow]

currently working on BP but planning to shift to C++ later.

I am not getting any debugger value from EQS

I am running EQS from BP_ThirdPersonPlayerCharacter BeginPlay().

[dense owl]

it's generally good practice to assume you did something wrong before you start thinking you've actually encountered an engine bug. In 9/10 cases, it's you.
You probably don't have the right abort settings on that Heard Sound decorator. Also, your subtree Selector only runs down the one branch. It is good practice to have a fallback behaviour, i.e. a wait node on the right, in case the main branch fails.

[uneven cloud]

How are you running it?

[sand kettle]

I know, but atm it just seems odd to me that a nested tree with the same behavior as a subtree in the main BT would work differently. If all branches fail in a nested tree, it just gets stuck at the root node and it wont abort it again. Whereas it's fine with a normal subtree. But I prob don't fully understand it yet.

I tried both value and result change aborts so I don't think it's the settings.

Having a fallback branch is sort of how I've fixed it. I put a Force Success decorator on my sequence, but that is good to know, ty for helping 🙂

[orchid meadow]

I created EQS blueprint and then run the EQS query from BP_ThiredPersonCharacter on 'L' Key pressed from keyboard in event graph.

[uneven cloud]

You need to send it a querier. You also need to bind to it being finished.

[orchid meadow]

ok
I try.
thanks.

[lyric flint]

How does the system know which ability to pick? Are they attached to some kind of utility/float calculation?

I've been trying to learn how Supported Agents work for the nav mesh. I am trying to add a "Small" character as a supported agent. However, my character refuses to move and the Visual Logger states:

LogAINavigation (Warning) Unable to find NavigationData instance while calling AAIController::BuildPathfindingQuery

I believe my settings are correct. Attached are my Project Settings > Supported Agents settings, my character's collision settings, and my nav mesh's settings, respectively.

I was assuming that my character will choose to the supported agent that matches its own size. Is this wrong? Am I missing a setting somewhere?

[uneven cloud]

The EQS is used to select the best ability to use given the world state.

[dense owl]

Hehe, you make it sound so easy

[uneven cloud]

Your supported agent settings need to be larger than the collision settings. If I remember correctly it just needs to be 1 unit more.

[lyric flint]

Ah, that makes sense. I'm curious, if you're able to say, if you set up those those tests in the EQS queries, or the designers do?

[lyric flint]

Thanks! Increasing to 100.0f and 100.0f seems to produce the same error, so it seems like I'm missing something else also?

Sorry ignore that, I'm dumb. I needed to rebuild the paths.

[uneven cloud]

I set up the tests, but a lot of it is data driven. All abilities have AI data associated with them. I have a condition system and there's a test if the ability passes the conditions associated with the ability. So like distance, facing, line of sight, etc.

[lyric flint]

Very cool, thanks!

[uneven cloud]

I haven't looked at it yet, but I think the new world condition system is very similar to my condition system.

[dense owl]

what's that?

[uneven cloud]

It's a new system in 5.2

[dense owl]

ooh, it's a new plug-in. Weird, I couldn't find anything on google that references it. I guess there's no docs yet?

[uneven cloud]

I haven't seen any docs yet. I saw a tweet a while back describing it and it sounded like my system. We aren't on 5.2 yet.

[ocean wren]

Haven't been paying attention, too busy buying guitar stuff, what did they do?

[harsh storm]

https://www.youtube.com/watch?v=dR4IuN2tF78

[celest python]

and this #programmer-hangout message

[dense owl]

I feel like I know I'm doing this in a stupid way. Current Target is a BB key that is set before this task is reached, but this was the only way I could extract its value as Actor. So you know, feel free to throw the book at me, I'm ready lol

basically I'm having to get the BB key's value as Object, then plug it into a key inside the task, and then get its value as Actor

because get BB value as Actor is not available directly from get Blackboard

[uneven cloud]

CurrentTargetKey is a blackboard selector, right? Just make that public and select it in the BT.

The entire point of using a blackboard selector is to not have to hard code the key name!

There is no such thing as get BB value as actor. It's get BB value as object and then you cast to an actor.

[dense owl]

I mean there is that node but you can only use it on a BB key but yeah I get what you mean

Ty

[sudden stag]

whenever i use any "AiMove" node the character has it's velocity and accelration set to zero even though it's moving. if i use "addMovementInput" those variables are updated correctly and the currect running animations are playing. what am i doing wrong here?

[uneven cloud]

To use acceleration for paths, it needs to be turned on via the movement component. You need to double check that velocity is 0, because that's untrue or something weird you are doing.

[sudden stag]

so ticking use acceleration for paths fixed it (didnt know that was a think. but i never had this issue) and as you can see here the velocity is set to zero even though the character is moving

again ticking use acceleration did fix the issue. it might be something dumb i did when i was messing with CMC 😅
thanks a lot tho!

btw is this like a new 5.2 option? i never recall it being a thing in previous versions...

[dense owl]

pretty sure it's been there for a while

[sudden stag]

huh

well at least my char is running instead of floating now

[uneven cloud]

Personally I think it should be turned on by default. It makes the movement look better.

[dense owl]

I don't understand why my test is failing. If I don't turn off reject incompatible items, it just ignores the gameplay tags altogether. I've made sure those targets have at least one of those gameplay tags on begin play

but the EQS is perceiving them as GameplayTags(0). I'm thinking I am supposed to implement the IGameplayTagAssetInterface from cpp for this query to work.

[fierce carbon]

Is it possible for navmesh to work on the lower level as well as the top level? Or would it require something other than a navmesh?

[sudden stag]

it should work just fine. just scale your volume on the z axis

[lyric haven]

Somebody can help me about making a simple enermy shooting?

[oblique basin]

For clarification, there is an actor getter but the setter is object only as the object type can be specified in the BB key.

[hollow cloud]

Hello everyone
I'm trying to create an AI system for the enemy in my game, where the enemy continuously stores the player's location in the 'Player Location' variable and moves towards that location. When the player becomes hidden from the enemy's view, the last known player location is stored in the 'LastKnownPlayerLocation' variable. The enemy moves towards this location if the player is seen again, but otherwise returns to the initial position or 'StartLocation'. I initially implemented this system and it worked fine. However, when I moved a part of the code that involves storing the variables 'Player Location' and 'LastKnownPlayerLocation' into a service within the Behavior Tree, it no longer saves the locations, and the enemy only moves towards the 'StartLocation'

Codes:
ShooterAIController: https://codefile.io/f/B9iTbCHvQ6
*The commented section is for when I wasn't using the service and had written it in the AIController, which was working.

BTService_PlayerLocationIfSeen: https://codefile.io/f/SHw85J0HRX

BTService_PlayerLocation: https://codefile.io/f/RGh6gNxh6n

[frozen swift]

You might store those values on the PlayerController (or PlayerCharacter whichever suits you), and use an interface to set/get those values wherever needed? You might even have the PlayerController control the 'Player Location' and 'Last known...' variables, and just retrieve them as needed.

[glossy basin]

Hi everyone! Quick question, can someone try to explain me how the avoidance config works in UE5? I have some AI Enemies with a Detour crowd AI Controller that surround the player, and they do this by walking towards specific points around said player. The thing is that sometimes, if, for example, enemy A is on the way of the location that enemy B has to move to, instead of Enemy B evading enemy A by walking around it, it gets stuck ☹️

I tried to tweak with the values, like changing the amount of adaptive rings so that my enemy had more rings to look for a better path, but the change was still the same. They walk with a slow velocity when surrounding the player, maybe this is the cause?

[dense owl]

set breakpoints and find out where your player location fails to come through

[uneven cloud]

I recommend using the visual logger to debug. UE log can get really messy. You want to check if the blackboard keys are valid (255 is an invalid key id).

Also recommend not dereferencing pointers that you haven't checked.

[hollow cloud]

I don't know how exactly, but somehow I managed to revert everything to the time when the system was functioning and reconfigured the services in the behavior tree. Now it's working! :D
I'm grateful to the friends who made an effort to help me <3

[gleaming hemlock]

Does anyone know of a very advanced Behavior Tree tutorial? All the tutorials i found on youtube are pretty much the same. Sense enemy, pursue, attack.
Im doing a strategy game, and need to see how something very complicated is done?

[uneven cloud]

I recommend starting with the AI with Blueprints one on the unreal learning library. It will go over all of the AI systems (except for the new ones).

[gleaming hemlock]

oh how did i miss that

https://www.youtube.com/watch?v=ov3XVziSg-Q&list=PLDnygpcOYwFW2XtNyiandrLDG__OAZs7Q&index=48

this one also seems to be good

[uneven cloud]

You are unlikely to find a tutorial on a "very complicated" AI.

[gleaming hemlock]

yup. but that one in the video looks complicated 🍝 🐺

[uneven cloud]

The actual behavior is simple, but they over complicated it.

[gleaming hemlock]

it does look like he just goes on and on. i dont understand anything of whats going on there. but i need to watch his earlier videos

but the ai of strategy games is complicated

its not like just a dummy going around looking for enemies

its too many factors

but idk

[dense owl]

btw the 3rd pinned video is a very good at showing you what you can do with AI in UE

[orchid meadow]

thanks for all the help
that works very well.

[gleaming hemlock]

https://www.youtube.com/watch?v=Qq_xX1JCreI

[gleaming hemlock]

this one?

[dense owl]

https://www.youtube.com/watch?v=iY1jnFvHgbE

[uneven cloud]

I believe that one is part of AI with Blueprints.

[gleaming hemlock]

i went through that one already yesterday

[uneven cloud]

https://dev.epicgames.com/community/learning/courses/67R/unreal-engine-introduction-to-ai-with-blueprints/mX27/introduction-to-ai-with-blueprints

[gleaming hemlock]

thanks

ok i already have lots of tabs with videos

i think this will be enough for my workout session 🐺

🏋️‍♂️

[quaint bolt]

I'm currently learning AI in Unreal* too, this is what I've been reading in the past day: https://www.amazon.com/AI-Games-Third-Ian-Millington/dp/0367670569

I feel like the Unreal BP course shows you the "how", but you need some other resources to show you the "why"

The book above has a good chapter on choosing the right AI architectures given your game's design reqs

[gleaming hemlock]

nice i put it on my list

is it theory

like theory of ai ?

or it goes into specific examples

thats a big book

900 pages

[quaint bolt]

It covers the full gamut. Yeah we ain't reading all 900 pages 😛 but I'm keeping it around as a reference to understand how things work. I am only reading the chapter on the design process to start

Like, "how do I choose between BTs, FSMs, utility AI, etc etc"

[uneven cloud]

AI for games is OK. Pretty old though. GDC has an entire AI summit, many of which are free. There are also the Game AI Pro books, which are free online.

[quaint bolt]

Ah interesting 👀 adding some new bookmarks!

[gleaming hemlock]

im terrible at reading. i read slow. i do very well with videos on 2x speed

[crystal hatch]

for what it's worth I'm a slow reader as well. I do however have a talent for building mental models of how stuff works. Find your talent and build on it!

[gleaming hemlock]

i have that talent too. im a very visual person/creative type. but i get bored reading.

[dense owl]

Yeah and also for building AI models and data-oriented calculation frameworks 😛

[crystal hatch]

how about you doodle while reading? Creating so called "mind maps" is at an very intersection of creating and learning 🙂

[crystal hatch]

oh yeah, that too 😉

but not reading 😄

[gleaming hemlock]

reading for me is like eating boiled potatoes without salt. but watching videos i just absorb things much better.
if its something short that my brain needs in the moment, i can read and learn it. but if its like, read this book of 1000 pages to just learn everything in general, its hard. so its like just in time learning works very well for me

[crystal hatch]

like eating boiled potatoes without salt
this makes me think you come from one of the slavic nations 😉

[grand saffron]

I imagine that was why school was hard for some in my "era"... books were the only option to learn the material

[dense owl]

Can relate 😅

[crystal hatch]

To clarify, I'm from Poland, so I know perfectly well how discusting unsalted potatos are 🙂

[dense owl]

I’m from Romania originally, so close enough

[crystal hatch]

Oh yeah, same diet 😉

[dense owl]

Also, YouTube must be tracking my discord usage cause this popped up on my feed a few minutes ago lol https://youtu.be/ZRBXoQTuEgk

[crystal hatch]

I'm thinking more https://www.youtube.com/watch?v=Pf6pekk5CqU

[sudden stag]

im not slavic but i do enjoy me a salted potato

but i like it baked rather than boiled

[uneven cloud]

Not from a Slavic nation, but my family is. Grew up on a very similar diet.

[still crypt]

Is the PostProcessMove Delegate not called if you're using the UCrowdFollowingComponent?

[still crypt]

Also, on the note of crowd following, the docs say All agents will operate on the same navmesh data, Does this mean you can't have different agents (Say for different sized characters) when using it?

[harsh storm]

TIL that #gameplay-ai is made up of potato diets @uneven cloud @crystal hatch

[tawdry zephyr]

@crystal hatch does this mean it was accepted/merged?

Or was it just added to your Jira

https://github.com/EpicGames/UnrealEngine/commit/bd0b2994c7810d040bf955eb185f8f34c8b59ff8

[crystal hatch]

It means your PR is in 🙂

and has been in for two weeks now

[tawdry zephyr]

Thought so 🙂 Thanks

[elder pivot]

Has anyone some hints/best practices for open world navigation. I need to support a 50km² map with ~1k ai units. I guess Invokers will have a huge performance impact at this amount, so I guess that is not feasible? Should I tile the mavmesh by myself or is the 5.1 world partitioning a reliable feature for navmeshes too?

[reef shore]

how do you generally make AI Characters not damage each other?

I'm using the same projectile class between the main character and the ai characters and it mainly only ignores the instigator.

[bronze zephyr]

Tag friends?

[undone heron]

Hey, how do I test if movement fails on ai? Say it can't reach its target for example

I want to include a mechanic where the ai loses interest of the player if it can't reacht them for a few seconds

[bronze zephyr]

Working on a shark AI system for my survival game. EQS not working on a floating pawn. Using multiple box traces atm to determine a valid location to move. Not really ideal. Anyone suggestions would be greatly appreciated.

[bronze zephyr]

Maybe run an eqs distance trace to player. If it can not reach the allotted distance in X time it will reset state to random roam or back to patrol point.

[frail bough]

The ai character here is not following me, however, the printstring at the end is triggering. This confirms, I think at least, that the playercharacter is being sensed properly. Any ideas?

[tawdry zephyr]

Surely you don't have 1000 on-screen?

My game is a large open world. I don't place any characters/pawns in the world at all. I built a robust spawner actor (from AActor) which has "Spawn Relevancy", which is just net relevancy, but shorter, and extended to factor all waypoints. If any player is near a spawner or the bot itself or the waypoint then it'll be spawn relevant.

And yeah, I use navigation invokers.

[tawdry zephyr]

Any idea what the turnaround time might be like on the other ones? They're all other departments I think but hoping you might be familiar with those teams https://github.com/EpicGames/UnrealEngine/pulls/Vaei

[crystal hatch]

anywhere from "a couple of days" all the way to "never"

[tawdry zephyr]

I could have just wandered down the street and asked Bob 😉 Haha. OK point taken

Was hoping you'd be familiar with them but all good

[crystal hatch]

We split into teams so that I don't need to care what they're doing 😉

[tawdry zephyr]

Fair enough haha 😄

I totally appreciate that you're on here, it goes a long way IMO

Wish other departments would follow suit 🙂 Dan over in audio is amazing too

Without UDN access it can be pretty hard to get even basic changes and fixes in

[harsh storm]

Mieszko is GOATed. Sucks we lost MrHibbitts in #cpp though 😭

[tawdry zephyr]

#cpp energy is way too weird for me

I know it sounds like a joke but I just don't know how else to phrase it

[harsh storm]

It's not often you get to receive help (for free no less!) from the person to blame thank with the AI systems of a given engine!

[celest python]

its likely you're keep retriggering moveto

and acceleration gets zeroed so your velocity is

[candid lantern]

i probably shouldnt ask.. but what about #cpp weirds you out?

[unborn sphinx]

All the macros 😛

[candid lantern]

haha

[uneven cloud]

Invokers are incredibly expensive. It's better if you put them on spawners instead of moving actors, but they are still quite expensive. There is world partition navigation support for navigation streaming, but I haven't tried it.

[tawdry zephyr]

Is this likely to change in a future release? The cost

[harsh storm]

I wouldn't place my bets.

[uneven cloud]

Unlikely. Navigation generation is just expensive.

[tawdry zephyr]

Mm that's a shame. I might have to revisit my use. Alternatively I could just place invokers that envelope AI heavy areas such as towns/camps. I already have them tied to my spawners, so I can just remove them from my AI pawns and make them envelope waypoints.

Is the general idea that if they're not causing anything to change on a given frame, then they don't have high cost?

[uneven cloud]

They have a high cost, because they generate navigation. Being on static actors means they don't constantly cause regen, but they do when that area is loaded.

[tawdry zephyr]

Thanks, that gives me a path forward 🙂

[visual dawn]

Hello am looking for a comprehensive tutorial for AI with cpp that has EQs and other essential to make AAA AI’s any available?

[uneven cloud]

The team interface. You can get team affiliation for any actor that uses it.

It's only available in C++, so if you are BP only you need to build your own functionality.

[harsh storm]

Won't find one. Rely on Game AI pro book series and GDC vault. That'll be your best route, other than just sitting down and doing the work.

To get started with AI, there are some pinned resources. And there is a course on the UE learning site...uhhh - Blueprinting for AI or something like that

[uneven cloud]

The AI with Blueprints course on the learning library is still the best first step. Anything in BP is available in C++. If you are making a AAA game, you should be able to read source without problems.

GDC AI Summit and Game AI Pro are other general resources.

[visual dawn]

Am not a novice am just wanted to Rili Rili Rili expand my knowledge about Ai and I am a c++ fan boy I implement all my codes in cpp no disrespect to the BP guys just my preference

[visual dawn]

Any links t the summit?

[uneven cloud]

The AI with Blueprints course goes over all the systems. Don't let your ego drive your learning.

[harsh storm]

Sounds like your a novice if you don't balance C++ with BP and vice versa.

[uneven cloud]

https://www.gdcvault.com/

[tawdry zephyr]

Completely true

Dismissing a useful tool to stick to a more complex one doesn't make you a better dev 😄

[visual dawn]

Ok 👍 mr professional

[visual dawn]

Appreciate

Am out

[uneven cloud]

To be fair, large games need to really limit BP. But you shouldn't be making that size of a game if you still need tutorials.

[visual dawn]

Lol u dnt knw me

But it’s understandable

I appreciate ur effort for the link

Ur a hero

[uneven cloud]

Tutorials don't go over best practices for games made by 100+ professional devs. They are made by hobbyists for hobbyists.

[visual dawn]

I checked ur link and it’s just a lot of archives

Am I meant to swim in it

[uneven cloud]

There is search functionality and filters.

[uneven cloud]

You test the path before you move. Using the EQS makes it easier to find a location to move to.

[elder pivot]

I'm not working on a game, so I can't ignore AIs that nobody sees unfortunately.

[uneven cloud]

Then you should be looking at Mass or rolling your own ECS instead.

[elder pivot]

We already have that, currently we use havok for physics and navmeshes/navigation. But our graphics engine looks a little bit dated, so we are evaluating Unreal. My task is to look at the navigation options unreal has to offer. But so far it doesn't look promising for this scale at all.

[tawdry zephyr]

This is an option that exists (not making an actual recommendation) https://mercuna.com/

I'm rather curious if its any good myself, esp. since it costs a decent bit (depending on your level of funding)

[gleaming hemlock]

In behavior trees we only have sequences or selectors

what if i want to run all the nodes below

[uneven cloud]

Havok navigation is significantly better than recast. And they have a UE integration. I can verify that the navigation streaming for world partition does work as that's what we use.

[crystal hatch]

not true, you have sequences AND selectors 😉
What do you mean by "all nodes below"? Do you mean "in parallel"? If so then UE BTs don't have that feature. But you have Services that can all run in (perceived) parallel.

[tawdry zephyr]

Can't find pricing for that 😄

[ivory rune]

I think you need to contact MS for the price😜

[tawdry zephyr]

That generally means its really high 😄

[ivory rune]

It is not really open price but you need to negotiate with them for your service, lol

[gleaming hemlock]

So like imagine you have a bunch of tasks you need to run.
The sequence stops running once it finds one node that fails. And the Selector stops running once it finds a node that succeeds.
What if we need to just run them all regardless

[tawdry zephyr]

I'm sure if I wait long enough Epic will buy it

[harsh storm]

Epic will buy it if Fortnite needs it.

[crystal hatch]

There should be a decorator forcing result of the underlying BT node. Just force result to success and use sequence.

[uneven cloud]

Probably really expensive. I asked for it and other people dealt with the cost and approved it.

[harsh storm]

A couple days of Fortnite monies

[uneven cloud]

That assumes Microsoft will sell it.

[harsh storm]

Oh - M$ owns it? 🪦

[ivory rune]

Yeah, years ago MS acquired Havok

[harsh storm]

Make a new nav system and call it "MetaNavigation" and Tim will certainly notice.

Could even get a grant for it most likely.

[gleaming hemlock]

got it

thanks alot

[celest python]

These days Epic buys stuff for Metaverse thingy instead of Fortnite, otherwise unless its absolutely necessary they workaround things to make it work with Fortnite

[harsh storm]

Their metaverse is Fortnite

[celest python]

Gameplay/engine code is not directly related with workflow and Tim's obsession

[tawdry zephyr]

So how does Mercuna compare to Havok

[crystal hatch]

not quite

[harsh storm]

Well. I can't debate with someone who probably sits in on the meetings about Unreal in 2026 🤣

[crystal hatch]

The whole company does, we have no secrets internally 😉

[celest python]

How so though? Doesnt all content exist in Fortnite? like characters from other universes

and UEFN itself

[crystal hatch]

for now.

[harsh storm]

So get hired, learn the secrets, quit. Got it.

[celest python]

thats indeed a plot twist 😄

[crystal hatch]

don't forget "spill the guts, get sued for everything" 😉

[harsh storm]

Oh no no no. Not me good sir. I spill no guts.

It's more so I can chuckle silenty behind my screen on Discord.

[crystal hatch]

also, "get hired" might get tricky 😄

[harsh storm]

Yeah...that requires effort.

https://tenor.com/bcalq.gif

[celest python]

I think part after getting hired is even more exhausting

Engine dev is too stressful

[crystal hatch]

I never noticed 😄

[harsh storm]

My plan has been thwarted 😭

(I don't have any good emojis)

[harsh storm]

I actually don't mind engine dev. I'm just more interested in actually making games at the moment.

And you don't make games if you're making engines!

[celest python]

Since after getting insanely burnout from working with Blueprints VM a couple of times, I sometimes open up niagara and chaos modules and stare at the classes to think how epic devs able to keep up with same pace to rush features to next version

[crystal hatch]

unless you're building generic systems for the engine because the game you're working on needs them 🙂

[harsh storm]

I'm indie dev. I don't have anyone else to do the gameplay programming 😅.

[crystal hatch]

that's your problem right there!

[harsh storm]

Besides - you've already built these generic systems for me!

[crystal hatch]

you're welcome 😄

[harsh storm]

https://tenor.com/bHZey.gif

Found a better "thank you" gif

[dense owl]

“I need Havok.” “Luthage, that’s going to cost us $1M doll…” “I need Havok!” “Ok, ok, we’ll buy it.” 🙃

[tawdry zephyr]

"Fortnite needs Havok!" *

[celest python]

I think if you're a promising indie studio with arguably enough budget and a team with past experience on AAA companies like Havok tend to agree on revenue share

Thats how Kythera also does

[tawdry zephyr]

Why do people usually license Havok, are UE's tools not adequate, or do they just want flying AI etc

[harsh storm]

UE's tools might not be adequate for that specific problem

[celest python]

One of my friends was told most of their programmers was familiar with Havok so instead of building new systems on top of the existing AI they were considering licensing Havok

[tawdry zephyr]

I notice BOTW used it, but their AI is so simple. Guess they needed something since they don't have UE 😄

[harsh storm]

Well, a 3rd party engine, it'd make a lot of sense to license Havok

[tawdry zephyr]

Yep

[celest python]

Their so raved physics engine is also Havok

[tawdry zephyr]

Yeah, they definitely did a good job with it, because its verrry reliable, their shrine puzzles wouldn't be possible otherwise

[ivory rune]

yeah, havok is solid.

[celest python]

Its probably default havok btw 😄 I dont think they modified it more than slightly

[uneven cloud]

Havok AI has a lot of features that Recast does not. Like automatic traversal markup and really good collision avoidance. It's also more performant.

[tawdry zephyr]

Ah yup. That would be a no brainer for many projects

Well, I'd like all that too, but 😄

[uneven cloud]

Haha. It's more like "using Havok will give us these features, that we don't have to build, so it will save us dev time."

[tawdry zephyr]

That's a great point, buy it and put it in the engine for me

[dense owl]

I don't think it works that way lol

[tawdry zephyr]

😄

It did with live coding, right after I bought a year license

Back when it was Live++

If I license HavokAI Epic will buy it within the month

My superstition is definitely rooted in fact, you should shout me a license

[uneven cloud]

I'd like to keep my job. Also it doesn't work that way.

[tawdry zephyr]

I know that

[worldly quarry]

Hi how are you? Just a silly question,
Is anyone using State Trees in a moderately successful way?
I'm having a hard time trying to do very basic things and the functioning is extremely erratic. I surely have problems with some concepts, but there is also no documentation or the existing one is superficial.
Is this really production ready?

[crystal hatch]

Is this really production ready?
no, it's not.

[tawdry zephyr]

Its a very new feature, definitely not ready

Maybe 5.4, but probably not

[crystal hatch]

5.3 will be already a big improvements, including a first draft of the ST Debugger.

[reef shore]

IGenericTeamInterface?

[uneven cloud]

Yes.

[harsh storm]

@crystal hatch Curious - any particular reason you haven't gotten the "Epic Staff" role?

[crystal hatch]

I don't care for stuff like that. Also it results in funny conversations sometimes 😄

[harsh storm]

"They don't know that I'm the one who wrote the system" - Mieszko while conversing with someone about a tool in #gameplay-ai or #mass

https://tenor.com/w5Nj.gif

Actual gif of Mieszko behind the screen

[crystal hatch]

I gotta get my giggles somewhere!

[harsh storm]

https://tenor.com/1Lh4.gif

[celest python]

In case you didnt know btw there is a secret epic section in this server

only admins + epic staff see it

[crystal hatch]

Sounds snobby 😄

[spring inlet]

SmartObjects cant move? 😦

[urban turret]

Need quick prefered setup answer. Setup AI perception component on AI controller, should I just place all perception components on the controller or place the Stimuli source on the pawn? Also should the TeamInterface be on the pawn or controller?

[harsh storm]

More like DumbObjects, am I right

[spring inlet]

well i think its because of the cache they use?!

and yea in 5.1 they are really dumb (and broken by design)

[uneven cloud]

Smart objects also can't replicate their state either.

[spring inlet]

i don't need replication, but i can see how this is annoying for those who need it 😄

[uneven cloud]

Perception on the controller. Stimuli source on the pawn. Team interface is already on the AI controller.

[sonic garnet]

guys please.. does anyone know why the " ai move to " or " move to actor " acceptance radius wont work if you are standing on a higher/lower ground then the ai?
they just come up real close to shoot.. picture for refrence to what happens.. they dont shot from there, even tho i AM in the range of acceptance radius.. he will come around all the way up to me and shoot. This problem is not present when we are both on a flat surface.. please help--thanks 🙂

[celest python]

acceptance radius just does math rather than relying on geoemetry i think, can you check visual logger to see what kind of log MoveTo outputs when its finished?

[crystal hatch]

Also bear in mind, that AcceptanceRadius is just a runtime parameter of when to stop moving, it doesn't take part in pathfinding.

Also2: AcceptanceRadius is being checked on the last segment of the path. You'd see the same issue on the flat surface if there was a fence (or something else untraversable) forcing similar holes in the walkable navmesh.
You can fake a "check AcceptanceRadius all the time" by adding a "check distance" decorator on the move to task (to abort move when within given distance from the target)

[sonic garnet]

Okay, ill check when i get to the pc

[sonic garnet]

Hmm i dont understand the second part, hos to i check radius all the time? What node is it?

[crystal hatch]

You need a "distance to BB key" decorators. I don't remember if there is one provided by the engine. If there's not then it's a great opportunity to learn how to create one since it's trivial and can be done with BP if you're not a coder.
That's assuming the "move to" target is in your BB.

[uneven cloud]

There's an is at location decorator that I believe also allows you to set the radius.

[lethal helm]

Spawning some actors from my gamemode during PreInitializeComponents how do I get nav data to generate for them?

doing this on ABP doesn't work

if (NavigationSystem)
{
  NavigationSystem->Build();
}```

[dense owl]

Rotate to BB entry gets stuck as if it were missing a Finish Execute node. Google says make sure use controller rotation yaw is unchecked, but that wasn't it. I thought I'd found the issue (abort self causing the EQS service to constantly refresh and change targets), but that I fixed that and still nothing. Thoughts?

More info from Visual logger. Looks like after the BB condition is met, I get a perpetual stream of suspended/resumed branch actions

[uneven cloud]

What are your navigation generation settings?

[lethal helm]

dynamic

Adding a 1s delay to build after ABP works

[uneven cloud]

You need to wait until the navigation is generated before spawning them. Do not use a delay. There is an event you can bind to.

[lethal helm]

can't wait actors need to be spawned as early as possible

[uneven cloud]

As early as possible means "after the navigation is ready"

[lethal helm]

which is apparently sometime after ABP

[uneven cloud]

ABP?

[lethal helm]

actor begin play

[uneven cloud]

Well actor begin play can happen at literally any time. I take you mean the game mode begin play.

[lethal helm]

Yes

Whats this event?

[uneven cloud]

On Navigation Generation Finished

[uneven cloud]

What is the precision set to? If it's too small it might not end correctly

[dense owl]

45 currently. I've also just tried 80, same result

oh, 180 seems to work better

[frail bough]

https://medal.tv/games/unreal-engine/clips/1gQqtDdenrIM0l/d1337chDUASw?invite=cr-MSxLM1EsMTA1NTU1ODkyLA Hey guys so I decided to go back into my AI testing level because I noticed how unthreatening the enemies actually are. They're made using a simple follow player blueprint, and I'm happy to change that if necessary. You'll notice in the clip below that the AI will essentially only attack me when I'm standing still. I've tried tuning acceptance radius to no avail.

[lethal helm]

Lots of things wrong here imo

1. You should have the attack animation on the enemy be upper-body only so it doesn't slide while it move-attacking

2. You should have the attacking and the moving be concurrent instead of out-range -> move closer -> attack -> out-range -> move-closer -> ect

[frail bough]

Yeah I'm working on the upper body thing, was just going to fix mechanics before anims

[lethal helm]

Okay. Easiest solution is to just put the attack logic on your dude

SetTimer TryAttack on 1s timer

if AggroTarget is InRange do Attack()

[frail bough]

Yeah so I was setting something like that up, however I didn't really understand howw to use the timer. One of them needed a function name, and the other needed event.

Do I need to put the timer logic inside my attack event?

[lethal helm]

drag off the event pin and search custom event

You might want to go through a "basics of ue4" tutorial first before diving into something like AI though

[frail bough]

Alright, thank you.

[dense owl]

think of it as a more malleable Event Tick, in that you can modify the rate at which it fires and whether or not it fires perpetually (looping)

there's more to it than that, but that'll give you some idea

[lethal helm]

This doesn't get called when I load into a level in-game

[dense owl]

works no problem

[lethal helm]

BeginPlay
NavigationSystem->OnNavigationGenerationFinishedDelegate.AddUniqueDynamic(this, &AMyGameMode::UpdateNavigation);

never gets called

[dense owl]

My cpp knowledge is still very limited, but the screenshot I showed you was on the Game Mode's Begin Play

[lethal helm]

mine is too

[dense owl]

so if it doesn't work, you might be missing a step

[lethal helm]

our code is identical

GameMode Begin Play -> Bind DoThing() to OnNavigationGenerationFinishedDelegate

[dense owl]

🤔 are you certain you're properly referencing the navigation system?

I guess if it was nullptr it'd yell at you, so not sure

[lethal helm]

It would crash if it was nullptr

this looks promising

nope doesn't work

Rebuilding right after those actors are spawned doesn't work

So looks like the good ole 1s beginplay delay is the winner

NavigationSystem->Build() doesn't trigger the delegate either

[dense owl]

I don't understand why it doesn't work for you

btw are you in UE4 or something?

[lethal helm]

what version are you on

most people are

4.25

Toss a cube or something in there during runtime though and Bam there goes the delegate

[dense owl]

5.2

That’s odd

Idk about most people that seems pretty outdated. But then again I haven’t checked any polls 😅

[lethal helm]

ugh

visual studio can't find where OnNavigationGenerationFinished is called either

[dense owl]

Check UNavigationSystemV1, see if it’s anywhere in there

If not, I’m sure one of the greats in here know

[lethal helm]

Nope. Are parts of the navigation system closed source or something?

[dense owl]

Not likely

[lethal helm]

Looks like it's being called in RecastNavMesh

And visual studio search is just stupid I guess

it's literally highlighting it yet it's still not in the search results

[dense owl]

I hear Ryder is better

Btw, maybe run your code by #cpp guys, just for a sanity check

[lethal helm]

hur dur being stupid was the issue

NavigationSystem::Build() turned out to be sync so it finished before execution even got to the bind the next line

That helps a bit. Still dunno why the initial build when I load in isn't happening though

[lethal helm]

Wrong function delegate

The one I needed was
NavigationSystem->OnNavigationInitDone.AddUFunction(this, "LoadCustomActors");

[gleaming hemlock]

whats the difference between a wait node and a cooldown decorator?

they seem to do the same thing. just wait x seconds

[dense owl]

It’s in the description. The cooldown returns failed after it waits

[gleaming hemlock]

i see now

thanks

[uneven cloud]

The wait just means it does nothing and then reevaluates the tree.

The cool down means after the execution is finished, this branch can't be run for at least x seconds. So lower priority branches will run.

They are completely different.

[dense owl]

Ah, a much better explanation

[gleaming hemlock]

got it thanks

[sudden stag]

is there a way to get the Ai sight config?

[sudden stag]

btw i just want get. im know that you cannot change the sight config values at runtime with bps