gameplay-ai

[pine steeple]

ok

[pine steeple]

@lament linden it looks like they are set from the image

@cobalt palm did you verify that target actor and state is being set?

you can have the BT open and see the values in real time

also did you set the aborts up

like this?

[cobalt palm]

It should be self?

[pine steeple]

or lower priority depending on where the decorator is

self will abort the green

lower priority will abort the blue

both will abort both lower and self

[cobalt palm]

When I select lower priority the other selector with 5s wait doesnt highlight blue

[pine steeple]

show me the decorator

properties

and your graph layout

[pine steeple]

switch them round

higher priority on the left

[cobalt palm]

oh. I didnt know that mattered

[pine steeple]

BT always executes Left to Right

now the wait should be blue

[cobalt palm]

Ok, so I had the Behavior Tree open while running that time and it always stay on the wait selector, so that must mean that the enum key is never set to combat to switch to the other selector.

[pine steeple]

you can see the values

at runtime

[cobalt palm]

How do I do that?

[pine steeple]

at the top choose the instance whilst playing

then these values will be live

[cobalt palm]

Ok. Yea so the State never changes from idle, so its something within the VisionCheck

[pine steeple]

now at least you have some ways to debug

hopefully find your issue

PS. Try using DebugLines/DebugCone, etc to draw to the world

so you can visualize thing

[cobalt palm]

I watched the VisionCheck this time during runtime and it doesnt go past the cast so its something in here

[pine steeple]

why are you passing in Get Player ?

not the Controlled Pawn from the event?

[cobalt palm]

huh. I kept going back and forth on that let me try again 😂

🤦‍♂️ Ok now the execution goes through but it doesnt move to player. Let me try again

It finally goes to the branch but never set the values

[pine steeple]

what branch

[pine steeple]

so your dot angle check is broken

draw some debug lines

see if your forward vector is where you think it is, etc

debug draw line to player from tank, etc

[cobalt palm]

Yea, I feel the problem is getting the tank top but thats where I want it to stay so that the cone locks to the turret

[cobalt palm]

Is this correct? The start is getting the actorlocation and the end I take the actorlocation and add 1000 to it?

[lament linden]

Not quite. You should get the forward vector, multiply by some value (like 1000), add that to your actorlocation and set that as end

[cobalt palm]

Welp. I may be doing this wrong but either way i did it, it wouldn't rotate with the turret.

[cobalt palm]

@pine steeple After some later debugging I have moved the Set Blackboard Value as Object to the Event Receive Activation as It only needs to update the key once and I can see that the execution "orbs" go to it, but in the blackboard the key is never set.

oop.

Well. Everything while looking at the Behavior tree seems to be fine. In the blackboard the key switches to combat and then in the BT it goes to the move to node but he doesnt move.

[pine steeple]

do you have navmesh setup properly?

[cobalt palm]

Yep. I see the big green area on my level. There is like a square missing around the ai, I dont know if that make a difference?

[pine steeple]

that would cause it

make sure your AI meshes does not affect navigation

you must see green underneath it

[cobalt palm]

Hm. I was able to remove the collision and now its fully green but it still doesnt move.

[pine steeple]

now its time to learn the visual logger

[cobalt palm]

Even the debug says its supposed to do it

[pine steeple]

https://docs.unrealengine.com/en-US/TestingAndOptimization/VisualLogger/index.html

[cobalt palm]

oh no 🤦‍♂️

[pine steeple]

?

it is really simple

[pine steeple]

ah well there you go

your pawn has no movement component

[cobalt palm]

but, its a pawn ai

[pine steeple]

that does not have a movement component

[cobalt palm]

I thought only Characters could have that

[pine steeple]

you can add a PawnMovementComponent

to your pawn

[cobalt palm]

Theres a floating pawn movement

[pine steeple]

there is a normal one

[cobalt palm]

The only one is floating movement. Characters can have the normal one

[pine steeple]

ah PawnMovementComponent is abstract

[cobalt palm]

The floating one worked though 😂

[pine steeple]

why is your tank not a character?

that is what we did 🤷 lol

[cobalt palm]

Not a humanoid

[pine steeple]

i use it for non humanoids just fine

[cobalt palm]

So making a tank as a character worked?

[pine steeple]

4 legged monsters, flying monsters, etc 😄

all ACharacter based

[cobalt palm]

I was always told that the Character class needed a skeleton and was a humanoid figure

[pine steeple]

needs a skeletal mesh

but does not need to be humanoid

[cobalt palm]

Ah so you rigged your own?

[pine steeple]

if floating movement works

then use it, but its not ideal

this is not multiplayer right?

[cobalt palm]

Correct.

[pine steeple]

should be fine then

[cobalt palm]

Ill have to look at some videos because just rigging a tank mesh seems weird let alone making the wheels tracks move.

[cobalt palm]

@pine steeple After what has seemed to be a lot of work but doesnt look like it. I made a new BT task where I have the tank rotate and move to when the State = Combat. It all works as you can see in the video however the tank turret seems to rotate relative to the world or something. How could I get it to not worry about the relative of thats the problem? https://streamable.com/npcx83

[celest python]

Can CMC fly though?

[misty wharf]

Doesn't have have a movement mode called flying or something like that

[gritty peak]

So i am having an issue with my larger ai enemies that are quadrupeds. they have a charecter capsule collision that is verticle (it wont let you rotate it). So i added extra capsule collision parented to its bones. this works great except for one bug. when i have one (bi ped) enemy infront of it and they are walking together everything is fine. However if the bi ped enemy stops to attack the quadruped will continue walking forward thinking that the charecter capsule collision is what it should use as its navigation barrier. So the enemies get stuck in one another. Any idea for a fix?

[warm ibex]

Hi Peeps,
Has anyone here used either
UAITask and or UGameplayTask
Pros and cons?
I see that the MoveTo behavior tree task just uses the AITask version of MoveTo
Haven't seen too much on AITask or UGameplayTask was seeing if anyone here has used them and or might have a great reference resource to study on them.

[misty wharf]

I've been wondering the same. It seems those things are completely undocumented and nobody anywhere on the internet seems to have much of a grasp of them either or if they do, they've never bothered writing about it

[dawn loom]

Ah I guess I should have put it here

does anyone know if there is a way to rebuild the navmesh once at runtime?

I have level generation that happens at runtime and I need a navmesh on it but I'm completely struggling to get it done

if someone could take a look here it'd be awesome #level-design message

[pine steeple]

play the game, and bring up the console, and type show navigation

do you see anything>?

[cerulean coyote]

Hey
I've been using some EQS and it works pretty well, but for my game I mainly want to use it so that it still pathfinds to the player (enemies chasing the player) but I want them to take the best path to the player while avoiding environmental hazards (that are all have their own actor class)

Any ideas?

So currently I have a bunch of traps and various hazards that cause damage to both enemies and players, but the enemy will still go over hazards if it needs to, I want to make that logic much better so they path around it instead

[dawn loom]

thanks for the info, I tried it and it shows nothing

[dawn loom]

I think there is a way to add constraints to the pathfinding but I'm not totally sure about it

IIRC there is also way to substract from a navmesh but I'm also not sure about it

I tried doing it on the server and now it shows this

the navmesh isn't being built on the spawned actors however

on the client it doesn't show anything so I guess it's not replicated but that should be easy to solve

I don't see why it wouldn't build a navigation mesh on the actors

the static mesh components all have Can Step set to true

and I can put pawns on top of them without any issue

I'm not sure if the clients aren't allowed to see the navmesh as a setting or if it's not being replicated to the client

[dawn loom]

https://m.youtube.com/watch?v=dDnHAUgaQQk I just found this while trying to solve my own issues

[dawn loom]

Btw if anyone has a response for my issue please @mention me

I keep opening this channel again and again with no messages sent in between, it's depressing

[fresh remnant]

Why does the navmesh generate a lot of cracks on hills between tile regions? How can I avoid this? Chunky Monotone generation helps a little but there's still cracks

[lament linden]

Hey guys,
I have a ChildActor inside a Pawn in blueprint. The ChildActor is another Pawn with AIPerceptionComponent.

If I place that Pawn in the world (i.e. not attached to another Pawn as ChildActor), it correctly starts picking up sight/hearing senses and shows in the AI debug tool.

But when it spawns as a ChildActor, AIPerception does not start (even if I call AIPerception->Activate on BeginPlay)

When I reset the ChildActor however, it correctly starts.

By reset, I mean clearing the ChildActorClass variable and setting it again.

No perception debugger when attached as ChildActor

Correct debugger when placed as a standalone pawn

[pine steeple]

that seems a really weird way to do things

and ChildActors are really bad also.

[lament linden]

why do you say that

[pine steeple]

what is the purpose of the child actor?

[lament linden]

It will work as a sensing component that can rotate without having to rotate the entire actor

Imagine the childactor rotating to look at somewhere else, but the main actor stays the same

[pine steeple]

BasicSensor is another AIController then?

[lament linden]

It is a Pawn that has its own AIController

And it has the AIPerception

[pine steeple]

i would not do a child actor

i would just spawn the pawn

in beginplay

then attach it

ChildActors are buggy and garbage

[lament linden]

😦

They allow me to configure different defaults for the same class easily though. That would require more work to spawn in BP

Still doable though

[pine steeple]

you can use Expose on Spawn

and set them in the spawn actor node

[lament linden]

Well I must configure the properties of AIPerception

[pine steeple]

could make a function

that you call

[lament linden]

I don't think I have access to SensesConfig during play

[pine steeple]

not in blueprint

[lament linden]

Well, at least not from BP. I saw a workaround using C++ but it was kinda ugly

[pine steeple]

but in c++ you can

[lament linden]

Alright let me see what I can do

[pine steeple]

why are the senses not set by default?

do they change that much?

[lament linden]

Well I don't want to make different classes for each little nuance of change

[pine steeple]

yeah but i assume they will all have sight

maybe different range/cone angle

[lament linden]

Yeah exactly

[pine steeple]

but that can be adjusted dynamically

its harder to put a new sense in at runtime

but doable

[lament linden]

In C++ again, correct?

[pine steeple]

yes

[lament linden]

Oh wait I have done this in a previous project

You keep a pointer to AISenseConfig_Sight

[pine steeple]

you can get the config

[lament linden]

Right?

Cool

So the issue is with ChildActor then

[pine steeple]

{
    int32 ConfigIndex = SensesConfig.IndexOfByPredicate(FConfigOfSenseID(SenseID));
    return ConfigIndex != INDEX_NONE ? SensesConfig[ConfigIndex] : nullptr;
}```

[lament linden]

But I don't remember this happening when everything was BP

[pine steeple]

well ChildActor is just known for being bad

[lament linden]

What would SenseID be here

[pine steeple]

UAISense::GetSenseID(UAISense_Sight::StaticClass());

will return the sense ID for that sense

[lament linden]

I appreciate the help.

[pine steeple]

the fact it fixes itself when you change class

smells like Child Actor issue

[cobalt palm]

Hello, in the video I have an ai tank line trace to the player if the player is within a certain angle of the tank. As you can see in the video the tank only checks the angle when the rotate is a certain rotation in the world.
https://streamable.com/13mm3p

Heres the code that gets the angle from the ai to the player

[pine steeple]

like i said before, draw debug lines

of your vectors

or draw arrows

so you can visualize what is happening

[cobalt palm]

So just draw debug line in the forward vector from the aitank and see if they rotate?

[pine steeple]

or draw an arrow, you need to visualize what is happening

[cobalt palm]

Yea, because for some reason it doesnt seem to be rotating but the get forward vector is in a tick so I dont know why it would be.

🤦‍♂️

[cobalt palm]

I was taking the actor forward vector which does seem to rotate but when I take the forward vector of the tank bottom it works.

So the next problem is in the bt where if the tank can see the player, it sets an enum to combat and then the bt activates a selector that does the combat moveto/rotateto service that I made. It works, however when the enum is set to idle, it does switch to the other selector.

[dawn loom]

so I tried RebuildNavigation and it correctly built the navmesh on top of my generated actors

but I'm wondering if using a console command in the game at runtime is a good idea or not?

is it something that should be done?

[cerulean coyote]

@dawn loom YO thanks a lot!!

[dawn loom]

np np! I also found this https://docs.unrealengine.com/en-US/Basics/Components/Navigation/index.html doesn't look very helpful (just like all of the documentation when it comes to navigation) but well

[cobalt palm]

Hello, I have a service that switches an enum variable. That variable has two states, Combat and Idle. When I start the game its set to idle and when the ai can see the player it is set to combat. However while in combat and it cant see the player the enum is set to idle but the selector doesnt change to the idle task even though I can see the value changing?

Could it be that the enum is updating in code but it wont switch until the task finishes?

[lyric flint]

Anyone know a good tutorial on how to make flying enemy ai? I have looked everywhere but cant find anything
help me Im desperate 😦

[cold trout]

Are you using decorators?

Something would need to abort the task

[cobalt palm]

Yes. They check if the value has changed.

[cold trout]

And the service is definitely changing the state bbkey?

[cobalt palm]

Yep. I have it to the side and watch the state change.

[cold trout]

I've had trouble with a similar looking setup

I was setting the state on service activate

And the decorators wouldn't observe the change

Switching to search start ai does work tho

But if your service is running a tick function that night be different

[cobalt palm]

I have an event receive Activation ai that sets the state to Idle then the tick function does the work of checking if the player is in view then sets it to combat if true.

[cold trout]

Yeh I think that's a similar issue

Try changing the state on activate to one or the other

And see if the decorators even respond to it

Cos I think they won't

[cobalt palm]

This should show you better of whats going on. I did set it to set the state to combat right at the beginning. https://streamable.com/p7txe9

[cold trout]

that looks more like the MoveToIdle task just failing a lot doesnt it

[cobalt palm]

Yea, but it shouldnt be flickering as the state is set at idle, there shouldnt be a reason for it flickering.

[gritty peak]

if I lower the tick rate on my enemy BP would that improve performance even though the enemy does not use event tick?

[tawny rune]

People such a question, how to optimize a large number of AI? I noticed that the char movement component is a very large and expensive thing, is that true? There is an option to implement each AI through a pawn, but then you have to write your own movement component, which is quite difficult for me, since I did not find suitable tutorials, so either it is very difficult or not necessary.

[lyric flint]

@tawny rune https://www.youtube.com/watch?v=CqXKSyAPWZYon

[pallid trout]

Yes. If the enemy doesn't use tick then you can turn it off completely

[pallid trout]

Its not failing, just flickering. it's checking if the player is visible

Try increasing the time interval in the bts_visioncheck

[west saffron]

hi! quick question: is EQS inextricably tied to NavMesh? I'm thinking about AI design in 3D space for a space simulator game and was wondering if EQS would be a good fit to drive my AI's decision-making

(since NM cannot be built for 'true 3D' environments as it only operates in planes)

[cobalt palm]

I increased the interval for the service but that made no difference. As of right now, I can see it switching the state variable from combat to idle, and sometimes the behavior tree switches the selector and other times it just disappears but the aitank still move to me.

[pallid trout]

Did the time b/w flickering increase when you increased the interval?

[cobalt palm]

The flickering seemed to have stopped. However at some points the only thing lit would be the root.

[pallid trout]

It's flickering because after each interval, the moveTo part is stopping to check if the player is in the line of sight (for a frame)

[cobalt palm]

Correct. But when the variable is set to idle, it should then go to the other selector.

[nova prawn]

Guys I have a question ? If i have 2 Types of Units a Worker and a Attacker would I do better having 2 behaviour trees for each unit type or 1 tree with shared behaviours and then switching based on a Unit Type for example a Worker will Walk to Resources then Gather where as a Warrior would walk to wards resources and do nothing.

Im not sure if Inheritance works on Behaviour Trees so they could both Walk To Location but then the Worker could Gather.

[cobalt palm]

What other thing could I do?

[gritty peak]

@pallid trout i turned off tick for my overall charecter. Do i need to further disable tick for each individual component like mesh and charecter movement component or should i be good?

[uncut python]

hey guys, ive been trying to get my ai follow my character and im having an issue with it, they all surround me when the game starts then they ignore me for the rest of the game

I made a decorator and all its a bit odd

Thats my bp

the tutorial i followed was very simple

it just struck me as odd

[dawn loom]

is there a SimpleMoveToLocation (in C++) that's less simple?

I want to select a radius and/or a timeout to stop trying to reach the destination

AAIController.MoveTo?

[lyric flint]

You can do two things:

1. Tinker with acceptable radius for goal destination (Don't remember if it's exactly called like this, quoting from memory :-))
2. Set the timer for success/failure status
   You can do it either in behavior tree or C++, maybe even in blueprints, I just don't use blueprints @dawn loom

[pallid trout]

It's working fine already. In your gameplay you can't see any effect

[pallid trout]

You're good

[humble mica]

Can someone send a screenshot for the blueprint for making a physics based pawn cube roll to random locations?

[waxen ore]

Hi guys, is there any way to stop Enemies blocking each other this way? I used RVO avoidance for my Enemy AIs (Consideration radius 300, Weight 0.5) But it doesn't do much.

[pallid trout]

DetourCrowdController

[waxen ore]

Ok will I have to renable it somehow afterwards?

[pallid trout]

You will have to replace your AI controller with the detourCrowdController and also turn off RVO avoidance in your character

[waxen ore]

Ok. I'm using satndard AI Controller now, so I need to reparent to Detour Crowd Controller right?

[pallid trout]

Yes

standard controller is the parent of dcc so all the remaining stuff can be copy pasted

[waxen ore]

ok I made DetourCrowdController to be the Parent Class, turned off RVO avoidance on my Enemies. And now it's even more weird...

p.s. White Guy (Player) is still using standard AI though

[pallid trout]

Using AI Controller

Using detour

pick your poison

[unborn jungle]

How can I stop navmeshes from being rebuilt every time I hide or show a sublevel in the world?

I have navmesh set to static, there is no nav mesh bounds volume in the persistent level (only sublevels) and I have built the sublevel navmeshes separately

Is the only option here to just keep the navmesh dynamic and wait for it to rebuild each time?

[pine steeple]

you can't have navmeshes on seperate levels

[unborn jungle]

So it has to be dynamic and rebuilt from the persistent level bounds volume?

[pine steeple]

as soon as they join the main level, they need to be rebuilt

we tried the same

i also tried some workarounds, but it just broke

[unborn jungle]

That's a shame

Since this'll increase load times which is one of the reasons I was using streaming

To not have to seamless travel every time a similar map is loaded

[pine steeple]

yeah, i am in the same boat as you

navmesh generation is slowing our game loading times

[unborn jungle]

I already have it at horribly low res too 😄

Guess I'll just try to reduce my level sizes as much as possible

[pine steeple]

you can tweak tile sizes etc

[unborn jungle]

At least only the server has to build it

[pine steeple]

what size are your agents?

[unborn jungle]

Yeah mine are at bare minimum

Going any lower doesn't build properly or has huge gaps

[pine steeple]

i can send you a config we use, maybe it would speed it up a bit

[unborn jungle]

That'd be great thanks!

[tepid pasture]

Hey all, I'm in need of help with a problem,
I'm using the "RecastNavMesh" to change the variable "Agent Height" to 60, but every time I restart the level, or restart the editor it resets back to 144, breaking the path finding for my AI, How would I go about saving the options here?

[pine steeple]

bDistinctlyDrawTilesBeingBuilt=True
DrawOffset=10.000000
bFixedTilePoolSize=False
TilePoolSize=1024
TileSizeUU=1024.000000
CellSize=22.000000
CellHeight=20.000000
AgentMaxSlope=60.000000
AgentMaxStepHeight=40.000000
MergeRegionSize=340.f
MaxSimplificationError=0.990000
DefaultMaxSearchNodes=4028
DefaultMaxHierarchicalSearchNodes=4028
RegionPartitioning=ChunkyMonotone
LayerPartitioning=Monotone
RegionChunkSplits=2
LayerChunkSplits=2
bSortNavigationAreasByCost=True
bPerformVoxelFiltering=False
bMarkLowHeightAreas=False
bUseVirtualFilters=False
bUseVoxelCache=False
HeuristicScale=0.999000
RuntimeGeneration=Dynamic
bUseExtraTopCellWhenMarkingAreas=False
AgentRadius=24.000000
bDoFullyAsyncNavDataGathering=False```

could give that a try @unborn jungle

it reduced our build times quite a bit

[unborn jungle]

Thank you very much I'll do a bunch of tests with these values

Much appreciated!

[pine steeple]

yeah

switching to chunky monotone, and cell size of 22 and 20, with a tile size of 1024 will be the big increases

but just cherry pick. make sure you turn off FullAsyncGathering

that is super slow!

[unborn jungle]

I have never tried changing region partitioning etc.

Very excited to try these

If I can get build times down to say 2-3 seconds on the server then that's fine

[pine steeple]

2 years of tinkering

[unborn jungle]

Clients by default will never build navmeshes right!

[pine steeple]

to get those values 😄

unless you need them to use it

[unborn jungle]

😄

[pine steeple]

then no.

[unborn jungle]

Nah don't in this case

Great!

[pine steeple]

@tepid pasture there is a bug

best bet is to modify your DefaultEngine.ini and set it

with editor closed

[tepid pasture]

@pine steeple Thanks,
How exactly would I do that?

[pine steeple]

Sometimes those settings just reset, i have had it happen a lot

open DefaultEngine.ini in your config

find[/Script/NavigationSystem.RecastNavMesh]

AgentHeight=80.00000```

for example

[tepid pasture]

Thanks again, but I don't know where to access the config.

[pine steeple]

its in your Project folder

Config directoy

[tepid pasture]

Thank you, I'll get on that.
Hope it works (:

[dawn loom]

my AI is extremely simple so I'm not using any behaviour tree (in fact all it does is move) but where would I find the acceptable radius and/or the timer?

[pine steeple]

what move node you using?

i like the Move To Location/Actor Task node

as you can come off the Finished move pin, to start moving again

[pallid trout]

kaos, any way to fix this?

[dawn loom]

@pine steeple I'm using C++ and I'm using UAIBlueprintHelperLibrary::SimpleMoveToLocation but it's too simple

[pine steeple]

in c++?

@pallid trout we used a move target actor that the AI track to solve the stop/start issue, we just teleport the move actor and have the AI move to the goal actor via goal tracking.

[tepid pasture]

It's working perfectly now, thanks for the help.

[unborn jungle]

@pine steeple Thanks it's a lot faster now it seems!

How big is your navmesh bounds btw?

For an average level

I had mine at like 80k XY

But might be able to get the levels smaller to about 50K

[dawn loom]

yes

ah sorry

I thought you were talking to me

😕

I found my answer (it's AIController->MoveToLocation() )

[pine steeple]

@dawn loom also override MoveCompleted in your AIController

if you want to start pathing again

(i think there may also be a delegate you can bind)

[dawn loom]

thanks for the tip!

[warm ibex]

In a Behavior tree Composite blackboard condition.
I see you can pick any blackboard value then it gives you different Key Query options based on the type of blackboard value you have set.
Can anyone point me to how they're changing the options available on the editor?

[pine steeple]

can only do it via C++

if you are on about filtering the keys you can select.

[warm ibex]

yeah im in c++, been doing a lot of internal setting, i've been getting to know how to set like the default filtering so that ONLY a specific type or types can appear on the drop down for the blackboard key you can select.
But as far as like
here's your key type
and because you have this key type these are extra options on that key type
maybe 'compare checks' or 'oh you're looking at this specific class type? ok well in this composite these 3 new drop down options appear now.

[uncut python]

hey everyone quick question, i have this code for my ai sensed. My ai wont follow me, and I just realized that my ai is a child bp of my basecharacter that I am casting

will that affect my ai at all?

"Parent Class:BP_BaseCharacter"

[uncut python]

is my perception not updating?

[warm ibex]

@uncut python your AI comes from AIController
So no it shouldn't matter your AI inherited from Base Character

Hi peeps!
Question on component update related to inheriting from : public UAITask
I see we have NewBTAITask< for template creation from within a : public UBTTask_BlackboardBase

I saw inside of void UGameplayTask::InitTask(IGameplayTaskOwnerInterface& InTaskOwner, uint8 InPriority)

` UGameplayTasksComponent* GTComponent = InTaskOwner.GetGameplayTasksComponent(*this);
TasksComponent = GTComponent;
bOwnedByTasksComponent = (TaskOwner == GTComponent);

// make sure that task component knows about new task
if (GTComponent && !bOwnedByTasksComponent)
{
    GTComponent->OnGameplayTaskInitialized(*this);
}`

I was wondering if because my gameplay task is owned by a BehaviorTree Node and bOwnedByTasksComponent is false
If that would be the reason why the gameplay task might not be updating?
Breakpoints through out the entire UGameplayTasksComponent shows none of its updates are getting hit what so ever.
But the AIController is obviously updating if the behavior tree is processing, I'd figure?

[uncut python]

@warm ibex touché I’ll have to Investigate more

[warm ibex]

@uncut python sorry I can't be more helpful I dont use EQS for the stuff I've built, but if you're using behavior trees double check that you're setting up the EQS accordingly and that your AI character is actually hooked up to the AIController

[uncut python]

@warm ibex no worries! I appreciate the response, saved me the hassle from testing out that theory of the base character

[lyric flint]

@warm ibex If you still need to figure out filters for your keys in C++, look for things like AddObjectFilter or AddVectorFilter etc. in the engine source code, hopefully to give you an idea 🙂

[uncut python]

Do I need a crowd ai controller if I’m spawning in a horse

Horde

[warm ibex]

@lyric flint its not a filter its a sub new option of a possible operation, depending on the blackboard key type specified.
I was looking at the blackboard condition composite in c++ for example but their operation expressions dont seem to append to anything even though it seems like it might be doing.

[lyric flint]

@warm ibex oh, I apologize for the misunderstanding! everything I learned AI C++ related was from browsing C:\Program Files\Epic\UnrealEngine\Engine\Source\Developer\AITestSuite\, But I'm guessing you already did that 🙂 I don't really use visuals in unreal, I do pretty much everything in C++, so I don't have an answer 😦

[warm ibex]

Yeah lol same I just do c++ but it's a waste of effort to not take advantage of the editor so i've been practicing more on making generalized services/composite/tasks so I can do more rapid AI designing rather than needing a new c++ implementation for another specific solution.
I'll figure out the extra options addition/removals sooner or later heh

[lyric flint]

Perhaps consider https://www.youtube.com/watch?v=CqXKSyAPWZY for really huge horde

[uncut python]

Aha I’ll take a look thanks

[thorny jay]

Hi all, I have a really frustrating problem with a behaviour tree. I have a very simple sequence which just waits 2 seconds, and then runs a task, the idea being that the task is run every 2 seconds or so while the appropriate conditions are met

The problem I have is that for reasons I can't figure out, the first task keeps getting interrupted and restarting itself

This means that if the wait comes before the task, then the AI just ends up staring the target down for a good 10-20 seconds before it seems to correct itself and acts as it should

If the task comes before the wait, then the AI will go into a frenzy for 10-20 seconds or so before correcting itself

I can't see any evidence that the behaviour tree is branching elsewhere during that time, thereby interrupting the wait task

It just seems like the wait task keeps getting down to 0.5 seconds or so and then resets back to 2 seconds several times over before finally counting down fully

This happens regardless of whether I check the "ignore restart" checkbox

The tick rate for the task is also on -1.0

[pine steeple]

going to need to show us

also i highly recommend checking the Visual Logger (google it)

[thorny jay]

I'll grab a screenshot in a moment, sorry I was in the middle of compiling

https://gyazo.com/c2c58091805e431a1a96801679ffdb0e

The culprit is the wait 2.0 in the bottom right

It continually resets, so ManageLineEngagement never gets executed

I'm just not sure what would be triggering this. When observing the behaviour tree during gameplay, the execution remains in the wait task, I don't see any other branches executing even for a moment

[pine steeple]

don't see anything wrong, if you are sure nothing is aborting it out

[thorny jay]

I'm pretty sure, let me chec kthe visual logger you mentioned

I use the ' key on the AI to highlight it

[pine steeple]

Windows -> Developer Tools -> Visual Logger

run it, and see what is happening in the BT

it tells you a lot of stuff

[thorny jay]

Is there a better way to have a task only execute once every 2 seconds?

Without using a wait task node?

basically the AI is commanding line infantry, giving them orders to crouch, reload, stand, present, fire etc

All I want is to stop them issuing commands too quickly

[lyric flint]

Sure, you can issue your troops a command that triggers an event that triggers an animation that triggers a timer that triggers an end. At start set the bool true, at end set the bool false. While the bool is true, don't do anything. You don't even need BT for this, although you can. Tick should be enough. But why? BT may have a learning curve which may be frustrating, but there are definite benefits overall 😄

[pine steeple]

@thorny jay just ditch the wait, run your task, and just use a timer to keep repeating

when it aborts, AbortTask gets called (which you can override to cleanup)

but this will keep it locked to that task

which might not be idea.

[thorny jay]

Hmm

@lyric flint Only problem with that idea is it requires significant work to implement, whereas simply having this task run every 2 seconds will solve everything

[warm ibex]

is it possible to Set a value of a blackboard variable on a Service?
I tried but I fail in here

bool UBlackboardComponent::SetValue(FBlackboard::FKey KeyID, typename TDataClass::FDataType Value) { const FBlackboardEntry* EntryInfo = BlackboardAsset ? BlackboardAsset->GetKey(KeyID) : nullptr;

it returns null

in the service constructor I have this variable set up
bCreateNodeInstance = true;

I was thinking that would allow me to change blackboard variables safely

[somber star]

Usually you just expose a blackboardkeyselector as a uproperty on your class and set the one you want to use in the behavior tree. If you look at the implementation of the already defined stuff in aimodule, you can see how it works.

[warm ibex]

yeah thats what I've done, its interesting the selector name is filled out SelectedKeyName but GetSelectedKeyID comes out invalid.

yup weird GetValueAsEnum works just fine passing SelectedKeyName
GetValue<UBlackboardKeyType_Enum> passing GetSelectedKeyID() passes null and fails.
Not sure why the selected key might be null but at least I have one approach to accessing the blackboard variable

[somber star]

I had that problem with a task I wrote, and it was because nothing was calling this on my selector in C++:
FilterClassBBKey.ResolveSelectedKey(*BBAsset);
The task has InitializeFromAsset, not sure if the service has that same function

[warm ibex]

@somber star that did it 👍

[pine steeple]

https://www.thegames.dev/?p=70 @warm ibex @somber star

going to also cover Decorators and Services in the future

[near jetty]

@pine steeple I generally avoid making BTTasks in cpp

[pine steeple]

the benefit for frequently used tasks is the plus side

[near jetty]

inmense mayority of the time i have them as BP in the form of very high level tasks that interface with a AIController or Component where the actual logic is

the reason is that BP lets you do delay nodes

[pine steeple]

ie, i make them non instanced, and saves a BP vm call

[near jetty]

writing time-based code in cpp is a pretty annoying thing

yeh but thats more important for things like decorators and services (which i like to keep cpp only)

[pine steeple]

i have tasks that get called quite a bit, less time i have to spend entering the BP vm, the better

when your running 120ish AI

[near jetty]

when you are running 120 ai you dont do BT

or character class either

[pine steeple]

yeah i run character class also 😄

but i optimize the hell out of the AI when they are in FOW

and not visible

[near jetty]

yeh 120 AIs on character class with BTs running... that would not run at 60 fps on consoles

[pine steeple]

reduced tick rates, stop skeleton ticking, etc

[near jetty]

on DWVR i had my characters as BT + character classes

[pine steeple]

CMC ticks at reduced rate

[near jetty]

found that just 15 of them would tank framerate in PSVR

ended up having to also implement logic-lod type stuff (reduced tick at distance and the likes)

[pine steeple]

i can get 100 AI in fow at around .8ms on the CMC

[near jetty]

with some heavy throttling i guess because moving 200 character-style actors will spend 1 ms just in MoveComponent calls

[pine steeple]

oh before i optimized i was doing around 4-5ms for CMC for about 150

[near jetty]

its kind of pathetic this even has to be optimized

[pine steeple]

thing is, its not really just the CMC that costs

the bit thats costing me is the transform updates

[near jetty]

yeah thats a huge hit

the CMC itself doesnt cost that much if you use navmesh snap

one particularly nasty trick is to not have the character meshes attached to the capsule

you have 2 actors

[pine steeple]

when agents are off screen, i disable floor traces, and grab the path from the PFC, and just have the AI move from path point to path point, with no calculations

[near jetty]

one is the moving actor

and other is the agent mesh

[pine steeple]

(floor navmesh projection, not trace)

[near jetty]

and you move the agent mesh (visuals) from a centralized subsystem

[pine steeple]

o_0

[near jetty]

i tried that one, but its very problematic

the disable floor traces thing

you can get stuck in geo or inside other characters very easily

from my tests, navmesh point projection is crazy cheap

so its spammable

on the "1000 traces per ms" level

its cheaper than a single blueprint tick XD

[pine steeple]

they don't really get stuck in geometry (floor wise anyway)

not that i have seen

i turn it on and snap them back to navmesh before player sees them

[near jetty]

ive had them stuck into geo a lot when doing that

[pine steeple]

interesting, yet to see that

i have seen them stuck in walls

but nav recovery shoves them back out

[near jetty]

nav recovery?

[pine steeple]

made a system to recover agents that end off of the mesh

X amount of failed moves, it checks to see if there is navmesh under the agent, if not, runs a recovery

[near jetty]

btw, the trick where visual mesh is different from actual character gives massive perf improvements

'character movement likes to end up calling move object multiple times

specially in mp

mostly in the cases where the actor has multiple stuff attached to it

[lyric flint]

Yo short question

https://www.youtube.com/watch?v=qoTqfHgs-5Q

is the limit here the 5000 Rendered rigs OR

the 5000 ai's?

[near jetty]

it just runs like shite

the AIs isnt that much the problem

5000 Characters running around is

[lyric flint]

@near jetty so technically if i had 5000 characters as squares on a 2d map it would work just fine? it wouldnt render anything

[near jetty]

if they were 5000 actors with character movement components (derived from ACharacter) it would still run like absolute shit

as a bonus

if they were 100% empty actors

with absolutely nothing on them

also not moving

but with the Tick node active

it would already be unable to reach 90 fps needed for VR

[lyric flint]

So what if i make a center node which has only tick nodes

and just is like a manager for all ais

?

[near jetty]

that would run much better

but still like shit if you are moving 5000 actors

even if they are near empty

[lyric flint]

is it because of unreal engine or is it a generall issue?

[near jetty]

to run 5000 objects (of any kind) you need to look into niagara and/or instanced mesh components

unreal engine

[lyric flint]

oh okay

thanks for the info

[lyric flint]

so anyone know how I could have it so a root motion of walk animation of my ai can work

at the moment when my AI moves around it jitters cause velocity is always reading 0 so animation never switches from idle to walk in the blend space ??

[waxen ore]

Yean I do the same, but still I have weird foot sliding. Nevertheless - thanks for help!

[rapid ridge]

is it possible to do EQS without an AI character as the querier?

[misty wharf]

Yes, you can do EQS from any actor or such iirc

[high summit]

the red one is not executing, but the green one is executing, why this happen?

any behavior tree expert that can explain why toggle breakpoint not hit, but it hit on green side?

the green one is executing, but red one isn't

[rapid ridge]

if an EQS to find actors doesn't find any actors is it considered successful still?

[pine steeple]

if the generator fails, it will be a failure

[rapid ridge]

okay thanks

[high summit]

this video explain : https://drive.google.com/file/d/15YykZKkmUd0k9U_gLeCbSq0_bQ5pXCoD/view

here is above part, you can download video or it would be available after few minutes

or try to refresh

so the finish execute should be false?

inside playhumanoid task?

[unborn jungle]

When moving navmeshes at runtime, how come it's not rebuilding? The transform is at the correct location but only the original area ever gets rebuilt

Do I need to create new navmeshbounds volumes at these locations rather than move existing ones?

[pine steeple]

You can't move the navmesh actor

there maybe some workaround, like telling the navigation system that the area bounds had been moved, but would require some looking into the navigation system.

but normally your bounds actor is set and updated once only during runtime

[unborn jungle]

Ok thanks!

I'll try spawning fresh ones in and removing the old ones

[pine steeple]

you cant

[unborn jungle]

Hmm that udemy C++ course did it AFAIK for their endless procedural level game

They had AI walking around in an endless forwards path of new levels

[pine steeple]

hmm

[unborn jungle]

I believe they spawned new ones in and didn't move anytyhing

[pine steeple]

well i could never get it working, even when the nav was dynamic

[unborn jungle]

I'll give it a shot and let you know

[pine steeple]

we tried to do that with our prefabs

have navmesh bounds pre-set in the prefab

and spawn the entire prefab with its navmesh bounds

tho now i think about it, i think our issue is we wanted to keep the data, so yeah it might work, been a few years since i tried

@unborn jungle what you could do is..

    if (NavSys)
    {
        NavSys->OnNavigationBoundsUpdated(YourBoundsActorHere);
    }```

this might force it to update when you move it

[unborn jungle]

Thanks will try that also!

And just to make sure, sublevels can't have their own nav mesh bounds right?

Only the persistent level can have it, so if I wanted a long line of levels, the only way to get navmeshes on all of them is to update the persistent one?

[high summit]

so it mean if both blackboard condition are false then it would run parallel node?

[unborn jungle]

It seems the udemy course just calls GetWorld()->GetNavigationSystem()->Build(); after moving

[pine steeple]

eww

[unborn jungle]

Is this a lot worse than your method?

[pine steeple]

i mean it will work, but w/e works for you

try both

[unborn jungle]

It's actually calling the editor build paths or something?

Just want to understand why one would be better

And of course would go for the cheapest option

[high summit]

in above screenshot you can see parallels node is working, but how these two other red condition become fail?

does it mean if bool value is false then blackboard condition is false or it is other failure

[unborn jungle]

Works thanks!

[winged cargo]

@lyric flint when did you see the light?

[unborn jungle]

Is the correct way to reduce the perceived performance hit of a dynamic navmesh rebuilding at runtime to lower the Max Simultaneous Tile Generation Jobs Count?

Seems to have a much smaller impact on perf at the cost of build speed which is fine in my case as I can have it generating ahead of where it needs to be

[pine steeple]

you can turn on fully async

this will not impact your gamethread

but at super slow build speed

[warm ibex]

Hi peeps,
Has anyone used the MoveTo task as a sub task within their own task before?
If so did it become an extreme hassle.
I see the BTTask MoveTo just calls the AITask Move To
Was thinking of doing a moveTo part to a bigger task internally in c++ so just seeing input on using the task move to internally and if it was too much of a pain in the butt lol

[rapid ridge]

I have some AI and I need to set some blackboard values before it spawns, but I can't access the blackboard if I defer spawn, what should I do

[clever skiff]

wasnt there a way for ai perception to be seeing after being compiled i cant seem to figure out which way my character is looking.

having to play the game to see the sight is annoying

[glass onyx]

I would probably instance blackboards in the gamemode and set the values in them from there. When a pawn is spawned, pass it the setup blackboard to use

[rapid ridge]

What happens with the Behavior Tree? I run the behavior tree on possess, should I still run it on possess with an empty blackboard asset or does your method do something else?

[misty wharf]

It sounds like the easiest solution would be to have a method on your actor that starts the BT when called instead of starting it automatically

this way you can set whatever values on the BB before starting the BT

[potent cosmos]

Do you know a way to make AISense_Touch from AIPerception work in blueprints?

[pine steeple]

not really sure what touch is supposed to be or do

it seems like it was never fully implemented

[lyric flint]

Yes, it's called Collision with the capsule component 😄 Seriously though, touch versus hearing is just sense radius, put it at zero and hearing become touch hehehe

[pine steeple]

yeah but it seems like it was not properly implemented

[lyric flint]

I know, I was just being silly 😄

[pine steeple]

its like most of the AI systems, half implemented

[potent cosmos]

but what when you need also hearing normaly 🙂

apparently , only way is own code to call FAITouchEvent

[misty wharf]

You could probably make a BlueprintCallable wrapper for the code pretty easily if it works similar to the other senses

[glass onyx]

You’d call to get the prefilled blackboard in your OnPossess. What’s the use case here? Are you trying to load blackboard data from a saved state?

[lyric flint]

Hearing is a sight with 360° cone. Well, sphere in this case 🙂 but I still think of functional approach is collision with your mesh, instead of your capsule. And you can also make sure to turn on Use complex collision as simple Which in effect it should basically have a very fine touch result. I don't really understand your use case for touch so I'm just brainstorming 😄

[storm gulch]

Hi! Could you help me with one issue - trying to implement builders for an rts. Everything is more or less done, but if a building is represented as an obstacle on a navmesh, builders occasionally walk right through it. If it's an empty navmesh, then they can't find it and get stuck on a MoveTo node

[cosmic stag]

Im running a EQS test for PathExist to item, and it still returns QueryItems with incomplete paths. Is it supposed to happen that way?

[storm gulch]

thank you, this may be a solution to my problem

[nova prawn]

Hi, Whats the best way to implement RTS Units moving to a position, I have all the selection and stuff and can click a location for the Units to move to but I added a Node with a Radius of 300 to create a random spot near the clicked location but this seems alittle weird.

Create Random Spot for Unit

[pine steeple]

just project the mouse click location to navmesh

if it fails, don't move unit

otherwise move them to that location

point would be your clicked position

[south bobcat]

if i drop an AI BP multiple times in the world, do they share the same controller, or do they all get their own instance?

[pine steeple]

all have there own controller

one controller can only control one pawn

[south bobcat]

alright, thanks ^^

[lyric flint]

https://streamable.com/j4vfta

Why is it doing thiiiis

[mint elbow]

Hi, I'm having an issue with my AI running the wrong Blackboard. I have an ai "AlphaJackal" and he uses the "AlphaJackalController" and you can see here that I have him set to use the AlphaJackal_BB and the AlphaJackal_BT. Well, for some reason, the AlphaJackal_BT is not running the AlphaJackal_BB, it's using a different BB and I don't know how to get it to use the correct one.
Anyone see what I did wrong?

[misty wharf]

@mint elbow check in your BT asset that you've set the Blackboard Asset property to the correct BB. I don't know if the Use Blackboard node overrides it

[mint elbow]

I think that did it, thanks!

[nova prawn]

@pine steeple Thanks , Just one last thing if i have say 10 units selected will they all "fight" to get on the one spot and if so how is the best way to approach so they say to themselves "Someone is already on that spot I need to find a spot nearer."

[echo lark]

is there way to modify cost of path without using nav modifiers ?

Ie I want to plan path where the AI will be least visible to player (effctivly avoiding player forward vector at the start of path planning)

ok I see some solution FindPath(), but that's really global override not per move request -;-

[patent hornet]

you'll need to EQS that @echo lark

make a grid around the player, score them by - (Point - PlayerLoc) DOT PlayerForward

for an entire path that will get tricky though

you can spawn a nav modifier in front of the player, update navigation, find a path, destroy the nav modifier and update the navigation again... if its small enough it will not kill your performance

[pallid trout]

You need to move towards a point while avoiding the player. An eqs with a trace test from the player pawn and a distance test from the target point(prefer less distance) will work

[feral marsh]

Hey guys, how are you all doing today? quick question: I created a new blackboard but it has the same keys as the other blackboard i have, does anyone know why does it happen? (I have 2 different enemies and I want both of them to have different blackboard but they all share the same keys and I don't want it I want like a clear blackboard to work with)

[pallid trout]

DId you check if their behavior trees have the corresponding blackboard selected?

[feral marsh]

Thanks for the help brother I didn't see that🙂 @pallid trout

[shadow isle]

I've got an AI controller with a AI perception stimuli which constantly gets sight and then loses sight:

The perception sets the target actor blackboard key, so unfortunately, this constant switching has effects on the BT and the AI behaves weirdly

does anyone know why this happens?

[verbal violet]

Hi people, how i can set my character to use specific Nav Agent config. I've made in Project Settings -> NavigationSystem in supported Agents new config, and now I want to assign that config on specific Character, but can't find there I can do that, on some posts i read to engine select proper config based on CapsuleComponent size, i tried it but same result. I've made NavLinkProxy and i want to only one enemy can use it

[pine steeple]

use nav filter

[pine steeple]

better than using agent

[verbal violet]

this give me always Default

ok, I will try

[pine steeple]

if you want to force agent

goto MovementComponent of character, and set its nav agent properties

[verbal violet]

I don't know how to use nav filter here

there is only setting for agents

[pine steeple]

its the area class

you set this to a new Area

say "JumpPadLinkArea

i would not use multiple agents as filters

[verbal violet]

should add new area in front of nav link and there set that only one type of enemy can walk, in nav filter?

[pine steeple]

cause you will be making 4x the navmesh

1 navmesh for each agent

[verbal violet]

i understand it is problem

aha I understand you...I actually used it before as personal space for enemies

tnx man

[pine steeple]

so filters can exclude/increase cost of nav areas

you apply the filter to the AIController of the different enemy types

so maybe soldiers can say go in the tunnel, but Heavy can not because they are too big

that kinda thing

like this for example

[verbal violet]

yes it's logical and optimized, and can have multiple enemies with same agent type

tnx @pine steeple

[pine steeple]

np

[shadow isle]

For anyone wondering: setting the auto success range value to the sight radius solved this.

[verbal violet]

@pine steeple sorry, i make nav filter as on sc, but not understand? Does I need separated agent configs (i removed them now keeping only Default and Heavy) for this, or i need to set on character some nav flag ?
How area know whom to let inside and whom no? based on what, on agent config or this nav flag ? and should assign nav filter somewhere ?

[pine steeple]

you just set that in the AI controller

for that enemy type

Default Navigation Class

[verbal violet]

aha, so I need separated nav filter for each enemy (or at least one who can't go inside area) I tried now, assigned this in ai controller for swarmer but he still try to go through nav link

[shadow isle]

One question around Navigation Invokers: if you have many AI in a small environement, is it better to use them or not?

(the nav needs to be dynamic as there are moving platforms and doors)

[pallid trout]

Navigation invokers are glitchy in packaged projects.

Might work perfectly in the editor but most of the time they break when i try in the standalone

[shadow isle]

ah. well, that solves it 😄

thank you.

[pallid trout]

That was on 4.25 though

[shadow isle]

i am and staying on 4.25.4

[pallid trout]

There was a stream by ian shadden on nav links. That might help you

[shadow isle]

ok thank you.

[lyric flint]

anyone able to help with tagging objects and finding the closest one?

trying to use 2 loops but it kinda breaks..

first loop is finding all the tagged berrybushes and putting them into an array, second loop is then finding the closest bush among those and clearing the array

somehow it breaks after a while tho

[pine steeple]

use EQS

[lyric flint]

thanks! Ill try that instead 😄

[lyric flint]

if I only knew about this 3 days ago would of saved me a lot of time

this is so much simpler lol

[orchid agate]

hey guys i have this in my character ai bp and was wondering why when it is tripped ALL zombies see me instead of the 1 who set the value in its own BB its like they have a hive mind :/

[pallid trout]

There is an option for "instance synced" in your blackboard.

[orchid agate]

ahhh thank youuu 🙂

this should be disabled yeah?

[pallid trout]

if it's enabled then all the zombies (on that blackboard) will work as a hive

otherwise they will be completely separate

[orchid agate]

thank you so much that feature will help with many game mechanics 🙂

thanks again

[shadow isle]

I have an issue where the On Target Perception Event of the AI Perception component on the controller gets called continuously with the sight stimuli's Successfully sensed value switching quickly from true to false.

I'm basically using the Move To node to strafe left to right when the AI is in combat mode. However, when reaching the Move To node the Perception Event is triggered with a Successfully Sensed value of false, even though the player always remains in sight (the AI is strafing and it has a vision of 90 degrees), and this is followed immediately by another Successfully Sensed with value true and so on, in a close loop.

This is my configuration:

This is where I check the value:

And this is the result:

If I remove the MoveTo node in my BT, then this behavior stops and the AI does not stop to sense the player unless the player moves away from sight (so, the event On Target Perception Event is no longer raised with a successfully sensed value of false).

I've seen similar questions in this forum, however no real answer here. Has someone seen this behavior? What can I try to solve it?

Thank you....

You can see here that the node MoveTo is not followed by the wait node, and that's because the MoveTo resets the Target Actor so the decorator aborts the whole branch (but then the branch is run again immediately afterwards):

https://i.gyazo.com/638af0a20242973bff28273402ae7b54.gif

[deft sedge]

why is your fire your main task in that parallel and not the background task? asking out of curiosity as I haven't used a parallel for anything yet

[shadow isle]

because in this way it keeps shooting while having separate nodes for moving

when the fire task is interrupted, the pawn gets notified

[pine steeple]

your move to failed

when it fails, it does not continue across the sequence

[shadow isle]

well yes and no

because as I said, the issue is that the Move To makes the AI perception of sight trigger with a perception value of false, which unsets the Target Actor, which aborts the node

the issue is not whether move to fails,

the issue is that move to generates a lose of sight perception, which aborts the whole thing

Other similar cases:

• https://answers.unrealengine.com/questions/580884/ai-sight-perception-triggered-and-immediately-lost.html
• https://answers.unrealengine.com/questions/1005468/view.html
• https://answers.unrealengine.com/questions/331810/ai-perception-losing-vision-after-move-to-task.html

[deft sedge]

that may explain why I've had fails too

[shadow isle]

It looks like using Move To with an actor as reference does not present this erratic behavior, it does present it with a Vector

I might put an invisible actor in the world just to hack my way through this, but before I try this out I'd like to fish for ideas

[deft sedge]

selector on blackboard key possibly

[shadow isle]

in both cases using a blackboard key. If just set MoveTo with a vector I see this issue, with an Actor it works as expected instead. weird.

need to investigate further

[pallid trout]

maybe try putting the perception in the pawn instead of the controller.

[shadow isle]

tried that, same result

[deft sedge]

do you have the perception attached to the head socket so it matches where the eyes are

[shadow isle]

no, I cannot set the parent socket for some reason in the settings

[deft sedge]

you have to do it in c++

otherwise your perception is probably not pointing where you want

I don't think that's related though, was just curious

[shadow isle]

it is pointing where I want, on the X axis of the character

I've tried that from many different angles, and can see it in the AI debugger

[deft sedge]

did you make custom decorators for this? If so why do that and not use the built in "Gameplay Tag Condition" ?

[pine steeple]

the built in one does not handle aborting

mine handles aborts, etc

{
    NodeName = "Gameplay Tag Condition";

    // Accept only actors
    ActorToCheck.AddObjectFilter(this, GET_MEMBER_NAME_CHECKED(UBTDecorator_CheckGameplayTagsOnActor, ActorToCheck), AActor::StaticClass());

    // Default to using Self Actor
    ActorToCheck.SelectedKeyName = FBlackboard::KeySelf;

    // For now, don't allow users to select any "Abort Observers", because it's currently not supported.
    bAllowAbortNone = false;
    bAllowAbortLowerPri = false;
    bAllowAbortChildNodes = false;
}```

[vast relic]

Is there an easy fix to custom collision and AI or am I stuck using Pawn object type?

[rigid portal]

Is there a percent path completed on a navigated path? Say I use a MoveTo for going from pointA to pointB. Any way to query when the pawn is 90% traveled along the path?

[lyric flint]

hey guys, I have a super annoying problem that you guys probably will instantly know how to fix.. here is a gif and 2 pics

https://gyazo.com/a32c8d04a4358127ee002dbb29031cd9

so its basically a kinematic "hovercraft" which detects the average surface normal with 5 raycasts, thats not important, that works..

the problem now it that i need the hovercraft to rotate towards that green vector (sometimes blue or purple because other vectors overlap)

the problem is that the green vector, the one i rotate to, also resets my Z rotation when i rotate towards it.. im out of ideas.. i tried everything 😦

[lyric flint]

do you mean in a straight line or like a full path with random directions?

[rigid portal]

Not in a straight line

Maybe around some obstacles

[pallid trout]

A dummy actor on the same controller and settings but no visibility and collision. It will move on the same path from A to B as your AI. Set its speed extremely high and calculate the distance. Now when your ai starts walking you can check the percent.

[rigid portal]

Oh that's kinda cool

How can I get the distance ? D = R/T ?

[pallid trout]

Yeah

[rigid portal]

Sweet, I'll try it out. Thanks!

[pallid trout]

I don't think this will be perfect if your character will slow down around corners. Worth a shot tho

[rigid portal]

I'm sure there is a function, I'm reading through the API now

[pallid trout]

Get path length node

[rigid portal]

Oh! Yup... that's it

[static crater]

Suddenly this check fails, anyone knows why? I do have a navmesh bound in level

[pallid trout]

This is better than using a dummy actor:Preprocess the path before even starting with "Find path to location/actor aysnchronously".

Length, cost or even draw the actual path

handy

[rigid portal]

Thanks!

[manic karma]

Hi there.
Is there any way to allow AI Character strafing during movement without using a behaviour tree?

[wraith anvil]

What does AiPerceptionStimuli does? if i do ReportNoiseEvent on an actor that doesn't have this component the Ai with hearing perception still hears it

i thought that the actor needed to have the AiPerceptionStimuli to be heard

[wraith anvil]

Sight sense works as expected

[pallid trout]

If a vase falls and you report noise, does the vase have AiPerceptionStimuli

[wraith anvil]

it doesn't

but the AI catches it

same with MakeNoise and MakePawnNoise. the actor doesn't need to have AiPerceptionStimuli for the AI to catch it

and i'm extremely confused

[ocean delta]

should i make a regular blueprint blackboard or are there use cases for using a blackboard CPP base class?

[noble shadow]

So I followed: https://docs.unrealengine.com/en-US/InteractiveExperiences/ArtificialIntelligence/BehaviorTrees/BehaviorTreeQuickStart/index.html
And several other tutorials like this.

But my AI wont "move to" a location. It will follow the player, it will move directly towards an actor if I have placed one and connected it, but a random "move to" doesn't work. I have been stuck at this for like two days now. 🙂 If someone can help that would be appreciated.

• Navmesh has been placed.
• Tutorial has been followed.
• Move directly towards works.
• Move to doesn't work for any patrol points in 3 tutorials now.
• Behavior Tree loops over the Patrol Point, but doesnt seem to understand it.
• Tried in fresh project and working project.
• Engine version 4.26.1
  I'm in the support channel if you want to have a look at it

SOLVED 🙂

[midnight scroll]

@noble shadow Have you tried putting Prints in the BTT_ChasePlayer to see if the cast succeeds or not?

[noble shadow]

@midnight scroll I just did and it is posting the strings, All the way to the end, but for some reason it does not update the patrol location. 🤔

[pallid mica]

Would anyone know why a NavArea_Null child class would not actually set the Area to 0?
I can still see the edge of the NavMesh when using a child class of it.

It seems like only the Null one is actually properly cutting holes?

[pine steeple]

bug in the nav system

i did find the issue once upon a time, but i wouldn't remember now where to look

but basically any child null areas would not cut a hole cause of the issue in the generator

[pallid mica]

@pine steeple Hm, I kinda need custom null areas. Anything that you remember where I could start looking?

I checked where they use the Null class directly, but nothing giving me any pointers

Also strangely enough not hitting any breakpoints that would make sense

[pine steeple]

yeah, hmm let me see if i have it on my notes anywhere

so

this is how the null gets added

[pallid mica]

Right, I tried to do that with my custom class, but didn't do anything

[pine steeple]

iirc childs do not set the RECAST_NULL_AREA

i need to remember why

[pallid mica]

Because UE4 automatically increments the AreaID

Why is AreaID even important if the AreaFlag is 0?

Can the DetourNavMesh only have 1 AreaID that provides 0 Flags?

[pine steeple]

ah from GetNewAreaID

now its ringing a bell

i overrode that

and made AreaClass->IsChildOf(UNavArea_Null::StaticClass())

{
    if (AreaClass == FNavigationSystem::GetDefaultWalkableArea())
    {
        return RECAST_DEFAULT_AREA;
    }

    if (AreaClass == UNavArea_Null::StaticClass())
    {
        return RECAST_NULL_AREA;
    }```

[pallid mica]

Right, I tried something similar by just returning RECAST_NULL_AREA when it's my custom class

You sure* that's all there is do that? Will try again

[pine steeple]

i can't seem to see anything other that i did

[pallid mica]

So basically if ChildOf, return 0 (NULL AREA) and if not, return Super?

[pine steeple]

i just copy and pasted the entire lot and did not call super

{
    if (AreaClass == FNavigationSystem::GetDefaultWalkableArea())
    {
        return RECAST_DEFAULT_AREA;
    }

    if (AreaClass && AreaClass->IsChildOf(UNavArea_Null::StaticClass()))
    {
        return RECAST_NULL_AREA;
    }

    if (AreaClass == UNavArea_LowHeight::StaticClass())
    {
        return RECAST_LOW_AREA;
    }

    int32 FreeAreaID = Super::Super::GetNewAreaID(AreaClass);
    while (FreeAreaID == RECAST_NULL_AREA || FreeAreaID == RECAST_DEFAULT_AREA || FreeAreaID == RECAST_LOW_AREA)
    {
        FreeAreaID++;
    }

    check(FreeAreaID < GetMaxSupportedAreas());
    return FreeAreaID;
}```

this is what i have

[pallid mica]

Will try that too, what I did had no effect yet

You can still see it's not a cut but just a cost change -.-

[pine steeple]

could it be the debugger?

i mean can you pawn walk into it?

during runtime

[pallid mica]

Let me try again, to be sure

Yop

Compared to the actual null one, the AI wiggles itself over it

[pine steeple]

and you regenerated the navmesh after your changed?

[pallid mica]

Yeah it dynamically does

[pine steeple]

interesting, give me a sec

can't see what else i did here

[pallid mica]

One of these frustrating things

I'm also not hitting any breakpoint on the GetNewAreaID. When is that even called?

[pine steeple]

when OnNavAreaAdded gets called

[pallid mica]

I breakpointed FRecastNavMeshCachedData::Construct and looked at the SupportedAreas, and my Child Class seems to have ID 3, so something doesn't seem to actually call

Is this like a config thing where it's only calling it if it doesn't exist or so?

Fixed it @pine steeple

The SupportedAreas are serialized into the Actor in the level

[pine steeple]

sorry got dragged into fixing a bug

[pallid mica]

What a horseshit idea

[pine steeple]

oh yeah have to delete the Navmesh

inside the level

[pallid mica]

Yeah I misunderstood that

[pallid mica]

Thanks though, glad I was actually on the right track

[pine steeple]

have to delete these when doing things like that

dw, i got bit by that many times

[pallid mica]

Right, I was wondering why the SupportedAreas were not clearing -.-

And where they are filled. They aren't if the actor already exists

https://giphy.com/gifs/culture--think-hmm-d3mlE7uhX8KFgEmY

[pine steeple]

but the engine hardcoded nulls tho i knew i only overrode that one function to fix

[pallid mica]

Yeah I'm still not sure why the AreaID translates to the Flags

But if this works, I'm fine

Yep, works. Can cut holes with custom NavArea and finally only cut them into some of my navmeshes..

That took too long -.- Thanks so much!

[pine steeple]

yeah good old Navigation system

2 years and counting and still fighting with it daily.

[tall rock]

Anyone have experience using ESQ trace queries? I'm trying to do a capsule trace (instead of a line trace) but dont get any results when I make the capsule the same size as my TargetContext.

Is there a way to debug the traces in esq?

I know you can hit 'apostrophe and turn on ESQ debugging but it doesnt show trace information there.

[wraith anvil]

Anyone got any insight about this? All tutorials show that AI_Hearing needs to be added to the PerceptionStimuli component but ReportNoiseEvent works with any actor that calls it (no need to have the component)

[lilac musk]

try to use EQS testing pawn - https://docs.unrealengine.com/en-US/InteractiveExperiences/ArtificialIntelligence/EQS/EQSTestingPawn/index.html

[manic karma]

Hi there.

I'm trying to make a sort of 'afraid' AI.

I have a bunch of little jawa things, and I want them to get to 500u away from the player.

If the player moves away, I want the jawas to follow, and if they approach the jawa, it should back away.

Imagine 10 of them forming almost a circle around the player, and keeping that shape as the player moves.

What do you folks think is the best way to do that?

[fresh remnant]

@manic karma make a circle around the player, have the individual jawa find the closest point on that circle to itself, navigate there

[manic karma]

Makes sense.
How do I smooth the movement out?
Too high a tick speed means the jawa stutters with movement

[fresh remnant]

FMath::VInterpTo( CurrentPosition, NewPosition, ..)

not sure if ur using blueprints or not, can use the Vector Interp To in blueprints too, I'm sure it's exposed

[manic karma]

Is there a standalone function to project a position onto the navmesh?

[fresh remnant]

You need to grab the navmesh, but then u can use it afterwards to project

if (!RecastNavMesh)
{
  return;
}
auto NodeRef = RecastNavMesh->FindNearestPoly(AdjustedDest, Extent, nullptr, this);
if (NodeRef != INVALID_NAVNODEREF)
{
    if (RecastNavMesh->GetClosestPointOnPoly(NodeRef,  AdjustedDest, OutLocation))
    {
        }
}
``` @manic karma I do something like this

Find nearest poly, then find closest point on that poly

[manic karma]

doing this, which seems to be working quite nicely

Only problem is there's an initial snap to a position

and they clump up together

I'm working on some spacing behaviour now

[fresh remnant]

@manic karma best spacing behavior is usually find nearest other javas and move away, add that to their velocity each frame, a move away from other java vector

[manic karma]

i've used a personal space sphere and I only move away if they're in that

20 as a force just seems to work okay

only issue now is a huge snap when they start tracking

@fresh remnant don't know if you're cool with @s

[fresh remnant]

that's ur interp speeed

150 is too high

do like 1

[manic karma]

hm

I probably need to scale it based on distance

[fresh remnant]

or use Constant Interp. I thik this Vinterp does a curve, it snaps really fast

then it slowd down

use VConstantInterp?

or something like that

[manic karma]

I like the smooth interpolation

[fresh remnant]

I think VInterp expects range of a lot less than 150

[manic karma]

tend to lose that with constant

[fresh remnant]

try 1, or 4

[manic karma]

honestly they back away so slowly haha

[fresh remnant]

try 10?

[manic karma]

even then

Ideally I don't want to really be able to get near them

[fresh remnant]

try 30? haha 150 is obviously the reason it's snapping tho

[manic karma]

yeah

I'll scale it on distance

it works really nicely after the snap

cause the 150 keeps it in

[fresh remnant]

ic

[manic karma]

I think I'll ramp up the interp speed when it starts tracking

just lerp 1 to 150 over like 2 seconds

but you're right - it is that

[fresh remnant]

cool, but btw, those jawas are not getting the closest distance to teh circle

so gotta fix that code too probably

they seem to be offset from the closest point in the circle around the player a bit

[manic karma]

yeah it's just vector from player atm

I might change that tomorrow

the ramp works

i'll let you know if you want

[fresh remnant]

is cool just post here, prob not on tomor

[clever skiff]

close range attack plays fine.

the animation play fine on it own so somewhere there a disonnect

[glass falcon]

is there any way to see the complete execution process of an AI

like all the trees actions up to a specific point ?

[clever skiff]

who me?

[glass falcon]

wait no

I was trying to ask a different questin

question

imma try and take a look at your stuff

[clever skiff]

oh. the only way to see execution flow of behavior tree is to pause it

and then use the back buttons

[glass falcon]

back?

please teach me this sorcery

[clever skiff]

when you open the behaviour tree and pause it therre button that you can use to go back thru the flow

[glass falcon]

I dont see anywhere here when the attack is called

and is this multiplayer or single player ?

[clever skiff]

if you are in game then hit the pause button for the button to show

attack is called by task

[glass falcon]

imma test it out

[clever skiff]

see it being call just not actually seeing the animation done

[glass falcon]

can you open the attack task ?

[clever skiff]

it at the top

[glass falcon]

i mean like can you open it

[clever skiff]

it iz

the piic above

it callin a montage

[tall rock]

@lilac musk Thank you, great idea - i'll give it go tonight

[vast wharf]

Has anyone tried saving and loading ai states with any success?

[misty wharf]

It seems to be a bit tricky. You can do it by building your BT's in such a way that you can just load the right values into the BB and it'll go into the previous state

[vast wharf]

I can save out all the vars from a blackboard and then load them back in for my AI controller, but if the still have weird residual issues with perception system to restoring to original state

[misty wharf]

But it does add a fair bit of complication if you want to ensure everything restores into the right state in the BT

I've not tried with the perception system stuff 🤔 I guess if you can restore the internal state of the whole perception system for the AI that might do it, but not sure if that data is exposed

[vast wharf]

hmm

I can trick my AI, by saving the game after it lost sight of me (stopped perceiving) -- save the game -- continue playing and get the AI to see me again, then move some where else where it looses track of me again, (put still pursuing) then -- load the game -- the AI doesn't try to find me at my original saved last known position, but keeps going towards the after save last known position...

[scarlet bramble]

Any advice or neat way to make AI spread out a little bit when they try to melee attack you? 😄

I'm using this blueprint to make them follow me. It seems to be continues, or update automatically. So they always go where I go. I just need them to spread out around me.

[lyric flint]

Maybe some tutorials on YouTube with RVO Avoidance and/or Detour Crowd can give you some ideas 🙂

[scarlet bramble]

Thank you. I'll check it out 😉

[clever skiff]

any idea why my montage not playing when being called in behaviour tree? it me the in range bool but animation dont play. pics are all above.

[clever skiff]

anyone able to help?

i found that i didnt have the abort set. but i change it to self and still not able to play animation it just walk towards me.

[ocean delta]

sup. i have my AIPerceptionStimuliSource set up but my actor is not perceiving. anyone have any ideas why this might be?

[deft sedge]

Is there a reason the blackboards don't support gameplay tags as keys? Is there a reason I should use blackboard keys instead of tags?

[deft sedge]

I can help you quick

[pallid trout]

In setting check for friendlies, enemies and neutrals and add a perception source component on the characters

[deft sedge]

that's bad for performance. Should set up teams. Simplest way to set up teams is the free faction plugin

[pallid trout]

first to check if that is actually the problem

[deft sedge]

he probably doesn't have a stimulus source or is not auto registering

[ocean delta]

Yes I am lol

[ocean delta]

Yes to both of those things

[ocean delta]

turning on all friednlies, enemies and neutrals worked

[ocean delta]

THANK YOU

[deft sedge]

you should definitely use the free faction plugin so you don't have so many unneeded detections going on. Or add your own teams implementation.

[earnest kelp]

Hello! Is there a good way to alert all enemies if the player is spotted by an enemy? Thanks

[lyric flint]

Absolutely! broadcast an event to all the members from the enemy team that spotted the player. The events should include current hostile state (Like suspicious if received the stimuli via hearing, or full-blown attack if by sight), and target, either by location or by object, things like that...

[earnest kelp]

Okay thank you! Been having trouble trying to implement it!

[lyric flint]

Take your time and look at some YouTube tutorials about AI perception in unreal, They should definitely help point you some good direction!

[earnest kelp]

Alright, thank you!

[opal bolt]

Hi everyone. I use different supported agent to have different recast nav meshes. In EQS I can use Navigation Filter. In Navigation I can filter for Nav Area, but not for specific Recast Nav Meshes. How can I use the "Navigation Filter" in EQS (e.g. with PathfindingGrid) to limit the the query to a specific Recast Nav Mesh of a specific supported agent?
It seems also a supported agent spawns a "default Nav" mesh and nothing I can filter for in "NavigationQueryFilter".

[opal bolt]

I think the correct question is, how do I use a "NavigationQueryFilter" to filter for Recast Nav Mesh of specific supported agent?

[ocean delta]

what decorator should i use when i need to eval if a boolean in a blackboard is true

is this the correct decorator?

turns out it is

[opal bolt]

@ocean delta yes, it is

"is set" means true in that case

vor "actors" it checks "if valid" so it is true when it has a valid reference

I am nit sure for locations, I guess its true in every case there

[opal bolt]

No one active today with knowledge about navigation system. I googled hours but not really find any help. Seems such topics are not discussed public. 😦

[misty wharf]

You might have to look at the EQS source code to see how it chooses which navmesh it uses

It's entirely possible it's either not actually implemented and it just uses some default, or it's only available in C++ via some trickery

[uncut python]

@clever skiff im having a similar issue

this is my sevice

my bt

and it wont actually play the animation when I am close

im dense

i forgot to set the thing there

the selectors

[clever skiff]

what did you forget?

oh the condition

[opal bolt]

Thanks, Yeah, I also think that it will work. But my c++ skills are very limited, so look for someone who can give direct advises for this.

[uncut python]

@clever skiff yes

lol

[clever skiff]

mine still wont play. do i need to set the montage in the animationbluepprint with the idle and run animation?

i think that what i didnt do

[opal bolt]

postet in c++ channel, perhaps it has more chances there

[misty wharf]

It looks like it might be using the navigation agent of the querying actor as the source for the navigation data... but I haven't really looked at those systems in much detail so can't offer any specific solutions

(from EnvQueryGenerator_ProjectedPoints.cpp line 22, then looking at EnvQueryTypes.cpp line 291)

[uncut python]

@clever skiff i just did animation i didnt set a montage

[mighty mesa]

Hello. I can use the blackboard and the behavior trhee using a pawn e not the character?

[opal bolt]

Someone here knows a bit of **INavigationQueryFilterInterface **, **ARecastNavMesh **and GetNamedFilter and can tell me how I filter for specific RecastNav Meshes for specififc supported agents?

I guess I am really close and on the right track. But do not understand what I have to do with it to filter for a specific recast navmesh

[pine steeple]

what you trying to do?

NavigationQueryFilter has nothing to do with GetNamedFilter

[opal bolt]

@pine steeple It used in this combination in UE4 code, so I guess, it at least has something to do 🙂

#if WITH_RECAST Filter.SetFilterImplementation(dynamic_cast<const INavigationQueryFilterInterface*>(ARecastNavMesh::GetNamedFilter(ERecastNamedFilter::FilterOutAreas))); #endif // WITH_RECAST

from RecastFilter_UseDefaultArea

My goal: "... how I filter for specific RecastNav Meshes for specififc supported agents?"

GetNamedFilter sounds fine for me, but I do not understand how I change this filter to not get all default recast navmeshes, which seems to be all recast meshes available. But only 1 specific for one supported agent.

oh @pine steeple it's you. Nice to meet you, you helped me a lot with GetNavDataForAgentName. Thanks again, and I hope your project is runnig fine!
This time I have to use filter in EQS to use only a specific nav mesh in EQS. I found UE4 built in RecastFilter_UseDefaultArea, which has the code posted above. I think with a similar code snippet like this, I could filter for supported agent recast navmeshes.

[pine steeple]

    if (NavAgent)
    {
        return NavSys.GetNavDataForProps(NavAgent->GetNavAgentPropertiesRef(), NavAgent->GetNavAgentLocation());
    }```

ah so this is not what you want?

if you want a specific navmesh for agent type, sec

you mean you want to match it to a filter?

cause filters don't hold agents

[opal bolt]

One moment, I show you better:

`URecastFilter_UseDefaultArea::URecastFilter_UseDefaultArea(const FObjectInitializer& ObjectInitializer) : Super(ObjectInitializer)
{
}

void URecastFilter_UseDefaultArea::InitializeFilter(const ANavigationData& NavData, const UObject* Querier, FNavigationQueryFilter& Filter) const
{
#if WITH_RECAST
Filter.SetFilterImplementation(dynamic_cast<const INavigationQueryFilterInterface*>(INavigationQueryFilterInterface::GetNamedFilter(ERecastNamedFilter::FilterOutAreas)));
#endif // WITH_RECAST

Super::InitializeFilter(NavData, Querier, Filter);

}`

This is EQS, you can define/use filter there. I looked into code of one ue4 default filter. This it is.

But I do not want to filter for default recast navmesh, I want to filter just for one specific recast nav mesh for one of my supported agents

[pine steeple]

yeah not sure that is really possible with a filter

as filter doesn't have any concept of agents

[opal bolt]

Hmm, but I want to have EQS only search possible results on the recast navmesh which fits the supported agent and not on the default recast navmesh

I am wondering when this is not possible

[pine steeple]

yeah one thing i can think of doing is..

making a fake props

(with the dimensions that match the navmesh you want)

and calling the above function i showed, but passing in your fake props

problem is

that would have to match an exisiting agent that has spawned..

let me spend a few minutes, i have never needed to do this

[opal bolt]

But your function is returning "NavSys.GetNavDataForProps". The default UE4 built in function I posted, is not returning anything. It is a "filter". And as I see EQS gui, I have to select some C++ which is a filter and not a C++ code which return something.
Sorry, this is hard for me to combine 🙂

[pine steeple]

right but you want a ANavigationData for a specific agent type right?

thing is, ANavigationData is not type specific, it adds the agents to the closest navmesh based on its capsule radius