gameplay-ai

[round grove]

so the task object has one thread running the queue and another thread listening for an abort which can then interrupt/clean the other thread at any time?

[misty wharf]

I would stay away from threads. You can just make use of ticking if you need to run something like that

[deft mural]

Is there not some sought of C++ only TQueue type?

[deft mural]

How do I define a AIController pointer property so I can bind it as an input in the State Tree asset file?

This is how it looks at the moment.

[round grove]

Just wrapping my head around this - do you mean something like this?

[misty wharf]

Are you running this state tree in an AI controller or somewhere else?

[misty wharf]

Something like that, but you don't really need to tick to do this. Let's say that this is a component on an actor, you would just set it up so that your input actions call a function on this component when it needs to abort. Similarly, once a task has been started, you don't need to keep telling it to continue

[round grove]

I've been messing about in state trees, and man I want them to work so badly but I just can't get them fully functional

[deft mural]

This is in the state tree asset.

This is how my blueprint task looks.

I am trying to move it into C++.

[misty wharf]

Yes the point is that if you're running this in an AI controller, then your Context actor would be the AI controller

[deft mural]

I even looked at the generate header preview to make sure my specifies were right. That did not help.

Why can I not get the correct UI to come up when binding inputs?

[misty wharf]

Ahh that's what you meant

[deft mural]

Sorry.

[misty wharf]

try this

UPROPERTY(EditAnywhere, Category=Input)
AActor* Whatever;

[deft mural]

Okay.

I have added that as a new field.

[misty wharf]

also this needs to be in the InstanceData, not as a property on the task itself

[deft mural]

InstanceData?

[misty wharf]

A separate struct used to store instance-specific data like this. The builtin ones should have examples on how it can be defined

[deft mural]

Okay.

I am still new to the C++ side of things when it comes to State tree.

[deft mural]

Cool. I found how the Delay task is done.

[round grove]

Sorry, trying to wrap my head around this (I am newbish). What kind of component would I put on my actor that would allow for this semi-autonomous flow?

[deft mural]

I see how easy it is in Blueprint.

[misty wharf]

A custom Actor Component would probably be the way to go

[deft mural]

What does the Hidden specifier do?

I was just looking through some of the State Tree source code and found this.

[misty wharf]

I'd imagine it prevents the struct from showing up in some lists

[deft mural]

Probably.

It's interesting that you can define all properties inside a blueprint task. I wonder how this works under the hood?

[minor geyser]

is there a way of saving a BT as a .png? so you can reference a previous version easily if you break it :x

[misty wharf]

There's a BlueprintBase or something like that for the state tree tasks, that probably handles it

[misty wharf]

Good question. Why not just duplicate the asset?

[deft mural]

Or use blueprint pastebin.

It has a version history system.

It's weird how you need to put public for inheritance for structs.

[misty wharf]

it's just how inheritance in C++ works... if it wasn't public then methods on them would become protected or private and potentially break stuff

[round grove]

Is this what you mean?

[misty wharf]

Pretty much

[round grove]

ok, thanks - took me a bit to understand. The advantage here is that I gain a bit of modularity and can cancel the current task without having an on tick 'interrupting key pressed?' bool?

[misty wharf]

Yeah.. in general in UE you don't need to poll for inputs

you get events and then you can react to those events

[bitter wyvern]

is there a way to disable an AIStimulusSource during runtime so AI Perceptions wont sense it?

[stark tangle]

hey guys, i have an issue with a Service node of my Behavior tree
i need a Service, which must force an AI-controlled pawn immediately drop a right branch (moving to waypoint) when they see an enemy, and go to that enemy to attack it
i have a Perception logic in a AIController, so i need just force a pawn to follow it
what do i need inside of a Service then?

[tawdry zephyr]

@crystal hatch I can't DM you, think the server default settings changed
I sent Daniel a couple more engine bugs, one with a fix included, but I don't think he checks Discord
If its not too much trouble could you ask him to check his DMs 🙂

[harsh storm]

I thought I understood the NavModifierComponent, but apparently not. It works as expected with the doors, but with a different static mesh, it doesn't do anything 😭

[uneven cloud]

Yes. There is a function in the perception system.

[harsh storm]

Trying to use it, because a crane is supposed to move a shipping container that is in the play area and then it gets moved to an area to form a "bridge" pretty much. I want to dirty the tile where it sits originally, so it becomes an open path and then dirty the area where it forms the bridge so that AI can cross it as well.

[uneven cloud]

You can't generate new nav mesh using modifiers only. In fact, putting a nav modifier component on it, will stop navigation from being built on it at all.

[harsh storm]

😭

[uneven cloud]

What you can do is the opposite. So build the nav mesh with it in the "bridge" position. When the game starts, move it to the starting position and add a nav modifier to where the end position is (to cut out that bridge nav mesh). Then when you move it back to the end position, disable the modifier.

[harsh storm]

Nice idea. Thanks!

[uneven cloud]

You're welcome. We do it a lot of the time for different things.

[harsh storm]

Figured out something about the nav modifier component with this mesh. It seems it's not finding the bounds of the static mesh correctly?

And for w/e reason, for this one, I needed the static mesh component to be able to affect the navigation - but for the doors, I don't.

And the nav modifier component even seems to have a check to see if the root component has that option checked or not, and it shouldn't matter 🤔

[fathom sun]

What's the difference between nav walking and regular walking in the character movement component? When should I be using the nav walking rather than the regular one?

[dense owl]

Weird. Collision issue maybe?

[dense owl]

nav walking is cheaper but less precise, prly best to use it when you have perf issues stemmed from nav https://forums.unrealengine.com/t/how-to-use-navmesh-walking/310732

[harsh storm]

It's supposed to be using the collision of the object, but the collision shape looks fine 😭

[dense owl]

If you add a box collision to it, does it change the shape the navmesh takes around it?

[harsh storm]

Didn't try that because I didn't want to wrestle with it at the time.

[dense owl]

Oh, well if it does what you want it to then yeah it’s moot

[wise sluice]

Walking = PhysWalking (It raycasts the floor and move the character to the hit impact + sweep when moving)
NavWalking = It relies on the navmesh (it tries to find the best location within the Navigation Data. if you don't have any navigation data, it won't work)

Generally you use Walking for your Players
And NavWalking for your AIs

Except if your players' pawns move thanks to a path

[dense owl]

🤔

[misty wharf]

I tried using nav walking in my project for AIs and it was pretty janky

but it would probably be worthwhile to look into because regular walking is fairly performance consuming thanks to CMC being CMC

[harsh storm]

I've always used nav walking for my AI to be honest

[fathom sun]

I personally have noted that using nav walking doesn't allow AI to slide along some round collision. So if one AI character walks into another, it'll stuck there. That doesn't include any crowd avoidance or RVO obviously

[wise sluice]

There is some if you enable it

[fathom sun]

What exactly? I have tried to search for properties in the CMC, but didn't find anything

[wise sluice]

Using the ADetourCrowdAIController

https://docs.unrealengine.com/5.0/en-US/using-avoidance-with-the-navigation-system-in-unreal-engine/

There is also another solution
Both are explained here ☝️

[harsh storm]

That doesn't include any crowd avoidance or RVO obviously
You may have missed this part

[obsidian delta]

Does anyone know why sometimes changing navigation mesh tile size, does absolutely nothing?

[wise sluice]

Yeah i didn't get it ^^'

[dreamy star]

Hi.

I Have a question that i would need to discuss with someone familiar with AI and AI behaviours or maybe even training AI via ML. I have a car game, but the NPC/AI should be able to move like frearoam on an open maop terraint, not after a path or a spline.

I would highly appreaciate if someone with infor or ideas, or knowledge of great videos/tutorials could give ´me some help here.

Tag me with your answer thnx in advance // Philip

[misty wharf]

There's a bunch of vids on YT if you look up machine learning car ai or something like that. I think game ai pro also has some sections on racing games, they are free on the game ai pro website

In general I think this is fairly complex for an open world'ish thing. A spline based approach would probably be a lot simpler to implement - they don't have to stick to the spline, but rather just use the spline as a "guide" towards which they steer. This would allow them to deviate from the spline if necessary, but make it so they don't really have to understand what's happening when moving normally

[deft mural]

What are AI messages used for?

[languid agate]

Hi guys this should be pretty simple but I am not sure how to go about it.

Basically, I have a 90-degree left and right turn for my boss character, currently, they are set to rotate to their new target destination before moving.

How can I set up a way to determine if it is a left or right turn and have it play the correct animation during the rotate to BB entry function?

https://streamable.com/2cyye4

[dense owl]

That’s up to you, isn’t it?

[languid agate]

?

[dense owl]

What determines whether he should turn right or left?

Also try not to cross-post, it’s against #rules

[languid agate]

Thats what I mean I dunno how to define that information to use as a variable.

I guess I would have to maybe do something with a Dot product times it by 360 and use that somehow to determine left and right but again I would be just guessing kinda

I will note that for the future just thought this channel might be particularly quiet

[dense owl]

I mean maybe EQS with dot product but my point was why does he need to turn into a specific direction?

[languid agate]

So when he rotates he isn't skating and actually turns I will show you the animations

https://streamable.com/jsg757

If you look at the previous clip he is just playing his idle animation when rotating without any foot movement

It doesn't need to be perfect like with IK's or anything as long as it plays left or right turn to match the rotation roughly

I just need a way to get if it is a right or a left basically I can figure the rest out with triggering bools, states etc. Just unsure how to know which way he is turning

[dense owl]

Ok, so this isn’t about determining whether he should go left or right but more like deciding which #animation to use depending on the turn he is making

[languid agate]

Pretty much yeah but it's not the animation I am struggling with I just need a number I can use a greater or less than node on to plug into a branch to determine which turn animation to play

[dense owl]

Yeah, I get you

[dense owl]

Normally you’d prly use one walking animation but if he needs to lean over or something, then you’d prly need to do something like subtracting the current rotation from the target rotation, and pick the animation depending on the result. For example, if the result is positive, then it’s right and if it’s negative it’s left. This would require some testing and there might be better solutions out there but that’s where I’d start

[languid agate]

I tried that but I am pretty sure I had the sequence messed up a little i will try this again with a dot product and using greater or less than 0.5 should determine left or right I think if I make a dot product out of the forward vector Z axis maybe

[uneven cloud]

AI messages are for the BT to wait for a message. It's not really used much, because it's based on FNames.

[uneven cloud]

You determine the direction by using a dot product of the direction to the target and the AI character's right vector.

[dense owl]

Yeah, that is indeed much cleaner 😅

[deft mural]

If IGenericTeamInterface is not useable in blueprint, what's it's use?

[dense owl]

It’s usable

Just needs like 5 mins of work in cpp to expose it

[deft mural]

Okay.

Thought so.

I will do that later.

[karmic pelican]

why is this node running while it's returning false?

[karmic pelican]

nevermind, fixed it

[dense owl]

What was it?

[karmic pelican]

the issue was the decorator, I had sloppy code

for the IF statement, still not sure what to do, but I kept both

the Service runs all the time? in AI

[dense owl]

Yeah service is for things you want to run continuously, usually

[karmic pelican]

Deal, thanks

[bitter wyvern]

Is there a way to abort a simple move to before its complete

[dense owl]

You can call stop movement

[worn widget]

Random aside here, but I also find services really useful for handling scope - you can use activate/deactivate events to add/remove state, etc

Means that whenever the node it's attached to deactivates you can get an opportunity to clean stuff up

[karmic pelican]

I just do them from dispatchers
For now

But I've got another thing

I'm doing this, but if the pathfinder from the EQS fails. I want it to skip the MoveTo or do another EQS instead.
Not sure on how to do that tbh

I'm quite new to AI and EQS stuff

I have this but always always returns false

[dense owl]

I would recommend the 4th pin if you haven’t checked it out already

[karmic pelican]

The RunEQS?

[iron nymph]

Does anyone know if the default Team attitude solver resolves team 255 as neutral for all? I was under the impression it should but when I assign agents to team 255 they still show up as hostiles for other teams

[dense owl]

4th pinned link in this channel

[karmic pelican]

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

[ashen trail]

Does DetourCrowdAIController not interface with regular "dumb" AIController?
I'm moving my pawns along spline points.

I want the "regular" pawn to always go linearly between the spline points and NOT go around other pawns
I want the "smart" pawn (which is a bit faster than the "dumb" ones) to go around the other pawns.

I setup the dumb ones using default AIController and the "smart" ones using DetourCrowdAIController but nothing really happens - instead of avoiding the slower pawn, the "smart" pawn just gets its velocity lowered and follows in the same line.

Any tips/ideas?

[karmic pelican]

https://forums.unrealengine.com/t/how-to-use-eqs-to-check-if-path-to-target-exists-is-valid/508900/2
this helped to detect if the pathfind fails
while the video taught me something new about failing a node and such, thank you!

[uneven cloud]

That advice is terrible. The EQS is time sliced, so it's not really that expensive. Also the does path exist EQS test is considerably cheaper than Find Path. If the EQS has many points that are valid and it keeps returning one that isn't, because it's the highest score, your AI won't move.

[dreamy star]

Hi.

I Have a question that i would need to discuss with someone familiar with AI and AI behaviours or maybe even training AI via ML. I have a car game, but the NPC/AI should be able to move like frearoam on an open maop terraint, not after a path or a spline.

I would highly appreaciate if someone with infor or ideas, or knowledge of great videos/tutorials could give ´me some help here.

Tag me with your answer thnx in advance // Philip

[dense owl]

Pretty sure someone already replied to you on this yesterday ?

[gilded tree]

Hey guys, how can I ensure that my ranged AI can see my player before they attack? My AI decides whether to chase down the target with melee attacks or long ranged attacks depending on the distance from player to AI. However, if I hide behind a wall the AI will just stand there shooting at my location. Any tips? 🙂

[dense owl]

Is your wall blocking visibility ?

[gilded tree]

Yeah

[dense owl]

Are you using EQS for this yet?

[misty wharf]

Sounds more like a perception issue rather than EQS

If you are using perception, you will get a perception event with successfully sensed set to false when sight is lost

[dense owl]

Yeah but I mean if it’s a half wall or something and it needs to go around

But yeah you’re right about the perception

[misty wharf]

Yeah depends on how it should work I guess, easy start would just to have the AI pathfind normally towards the player's position

[dreamy star]

Hmm really, can't see it ?

[dense owl]

#gameplay-ai message

[dreamy star]

Oh yeah, well I wanted to find someone to talk to about this stuff that's why I posted again

[misty wharf]

Tbh unless you get really lucky you might be hard pressed to find someone

It's a complex and kinda niche topic, but who knows :)

[uneven cloud]

Use the has line of sight function on the AI controller.

[misty wharf]

Huh, there's a function like that in the AI controller? :P

[uneven cloud]

Why do you think you need GOAP? What does it give you? What is the difference between GOAP and a BT? If you don't know the answers to this, you need to do more research.

[gilded tree]

Cant find that function 🤔

Does it maybe not inherit from the Detour crowd AI controller?

[misty wharf]

I think the one she's referring to is LineOfSightTo

[gilded tree]

Ooooh

[misty wharf]

(but if you're using perception you probably can do it in a different way)

[gilded tree]

yeah, would hope so 🤔 Im using both vision and hearing though

[misty wharf]

Right, in that case you want to check what I mentioned above

You should be getting a stimulus event from perception for sight when line of sight is lost

[gilded tree]

I can just have the AI move to a closer location after attacking though, that could work 🤔

[uneven cloud]

If the NPC is still shooting at the wall and they are using perception to pick a target, then the problem isn't with perception.

[misty wharf]

It could be just a mistake in how the perception is being handled, it's kinda tricky to understand how it all works at first so those are pretty common problems with it

[gilded tree]

Well, I can have the AI run one montage of the ranged attack and then move to a closer location based on their previous location, that would force the AI to change locations 🤔

[karmic pelican]

Yeah I noticed the problem as I was testing. And I couldn't find the Does Path Exist.

[uneven cloud]

What kind of complex and dynamic behavior are you actually looking for?

[gilded tree]

Like, have the AI choose a point to move to between their last moveto position and towards their perception target

It's not failproof, but could give the impression that it's tactically moving about

[uneven cloud]

The EQS batch pathfinding test. Set it to filter only.

[dense owl]

“coding to generate emergent behaviour” sounds a bit contradictory

[uneven cloud]

Why are you trying to work around just finding a location that has line of sight to the target?

[karmic pelican]

I have added the batch one, but what is the difference?? should I replace the first one with the match?? how will I get the Bool if a single path is valid or not?

[gilded tree]

Well, not quite sure how to do that 😅 I'll check out some vids on the LineTrace function you mentioned

[uneven cloud]

The batch one is cheaper.

[karmic pelican]

ok, how can I return if a pathfind is valid or not?

like I want the actor to make another EQS for another location for example

[uneven cloud]

The EQS does it for you. It filters out any locations that are unreachable. If no points are reachable, the Run EQS task will fail.

[karmic pelican]

and the rest of the sequence will not run

[uneven cloud]

You can put another generator to the right and it will be run if the first one fails. Or you can use how the BT functions to do a fall back behavior

[karmic pelican]

doing something like this

[uneven cloud]

That can be done in a BT. I'd use Utility before GOAP for that, but it can also be done in a BT.

[uneven cloud]

In your case, because the sequence is the same, I'd set up a 2nd generator in the EQS.

[karmic pelican]

second generator?

[karmic pelican]

like 2 of em in the same EQS?

ohh okay

didn't know we can do that

[uneven cloud]

You can set up a multiple generators in an EQS. It will do them left to right until one has a valid item.

[karmic pelican]

thank you

and the percieved actor will check all actors currently in the actor's sight?? not age

[terse panther]

is there any way to set the default values of keys in a blackboard 🤔 ...
as far as i can see there is none...
its sometimes annoying to set the key default value right after running the behaviour tree...

[misty wharf]

I think you just have to set them f.ex. in your AI controller's BeginPlay before you start the behavior tree

[uneven cloud]

Starting the BT should not happen in begin play, it should be on possess.

[rigid tulip]

Anyone knows why I keep getting these message on client (client side allow navigation is OFF):
LogNavigation: Warning: ConstructTiledNavMesh: Failed to create navmesh of size 0.
(UE5.1)

[uneven cloud]

BTs separate out the decisions from the actions. They aren't bad at making decisions, but you also don't need to put the decisions in the tree. BTs are a priority order set of actions. Sometimes that's great for what game you are making and sometimes it's not.

You can't really pick the right architecture without fully understanding the options. I will reiterate that you should do more research on how they work. Not research on what other people think you should use.

[uneven cloud]

There's a lot of really bad advice out there, mostly from people who don't understand the different options. Especially with "GOAP is better" or more advanced or whatever. Planners (arguably HTNs are better than GOAP perf wise) have pros and cons just like BTs do.

[dense owl]

Do we have any resources on other AI systems (other than BT and mass) within Unreal? I didn’t really see anything in pinned except for general AI concepts

[uneven cloud]

Game AI Pro has good articles on different systems. HTN, Utility and hybrids. While there is an unfinished HTN in UE and some mediocre plug-ins for others, it's completely unknown if they will add more than the BT and State Tree.

[dense owl]

Ah fair enough thx

[harsh storm]

There is still a lot of misunderstanding between State Machines and BTs. Good luck demystifying the other AI architectures 😅

[dense owl]

Yeah, I mean until recently I hadn’t touched animation at all, now I realize SMs are animation related ?

[uneven cloud]

Doesn't help that most tutorials treat the BT like a bad FSM.

[harsh storm]

They can be. But you also have logic state machines.

[dense owl]

Ah I c

[uneven cloud]

The CMC is also a state machine

[harsh storm]

You can have a state machine for pretty much anything

I always write my BTs as more like a behavior priority selector pretty much

"What is the most important thing for this AI to do". And then work down from there

2nd most, 3rd most, etc...

[dense owl]

Seems reasonable

[keen crow]

Is it necessary to inherit BTService node memory from FBTAuxiliaryMemory? I've just realized that I never did although it seems BTComponent actually somewhat relies on the fields of that structure 🤔

[rigid tulip]

In case anyone else will encounter it - fixed by setting auto destroy when no navigation data in project settings
(LogNavigation: Warning: ConstructTiledNavMesh: Failed to create navmesh of size 0.)

[misty wharf]

Ah yes, navmesh walking

I decided to try it in my project and immediately get mysterious issues such as the npc no longer appears to trigger overlaps

wonder why it would be affecting that...

Generate overlaps is enabled on capsule... it starts working if I also enable overlaps on the skeletal mesh, which seems a bit weird

[dense owl]

What about perf gains?

[misty wharf]

Hard to say. Will need to test some more

I was doing quick testing in PIE spawning 20 mannys who just run towards you and hitting like 30 fps drops as soon as they were spawned, I don't think changing it to navmesh walking had much of an impact

[dense owl]

Lawlster mentioned the CMC itself comes with big perf hit

[misty wharf]

It does yeah

[dense owl]

I would maybe run stat game and other #profiling tools to determine exactly what’s causing the drop, may be entirely unrelated to nav

[misty wharf]

Yeah I was using unreal insights but it was not being very insightful

mostly claiming that slate was taking majority of the render time (eg. the UE editor itself)

messing around with something that might need to spawn quite many characters so want to just see whether it's going to perform properly and where the issues are going to be, but will need to test some more later

[echo lark]

does anyone know how to access State Tree parameters from Task in code ? (or any other node), without using bindings.

[vivid fern]

in most shipped projects ive worked on I end up in a very hybrid type of place..

I usually end up with a set of high level behaviors in a priority order, that are "tested" to see if I meet the conditions to do the sequence of events each chunky high level behavior represents.. These can also be nested so that a single high level behavior can be broken down to smaller, but still chunky components

Typically a behavior tree runs these sequence of events/tasks, but the gating condtionals tend to vary per game ive worked on.. Sometimes its all done in a single behavior tree, sometimes its a set of functions that then runs smaller behavior trees, etc..

So like at a high level it looks pretty HTN-y as we select behavior but then when we find out what to do, it processes all the tasks and actions with a behavior tree.

State machines come into play to manage character state.. this is usually either the same SM or a tightly coupled SM with the animation state, though I have used them to drive AI decisions as well..

The above is engine agnostic explanation.. in 16 years i never have shipped an unreal game haha but in engines i've used (mostly internal tech) its how i've gone about it

AI perf only really gets bad due to counts and external systems not having good codepaths for AI to make efficient calls to ime

the actual decision logic is pretty quick typically in comparison

[dense owl]

IME?

[vivid fern]

in my experience

[dense owl]

Oh ok I thought it was some system 😅

[terse panther]

i always did it in the begin play :/
looks like from now on I'll have to do it in onpossess

[terse panther]

yeah i am doing all those default value stuff in controller, right after running the BT

[uneven cloud]

Most of my shipped games have been a similar system, but using a Utility/BT hybrid.

[vivid fern]

yeah

this seems to work well flexibility wise

[uneven cloud]

Yeah, especially if you have a lot of variants.

[uneven cloud]

You can run into situations when begin play is called before the controller has been possessed by a pawn.

[vivid fern]

well and also its easier to hand designers a big block of "this is behavior that does x" than "here are the little bits and peices for you to make behavior"

ive never met a designer that wants to futz with the behavior tree haha

[terse panther]

how can we learn other AI systems like HTN and GOAP etc, as for behaviour tree and FSM we can use them in unreal and unity. So do we have to create these on our own or is there another way? as for HTN i think there is a plugin by unreal engine, but never used it

[uneven cloud]

I have, but it never goes well.

[vivid fern]

🙃

at the end of the day they really just want knobs and levers to tune outcomes

[terse panther]

i never came into such situation, i think thats why i always used it in begin play...
from now on will run it in onpossessed

thank you for this

[uneven cloud]

There are articles in AI Game Pro that you can read for free.

[terse panther]

will look into it...
but about the practical part, looks like i have to create a simpler system like it 🤔

[vivid fern]

nothing wrong with creating a simple mostly naive implementation of some of these patterns to get the feel of how they would fit into your game if you have the time/bandwidth to do so

[terse panther]

well time is a big problem here 😅
as because of this i never got a change to try the state tree

[harsh storm]

The marketplace HTN plugin looks might nice to be honest. Always had my eye on it. Just, haven't needed it just yet 😅

https://www.unrealengine.com/marketplace/en-US/product/hierarchical-task-network-planning

[terse panther]

i got to know about this plugin by bigfry, as they are using it in their game Transience...
from that day its in my cart😅

[misty wharf]

Well that's certainly interesting... poking around the state tree thing and turns out at least witht the state tree component...

• if you use GetExternalData and your handle is to a pawn, it pulls the component's pawn
• similarly if the handle is to an AI controller, it pulls the component's controller
• if your handle is to a component, it pulls the component from the owner
• if it's a world subsystem, it pulls the world subsystem from the world
• if it's some other actor type it just assumes you want the pawn

imagine if this was documented somewhere beyond just "if you want external data use Get External Data" which never made any sense because how would it know what data you actually wanted... well turns out it just gets set by the state tree component

[echo lark]

External data is anything that matches class of handle and is defined in Schema - GetContextDataDescs(), and is initialized from that schema

for more details need to compile full debug and go in. That is from what I tested so far. It seems like it doesn't care about any specific types. It will just grab whatever is closest match

within hierarchy of classes

What's I dont understand is how parameters work..

and Why I can't bind properties within the same task -;-

[misty wharf]

external data is anything that is set into the state tree by something else, really

because if you ask for a game instance subsystem or something, you'll get nothing because there's no code to populate that into it

in case of StateTreeComponent, the code for populating it is in SetContextRequirements

I've not looked at parameters much tbh, I see there's a field to fill them in if you look at the details of the state tree component but that's about as far as I bothered with them :D

[echo lark]

SetContextRequirements
Yeah handles wont really work correctly if don't set it from schema in some way ; d

I tried to convert State Tree into "utility selector" and it honestly kind of works, without even modifying engine code

Wall I hit is how to create "results" for each actor. I have it working, but UX for it sucks hard 😄

it would be so much easier If I cloud bind inputs/outputs within the same task

or would be able to write into some global parameter from task and read it from other bound property

[misty wharf]

I'm currently attempting to create a state tree task in C++ that would allow me to use AITask_MoveTo or something similar but I'm not quite sure how exactly you're supposed to bind a delegate to the task 🤔

I have it in blueprints but I've noticed with sufficiently many AI's using the task it consumes 1/4th of the entire frame to run them so wanted to see if moving it into C++ would make it perform a bit better

[echo lark]

assuming you are using the default component for State Tree, you can just store delegates inside instance data, it should survive for duration of tree execution.

[misty wharf]

Yeah the problem is more on the side of how do you have the delegate tell the task to finish, or how do you bind to a dynamic delegate to begin with because you can't have UFUNCTIONs in a USTRUCT

[half stone]

what conditions need to be true for AI MoveTo to work? I know for a fact that the node is begin called, I created a navmesh bounds volume and pressed P, the character is set to AIController, but it is just not moving

is there something I'm missing?

[misty wharf]

I would look in visual logger as navigation logs more output into it

Various reasons for it, like trying to move somewhere invalid, or missing a suitable movement component, etc.

[half stone]

by visual logger you mean the visual studio output?

[misty wharf]

no, visual logger

[half stone]

oh I'll take a look

thanks

turns out I was forgetting something, I just had to call SpawnDefaultControlelr at BeginPlay

@misty wharf

[misty wharf]

Yeah it's often something simple like that lol

By the way if anyone's curious about statetree performance BP vs C++ - I had two state tree tasks running on about 60 AIs, getting called pretty often. BP version: 10ms / C++ version: 171us

profiled with Unreal Insights

[echo lark]

Ah ok. In that case... I see only option, which is to rewrite that entire task in C++. It's mostly wrapper around exposing it to blueprint anyway ;

[misty wharf]

Yeah. I looked at some of the builtins, seems the intended way is to just tick the task

I ended up implementing it like this:

EStateTreeRunStatus FShSTT_MoveTo::EnterState(FStateTreeExecutionContext& Context, const FStateTreeTransitionResult& Transition) const
{
    const FInstanceDataType& InstanceData = Context.GetInstanceData(*this);
    if(!IsValid(InstanceData.TargetActor))
    {
        //Target is not valid, can't move to it
        return EStateTreeRunStatus::Failed;
    }
    
    AAIController& Controller = Context.GetExternalData(ControllerHandle);
    Controller.MoveToActor(InstanceData.TargetActor, InstanceData.AcceptanceRadius);
    return EStateTreeRunStatus::Running;
}

EStateTreeRunStatus FShSTT_MoveTo::Tick(FStateTreeExecutionContext& Context, const float DeltaTime) const
{
    const AAIController& Controller = Context.GetExternalData(ControllerHandle);
    bool Moving = Controller.GetMoveStatus() == EPathFollowingStatus::Moving;
    return Moving ? EStateTreeRunStatus::Running : EStateTreeRunStatus::Succeeded;
}

[echo lark]

yeah, seems about right.
Other thing I learned is that Global Tasks/Evaluator are run on tree start until tree runs out of them. Then If you want to run states, you need to tick tree.
And if any of the global tasks return other tree status than Running.. You need to start tree again ;

[misty wharf]

Yeah it's a pretty big gotcha that if your global task returns something else than Running the entire tree just stops

Imagine if documentation existed

lol

[echo lark]

no way. None read it.

Ok I tried, and only learned basic how it work in editor 😄

[misty wharf]

Yeah at least there's a little bit of something

[crystal sequoia]

if I want agents using the nav mesh to be able to walk off all ledges anywhere on my map regardless of height is there a simpler way to do that then adding nav link proxies all over the place? I want my agents to be able to chase a player. When I do use nav link proxies they also seem to slow down and sort of stutter a bit at the top of the ledge before jumping so they are unable to keep up with a human player.

[dusk pewter]

@crystal sequoia you can do a task that detects if there is any walkable area at a certain distance or height and jump off to there regardless of nav mesh

[crystal sequoia]

makes sense, thanks

[halcyon dagger]

If I use nav mesh invokers en I don't need nav mesh bounds any more?

[echo lark]

you need

nav mesh bounds marks where nav mesh can be generated

[misty wharf]

Did you ever figure out what caused this? I just ran into it on a task that had no instance data and seems adding instance data fixed it 🤔 Seems kinda weird that it would force you to have instance data even if you're not using it

[harsh storm]

#gameplay-ai message

https://tenor.com/bVXiI.gif

(No - I didn't ever figure out what caused it, lol)

[misty wharf]

lol yep saw that message also

I guess it just really wants you to have instance data even if it's empty

[harsh storm]

Perhaps.

I haven't used ST since like Jan/Feb of this year though.

[dusky lodge]

How are the Supported Nav Agents supposed to work?

It seems like its only available as part of a NavMesh, but I cant find where you classify a Pawn or AIController as belonging to a particular Agent type?

[keen crystal]

My AI character is setup to possess automatically, however on OpenLevel or RestartLevel, the AI never possess. Any ideas why?

[dense owl]

Should be project settings -> nav -> agents

Sry I realized I misread

[dusky lodge]

I should have clarified, that is what I can find. But how does it relate to a specific Pawn.

[dense owl]

It has to do with the nav agent radius afaik

Which you can change on the CMC

Might be on the floating pawn component too, idk

[dense owl]

#gameplay-ai message

[dusky lodge]

Thats a really weird choice

You would think it was an explicit decision by developers to which agent settings a pawn or the like belongs to.

[dense owl]

Yeah, from what I’m reading, the movement component agent settings are as precise as it gets

[uneven cloud]

The navigation system finds the best fit nav data for the agent properties. It actually makes more sense when you consider games with NPCs of various sizes, but using buckets for nav data. Because of the memory cost, you really don't want more than a handful of nav meshes.

[misty wharf]

Ugh found yet another fun state tree gotcha

if you use GetExternalData and it so happens that the thing you asked for isn't available... it just silently does absolutely nothing. No log info, nothing. Good luck figuring that out if you weren't paying attention to the one line of comments somewhere inside UE's source code that says the state tree won't run if the data isn't there

[ocean wren]

Thought I'd share, skinned skelmesh from Luma.ai text to 3D model (I had a mess last night and this morning)

https://lumalabs.ai/genie?one=e7c71140-ec5a-404d-9d53-4103c762ade8&view=one&metalness=0&roughness=0.95&color=255%2C255%2C255

Thats the luma model, before I import it into accurig for automated rigging

clearly you'd retopo first.. but hey, works alright

[paper sparrow]

What's the most efficient way to make an AI Controller follow a road / path / route? Someone suggested lots of target points that you 'walk to' but that seems archaic to me. Is there some sort of Spline system you can setup that you can reference in a 'move to' or 'follow' command?

[wise sluice]

There is zone graph but let me verify if that's not only available for Mass

https://dev.epicgames.com/community/learning/tutorials/qz6r/unreal-engine-zonegraph-quick-start-guide @paper sparrow

Seems to be only for Mass tho 😔

You would need to use Mass and awake/asleep your AI to move from road to any other behavior

[paper sparrow]

Cool feature! No worries, I'm not using mass, I was hoping for maybe something simpler, like a spline template with a 'AI Follow Spline' command or something

[misty wharf]

I don't think it should be too hard to implement something where you dynamically adjust the point you're steering towards

Eg. you set up a spline which is your path, and then your actor picks a point slightly ahead of it on the spline to steer towards

and you just keep updating that

[paper sparrow]

Not a bad idea actually, yeah could do that, just wondering if there was anything already built-in

[lean cliff]

Hi all,
Once I've Called UEnvQueryManager::RunEQSQuery, am I able to cache and reuse the same return UEnvQueryInstanceBlueprintWrapper object ptr to call RunQuery again to avoid frequent creation of the UEnvQueryInstanceBlueprintWrapper obj? Or does some sort of de-registration happen at the end of the EQS query?

Nevermind, I can literally just bypass all of that and call FEnvQueryRequest::Execute and pass in the callback obj + OnFinished function to call bypassing the need for the wrapper at all, just noticed in my ill state that it's a blueprint wrapper - brain is clearly having a go slow day!

[rapid obsidian]

Hello I am looking for advice.

I am making enemy and minion ai. I got them to attack each other no problem. I created a token system so they can only attack so often.

Where I am confused is how to program how a fight between say 4 enemy slimes and 4 minions should work.

Currently I get closest targets, if he has an attack token available reserve It and attack. But each slime will just get closest and do that. A lot of times they will stand around because they are targeting same opponent. How can I go about getting different opponents? Any suggestions?

[misty wharf]

Maybe you can have some system in place that gives a list of alternative targets if the desired target is unavailable? Or just have a list of available targets and pick from there (eg targets with tokens)

[rapid obsidian]

Yea I was thinking of checking all targets with tokens and choose one with a free token, but then not sure if the AI would just change targets Everytime someone else took their target over and over. I feel like there needs to be some sort of threat or prioritizing or something somehow

[astral sinew]

Hello. Stupid question. Shouldn't Rotate to face BB entry be able to take any BB objects?

[harsh storm]

Not all objects have representation in the world. Click the dropdown and choose a specific type of Object. Like Actor.

I'd imagine the key has a restriction to Actors or vectors.

[astral sinew]

Yep that was it. Thanks.

[minor geyser]

when i use this, it never succeeds, how do i "succeed" it? do i need to put something in the gameplay behavior?

[misty wharf]

If your gameplay behavior immediately returns iirc it won't actually acknowledge it

so your gameplay behavior needs to at least wait until the next tick before finishing, or you need to write a custom version where it works correctly

[minor geyser]

but, what node do i put in the gameplay behavior to finish it? i dont see anything like execute finished for example :X

[misty wharf]

Isn't there End Behavior or something?

    UFUNCTION(BlueprintCallable, Category = GameplayBehavior, meta = (DisplayName = "EndBehavior"))
    void K2_EndBehavior(AActor* Avatar);

at least the code suggests this exists

[minor geyser]

yes! i will try, thanks 😄 totally missed it

[uneven cloud]

There are splines that you can use.

[paper sparrow]

Oh really? What are they called?

[uneven cloud]

If you use C++, you can write your own EQS tests to prioritize your targets in any way that you want. Including threat and token availability.

[uneven cloud]

Spline component

[paper sparrow]

Oh yeah I know about the spline component, I was wondering if there was an AI-specific variant or function you could use to make an AI actor follow a spline path nicely

[uneven cloud]

Not built in, but it's easy to do.

[paper sparrow]

The best thing I can think of is what 'zomg' recommended, continiously take the next point infront of the actor and move there

Ok, if that's the best way to do it then all good, just checking in if there' an alterative way

[minor geyser]

mmm it still does not succeed if i put the endbehavior in the behavior, i set a breakpoint to trap it if it does succeed and it never happens :/

[uneven cloud]

You get the next point when the AI gets to the current point, turn on use acceleration for paths in the movement component and adjust the deceleration speed to smooth out the movement.

[paper sparrow]

Really helpful! Thanks Luthage ❤️

[uneven cloud]

You're welcome.

[pliant ginkgo]

hey, how would i go about improving the performance for large number (300-500) of Ai agents from the CMC?

[harsh storm]

RIP

[pliant ginkgo]

I cannot afford to create my own cmc as the game is multiplayer

[harsh storm]

That's even more reason to make your own CMC honestly

You're going to need to do a lot of optimizations

[pliant ginkgo]

oh, is my only option to make my own?

[harsh storm]

Most people struggle having like 80-100

CMC is not designed for this high count

[pliant ginkgo]

i'd be fine with less accuracy, cmc doesn't seem to have that option tho

[harsh storm]

Navmesh walking movement mode helps some

[pliant ginkgo]

yeah emphasis on 'some'

[dense owl]

Ik you said it’s late in your development but it still sounds like #mass might be the right way

Tho I’ve heard of people faking stuff with HISMs, if you can afford to do that in your use case

Btw my comment about people saying make your own CMC was before you said you’re gonna have 500x of them 😅

[pliant ginkgo]

oh wait that mode, despite having not showed much difference earlier in my development, did just now show quite a bit

brought me down from 50ms to 20ms from the CMC

i'm not aiming for 144fps w/ 500 AI, just "Playable lag", ie 15-25fps

[harsh storm]

What an odd target FPS. But you do you

[pliant ginkgo]

its just an extreme case, the worst the game can get

generally you'd have less ai

[dense owl]

I would also do some profiling to see exactly what else is slowing you down, it’s not always just the CMC

[harsh storm]

Animations are costly as well

[pliant ginkgo]

well that screenshot is right from profiling :P

[pliant ginkgo]

surprsingly, they're not very high up in the list

compared to cmc and some of my code

[dense owl]

Mb my discord’s been acting up not loading screenshots until I restart the app,

[pliant ginkgo]

motherfucker

[harsh storm]

Slate be takin' up a lot of time

(I should probably look into insights more, lol)

[pliant ginkgo]

imagine your hud taking your entire 60fps frame budget 🤣

[harsh storm]

The real reason games like to go hudless, lol

[pliant ginkgo]

its the most basic ass hud too

abusing too many event ticks lol

[potent loom]

How many canvas' do you have merpl

[pliant ginkgo]

one per each part of each widget, eg

[potent loom]

ye

that's ur problem

[harsh storm]

Canvas can be costly

[pliant ginkgo]

id rather make my own cmc than optimize ui 😭

[potent loom]

https://youtu.be/TTB5y-03SnE?t=905

tldr; replace canvas with overlay

[pliant ginkgo]

thanks will do

[potent loom]

but canvas' will absolutely shred performance

also the rest of common ui is pog as well, saves a bunch of time not that hard 2 learn

[harsh storm]

It's so common, they made it a plugin instead of base.

[pliant ginkgo]

i wish i'd come across it 10 months earlier into development lmao

[potent loom]

yeah lol the curse of too many things in unreal 🤣

[harsh storm]

I still haven't really bothered with common ui

[dense owl]

Ik very little about #umg but I did read Cade’s blog about Canvas being absolute shit lol

[potent loom]

this is easier to optimize than the cmc tho prolly

[dreamy star]

Can someone pls help (live prefarabli) we cant get our AI spline to move

We have tried builds 100 builds and it cant be done.

[waxen portal]

does this mean can't be executed in the first 5 seconds?

[dense owl]

It means it will execute once, then fail for the next 5s, then execute again, and so on

[waxen portal]

it wont run the first 5

[dense owl]

Show your tree

[waxen portal]

this one means if not in cone abort or the other way?

[dense owl]

Could it be that the next decorator is failing? Have you hit pause and stepped through the tree?

[dense owl]

It fails if it’s not inside the cone

[waxen portal]

4.45

[waxen portal]

damn goodbye player character is set

[dense owl]

That doesn’t show whether it tried to run the first time and failed

Like hit pause and go back using the arrows

You can also remove the other decorators under it and just put a wait there or something to test

[dreamy star]

Ok so we FINALLY found the problem, but not the solution. There is something with the Spline that cant detect the Level (generated Landscape) but it can detect on a regular plain. Why is that?

[waxen portal]

can i change the brush?

[uneven cloud]

Making your own CMC is a really bad idea. There are lots of optimizations you can do.

[uneven cloud]

You really should profile using a packaged test build. You are going to get very different results when trying to profile via the editor.

[harsh storm]

You pretty much have to make your own CMC for smoother gameplay for a number of things. Because of FSavedMoves. (I should've been more clear on which part I was referring to. The networking portion of the comment. Not necessarily improving perf for the AI)

[uneven cloud]

It can be done and is actually trivial. How are you trying to use the spline?

Every single time I've seen a team do their own CMC, it's always worse.

[harsh storm]

I'm talking about inheriting from it btw. Not a full bespoke custom thing.

[uneven cloud]

That's completely different

[uneven cloud]

Change what brush?

[waxen portal]

da sprite thingy face

[uneven cloud]

Only by editing engine source

[pliant ginkgo]

Do you mean a full shipping standalone or 'play standalone' option in the play options?

[harsh storm]

Not in editor.

So package it up and play

[pliant ginkgo]

But that takes hours

[pliant ginkgo]

I suppose it would be worth it, for unreal insights do I need debug, development, or shipping build? (for getting a detailed profiling tree)

[harsh storm]

Definitely not shipping. But otherwise, I think the others are fine? I haven't used much of insights to be honest. #profiling would know though.

[pliant ginkgo]

I been using the 'Session frontend''s profiler

Oh yeah thanks

[uneven cloud]

A packaged test build. Not in the editor, a packaged game. Not shipping or development, but TEST. Test is the closest you can get to a shipping build, but still has the profiling events.

[pliant ginkgo]

Oh i never noticed a test setting

[uneven cloud]

Know how I knew you were profiling in the editor? Your slate numbers.

[pliant ginkgo]

Ooooh

So its not just due to my event ticks

[pliant ginkgo]

Do you know any way to reduce the time to build down from hours?

It does get significantly faster the 2nd time but the 1st one is too long

[uneven cloud]

You might have non performant UI, but it's unlikely to have that bad of slate issues in a packaged build

[uneven cloud]

When packaging, what takes the longest is cooking assets. So make sure you don't have a lot of unused assets that you are cooking

[pliant ginkgo]

Interesting, I'll filter those out then

[dense owl]

Yeah, extending from the base one makes alot more sense 🙂

[dreamy star]

Hej , we have some issue with landscape and spline . If we remove the landscape and use a plane the spline works in. Build. It always works in all cases in editor tho.

Might be something with collision when the landscape was generated or something with the material function we painted landscape with or maybe something else ... We can't figure out what it is .

[dreamy star]

@uneven cloud Do you have any ideas ?

Its something in the landscape material that has material funcitions, and check the material when AI is moving to make different sounds.

When we build with only a landscape without material it can move, when we build with material and paint the landscape, it moves on the first tick then stops (not visible but we hear the step sounds)

[waxen portal]

Do all the blackboard key get assigned the stuff they should? Relying on random literal names seems bad, how does it know when to put a vector value if I have 9 vector keys

[dense owl]

I don’t understand what you mean.

[harsh storm]

It's just a TMap with FName as the key. So, yes, they get the correct value.

[waxen portal]

Do I have to put the exact same name? Or if typo won't be assigned?

[dense owl]

Yeah, make literal is not ideal, granted, very bug prone to typos. But you prly also shouldn’t have 9 diff vector bb keys

[waxen portal]

Question guys, if I have a selector and the left branch (sequence) is executing, can it jump to the right if it's if it's true or it won't jump unless it breaks?

[dense owl]

Only if it fails

[waxen portal]

so the sound thingy never executes if the actor is not set right

pointless

cant jump

[dense owl]

Correct

You also don’t usually need that second decorator

If not set fails, it means it’s set

There are some instances where you need both tho

[waxen portal]

Gotcha thanks for the help👍

[uneven cloud]

What do you mean that it doesn't work? How are you moving it? You need to give information on what you are actually doing.

[waxen portal]

this is a notify when you land but absolutley nothing happens, any1 know why?

[uneven cloud]

You can make it abort lower priority.

[uneven cloud]

Have they changed it to a TMap? Last I looked it was an array.

[waxen portal]

no i mean its not executing, breakpoint dont hit

[dreamy star]

Usual way, tick and points on spline

[harsh storm]

Gosh dang it Luthage. You did it again. Caused me to actually look at it. It's a UDataAsset with a TArray<FBlackboardEntry> for the actual contents. So, yeah it is still an array. I've always thought it was a TMap because the way you work with it was very map-like.

FBlackboardEntry has the entry name as an FName. And a TObjectPtr<UBlackboardKeyType> for the type.

[harsh storm]

That's not much information for her to help you. You need to describe how you're doing things in a lot more detail. The less you want to type, the less of a chance someone will be able to help you.

[uneven cloud]

There is no such thing as "usual way." There are lots of ways to do things.

[uneven cloud]

Yeah. That's what I remember. If you use the key ID instead of FName, it's constant access to the array instead of iterating through it.

You can get the key ID from a blackboard key selector.

[misty wharf]

Anyone played around with customizing pathfinding? I'm trying to see if there's some way to make actors prefer moving only in cardinal directions

I tired setting up a query filter which increases cost on paths the more they diverge from directly on X or Y axes but it doesn't really seem to have an effect

[dull harbor]

so im making a game (blueprint) with chasing ai, but for some reason the ai likes to chase the other ai instead as well???

it likes to make clusters of ai

especially at like 0:49

for now it goes to enemies and neutral but:

• switching to enemies makes it chase nothing
• the ai doesnt have their own stimuli

trying to follow this tutorial: https://www.youtube.com/watch?v=R87HO3PeIso

[lyric flint]

how is the targeted char selected?

@dull harbor

[dull harbor]

hopefully you can read that

this

this is update actor bbkey

[dreamy star]

I'll attend later , not är the computer and the logic is not the problem, the problem is described and seems to be a unreal thing or a setting that we missed for physics materials

[lyric flint]

my guess is that they keep getting "distracted"

[dull harbor]

i guess so, by themselves

which is weird cuz i thought they needed stimuli

[lyric flint]

there's a way to make them respond to certain actors only but i cant remember it rn 🙂 , give me a minute pls

[dull harbor]

i swear ai was easier in 4.26

[lyric flint]

you'd need to make use of this

[dull harbor]

this is how it should work

[dull harbor]

yes but it doesnt know that im an enemy of them

they think im neutral

[lyric flint]

yeah, give me 1 more minute pls 🙂

@dull harbor

u can define it only in c++ it seems

[dull harbor]

why 😭

this is so mean of epic

[south ferry]

you can use LowEntryExtendedUtilities plugin

[dull harbor]

whats that

[south ferry]

they exposed the functions to set GenericTeamId

[lyric flint]

u can also use this i think

and just check the classes

[south ferry]

affillation detects based on the IGenericTeamAgentInterface

[lyric flint]

with for each loop

[dull harbor]

oh thank goodness

[uneven cloud]

If you aren't using C++, then you can't use the team interface that the perception system uses. That means you have to filter targets yourself.

If you don't want the NPCs to be perceived at all, you can disable auto registering pawns in the ini and add a stimulus source component to your player.

[south ferry]

default is 0 = neutral

[dull harbor]

how do i disable auto registering

[south ferry]

=/= is hostile
== is friendly

[dull harbor]

whats ini

[lyric flint]

a config file

[dull harbor]

oh...

those 😨

[uneven cloud]

https://forums.unrealengine.com/t/how-to-make-a-pawn-stop-registering-with-ai-perception/368928/2

[dull harbor]

lets hope this works 🙏

[south ferry]

https://www.unrealengine.com/marketplace/en-US/product/low-entry-extended-standard-library

with the plugin you can set those team id

[dull harbor]

no they still cluster oof

[dull harbor]

should these also be numbers

[uneven cloud]

Did you restart the editor after changing the ini?

[south ferry]

yes, 0~65565 only however

[dull harbor]

yeah

[dull harbor]

so... is:
undefined = neutral
0 = enemy
1-65565 = friend

??????????

[uneven cloud]

No. The default affiliation is team id != Other team id

[dull harbor]

oh ok makes sense

[south ferry]

0 = neutral
team id != other id > hostile
team id == other id > friendly

[dull harbor]

ah

cool cool

[dull harbor]

gonna try this see if it works

so should i set the team id of the ai to 2 and the player to 1

[karmic pelican]

how can I keep updating the AI MoveTo with the EQS??

it updates the EQS, but the AI moves to the location it set before updating

[dull harbor]

ok uh @south ferry so i set them to only follow enemies

and i put first person character team id to 1 in construction

and ai team id to 2 in construction

still doesnt work tho

[karmic pelican]

nv, fixed it, my bad

[dull harbor]

cc @uneven cloud @lyric flint

now they just dont follow

[lyric flint]

with blueprints, i'd just end up utilizing that node

[uneven cloud]

I've never used that plugin, so I don't know if or how it adds the team interface to the player

[lyric flint]

@dull harbor what do u have that set to?

[lyric flint]

also u might wanna try doing that on begin play

just in case

i'm unsure how it's supposed to work though

[dull harbor]

changed to this

[dull harbor]

same thing

[lyric flint]

make it set to neutrals

as well

just don't have friendlies detection enabled

@dull harbor

[south ferry]

i just remembered something

only AAIController has IGenericTeamInterface implemented by default 🤦‍♂️

so it wouldnt work without c++ anyhow

[lyric flint]

so the only option would be making use of this node I'm guessing?

@south ferry

[misty wharf]

The fact AI controller implements that by default is kinda confusing

[south ferry]

yea

[misty wharf]

It literally cannot work without implementing it on a pawn

[south ferry]

since it sense the pawn..

[misty wharf]

because perception system doesn't consider what the controller implements

yeah

[dull harbor]

waaaaaaah

so can i detect if its a player or something

[lyric flint]

no...

[south ferry]

ye so you have to detect neutral, from the array of perception, either use casting or actor tag to differenciate between player or ai

[dull harbor]

ok hmm

[south ferry]

this-to

[lyric flint]

u can also check (equal or whatever) the class (would be much better than casting)

[dull harbor]

how would i just check if the actor is a player

jeez this was supposed to be easy

[lyric flint]

use this

with for each loop

[south ferry]

they are both fine

you can do the checkings on the Actor reference

[lyric flint]

i should probably silence myself as idk how these events actually operate 🙂

[waxen portal]

do an ==

[misty wharf]

target perception update is probably easier to use

just cast the actor to your player class

and check stimulus' successfully sensed to determine whether sight was gained or lost

[south ferry]

also casting isnt so bad if the class is already loaded somewhere else in the game
casting is only bad when it loads an entire class unintentionally or having too much dependency

[waxen portal]

if true select player otherwise none

[south ferry]

if you dont want to care about classes, then use actor tags to differenciate them

[dull harbor]

nothing happens after

ah

this works

yay 🎊

[uneven cloud]

It can. You just need to override a function.

[dull harbor]

now these ai are really scary lol

they can use chase you and use doors and are fast 😨

in the 4.26 version they could open doors cuz doors kinda sucked

i wonder if i can have an ai tell the other ai in a certain area where the player is??? but this would kinda suck if there were multiple players

[south ferry]

you still can do that though, the ai just tells which player it is looking at (what is my target)

[lyric flint]

what would be the best way to implement broadcasting to nearby AIs like that?

with a collision box?

or maybe a multitrace?

[dull harbor]

why are they green guys instead of devils

huh

[misty wharf]

Oh? Which one? I was looking at it a while back and don't think I saw anything other than "implement this on the pawn and call the functions on the controller"

[dull harbor]

maybe each ai could have an array of actor locations (with max ages)

would be so complicated

and i kinda dont need to worry about this right now heh

[south ferry]

either a trace or a hearing sense

[whole tangle]

Hey there, I was wondering, is it possible to tell an AI character to jump, and to have some relatively fine control on how said character is jumping?

[dense owl]

The same way you would do it with a player, I’d imagine.

[uneven cloud]

One of the functions on the team interface. One of the get affiliation for functions that takes in an actor. We use the pawn, because we need the team id replicated, but in the past I've just used the controller.

[dull harbor]

what are all these voice channels for

are they just general

[dense owl]

Please stay on topic

[dull harbor]

i was gonna screenshare my ai

lol

[dense owl]

Better you just screenshot and explain the issue

[misty wharf]

Pretty sure the object it's sensing (eg. the pawn) needs to have the interface, because how else is it going to know what to call because I'm pretty sure it doesn't try to GetController() from it and check whether that implements the interface 🤔

[whole tangle]

The only thing I could find was a Jump() method on ACharactor, I'm trying to find if there's any other method than that to do it.

[uneven cloud]

It calls the interface function on the listener, which is the AI controller

[dense owl]

You could prly make your own jump function if you really wanted to, but it’s not going to be any different if you did it with AI or player

[dull harbor]

his name is carl... he is mean

[misty wharf]

Correct, but it compares it to the sight target which is the pawn

[uneven cloud]

It calls a function on the interface that sends the pawn. You can override that function and get the controller instead.

[misty wharf]

hmm

yeah I guess if you override GetTeamAttitudeTowards on the controller that's doing the sensing and have that cast Other and get the controller from it that would do it

It just feels a bit backwards that the one that is sensing needs to deal with that :D

[whole tangle]

If I wanted to turn off gravity for my agent, what would I do? I couldn't find a good way to do it online.
(in C++).

[dull harbor]

cant you just use the viewer and do it from there?

the viewport

[misty wharf]

Depends on what the agent in question is

If it's a character you can turn off gravity from the CMC

[whole tangle]

Yeah, that's what I found out, thank you!

[karmic pelican]

how can I keep the AI to move to the updated location??
the AI will fire only when the point is reached

what happens, the AI sets a location and goes to it
when the EQS updates, the AI will remain moving to the first location until reached

I instead, want the AI to move to the updated EQS location and on success we do the rest.

any ideas?>

[uneven cloud]

In the move to node there is a setting for observing blackboard changes. You need to set it to do that and set the tolerance.

[karmic pelican]

thank you!

[karmic pelican]

this is never going into the sequence, why??

[harsh storm]

Because it's under a selector and the task is succeeding, so it doesn't need to go to anything else.

[karmic pelican]

Ohhhh. My bad..

That's embarrassing

thanks

yup, all working well

[rapid obsidian]

This is what I am thinking on how my ai choose and fight other ai. Any thoughts on this?

Basically I got minions and Enemies. Slimes and stuff.

So if I have 5 minions fighting 5 slimes I want it to flow and look good. not just them all jump on 1 thing

[dense owl]

any idea why this would be happening? the AIMoveTo always returns success when really it prly shouldn't considering the path is never resolved

[rapid obsidian]

maybe because of partial path?

[karmic pelican]

what's the best way to deal with enemy reaction time??
the enemy will only be able to attack when the reaction time is >= 0 and we will stop reducing.
if not, we will keep failing and reduce the reaction time

was thinking with a service, but not sure how would I make it to fail within the condition?

[uneven cloud]

Please explain better

[dense owl]

I’m pretty sure I’ve tried it with both AI MoveTo and move to location or actor with partial path turned off, and still same. I’ll double check when I get back on

It can’t seem to project to the navmesh for some reason

[uneven cloud]

Your vislog log says it's a partial path.

[dense owl]

Ok, so if i try move to location again with accept partial path off, it should return fail, I imagine. I still need to figure out why it can’t find project to the navmesh though

[jagged verge]

Hi, I'm trying to make that AI Enemy able to avoid bullet(slow speed) by running EQS and MoveTo the location.
But Query doesn't get score from bullet actor's distance.
For Bullet Context, I just set Cast BP_Bullet. How could I make it?

also, I try another way like this. but AI Character only come to bullet actor

[karmic pelican]

I got it working
Reaction time says to the AI when to attack when it reaches 0
I ended up doing it in a service and a decorator
Service to reduce the reaction time until 0
And the decorator to check if it's >=0

And it worked well

[karmic pelican]

Try setting the bullet to the ground and see if anything changes

[jagged verge]

I tried it and nothing changes.

It's the Bullet Context node

[misty wharf]

That's never going to work unless the actor performing the query is a bullet

Note that the parameter is name is Querier Actor - the actor which is performing this query

[rapid obsidian]

for me i got the querier actor's blackboard and got the actor i set as target

but mine is for AI not sure about yours

[dense owl]

still need help figuring this out. Like yeah, it fails if I don't allow partial path, but this doesn't tell me what's wrong with it other than it can't generate a path.

I've tried diff move to nodes, diff AI Controller classes, testing the navmesh on the landscape vs on a mesh, using actor or location as a goal

[uneven cloud]

You need to give more information on what is failing. Add some vislog debugging, such as showing the start and end points.

What you are trying isn't going to tell you what is wrong. You need to actually debug it and not try random things.

[dense owl]

ik that lol, I initially showed my vis log

sec I'll get one with something other than AIMoveTo

[uneven cloud]

You did not add any of your own logging.

[dense owl]

ik you mentioned that before but I couldn't find how to do that in the docs, is it the cpp functions they mention?

[uneven cloud]

There are vislog BP nodes. Just search for vislog.

[dense owl]

oh, right, doh 🤦‍♂️

ty

[uneven cloud]

Start with doing vislog location for the start point (pawn location) and end point. It says that it can't project the end point, so showing the end point will likely show you exactly why.

[dense owl]

yeah, I added a vis log location with 50 radius and it's not even showing anywhere on the map, I gotta figure out what's going on lol

[misty wharf]

Anyone know if there's some particular reason StateTreeRef in UStateTreeComponent is not settable? As far as I can tell there is nothing in there that wouldn't allow switching it at runtime

(Looking to reduce my boilerplate a little so I could define the default tree in my pawn and the controller would grab it from there instead)

[dense owl]

I tried setting the Z to 0 as well, so the sphere is even lower on the mesh just in case

but now with move to location or actor I don't even see anything in the vislog about the actual pathing, only these redirects

I don't get this, I've made AI before with no issues 😅

ah ffs

I thought about this before but I didn't actually try it... 🤦‍♂️

Had to add a delay until next tick between the line trace I'm doing and the actual moveTo node

weird tho, it's not like I have to wait for the line trace to get the vector, I'd tried it with fixed vectors too

running this onPossess btw, so not like it's a BeginPlay issue 🤷

[misty wharf]

Hmm, it's kinda looking like state tree doesn't really have any mechanism of easily waiting for a task to finish, and then performing another task based on the finished task's data 🤔

Eg. you have a task which runs an EQS query and you want to use the result of it in another task - how are you going to do that? You can only link task parameters into tasks in parent states, but you have no way of determining whether a parent state's task has finished.... because if the parent state's task actually ever finishes, it causes the entire state to finish immediately

So it seems you either have to do all this work up front, or you have to keep retrying until the data becomes available, which you determine via some other property

[dense owl]

idk why I had to add a slight delay after Event Possessed for the AI to be ready to move (maybe bp too slow?), but it's not like I need it to go as soon as the game starts. the vislog nodes are def helping troubleshoot the path issues, thanks @uneven cloud 🙏

[misty wharf]

Hmm so there is an actual example in the engine source of how a delegate can be used within statetree tasks 🤔

It seems to suggest if you want you can write into instancedata in the delegate through the struct ref

It also unregisters the delegate if it's still valid in ExitState as one might expect

(this is in FGameplayInteractionSyncSlotTagTransitionTask if anyone is wondering)

[karmic pelican]

is there a way to run the generator on the right if the left one is valid?? (by context)

[misty wharf]

afaik the additional generators only run if the previous ones produce no results, so that would be no

[karmic pelican]

alright, thanks

[foggy sequoia]

What Have I forgot to do Cant seem to set to Target Actor

[dense owl]

Expose the variable

[foggy sequoia]

dont see any option to do so

[dense owl]

How are you setting this target, inside a task?

[foggy sequoia]

from the Ai controller

[dense owl]

Show code

[foggy sequoia]

cant atm playing BG3.

I will get back to this tommorow thanks anyway :L)

[mortal spoke]

Can I use multiple sights on a perception component or is this not allowed?
When I use second sight, it seems to not be registered

[dense owl]

sights or senses?

[mortal spoke]

sight, wanted to do two different configs (e.g. one for noticing for combat and one for stealing)

[misty wharf]

Two sight configs on same perception component won't work

You can add a second perception component and give it a different config

[mortal spoke]

Thanks, will check that out.

[rapid obsidian]

on possess happens before begin play so it needs a delay i just found this out too

ive never even heard of vislog i needa learn that

[dense owl]

I thought it was the opposite - well, the point is usually you want to wait for possession before doing anything, hence why OnPossess is preferable over begin play

[dense owl]

Tools -> Debug -> Visual Logger

[jolly lotus]

Does anyone know how to use FindPathToLocationSynchronously()? What is the WorldContext UObject first parameter and PathfindingContext supposed to be?

Also wondering do people generally follow the public/private split or just put all their code in one directory?

[flint matrix]

Hey folks, why doesn't State Tree component start its logic when you add it to the AI Controller instead of the Controlled Pawn?

Also why doesn't the State Tree enter/exit state debug feature work in 5.3.1? I can't figure out why the button is there, but it doesn't function.

[stoic cove]

Hello. I'm trying to get navigation mesh invokers to work. Followed several tutorials but for some reason my AI does nothing. AI works perfect with a normal navigation (non-invoker) volume. When using invokers pressing P also does not show the green nav mesh. But I guess this is logical as navigation only gets generated on runtime? Question still remains why my AI doesn't do anything? Is there a way to see the generated nav mesh on runtime?

Wait, ok so I reverted everything back to static, disabled invokers and now my navmesh doesn't work anymore either?

Everything worked perfectly fine before switching to invokers? What is going on? 🤔

[foggy sequoia]

OK, Anyone know why I cant select my target Variable here, Cant even see any option to expose them?

Strange AS my EQS can use it.

[jagged verge]

Do you mean that I need to make That Bullet's Behavior Tree ?

[jagged verge]

Thank you! I will try it!

[foggy sequoia]

nvm I just Made My Own, as the inbuilt one seems to have an issue.

[jagged verge]

I solved it. I use Get actor of class then it has affected. Thank you!!

[terse panther]

key type for you Target should be an Actor

[terse panther]

you can also use Focus/SetFocalPoint

[minor geyser]

when designing a generic BT to handle the most common NPC tasks, is it best to try to keep it all in one BT or should I have a "core" BT which then runs smaller BTs which are just for specific tasks? if that made sense :X

[dense owl]

Your use case generally gives you that answer on its own. If you have shared behaviours, you’ll likely end up breaking it down into subtrees so you can reuse things without duplicating entire trees

You can always start with one tree and make your way from there, refactoring is inevitable anyways

[minor geyser]

I see, I will start making some smaller BTs for individual tasks rather than trying to make just one big BT and see how it feels. I already have a robust BT for the common tasks, my problem is getting the BT to go "back" so it can start with another task earlier in the tree as it just wants to move right, this problem is easily fixed by just splitting it into smaller trees though. Do the BTs share a blackboard if they are all on the same aicontroller? that would massively streamline things

[dense owl]

Yeah, in fact you have to use the same blackboard for subtrees

Otherwise it’ll yell at you 😀

[minor geyser]

cool! i will have a play around, thanks for the info!

[uneven cloud]

Why are you directly using find path instead of the built-in functionality? A world context object is anything you can get the world from, such as an actor.

[jolly lotus]

You're saying there's an equivalent class functions for actors?

[uneven cloud]

Unless your project only has a few files, organizing your files into directories is incredibly important.

[jolly lotus]

Yeah I do organize in directories, but don't find a lot of value in private/{dir1} + public/{dir1} vs one set of folders other than unreal seems to expect the first way

[uneven cloud]

I don't understand what you are asking. Actors have a function to get the world.

[jolly lotus]

What do you mean by built in functionality?

[uneven cloud]

Most projects I've worked on has used the public/private directory set up. It's more for larger projects.

[uneven cloud]

If you are trying to make an AI move there are better ways to do it. Like the AI task or the function on the AI controller.

[jolly lotus]

I see, yeah that makes sense.

This is actually to find the distance to different players before I move though, to make the decision on who to target

[uneven cloud]

You can see the nav mesh during runtime by hitting F8 and toggling it on/off using P. F8 toggles simulate mode.

Delete your recast nav mesh actor (not the bounds volume) and rebuild the static nav mesh.

[dense owl]

EQS tests

[uneven cloud]

You rarely need to get the path length for target selection. Go with the simplest version of distance first.

[jolly lotus]

Ok thanks

[half stone]

Hello, I have multiple types of enemies in my game. I'm trying to make animation blueprints in a reusable way. I already made the ABP for the melee enemies and now I'm trying to use basically the same blueprint just with a different skeleton and animations for the ranged enemies. Is there a way for me to do that? I tried creating an animation template but I couldn't find a way to change the animations. Do you guys know a smart way to do that so I don't have to basically create the same state machine and variables in another ABP?

[misty wharf]

Probably a question for #animation

[half stone]

you are right, I didn't find the animations channel

thanks

[dense owl]

We need a Luthage appreciation day 😀

[misty wharf]

Somehow this channel gets a lot of animation questions so you're not the first one lol

[half stone]

now I might be stupid here but I can't see an animation channel

it shows up if I click on your link but I just can't find it otherwise

[misty wharf]

🤔

[dense owl]

Server settings check all categories

[misty wharf]

It's in the Content Creation category, yeah maybe you got it hidden somehow

[dense owl]

The naming of those categories is… lacking

[unkempt pulsar]

Any way to make certain AIs not use navlink proxies? I want them to not use navlinks in their pathing

[uneven cloud]

It is actually my birthday today

[karmic pelican]

I do not want this to generate here, since the actor on the right is out of range

but generate here since the actor is in range

is it possible?
or should I make a custom generator in cpp? making the actorsofclass does the cone?

[dense owl]

Oh! Happy Birthday!! 🥳 🎂

[karmic pelican]

happy bday!

[uneven cloud]

What is it that you are trying to do?

[karmic pelican]

I do not want to generate an EQS if the target projectile is out of range
I'm just trying to make the AI to evade incoming projectile coming their way

[misty wharf]

iirc you can mark the links as some nav area type, and then use a navigation query filter that excludes those area types

[uneven cloud]

Then you should make separate EQS. Then do a sequence of Run EQS tasks.

[karmic pelican]

so make an EQS to detect, if valid, run another EQS for the Cone?

[uneven cloud]

Yes. The first one puts the projectile into a blackboard key that the 2nd one can use as a context.

[karmic pelican]

okay, thank you

like this?

[waxen portal]

can i set/ get vlaues of a blackboard from the character bp?

like for making ai go to where the player see or smth like that

[dense owl]

As opposed to just doing it from the tree ?

[terse panther]

Better to get the reference of the player inside the Aicontroller and do there

Or directly from bt

*in bt

[waxen portal]

makes sense

[waxen portal]

yh basically get actor from class and get the event and feed the params

[rapid obsidian]

You can use get player character node, use an interface, cast to player all kinds of goodies

[harsh storm]

Happy Birthday Luthage. Thank you for always sharing your knowledge so willingly and especially thank you for always making me double check the code itself. I highly appreciate you 🥳 🥳

[hollow bluff]

Does anyone know how to increase the avoidance distance of moving ai actors (RVOAvoidance or detour) without making the character capsule bigger?

[dense owl]

Try increasing the agent radius in the CMC

[hollow bluff]

this?

sadly had no effect

if I make the character capsule bigger things work perfecly

but than they don't fit through doors

[dense owl]

Hold on

There’s a couple of settings under the RVO avoidance

Did you try changing that consideration radius

[hollow bluff]

yea I did

but I think it is just the radius in which range it considers other actors

not the actual avoidance distance

[dense owl]

And the weight?

[hollow bluff]

tryed some values but anything other than 0.5 just had weird results

[dense owl]

lol comments

[dense owl]

The 1st and 3rd have the same exact comment

/** The scaled collider radius to consider for RVO avoidance **/
    virtual float GetRVOAvoidanceRadius() = 0;

    /** The scaled collider height to consider for RVO avoidance **/
    virtual float GetRVOAvoidanceHeight() = 0;

    /** The scaled collider radius to consider for RVO avoidance **/
    virtual float GetRVOAvoidanceConsiderationRadius() = 0;

[hollow bluff]

how would I change the Radius without making the collider bigger 🤔

I use mostly bp, would I need to do this in cpp?

[dense owl]

idk if you can. Tbh I know very little cpp, but looking at the overrides in the CMC, it looks like that is directly tied to capsule size

float UCharacterMovementComponent::GetRVOAvoidanceRadius()
{
    UCapsuleComponent* CapsuleComp = GetCharacterOwner()->GetCapsuleComponent();
    return CapsuleComp ? CapsuleComp->GetScaledCapsuleRadius() : 0.0f;
}

[hollow bluff]

could I just put in some other value for the CapsuleRadius or would this require me to compile the engine from source?

because right now I am just using the one from the launcher

[dense owl]

Yeah, not sure if you can do it otherwise. There's the AvoidanceConsideration one that's not being overridden and is the one exposed in the settings there, but I can't tell what the diff is between the 2, I think maybe that one is used for rotation?

There are smarter people in here that might know if there's a way to change this otherwise 😅

You can try DetourCrowdAI instead (turn RVO off) see if that works better for you

[hollow bluff]

I think consideration radius is how far the character to avoid can be away

but I need the GetRVOAvoidanceRadius to be bigger as it seams to be t5e actuall distance they keep

[dense owl]

but afaik to make either of these options work smoothly, you need to go into cpp at some point

[dense owl]

yeah, that might be it

[hollow bluff]

@dense owlI think I just found the dumbest solution ever...
I thought what if it only runs "GetRVOAvoidanceRadius()" at begin play. Than I can make the capsule big by default, and than after some delay make it small again and it still uses the big radius. As dumb as it is it seems to work 😆 Thanks for the help 🙂

[dense owl]

I won't judge haha, just hope it doesn't break other things.

[hollow bluff]

yea me, too 😅 for not it works like a charm but if I end up with any other issues I will have to look into a cpp fix

I just don't want to have to compile the whole engine just to change one float value 😅

[dense owl]

it might not be necessary to do all of that, but I'm afraid I don't know have that know-how 😅

[hollow bluff]

same here

[uneven cloud]

You're going to have a lot of problems doing it that way. From what I remember, detour had more things you can tune.

[hollow bluff]

sadly I can't figure out how to tune the avoidance radius

[dense owl]

hehe, I had a feeling Luthage would know we're doing hacky shit 😄

[dense owl]

try the DetourCrowd AI instead like she suggested, might work out better. Turn off RVO when you do

[hollow bluff]

I already tryed both

but cant find avoidance radius for detour, too

[dense owl]

I think that uses actual collision

you could try adding a fat sphere/capsule to your char that ignores other objects

[hollow bluff]

I did that too but for some reason it just ignored that collison for moving even if set to blockAll

[dense owl]

I'm having a hard time reading through it but it looks like it's doing a lot more complex calculations than RVO

[exotic narwhal]

Hi, I have a question about the decorators of the behavior trees.

TL;DR - Is there any way to "short-circuit" the decorators?

I'd like to abort the lower priority tasks when all 3 decorators return success. Setting like this works, but the problem is the last decorator (Can go straight to) is rather expensive, so I want it to be executed only if the prior 2 decorators return success. Right now it runs every tick no matter the prior 2 returned fail or not. Is there any way to do this? I tried turning it into a composite, but no luck. I know it can be done if I make a new decorator that combines those 3, but I want them to be separate, as they can be used separately elsewhere.

[uneven cloud]

No. You need to make one decorator

[uneven cloud]

How small is your capsule?

[exotic narwhal]

😔 OK... Thank you for answering. Just one more question, at least is there any way to call another decorator inside a decorator or do I need to move all the nodes of those 3 to a blueprint library and make them to call the ones in that?

[uneven cloud]

There is no way to call a different decorator in BP.

[exotic narwhal]

Got it. 😂 Thank you for answering!

[ancient wedge]

Hey guys, what would be the correct way to replicate the focus to the ABP? We want the character to look at the head location of the focus.

[fresh vortex]

Hello. I'm trying to create a simple rts (base defence game). I'm rather a beginner when it comes to blueprints but i want to optimize the game as much as i can. So far I'm having issue with AI tanking the fps rather quickly. Having 18 AI drops fps from almost 90 to 40. Im only telling the units to move to specific location and attack building - I think i have most of the stuff on timers instead of ticks. Is there something else i can do to save performance (like some simplier navigation method or something?).

[wanton compass]

It's most defenitely not the navigation on its own. I've used up to 20 AIs with CrowdFollowingComponent on my dev scene with no major issues.

If you call the path following once at the start of your procedure, then the path is calculated once, and then the pawn just follows along. Unless you re-calculate path on tick there should be no issue with that.

[fresh vortex]

@wanton compass Thank You. I'll look into it 🙂

[wanton compass]

If you have any performance issues in general, I highly recommend using Unreal Insights to diagnose them https://docs.unrealengine.com/5.3/en-US/unreal-insights-in-unreal-engine/
It looks scarier than it is in reality 😉 The pre-built .exe should be located in your unreal installation directory

[fresh vortex]

@wanton compass Thank You again. I don't mind it being scary! It looks like debugging tool from Unity 🙂

[wanton compass]

Does anybody know, how to combine Navigation Invokers, with a simplified pre-baked pathfinding for the open world that would support them?
When I enable "Generate Navigation Only Around Navigation Invokers" I can't pre-build the navmesh in "NavMeshBoundsVolume". When I disable it, the Navigation Invokers stop working for me.
Is there a way to combine those approaches or are they incompatible by design? If so, how do I avoid my actors with NavigationInvokers getting stuck in dead ends?

[celest python]

Timers are not an answer to tick being slow btw

Related read: https://intaxwashere.github.io/blueprint-performance/#2-use-timers-instead-of-tick

[wise sluice]

Probably having two layers of navigation
One for long travel and one for detailled travel (the navmesh)
They are talking about that in the Death Stranding GDC

[fresh vortex]

Aaaa, why it's never easy 😄

[wise sluice]

But yeah invokers are for dynamic navmesh while prebaked is with the static option 😦

not sure about the static + dynamic option tho

[hollow bluff]

22, is best at representing it's size to fit though small spaces. But I want them to keee some distance from each other, it looks best with a size of 60. But than they don't fir though doors

[wanton compass]

As unfortunate as it is, I need to have access to dynamic navigation, since the enviornment in some places changes based on player action in an unpredictible manner (I'm not able to narrow it down just to few static layers that I could toggle between)

If static navmesh is trully unavailable for Invokers then the only thing that comes to mind is inplementing a custom node system for long-distance travel for NPCs (along the roads for example)
Are there any premade solutions for that?

Plugins are fine too

[celest python]

Blueprint only life is not easy in general, while C++ continuing to be a pita since 1998 too 😄

[fresh vortex]

So it's bad either way :d

[knotty kiln]

Hi guys. I am working on a project with a particularly large map in UE 4.27. I was wondering what is the best approach for the navigation for a large area with many AI. I read about Navigation Invoker's but I have some questions in mind. I am trying to keep the project as optimized as possible so I was wondering, would it be better to use a one large static Nav Bounds Volume or a dynamic one with invokers attached to the AI/player?

[versed maple]

You can make services that check the three things in the order you want and then activate a single Door decorator

[fresh vortex]

@eren I've managede to increase my fps from 20 units on screen at 18fps to 120units at 35fps 😄 Thanks for the help. I still wonder what would be a better solution to this 'set timer' - with the current red line connected, the fps still drops from 44 to 35 at 120-140 units on screen. Without the red even connection, it barely drops by 1 fps. I don't know how i could optimized it :/

[celest python]

You should profile

https://docs.unrealengine.com/4.26/en-US/TestingAndOptimization/PerformanceAndProfiling/UnrealInsights/

you're also likely measuring your fps on editor

[knotty kiln]

a 1 sec timer wont affect your performance that much :0

[celest python]

shipping build matters when it comes to BP

Editor build is 10x slower than shipping

[fresh vortex]

I see

[dense owl]

Always good to do actual profiling, as much as Eren’s blog says timers can be expensive, it doesn’t mean that’s what’s slowing down your game right now

[celest python]

timers can be expensive
timers can be more expensive than a tick call*

but still true

[fresh vortex]

I'll do the profiling then. I already gained a huge amount of performance just by removing one of the timer events. I'm also very early in the 'development' so I'm not sure how much i should worry about optimization - just the fact that i can have 120units now instead of 18 is a huge win. Thanks guys for all the help/feedback 🙂

[celest python]

Always profile on lowest common denominator at early stage

Performance comes from design, not from having tick/timer/other in different forms

And you're mostly bound to whatever BP exposes you when you want to optimize, for example default CharacterMovementComponent is most common overhead in the UE so far (and its not a thing you can optimize without deep C++ knowledge)

So you should do a wide research while profiling constantly and carefully structure your project

[fresh vortex]

Thanks, I'll try - i take since BPs performance can be so bad in editor, it's better to do all the profiling in the build? There's just soo much to learn at once. Every time i fix something, two new issues appears :d

[celest python]

Yes, set packaging mode to shipping in project settings

then package your exe

and profile with insights

you can also read the rest of the article that I've sent

(when you have time, because it wont provide an immediate information)

[fresh vortex]

Aye, i glanced through it quickly to find the things I was doing in my BPs wrong, but i will definitely dive deeper into it later on 🙂

[uneven cloud]

Via the character. Cache it off to the character anytime focus changes. Then replicate that variable.

[ancient wedge]

okay, thanks. Wasn't sure if that was the way to go 🙂

[uneven cloud]

How much smaller than your mesh is that? Can you show a picture of your character in the bp?

[uneven cloud]

The controller and the ABP do not replicate, so the character is the only way to do it.

[uneven cloud]

The only way you can optimize is to know what is causing problems. You do that by profiling a packaged Test build using insights. If you don't profile, you can only guess at what is slowing down.

[hollow bluff]

the small collider works well for normal walking around and fitting through doors. The big one makes avoidance look good so they arent all cluping up when running after you

[uneven cloud]

Why do you need invokers? It's the most expensive option. Modifiers only allows you to have a static nav mesh and then can cut the nav mesh with modifiers, but can't build new areas. Dynamic allows you to build the nav mesh at editor time and it only builds during runtime when the geo changes.

[uneven cloud]

When they are running after you are they all trying to go to the same place? The best way to keep them from clumping is to use the EQS to spread out the destination and detour to keep them separated while moving.

[ancient wedge]

Makes sense

[hollow bluff]

the destination is already a circle around the player, but that only spreads them a bit after all they need to reach you at some point, but for example when running around a corner they stack up again.
The result is perfect when detour our avoidance have a bigger radius but is seams like you can not increase it without making the capsule bigger, which is too bad ;/

[uneven cloud]

There's a lot wrong in that blog post.

[dense owl]

Hehe that sounds much better than using random point in navigable radius 😅

[uneven cloud]

Well yeah. They can be smart about where they go. Like preferring the same heading (dot product) or not going past the target (dot product).

[hollow bluff]

like shown here by NeoExidious the AvoidanceRadius is hard coded to be related to capsule size

[dense owl]

In RVO

Idk about Detour

Idk enough cpp to decipher the math they’re doing there, I just saw it was complex

[hollow bluff]

pretty sure Detour also uses capsule size

[uneven cloud]

Detour has more things you can tune, but it's been a long time since I used it.

[hollow bluff]

are these the settings?

because I had no luck tuning/ understanding them 😅

[dense owl]

Ah right I forgot they have them in settings

[hollow bluff]

I already cranked up max agent radius and my agents radius inside movement comp and it changed nothing

[dense owl]

But also like turn up that brightness 😀

[uneven cloud]

Invokers are the most expensive options and can cause navigation bugs. The best option is to use level streaming for the nav mesh. In world partition, the nav data is broken up by the world partition grid and streamed in with it.

[hollow bluff]

so many settings and nothing as simple as just the radius to avoid 😔

or maybe there is but I dont really understand what all of the parameters mean. I can also not find any documentation on the parameters

[uneven cloud]

Shipping compiles out the profiling markers. Test is what you want.

[celest python]

Like?

[celest python]

Hmm, yeah recently tried to run insights on shipping and didnt get anything.. And was asked here if I was doing something wrong but didnt get any answers. Maybe related?

[uneven cloud]

"Everytime the Blueprint VM evaluates a function, it just runs a code to invoke the C++ function." This section is pretty misleading. Someone on my team went through the code that BP uses to add to a variable. Get, add, and set. It was several PAGES of C++ code.

[uneven cloud]

Yeah that's why. Test config is just shipping + profiling events.

It is several pages. I'll look at it again today to see what exactly it was doing.

Hah. Didn't realize you wrote that.

[celest python]

I've been working on a tool automatically transpiles BP to C++ for a while, ended up memorizing everything in ScriptCore.cpp

So I thought I could write something about my adventures back at the day

though like my AI article its one of the articles I dislike, because when I wrote that I was still naive

[dense owl]

Yeah, well, now that it’s “feature complete” when is release? 😛

[celest python]

when its also "bug free" 😄

creator of fluid ninja live gave me access to his plugin

been trying to compile it since a week

and its not going well haha

[uneven cloud]

In the section: Do not use cast, its expensive, I would add that casting to a C++ class does not cause a hard reference. Often people cast to the BP version, when all they really need is an actor or a character.

[dense owl]

So casting to the native parent class is cheaper?

Ig it makes sense less code to load

[uneven cloud]

It does not create a hard reference to data. So it's cheaper in the memory sense, which is what is bad about casting in BP.

[celest python]

Thats the second time I get this recommendation so I guess I wasnt really clear about that there 😅 I'll add as you said

[dense owl]

Also put (credits: Luthage) in there 😛

[uneven cloud]

The point of using timers instead of tick isn't that they are cheaper (they aren't) it's that most of the time, you don't need to do the thing every tick. So you usually end up spreading things out across frames.

[celest python]

I think this explained well in the reddit post I linked, but majority of the people at #blueprint is under the impression timers are faster than tick just because, so I was specifically targeting them

[uneven cloud]

Fair enough. I didn't see anything about that in the reddit comment that is linked.

[celest python]

I'll rewrite it when I'm available then, thanks for the feedback

[harsh storm]

Casting to a BP is fine as well. What matters is the references inside of that BP. If you have no hard refs inside of the BP, it is perfectly fine.

[dense owl]

I don’t recommend them because they’re faster, but rather to use instead of delays and to be able to control their runtime without having to use bool checks

[celest python]

Casting to some class with insane amount of references is also fine (in terms of casting as an operation), its just it makes BPs loading at runtime very slow but the cast itself will still run at the same speed of casting to a native class

[wanton compass]

Huh, intriguing. I was under the impression that small invokers were more performant when the world scale gets too big, or at least I think that's what my coworker said.
Are multiple dynamic navmesh bounds really more performant than invokers? If so that could spare me a lot of trouble.

When the geometry changes, only that single navmesh bound that it changed in gets rebuit, do I assume correctly?

[uneven cloud]

World scale really doesn't matter, because only a section will be loaded at a time.

Dynamic nav mesh is more performant. Modifiers only is far more performant. Both start with a static nav mesh built at editor time and only update the cells when the geo changes. Not everything in the bounds, just the cells that are affected.

[wanton compass]

Just the cells? That sounds even better!
Thank you kindly I'll definitively pass that on to my coworkers and we'll reevaluate our decisions.

[lyric flint]

I made an ability system but i don't know how to apply the dmg to the ai enemy damage script i did

[dense owl]

Apply damage , on damage taken

[tough tulip]

So whilst using the debugger, I can see that due to me rechecking if we are still chasing the right target (After move to start > delay > Stop all movement > run EQS > move to start), it is creating a queue of MoveTo gameplay tasks. Is there a way to invalidate/remove these from the queue? After reaching about 10 in the queue the AI starts moving very slowly and jittery (likely because it is trying to figure out what to actually do).

[dense owl]

You can see things in that? 🙃

[tough tulip]

I might have started seeing things, as if the unreal debug gods are reaching out to me 🪄 I might just be going insane though, not sure which

[dense owl]

You shouldn’t be doing this way tho

Just use a service

And have your decorator observe on bb key change

[tough tulip]

Right that is what I initially did, but I couldn't find a way for a service to run the EQS task

[dense owl]

That is, if you’re using a BT

[dense owl]

That’s how I usually run EQS

Task didn’t work well for me

[tough tulip]

Here is the setup:

[dense owl]

Right click your selector

[tough tulip]

For more context:

🙃

[dense owl]

Yep

[tough tulip]

I might very well, and this has taken many hours of research, be an idiot 😂

The strange thing though is that I can only select "SelfActor" as the blackboard key it outputs into 🤔

So if I understand this correctly; The service will check every x seconds if its conditions are met. If it is, it will output the result into the key you provide, and will run the task beneath the selector right? If it returns false, it will run back up to the root node?

[dense owl]

here's mine:

[tough tulip]

Is that selector running straight from the root node, or does it have something else above it?

This is my problem at the moment:

[dense owl]

I mean I have another selector above it but shouldn’t make much difference

[tough tulip]

Yea I figured, just wanted to double check

[dense owl]

You prly didn’t select the right base class on your bb key

Should be Actor

[tough tulip]

🫠

Yep that was it