@solar bronze can you see if I did anything wrong cause I checked everything and it's the same
#gameplay-ai
south palm
solar bronze
but can you actually show me YOUR behavior tree?
hexed spade
the AI is walking in circles because it drops the ball, looks for it, grabs it, drops it again repeatedly every 0.3 seconds because its tied to MoveToLocation, how do I make it delay so this won't happen?
lyric flint
U can add a cooldown decorator so it cant enter the node if thats the case
hexed spade
ah I will give that try
old adder
Hello guys, do you have example or way to make group of AI swarm the player in a tight circle for melee attack?
I tried the CrowdController for AI and EQS but they still get stuck on each other or move really slowly when colliding each others.
hexed spade
hi guys I opened UE4 today and behavior tree is disabled??? how did this happen and how to fix? thanks
I found a similar problem here: https://answers.unrealengine.com/questions/736315/view.html no answers tho
lyric flint
did you even made a behaivior tree ? go to the tree and check there if the tree has this blackboard or something idk
hexed spade
yes i was working on it until last night. shut down computer, open it today and it wont let me switch
I guess I will just have to start over but maybe this is a bug?
what the now i have it
i just opened the tree and its fine now lol
lyric flint
yeah
real spire
Maybe you had a bug but what's for sure is that if you open a Blackboard asset in the content browser without first opening a tree asset linked to that blackboard you'll get the blackboard asset with the tree link at the top right greyed out because the Tree-Blackboard association exists inside the Tree. The Blackboard doesn't know which Tree it should open. I guess having it like that allows a blackboard to be used my multiple trees?
misty wharf
Are there any best practices in terms of organizing AI logic between pawn, controller and behavior tree?
Or is it all sort of "it depends" thing?
Just wondering as I'm working on some semi-complicated AI task logic and it feels like I'm constantly tweaking something in it because it feels like it's not set up in a nice way :D
i need to know
gaunt kite
@hexed spade Just go to the Behaviour tree and remake a BB again, it usually buggs out
pine steeple
@south palm not everyone is around when you are, also not many people do AI or talk in here. complaining within 10 mins is kinda silly
solemn nova
Can I run a behavior tree from a playercontroller?
wicked flint
I don’t believe so, the whole point of the behaviour tree is to act as the “brain” for an aicontroller
solemn nova
hmm, ok thanks, I need to continue the BT logic after possessing a pawn... I guess I can just posess it later
Has anyone implemented this suggestion of having everything posessed by AIControllers? And the PlayerController just nudges the AI controller in the correct direction
https://answers.unrealengine.com/questions/374052/is-it-possible-to-use-both-ai-controller-and-playe.html
I'm guessing it would result in some lag compared to local but maybe that could be hidden with animations
I'll need to revisit this when I look at the animation system properly
thin hatch
Hey folks new to the discord, so if this isn't the right place to post about this, please tell me. I'm having an issue where my navmesh will not draw on the landscape but will on the surface of static meshes. I'm using navigation invokers and everything works fine in other areas of my landscape. At first I figured it must just be a collision blocking that area. But there's nothing there and as this screenshot shows the navmesh still draws on the top of static meshes.
sturdy iron
You need to define in your navmesh how high the steps can be what angles etc
fiery leaf
How would I go about specifying different "zones" for an AI? Like I want them to be able to navigate outside of a room, but once they enter the room their navigation should be limited to that area. I'd also like to specify places they can't go in that room. If I use one giant navmesh for inside and outside, it will still look outside when using Get Random Reachable Point.
Never mind, a NavLink seemed to do the trick 🙂
midnight dune
I have a simple behavior tree with a task that finds the nearest player then moves to the player, how do I get the ai to break out of the move to and check if another player is closer? Right now the ai will run right past player 2 if it’s in the “move to” chasing a player 1 that ran past player 2
Looks like a parallel might be what I need, it’ll be tomorrow before I can try it out
misty wharf
Another option could be a BT Service
You could have it activate when the chase branch is entered, and then it can run at a certain interval to scan for other players
lyric flint
Yo i have a question cause i had my ai's on aicontroller i changed it to detour they were not spawning and then i switched it back wasnt working also, restarted still not working so idk what happened
last river
Does anyone know if EQS can have manually placed points of pathing? I am looking to have many simple minded entities (will spawn groups if near player) moving between these points of interest based on some sort of factors. Currently though I am stuck even finding an example or tutorial of EQS points being anything other than a grid or some sort of procedural formation. I was hoping there is a way to have the points be dynamic over a large map and AI could add more of these points during runtime but the initial points of interest would be manually placed by me.
misty wharf
@last river one thing that comes to mind is you could place your points as actors of a certain type, then use EQS to query for actors of that type. This way the items would be those points instead of a generated grid or such
last river
@misty wharf thank you, I'll see if I can find any information on how this performs since I plan on having many entities on a large world map deciding to move to and from these points and performing some sort of check if they win/lose against another entity already occupying a point. Hopefully all of this can be performed by one eqs and if the player is close to one of these interactions then I can have one of these entities spawn however many pawns that entity is supposed to represent and then I can have a more detailed EQS start on each of them.
I have a feeling that performance may not be too great on this, so I am also looking into if I could maybe have an AI manager blueprint that holds a very large array of each entity + their locations/destinations/and timers for each of the entities
misty wharf
Yeah not really sure about the perf side.. You can filter it by range for the query too so you could only query for actors within a certain proximity which would probably help
last river
Yeah, I was thinking about doing that, I do not know enough about EQS yet to know how that works or the expense. Right now I am also looking into what I might be able to pull off in blueprint concerning the large amount of dynamic variables in arrays I might try in keeping track of these locations and entities
misty wharf
I'd just go with whatever is simplest to get working :)
I'm using EQS for a bunch of random things in my game right now because it's so simple to utilize for those tasks... it might not be the most efficient way, but because it's so simple, it would be very easy to replace later if needed
gloomy vector
Does playing sounds with the PlaySound task in the AI Behavior Tree work differently? it just doesn't seem to work like other tasks like Wait or MoveTo.. I can't find any docs or tutorials about using sound with AI..
What i'm trying to do is when the enemy sees the player, it plays a sound once and moves to the player, if it looses sight of the player is plays a different sound and starts roaming. move and roaming works, but sounds play constantly.. if I use a Cooldown decorator, but it will just repeat less often.
misty wharf
are you sure the BT isn't just repeatedly activating the node?
in a situation where the AI moves a short distance, it would then finish the move task and possibly repeat the whole graph from start again, also triggering the sound along the way
gloomy vector
ya it could be,, but how would you debug that? there's no print string I can see..
misty wharf
You can add a breakpoint into the BT
or you can make a custom BT task that prints a string every time it runs or something :)
or a custom decorator could do that too
gloomy vector
ok thanks! you're right it is repeating. I have Ignore Restart Self checked but it doesn't seem to work or doesn't work the way I think it should : ) shouldn't that only play the sound if it's not playing already?
misty wharf
it depends on how the sound is configured and how the node works
you could structure your BT so that it doesn't exit when the movement has finished, and would instead just loop
you might have to set up some way for it to abort if needed (eg. using a decorator that aborts lower prio), but that would be one way of doing it at least
gloomy vector
cool, how would you setup a loop? I'm just getting into AI.. I kinda wish they had just made BP nodes for everything : )
misty wharf
you could do it in BP's too if you want
there's equivalent or close to equivalent nodes for most of the BT stuff
anyway, for looping, there's a decorator
so for example you would set it up so that you have a sequence, which first has the play sound in it, and then another sequence
you put the other nodes like the movement inside the nested sequence
and add a loop decorator on it, so that way it would only ever play the sound when it first starts this branch, and then keep looping the other nodes
gloomy vector
ok I'll try it, thanks!!
lyric flint
Yo i have a question cause i had my ai's on aicontroller i changed it to detour they were not spawning and then i switched it back wasnt working also, restarted still not working so idk what happened
@lyric flint 😦
misty wharf
TFW you go to google to look up some BT stuff, and find an answer from 2015 from an Epic staffer saying "wil will add array support to blackboards in 4.8"
5 years later feature does not exist :P
polar furnace
hi i need nav mesh in sea for fish
i dont want fish stick to the ground
how can i do this ?
tag me please if you have any idea
🙏
gloomy vector
try using the nav mesh for location and randomized z for height, maybe? or search for flying ai..
misty wharf
Anyone know what "project goal location" in the BT Move To task does specifically? I was trying to get the AI pawns to move to an actor, but they just wouldn't... until I turned "project goal location" off
I was under the impression that it projected it to the navmesh meaning it should work better for points that might not be directly on the navmesh, but it seems like the opposite based on the above result?
charred ruin
Guys, sorry for dumb question, but how do you check if a bool is true in a behavior tree?
Do you create a decorator that checks if a value is true, or compare the bool with a always true value? Or is there another way?
idle widget
@charred ruin are you talking about a bool that is a blackboard key or not?
charred ruin
Yes, I basically want to pass a bool from the character to the BB
and check if that bool is true in the BT
idle widget
so the decorator "Blackboard Based Condition" will compare if a BlackKey is set(true) or not set(false). Boolean Blackboard keys are always set to false by default
charred ruin
Oh, so Is Set actually means is set to true? I just thought it meant if the value is valid or not
idle widget
Oh, so Is Set actually means is set to true?
Well you can set a boolean to either 0(false) or 1(true)
so boolean are always set to false when you first declare them in member and are always valid because zero means false to a boolean.
that is the same for all primary data types in C++
charred ruin
I know but I thought Is Set was meant to be used as if a value has been set since the BT started running
like how it can take in a FVector
idle widget
that is true for any User Define Type like any class, structs
but not the case for integers, floats, and bools because 0 is valid for them
the blackboard declares the keys as variables when it start up and the actually value of them are 0(which for User Define Type like any class, structs is nullptr)
charred ruin
So is it basically if(condition) ? like if(bool) or if(pointer) or is it if(object.IsValid())?
idle widget
bingo
charred ruin
if(condition) or if(object.IsValid())?
idle widget
so they use a condition
for UClass:
return (Op == EBasicKeyOperation::Set) ? WeakObjPtr.IsValid() : !WeakObjPtr.IsValid()
WeakObjPtr is a weak pointer to an object
for boolean:
return (Op == EBasicKeyOperation::Set) ? Value : !Value;
Value is boolean
and in both Op is Set or NotSet
charred ruin
Kinda got it, but how can Op be NotSet? when does that happen?
Let me know if I am wrong:
If a value is never set, it will always return false
But if it was set, if the value is bool, it will return the value. If the value is an object it will return if it IsValid, right?
idle widget
Op is based on what you select in the decorator node details
charred ruin
Oh right
got it
Not used to using anything other than C++ lol
thanks a lot, I understand it now
idle widget
you welcome
charred ruin
Where did you find this by the way:
`return (Op == EBasicKeyOperation::Set) ? WeakObjPtr.IsValid() : !WeakObjPtr.IsValid()
WeakObjPtr is a weak pointer to an object
for boolean:
return (Op == EBasicKeyOperation::Set) ? Value : !Value;`
idle widget
return (Op == EBasicKeyOperation::Set) ? WeakObjPtr.IsValid() : !WeakObjPtr.IsValid()
is found in BlackboardKeyType_Class.cpp method: TestBasicOperation line 56
return (Op == EBasicKeyOperation::Set) ? Value : !Value;
is found in BlackboardKeyType_Bool.cpp method: TestBasicOperation line 40
charred ruin
I see, thank you!
idle widget
the decorator does eventually calls those methods when the BT evaluates the node
deft hound
Hi, I'm having trouble with an "AI MoveTo"/MoveToLocation when the place it's going is close in terms of vertical distance. If someone could shed some light as to why it could be failing that would be much appreciated. I have explained the issue in detail on Answerhub here: https://answers.unrealengine.com/questions/981036/view.html
Thanks
thorny jay
Hi all, is there a way to have a smart link only useable if an AI pawn meets a certain condition? I want a smart link to only be available if the bot is on a particular team, as some doors can only be opened by a defending team
lyric flint
Yo guys i need help, my ai mysteriously stopped spawning in the world and when i even manually dragg them in the level while playing they are in the level for a second but disapear after
pine steeple
Ah with my power of mind reading, i know the answer!
You did not connect Node A to Node B and Node C never got executed.
lyric flint
yes, mind reading
well it actually stopped working after i changed the controller to detour and yeah i tried changing it back to the controller that i was using but nothing changed
pine steeple
what does the Gameplay Debugger say?
or the Visual Logger?
those are your best friends with AI
if you don't know what they are, google them, learn them, and then come back to me with some more info.
pine steeple
your supposed to press start
then play the game
then it logs any issues
but it seems like you are starting your BT too soon
lyric flint
yeah i did press start and played the game for some time
i did that couple of times and it was the same
i just put on npc to log the location
but since he despawns like .0001 s after spawn then yeah
and i know that the npcs are spawning cause they do print string on begin play
thorny jay
@pine steeple Thanks! C++ doesn't bother me :-) I'll take a look
thorn ginkgo
Hihi! I'm looking for any reccos on the marketplace for non combat ai systems. I'm making something that needs an ai to explore/ meander from one point of a procedural landscape to another. maybe stop and smell the roses type stuff. Let me know if you've seen something neat! thanks!
thorny jay
@pine steeple I can't seem to find any useful documentation on doing something like this. Do you know of any links I can read, or happen to know how I can set a nav link proxy to be conditionally active for a particular AI? I can see a function called IsNavigationRelevant, but this appears to not take any parameters, so I'm not sure how I would check the AI's team and return true/false accordingly
Thinking about it, I could maybe do it using supported agents, but both team 1 and team 2 would have the exact same agent attributes, so I'm not sure how I would override UE4's default agent profile assignment behaviour to set it based on the pawn's team
By default it's set based on the width/height of the agent
deft hound
Hi, I'm having trouble with an "AI MoveTo"/MoveToLocation when the place it's going is close in terms of vertical distance. If someone could shed some light as to why it could be failing that would be much appreciated. I have explained the issue in detail on Answerhub here: https://answers.unrealengine.com/questions/981036/view.html
Thanks
bleak iron
Maybe the acceptance radius is too high?
Is the character failing to move? Or failing to arrive?
I have an issue with deceleration. I want my characters to slide after they stop moving. But no matter what value I input, the result is that they stop instantly
I've set all deceleration and friction to 0 and they still instantly stop
thorny jay
@bleak iron I think you also need to modify "Braking Friction" and "Braking Friction Factor"
By default "Use Separate Breaking Friction" is ticked
I have a setup for cavalry where the horse gradually slows down over time, and this is what it looks like:
bleak iron
Hmm and this works?
thorny jay
Yes, I modify the slowdown using "Braking Deceleration Walking"
bleak iron
Because I've tried this and even 0 friction and friction factor and still nothing
thorny jay
If i set it to 0 then the horse just runs forever
bleak iron
Still stops instantly.
thorny jay
Hmm
bleak iron
Must be something else going on...
thorny jay
I do have some custom C++ code in my movement component, but that was mostly to create tank controls and prevent players from strafing or turning the horse more quickly than they should. I don't think I modified the braking/friction cod
Maybe try copying mine exactly and see what happens, set braking deceleration walking to something like 1 and see if it works
thorny jay
Ok best of luck! I wish I could be more specific, but I did this over a year ago so I've forgotten the finer details
pine steeple
hmm
@thorny jay what might be simpler
is changing the navigation area of the link and use filters
so like RedTeamArea and BlueTeamArea and NeutralArea, then if its RedTeam only, then give the link that area class
and the navfilter applied can be determined by the team they are on
fiery spoke
What could cause AI to stuck when he runs and shoots at my player? It does this on the clean landscape; it stuck and kinda jitters for a couple of seconds, and then again walks and shoot at me.
signal tangle
are you using a behaviour tree, is there any kind of timer in there? have you brought up the debugging ' then 4 on the num pad to see what state he gets into?
fiery spoke
@signal tangle Yes it has behaviour tree. I use AIBehaviourToolkit. There are some wait time nodes.
thorny jay
@pine steeple That's a great shout, I'll look into that 🙂 Thank you!
deft hound
@bleak iron Hi Breezy. Yep the character still moves, it seems to go to the first waypoint but then on the way to the second it ignores the smart link proxy to the top platform, runs past and runs on the spot at the end of the platform, before stopping after a few seconds.
@bleak iron I have tried different Acceptance radii in both AI move commands, I've tried 100, 50, 20, 10, 5, 2, 1, 0 and -1.
In the words of The Fifth Element herself: Pleaaese Halp
wicked flint
Hi guys, can someone show me how to assign an aicontroller to my pawn when it is spawned? I'm not sure how to get the aicontroller to possess my pawn at BeginPlay()
idle widget
it is the AI controller Class property in APawn, you set this to the correct AIController, than if the auto possess is set the "Placed in world",. the controller will be created and the pawn will possessed by that controller when the pawn is placed in the world
wicked flint
thank you, i will look into this
idle widget
@wicked flint if you are spawning this APawns vs placing them in the world than you want to change the Auto Possess AI to spawning vs place in the world
bleak iron
@deft hound Looking at your question, I'd say the problem is not with the AI, because it works when the platforms are higher apart. The problem is with the nav mesh. Play around with the NavMesh's size and sensitivity settings.
My feeling is that the character's head is close enough to the upper nav mesh for him to think "I'm in this nav mesh" even though he's on the lower one
deft hound
Thanks Breezy I'll give that a go. I feel that you may be right. I've tried some settings, but also tried shrinking the AI character right down to 0.1 without luck.
stark zealot
I'm trying to make my AI do a jump attack. The animation works but I was wondering how to add more movement to it. For example in this attack he jumps up into the air with his sword and then slams down on the ground. I want to add more air to the jump and then make him come down at the target players location. Do I use an animation notify to add more input to him? Or is there another way?
tiny comet
@stark zealot if you are using root motion, then you can modify the attack animation. If you are procedurally moving character (eg using jump or launch), then you can modify the forces to jump or launch.
stark zealot
@tiny comet I'm not using root motion because I read that it's trickier with multiplayer. I've been playing around with it today and wound up using an anim notify that then executes a timeline that lerps the location of the character. It looks really good so I guess I'll keep doing this for more attacks lol
tiny comet
so if you are using a timeline to lerp the location - then you should be able to modify the location of the jump so the position of the character is correct. If the animation doesnt quite look right after this- maybe split it into 3 parts start/loop/land and the if the jump is longer play the loop longer
stark zealot
The only thing that seems inefficient is having to hand tailor a timeline for each attack and using trial and error tweaking with the timeline length in order to make it look right. I guess that's the drawback of manually doing it vs using root motion
tiny comet
yeah - and even with root motion you still have to do that work editing the animation.
stark zealot
Yea. Well as long as it's working I'm happy lol. It takes a little fine tuning but the results are worth it. 🙂 Thanks for your help
fading grotto
I'm working on a multiplayer game. I want my AI enemies to move to a set goal object, and when a player tries to get in the way basically they get the aggro of the AI monster. The problem is Behavior Tree seems very impractical for handling multiple players and network replication. What should I do?
fading grotto
@fading grotto If you AI Pawn is replicable and you can replicate movement, you can just basically replicate the position of the AI Pawn, from server to all players
@ancient grove I have issues with target selection too
Well it seems like its working.
But this graph ticks for every enemy, which might cause performance problems later on 😄
pine steeple
use distance squared
its cheaper
and tbh that is ok, tho i prefer to have a service run every .1 to .2
and update blackboard variables
have the decorator just check those BB keys
a decorator should NOT ever EVER set a blackboard key
that is what tasks/services are for
autumn kelp
Hey I have a question regarding AI simply not moving
So on simple AI MoveTo Node it always gets aborted and I don't know why
If I get close enough it succeeds but still doesn't move
I have AI actors that work just fine with the same setup
Can't quite figure out what the issue is
When setting acceptance radius value to -1 it moves for a brief second then stops
The error was simply me not initializing the character movement speed :)
hexed spade
hi guys im not sure why my AI has stopped moving to the ball. what could be going wrong here? why is there a hole around the ball?
hmmm now it works....but the ball is clipping the ground slightly
thorny jay
@hexed spade the ball is affecting navigation, and since the ball is placed in the editor, the navmesh generation assumes its a permanent fixture and therefore doesn't generate a walkable area under it
There should be a way to set it so the ball actor doesn't affect navigation, not sure off the top of my head what it is though
misty wharf
it's called "can ever affect navigation" or something like that ^
it might be in one of the advanced settings drawers that you have to expand
lean cliff
It is, it's under collision, and then under the advanced bit that's collapsed 🙂
hexed spade
thank you for your answers. it is behaving correctly now 😄
rapid ridge
it's the first time I'm going to dive into AI, any resource recommendation? My goal is to make a challenging AI for a topdown ARPG
charred ruin
Hey, when using AIPerceptionComponent, how do you know if an actor is sensed using a particular sense? So how do you know if it is sensed through sight or hearing?
pine steeple
need to grab the class
and check if class is Sight
its a bit crap in BP
in C++ i made some nice functions to convert to a ENum
charred ruin
@pine steeple how do you grab the class? Using OnTargetPerceptionUpdated or OnPerceptionUpdated I don't get any class which I can cast.
I can use Get Perceived Actors and use a specific sense, but then I have to do a loop on all of them.
Also it'd be nice if you could share those C++ functions or point me in the right direction
lusty egret
How can I associate a pawn to a specific nav agent? (so I have my default agent for the humanoid pawn and an agent for the car pawn)
twin loom
What are the benefits of EQS?
thorny jay
@twin loom EQS is asynchronous, so it avoids clogging up your main thread and causing hitching
twin loom
Does it have good performance?
thorny jay
Yes, it generally tries to be smart about the order in which it performs tests so it can discard items early, and it timeboxes the tests so they don't drag down framerate if you're doing a lot of them
twin loom
ok thanks
thorny jay
No problem
rapid ridge
An Environment Query is actually made up a number of different pieces. You can call an Environment Query from a Behavior Tree, and then the actual Environment Query will use its Generator , reference its Contexts , and use its Tests to give the Behavior Tree the highest weighted result.
Couldn't find performance wise differences but is this the main difference between EQS and AI Perception?
pine steeple
they are different
no way related
Perception is for the pawns to percept things in the world
EQS is to query things in the world
EQS can be used for many things, like grabbing all chests in range, generating points in the world, etc
nothing to do with perception.
thorny jay
A common use for EQS, for example, is to let an AI determine a good vantage point to attack the player from, that is in line of sight, not too close etc.
mighty light
So basically i have an ai which will chase me if i stand in his pawnsensing how do i make it so he stops chasing me after 5 seconds of not being in his pawnsensing?
pine steeple
A: Don't use pawnsensing, B: There are many ways to do it, could start a timer when not sensed, 5 seconds later, go back to roaming, when sensed, stop timer and start chasing.
rapid ridge
Just to be sure AI Perception's PeripheralVisionHalfAngleDegrees means 360 degrees when set to 180 right? That's how I understood it but want to be sure
rapid ridge
okay tyty
the SetBlackboardValueAsVector needs a key, and it can be a variable that is named as the key in the blackboard is named right?
twin loom
I'm using the same BT on multiple objects. The BT currently only makes the objects wander around using EQS. The problem is, that both objects are behaving the same way. I don't know if this is a BT problem or the EQS problem that decides the location.
This is the EQS, both test's are filter only. My hope is that since nothing is scored, the AI will choose a random spot to go to
misty wharf
You could probably write a custom test that gives items a random score if something like that doesn't exist yet 🤔
dunno if that makes sense, just a thought
twin loom
rn, I just wanna know why both my objects are moving to the exact same spot
twin loom
Just a quick question, can I have multiple BTTasks and services in 1 script? I wanna avoid making 20 different scripts for like 5 lines a class
@misty wharf There is a random option, I just didn't see it. It also fixed the problem of why the objects were going to the same place
oak pendant
so i am experimenting with EQS and it seems very cool for certain things. i noticed in the code that the GamePlay Tag query test does not "work" at run time.
meaning that if you add tags at runtime. they do not effect the test results.
it appears that the results of the query are cached the first time it is run so any new tags wont be on the cached objects.
class UEnvQueryTest_GameplayTags : public UEnvQueryTest
{
GENERATED_UCLASS_BODY()
public:
/**
* @note Calling function only makes sense before first run of given query
* by the EQS manager. The query gets preprocessed and cached then so the query
* value will get stored and calling this function will not change it (unless
* you call it on the cached test's instance, see UEnvQueryManager::CreateQueryInstance).
*/```a bit stuck atm as i want my AI to respond to events in real time. imgine i want an NPC to use a certain attack if you are close enough and stunned. (where stunned is a GP Tag)
i mean i can return the list and filter myself but thats seems counterproductive. any thoughts?
twin loom
In my blackboard, I have some variables that I set at runtime, where would I set them? Begin play in the character or begin play in the AI controller?
twin loom
Just a quick question, can I have multiple BTTasks and services in 1 script? I wanna avoid making 20 different scripts for like 5 lines a class
Still have this question as well 🙂
simple crest
haven't done it myself but it should be fine to put multiple BTTasks or other classes in one pair of .h and .cpp files. UE doesn't really care about matching file names to type names or anything
twin loom
ok, thanks
dire frigate
Hey all, just curious if someone can help me out with something
I went through the UE4 documentation on AI Trees - https://docs.unrealengine.com/en-US/Engine/ArtificialIntelligence/BehaviorTrees/BehaviorTreeQuickStart/index.html
The chase works, but the patrol doesn't and as far as I can tell, everything seems to be identical to what is on their documentation
It seems that the Set Blackboard Key as Vector is where it is failing. The Vector itself is updating, but it isn't setting it to the blackboard key correctly
I update a new location to this Blackboard Key, then I print it immediately after and the value isn't changing at all. Even though I have printed the vector that I am feeding into the "value" and that is changing.
dire frigate
Ok, I figured it out. It needs to be set as "Instance Editable"
dire frigate
Now I have a new issue though. At the game start, all of the Enemies Patrol Location is the same location at first until they reach that destination. Then once they get there, they move around
twin loom
How would I get the controlled character location from a BTTask's execute function in c++ or BTService's OnSearchStart function in c++?
midnight dune
I have two services, in the first i find the closest of the player characters that spawn into the game. In the second service I'm trying to get the value of the closest player from the first service. Is this possible if so how can i accomplish this?
patent hornet
you get the pawn from the controller
and get its location
@midnight dune set it as a blackboard key (object)
in the first service, access it from the 2nd
midnight dune
Ok, i guess I am struggling with the setting and accessing part.
patent hornet
google WFT is? videos for AI and watch those
its explained in good amount of detail there
from what i can eyeball you probably didn't set the key selector in the instance of the service in the BT itself
midnight dune
The find closet player works well
charred ruin
Hey, when using AIPerceptionComponent, how do you know if an actor is sensed using a particular sense? So how do you know if it is sensed through sight or hearing?
rapid ridge
Is there a AI Perception setting to stick to one target? it gets a bit wonky when it senses more than 1 enemy in radius
tidal void
I'm working on AI Navigation but I'm having an odd issue with finding a path to a point that should be navigable. At first I thought it might be that the point was too far away but testing shows distance (and thus number of nodes computed) seem highly unlikely. My next thought which I can't seem to find a way to debug and verify is that the grid nodes are too far apart, so some generated goal locations might be to far from a navigable node (if thats how it even works). Here's a video. You'll see two green debug spheres (one is the goal location, the second lower one is the goal projected to the nav mesh), the red sphere when present is the found goal path with each small blue node being a waypoint. Any insight would be greatly appreciated! https://youtu.be/riCzlpn1XCk
tidal void
Code to go with ^^^ https://pastebin.pl/view/c5fefc65
lunar bone
Heyo! I'm setting up a fairly simple AI. Here's what I want. If the AI has line of sight to an enemy. It should wait for 2s, then get the target location and move to that. If the AI doesn't have line of sight, it will continue with a simple patrol. As you can see in the picture, I have a Blackboard Based Condition on a sequence, that tells the sequence to abort self if Line of Sight is not set. I'm guessing this would immediately abort the whole sequence? That's not really what I'm after. What I want is that if the line of sight is broken during the Wait time, then abort the whole sequence. If the line of sight would be broken during the BTT_GetTargetLocation or BTT_WalkTo, then I want the AI to complete those tasks, and then continue with normal patrol. Anyone knows how I would set that up?
urban wadi
Anyone know how to chain montages together without using a delay?
I am trying to set up a AI node in which has a bool decorator in a sequence which plays a turn animation and then a roar animation, then enters the attack phase
I tried using a sequence but that did not work. I have it working with a behavior executed that plays the Rotate montage followed with a delay and then plays the roar montage. But i dont want to use a delay.
tidal void
@lunar bone I think you can move your Blackboard condition from the Sequence to the Wait node. That way it only aborts itself while its running, and not after. It also won't run the sequence if the condition is not met, so you get the same overall effect
dim sable
Hi Yall, Wheres a good place to look for learning how to program AI behavior?
Im kinda new To Unreal, ive taken some basic stuff, but im looking into making Coding my main path
sand barn
rapid ridge
is there a way to make a AI character not rotate towards movement?
simple crest
search in the MovementComponent for "rotation" and play with some of the settings @rapid ridge
may also need to mess with Pawn "Controller Rotation" settings on your pawn itself
rapid ridge
already tried various combinations using those settings without achieving what I want
simple crest
then you have some custom code causing your character to rotate
or you missed the one setting
orient rotation to movement or something iirc
rapid ridge
that is disabled,
fiery spoke
How to force roaming NPC to turn in place and then continue to walk. My NPC turns but at the same time moves forward which creates this weird sliding movement.
midnight scroll
@fiery spoke You kind of already answered your own question by asking it. Do exactly what you asked for. Make a turn then move sequence. Make them turn towards their destination, then once their rotation's Z nearly equals the look at rotation Z from them to their destination, successfully finish that execute so that the moveto will be played next in the sequence.
Alternatively, you could also make some logic in the character itself. Set it's movement speed to near zero or something until it's facing it's desired movement direction. But that's going to take a lot more resources than a simple BT sequence.
vagrant skiff
Anybody have an issue of identical AI placed in a level and some refuse to move? AIMoveTo function returns failed and "blocked" is the enum output for the reason why, i've yet to identify why the ai end up having this happen but generally it does not happen when i initially place a new one into a level, after a few seconds my ai are going into a randomly moving around state to test this and the "older" ones constantly fail to move, if i continue to just do stuff in the level editor eventually the ones that are working properly will not work anymore once played, in editor or standalone (not tested after build yet), its very confusing
not my best example gif but;
https://gyazo.com/d7f363506732f96722e34d6d1c624e89
im just trying random stuff now to try and reproduce the issue but ive got no clue why some just "dont work" when they are literally identical alt dragged of eachother / drag dropped from content browser
google also hasnt really yielded any helpful results
pine steeple
that looks like your using detour (crowd avoidance)
the way they are twitching whilst moving
pine steeple
thats RVO
vagrant skiff
oh
pine steeple
crowd avoidance is in the AI Controller
vagrant skiff
roger
pine steeple
but
i would recommend running the visual logger
and finding out what exactly is happening
run that, and let me know the results
pine steeple
i know UE4 ai system quite well (been working with it for over 2 years :D)
vagrant skiff
yea ive meddled with ue for a few years but this is my first time doing ai stuff
and your suggestion above has already fixed the problem
i swapped to the basic ai controller from the crowd avoidance one
but ill be looking at the visual logger aswell
vagrant skiff
yeah
its weird because i could drag one of them away alone
still was "blocked" permanantly
pine steeple
thing is, the crowd system really has nothing exposed to BP
and in default state, its terrible
vagrant skiff
i can imagine
good insight
i thought it would help with them running into eachother
xD
vagrant skiff
yh
pine steeple
i use it, but after a lot of tweaking
and its still not perfect
just haven't got the time atm to make a better avoidance system
and RVO is a no go for us
vagrant skiff
planning on having very sparse groups of ai so i dont think ill need much of what it has to offer anyway
hopefully
pine steeple
i am going to try experimenting with RVO when they are off camera, and switching to Crowd Following when near players
might offer what i need lol
pine steeple
behaviour trees get fun tho 😄
thats just one part of a massive BT
8 subtrees on 1 BT
pine steeple
oh i have around 30 different monsters
vagrant skiff
ah
pine steeple
all with different abilities
vagrant skiff
nice
pine steeple
some burrow underground
some jump into ceilings
jump through windows, etc
then they have ranged/melee attacks, etc
tidal void
Wow that BT is intense. Easy to follow for the most part though, you managed to keep it super clean despite the number of paths
silk spear
is there a way to set acceptance radius in a MoveTo node as a variable?
so i could set it depending on the weapon range
inland hatch
@vagrant skiff Could you have exceeded the maximum agents for crowd AI? You can change the value in your project settings here.
That would explain why some of them refused to navigate despite being away from the other agents.
fiery spoke
@midnight scroll Actually i was asking for some tutorial about this. Preferably video tutorial.
patent hornet
simplest way with turn in place then walk?
make a task, have it fetch desired rotation from the blackboard, interp current rotation to desired rotation on Tick and FinishExecute(success) when you're close enough to desired rotation to call it done
and put it in a sequence before the MoveTo
@fiery spoke
simple crest
You have to somehow calculate and store the full nav path, then move the character to each point individually, rotating towards the next point before continuing on
Not reeeally helpful but might help you plan your approach
verbal violet
@patent hornet FinishExecute finishing task? should call it in Tick or sowhere else?
I used FinishLatentTask but that is something about template tasks
patent hornet
if you dont' FinishExecute, BT gets stuck in that task forever
this use case, on tick you check if rotation is close enough, and if it is, FinishExecute
as the RInterp is done on TIck as well, it only makes sense
verbal violet
I do that on wrong way. when my rotation was close enough i called ExecuteTask AGAIN and return succes but when that didnt work i called FinishLatentTask on end ExecuteTask
🤦♂️
@patent hornet i can't find FinishExecute ?! that is bp method, i did it in c++. Is OnTaskFinished same thing?
simple crest
I bet you could ghetto hack turn in place by setting max walk speed to 0 or "very small" while the actor direction doesn't match the input direction... Lol
torpid juniper
Hi all. Is there a best practice for integrating behavior tree logic with animation blueprints?
E.g. in my current setup, I want to make an animal yell, and when the animation is finished, walk to a location. I have a bt task which sets the animation state to yell. Then the animation bp has a notify event at the end of the animation which updates a bool in the blackboard. The bool allows the behavior tree to progress further.
This works, but it feels bad. After the task tells the animal to yell, it just sits on a wait node until the task is aborted due to the bool changing. Feels gross to me.
Example: The task on the left tells the animal to yell, then wait for 10 seconds. When the animation is finished, the blackboard value is set to True, so the task on the left is aborted, and the tree moves the flow to the task on the right.
I dislike how this setup has a task which is doing everything its supposed to progressing to the next task because it gets aborted before succeeding....
fiery spoke
@patent hornet I have an AI which just walks around, turns, etc. And i need to synchronize this turning with animations.
misty wharf
@torpid juniper the way I've set up that sorta stuff in BT's is using an event on the pawn. The pawn has a func that triggers the anim, then the anim notify is triggered in the pawn, which then calls the event dispatcher. The BT task for running this action binds an event listener into the dispatcher and finishes executing only after the event fires
this way it won't advance to the next task until the action has been fully performed
torpid juniper
@misty wharf Hmmm.. oh, I think I get it. That's a big brain moment.
I've been thinking of tasks as single async functions. You're saying the calling of "Finish Execute" doesn't need to come from "Receive Execute", and you can instead make "Finish Execute" only accessible from custom bound events. Is that correct?
And the state of the behavioral tree will just sit on the task with nothing happening until that event is fired?
misty wharf
Correct
If you bind events in the task like this, make sure to also unbind them. Otherwise the results can be unpredictable
Eg. Receive Execute -> Bind Event Foo
Event Foo -> Unbind Event Foo -> Finish Execute
Receive Abort -> Unbind Event Foo -> Finish Abort
torpid juniper
Got it. Makes a ton of sense.
If that were not done, does a task have the ability to execute anything when it's not active on the behavior tree? E.g. if the tree were doing another task, and the event were triggered, could it run?
misty wharf
afaik it can but I've never actually tried if it would :D
torpid juniper
haha ok.
Thank you, this was immensely helpful.
misty wharf
👍
vagrant skiff
@inland hatch yea i have quite a bit more then 50 sitting around, after work today im going to look into it further
verbal violet
I have custom task for Jump, for small enemy who jumping on bigger and attach, in Tick i am checking is location of small enemy close enough to socket and when that happened i call OwnerComp.OnTaskFinished(this, EBTNodeResult::Succeeded);
Problem is when i have multiple small enemies who jumps, when first come on goal and call OnTaskFinished that finish my jump task on ALL small enemies ?
What i do wrong? Sorry i am pretty new in unreal and AI in general...
blue sphere is sign that task is finshed
torpid juniper
I would post the Jump Task implementation
verbal violet
if (SelfActor.IsValid())
{
SocketTransform = SkeletalMesh->GetSocketTransform(SelectedSocket);
JumpEndPoint = SocketTransform.GetLocation();
SelfActor->SetActorLocation(FMath::Lerp(JumpStartPoint, JumpEndPoint, JumpAlpha));
JumpAlpha += DeltaSeconds / JumpDuration;
Distance = FVector::Distance(SelfActor->GetActorLocation(), JumpEndPoint);
if (Distance < 10.f)
{
UE_LOG(LogTemp, Log, TEXT("+++++++++++++++ JumpFinished [%f] "), Distance);
//DrawDebugSphere(GetWorld(), SelfActor->GetActorLocation(), 12.f, 22, FColor::Yellow, false, 1.f);
//JumpFinished = true;
OwnerComp.OnTaskFinished(this, EBTNodeResult::Succeeded);
}
}
it;s only part, I have some things bellow but it's about playing proper montage when jump reach some limit, i have JumpStart, JumpIdle and JumpLanding
verbal violet
anyone, please?
verbal violet
i found what is problem if anybody interested in. i had some fields in bttask for caching some values for example
TWeakObjectPtr<AActor> SelfActor;
FVector JumpStartPoint;
FVector JumpEndPoint;
FName SelectedSocket;
when each of them (modules, small enemies) get SelectedSocket in ExecuteTask
SelectedSocket = BlackBoardComp->GetValueAsName(SelectedSocketBlackboardKey);
and continue to do logic in Tick, there EVERYONE has value of last selected socket, SelectSocket was everytime overwritten and and always was used last value.
like some kind of shared variables ! ? ?
solution is (probably bad) to get that values from blackboard in each tick frame .... some of them, but JumpStartPoint is cached vector so i can't get it from bb, or i have to save that in bb.
Is this really works on this way or I something really fuckup with references or whatever ....??!
smoky summit
Does SetSmartLinkEnabled actually work for disabling smart links at runtime?
wraith anvil
any idea why my navigation mesh doesn't rebuild with this ?
but if i do this on the level blueprint it works?
buoyant geyser
@simple crest how do you handle assigning units to combat in your AI?
say you have 8 units, the enemy has 4, 2 on the north side of the map and 2 on the south
your units are clumped together on the northwest
suppose 4 of your units can eliminate 2 of the enemy's units
so the ideal solution is splitting them in two groups and sending one north the other south
how do you handle that?
simple crest
you're talking about if "I" was an AI trying to determine how to send off my 8 soldiers? I haven't actually gotten that far ahead in my AI dev... but, maybe a couple of thoughts from a very high level to ping-pong an idea or two
In my system every unit ultimately makes their own decisions but part of that decision making process can be influenced. for example each of my AI units maintains a list of known targets in a KnownEnemies set, but a squad leader might assign some specific target(s) to the unit which get stored in another set AssignedTargetEnemies. When the AI is performing decision making, it scores which enemy it wants to attack from KnownEnemies... but if that enemy happens to be in AssignedTargetEnemies it gives it a big score boost.
As for the "upper" side of that, I would assume some kind of cost based system... maybe one could create some clever use of influence maps somehow. if squad leader AI knows about a strong enemy force, it might build an influence map with hotspots at clumps of enemies or at strong enemies. the squad AI could plan to "cool off" the influence map by sending friendly units into the area to fight? if AI sends VirginPeon to [X,Y] it will cool off the influence map by a small amount, if AI sends ChadTrogdor to the same spot it cools it off a lot. repeat until either all friendly units are occupied or there aren't any hot enough grid points worth cooling down.
I'm really just making all this up off the top of my head, it might be all BS. there has to be some smart blog about this somewhere on the net...
@buoyant geyser
an RTS could easily get extremely complicated and I would not envy anyone trying to make an AI for one 😛
Influence map -> process it to pick attack points -> figure out which ones to focus on including how many the AI side can handle -> use something like bin sorting to assign units into teams and then send them off to their doom
buoyant geyser
@simple crest sorry got sidetracked by dinner - I guess what I'm struggling to figure out is how to prioritize what task gets which units
cost-based system for sure, it's relatively easy to calculate the fighting force or power of a squad
and it's not that difficult to cluster units into groups either
simple crest
so basically the massive topic which I conveniently summarized with the two words "bin sorting"
buoyant geyser
friends and foes alike
yeah exactly
bin sorting
might be a good keyword
attack task needs 8 units -> only gets 6 -> calculates if it's worth doing the attack w/ 6 -> no -> some other task gets the 8 units -> etc.
simple crest
gets extremely complicated if you "want" it to... is there a rock-paper-scissors element in there for example
yeah
buoyant geyser
for now all the units are the same
well and I have a mech but whatever
I'll look into bin sorting
simple crest
it's complicated because first you have to figure out which bins (tasks) you actually have, then you have to figure out a reasonable way to fill them
buoyant geyser
yeah exactly
simple crest
"Bin Packing" another useful keyword. once or twice I've used "first fit decreasing algorithm" - it's simple enough for a 5 yr old to figure out and implement and gives "OK" results.
imagine if the "groups" in this example were like your Unit Strengths (Mech might have a strength of 6 and other peon units have a strength of 1) and the "minibuses" were your Task Requirements (big enemy group has a cost of 10, and needs 2 mechs or 1 mech + 4 peons)
little different because you want to make sure you fill/overfill the bin
@buoyant geyser ¯_(ツ)_/¯
simple crest
google -> looks like A* and stuff like that lol
verbal violet
when i write custom task, extended from UBTTaskNode with ExecuteTask and TickTask, it's mean to all my characters which has this task in its BT execute same instance of task (script) ? For example if use some FVector as field in task script to cache start lerp position, and in tick use it to lerp from that 'start' to 'end', 'start' will always last written value, overwritten every time for each char
Is this really works on this way?
verbal violet
@patent hornet where i can set it? this flag bCreateNodeInstance?
patent hornet
sounds right
thorny jay
Hi all, I have a really frustrating problem when trying to debug my AI. If I have a PIE session running and I open up the behaviour tree, only a handful of the AI actually show up in the debug menu. For example, I might have 10 AI running, but only 3 will show up in the drop down list for me to view
Whenever my AI starts doing something weird and I need to see what they're actually doing, they never appear in that drop down list. It makes debugging so much more time consuming because I have to keep restarting the session and waiting for them to get stuck again
I'm on 4.24
odd tide
hello, How i can destroy async function object if it is not already executing in behavior tree
ripe whale
Has anybody managed to start a behaviour tree using AAIController::RunBehaviourTree in 4.25?
I have code that was working in 4.21 but I can't seem for the life of me to get it to work in 4.25
I searched online and it seems most people use blueprints to do this but I would really like to have as much as possible in cpp
misty wharf
Have you checked how the BP node for that works?
Perhaps it does something in the C++ side that might point you in the right direction
misty wharf
Could be a race condition? Depending on when you're calling that
Not sure tbh, I've only ever ran BT's from BP's BeginPlay
ripe whale
yeah if I can't get it to work soon I'm going to switch back to doing it from BP BeginPlay
in cpp I am calling it inside of OnPossess
I guess I can try to move to BeginPlay
verbal violet
@thorny jay maybe to press apostrophe while looking in AI that doing something weird ? in that case BT automatically show controller/character you are facing and looking at
thorny jay
@verbal violet Ah interesting, I didn't know that
That will help, though it still doesn't explain why their behaviour tree instance isn't debuggable sometimes 😦 But thanks, it should prove useful anyway
misty wharf
^I've noticed this sometimes as well, haven't really figured out why it happens 🤔
glacial vale
Hello do you know If I have multiple AI running around
Can I set dynamic obstacle on them?
If I do, the AI auto conflicts the path of the Controlled Pawn..
and RVO avoidance is a bit weird
The sphere Collision with navmesh_Null conflicts with his own path
rapid ridge
This conditional loop is only executing the first node in the sequence, if I want all nodes in the sequence to execute what do I need to do?
pine steeple
@glacial vale you can't do that
@rapid ridge ofc it will, that is by design
it will only execute that one node and loop it, not the sequence
glacial vale
@glacial vale you can't do that
@pine steeple I’ve found a way of doing it
Hacky but working
pine steeple
always risky doing that, cause you can mess up its own path finding
glacial vale
I put spheres around the shape leaving a path forward ... and path finding works almost totally fine
frosty skiff
When my character is standing on a blocking volume, all ai in my game stops following my character, but when my character is standing on anything else, my ai will follow. Navmesh surrounds my whole level. Anyone know why?
honest whale
Looking for some debugging tips on pathfinding. Ive got an AI that isnt moving around the level because when I send Pathfinding requests it fails due to "Start point on NavMesh"....which fine, makes sense. But from the best I can tell looking at it in the Gameplay Debugger the AI is fully on the NavMesh and the NavMesh covers the whole space.......
pallid atlas
You're not using a behavior tree, @celest python ?
celest python
Yes
I will use "simple move to" later -- project shouldnt have any Behaviour Tree
I just move my pawns on AIController
atomic hill
Anyone got this issue before?
the pink sphere is where I tell my actor to "simple move to location", but he slides weirdly.
north vapor
is there more efficient way of doing this?
fierce zealot
@atomic hill could you show me the navmesh?
hexed spade
why can't I extend the nav mesh to completely cover the floor here? no matter if I scale, it doesn't seem to cover the edges
fierce zealot
since your agents need to be able to stand in front of your wall
so positions too close to the wall are invalid anyway and thus not part of the navmesh
hexed spade
@fierce zealot I see...what happens is that they seem to get stuck in the walls
simple crest
usually that's because you've made your agent radius too small (you've tried too hard to make the nav mesh extend to the walls, lol 😛 )
twin loom
How do I pause/stop the behaviour tree from running? In my AI_Controller, I've tried BrainComponent->PauseLogic("Dead"); This gives me an EXCEPTION_ACCESS_VIOLATION crash. Do I need to do anything special to set up a brain component?
midnight dune
I'm looking for a way to get my zombie AI to quit attacking after one player is dead and move on to the other players. Any suggestions?
misty wharf
That largely depends on how your zombie AI works to begin with
I'm assuming you have some kind of BB value or such controlling which player it's attacking - you could use for example a BT service to keep checking if the target is alive and if not switch it
midnight dune
Yes I’m using BT to move to the closet player, the part I having difficulty with is getting the variable from the player that died. I’m about to crash for the night. I’ll try to post some screenshots tomorrow.
rapid ridge
any resources on how to debug AI? My code seems to run fine with 1 AI but when there's multiple AI it seems to be bugged
simple crest
are you sharing a blackboard
dusk kelp
Hey, guys, cant understand how to generate NavMesh with WorldComposition
I just made a NavMesh in my level inside PersistentLevel. Works good if Im testing AI directly on level, but when Im trying to run a game from Persistent level its just not working
plush pasture
navmesh isnt generated where the wall is
so its not the issue
i dont get it
@twin loom plz halp
anything else i could be missing?
releting recastnavmesh
omg bugs
lyric flint
How would you make a pawn path find to the player using add force instead of using movement from a character blueprint?
I know I could do this but I'm not using a the native movement system and its a sphere actor with physics... (I am using AddForce to replicate a bunch of my own physics)
rotund magnet
the on fail doesnt occur, it keeps trying to succeed and go to the player even when it cant
this is the on fail stuff
he just stands there
random jay
In a behavior tree I want a node to only activate once ever. Is there node to do this for me? (Or do I just set a boolean flag to "has activated")
(Relatively new to trees so this prolly is a dumb question)
misty wharf
I think you'd need to use a BB value and a decorator to check for that
There's some other ways to do it as well but that's probably the most straightforward way to do it
lyric flint
Hey Can I make my opponent car racing player
misty wharf
it's possible yes
charred ruin
Hey guys, using AIPerceptionComponent, how do you know if a specific sense STOPPED sensing something? Like with the sense sight, once the MaxAge is reached, how do you know the AI stopped seeing the player?
using that specific sense
wary ivy
there should be an event that is fired when something goes out of sight for example
though I'm not sure if that takes age into account 🤔
charred ruin
Yes the event is fired, but I can't find a way to know which sense triggered it
wary ivy
anyway, there's the OnTargetPerceptionUpdated event and if you break the AIStimulus struct it should have "succesfully sensed"
in the case of sight that is true when something comes into the sight range and false when something goes out of sight
charred ruin
For example, when something enters in sight, I use LastSensedStimuli[0].WasSuccessfullySensed to know if the sense in index 0 is sensed
but if I have 2 or more senses
LastSensedStimuli[0].WasSuccessfullySensed will return false if any of the 2 senses fail
charred ruin
yeah
wary ivy
looks like there's a non UPROPERTY FAISenseID Type; that might tell you which sensory even is which
in the FAIStimulus struct
it's a bit odd that some of those fields aren't exposed to blueprints 😄
charred ruin
I'll look into it, beats having to switch on an integer to know which sense is used
misty wharf
^I used tags for this when in BP's
Sight just works automatically usually and you can't give it a tag, but when using sounds for example you'd usually trigger it via calling the report noise event or whatever it was called, and you can give those a tag
so if tag == '' then it's sight, otherwise something else etc.
but using the SenseID or something in C++ is probably more robust
charred ruin
@misty wharf I think you can only add a tag for noise events
or did you do it with another sense?
misty wharf
just noises in my case but I'd assume any sense that you have to manually report for would support it
charred ruin
Just checked, only noise event asks for a tag
misty wharf
hm maybe it's just for that then
charred ruin
pine steeple
i will get this small AI utility plugin out
which will have a whole bunch of stuff to make the perception system easier to use
plus other AI stuff (some custom BT nodes and decorators0
charred ruin
That's awesome, any ETA?
pine steeple
towards the end of next week
charred ruin
looking forward to it
silk spear
How can I make AI avoid an obstacle? I ticked CanAffectNavigation on my spikes
but the AI still charges into them to it's death
verbal violet
Anybody experienced in modular characters, Mesh Merging? Some recommendations, links, I've just started with official docs and there some compile errors
https://docs.unrealengine.com/en-US/Engine/Animation/WorkingwithModularCharacters/index.html
Take a look at the TArray declarations and notice the missing types in all of them. I can not compile my code without these TArray types and I can not figure out what types they are?
ripe whale
Can you download the version of the engine that the docs were written for and follow the tutorials like that? Maybe intelisense could help you find the types once you had compiling code as well?
pine steeple
@verbal violet please don't post in multiple channels, especially channels that are not relevant. #old-rules
ripe whale
Is there a way to get my nav mesh generation tighter so that it goes right up to the tree and the cube in the photo above? I want my character to be able to navigate right up to the bounds of these objects but the hole that they place in the nav mesh prevents that
pine steeple
adjust your capsule radius
it looks like it is fairly big
this is what out navmesh looks like
ripe whale
by capsule radius do you mean the collision bounds on the static meshes shown in my screen shot?
I was able to get a much better result by reducing the "Cell Size" in the RecastNavMesh instance
ripe whale
That does help me out thank you, my cell size was 40 before
I've put it at 20 now which is much better
ripe whale
I'm still having an issue getting my character to navigate to one of these actors, basically I am getting the actor location and then I put that into a a MoveTo BTTask and the EPathFollowingResult I get back is always just "Invalid"
I would have thought that the code would have been smart enough to project the location given onto the navmesh and then use that, or use a partial path or something to get as close as possible
How is this case usually handled? It seems like people would want to move their actors close to static meshes that have collision pretty often, how are you suppose to do this in a reliable way?
pine steeple
turn on partial path
ripe whale
It is on..
Do I just need to increase my "acceptable radius" enough so that it covers the gap in the nav mesh?
actually even that doesn't work I still get the Invalid PathFollowingResult
The only thing I can think of doing is adding an offset off of the actors location to put it ontop of the navmesh but that seems like a really shitty solution
ripe whale
yeah my character does move to any other location
ripe whale
ah ok let me try that
bingo that worked
Pretty silly that that one checkbox cost me like 3 hours
oh well
pine steeple
:/
been there many times in the past 3 years
with UE4 and one silly checkbox issues 😄
ripe whale
haha
misty wharf
the project goal location is weird
I thought it should help with cases where the target isn't on the navmesh because it projects the point to the navmesh
but it literally seems to do the opposite and stop it from working :P
I had the same problem at one point as well
I must be misunderstanding its purpose but never could really figure out what it was really for
ripe whale
Maybe it is for locations that are directly above or below the navmesh? Like maybe it only projects along z axis?
I guess I could look at the code and figure it out
I just did a simple test, moved the actor way above the nav mesh on the z axis and project goal location did nothing, still got invalid with it both on and off shrug
ripe whale
So what does "Project Goal Location" do? When would you want to use it?
ripe whale
So I found out some stuff, basically the "Project Goal Location" will take the "Default Query Extent" specified inside of the Navigation System Project Settings and use that volume to project the supplied point onto the navmesh
For example I was able to solve my "Invalid" path following result issue by making the "Default Query Extent" large enough to include a portion of the valid nav mesh
misty wharf
Interesting
I wonder why does it navigate mostly correctly with that turned off though 🤔
I guess it might be generating an incomplete path, and with that turned on, it's not generating anything at all if it can't project it correctly?
ripe whale
Yeah if it is turned on and the projection fails it doesn't do anything
If it is turned off and partial path is enabled then the projection doesn't happen at all so it can't fail from projection failing
misty wharf
that makes sense, good job looking into it :D
hexed spade
hi guys how do I increase the radius on a navmesh where the AI can't go?
I want to increase the area around the pole that the AI can't go to.
lyric flint
@hexed spade That's actually intentional to prevent characters from clipping into obstacles
rapid ridge
If I have a bunch of AI following me, and when they reach me, the ones behind still try to move to me, how could I stop this movement if they are as close as they can get
anyone dealt with this?
lyric flint
@rapid ridge are you using the detour crowd ai controller?
misty wharf
@hexed spade you can add a collider into the pole actor to act as an additional hitbox, or you can add a nav modifier volume
hexed spade
I can make the AI chase the player but how do I make it run away from the player?
like if the AI has posession of the ball how can I make it intelligently avoid, run away from the player while moving towards the goal?
bitter veldt
what have you tried? that's not straight forward to answer in a few discord messages
pine steeple
EQS
opal crest
If you are using environmental queries, create a grid of candidate points, choose one that is far from the player (and toward the goal) and navigate toward it.
pine steeple
or get the dot product of the normalized vector of Enemy and Player, and choose a position that is not in that direction
EQS is probably the best though.
hexed spade
hmmm I like that dot product approach as well
rich marsh
One thing I am confused about, with the C++ UBTDecorator class, is that methods such as OnNodeActivation(), OnNodeProcessed(), etc., mention that they should not modify the object's state
I wanted to have a shared parent class that some of my decorators inherited from to set some common properties - based off of the documentation, am I not allowed to do that?
For example, several decorators need to have a weak object reference to the specific AI character pawn class that I created. Instead of setting that every single time the condition is checked, I was hoping to have that value populated when the decorator gets created
ebon zodiac
Are BehaviorTreeComponent and BlackboardComponent intended to belong to a Pawn or an AIController?
Updated:
(it's AIController)
{
Super::OnRegister();
AIOwner = Cast<AAIController>(GetOwner());
}```Is there something wrong with my BT? node #3 is interrupted before it finishes the movement completely
misty wharf
MoveTo SelfActor?
Isn't SelfActor usually a ref to the actor whose BT this is?
oh nvm I think I was looking at the wrong node because I got confused about the nodes being selected
:D
The MoveTo shouldn't finish before it has reached the destination, if it finishes before that then it seems the path it would've found was incomplete
rapid ridge
it stops in the middle of the movement, is there a way to debug it?
hexed spade
okay when I set FindPlayer EQS query to the AI character "CH_AltPlayer" it now works....but why won't it work on the player (CH_Practice)?
hexed spade
the problem is I have a PlayerStart actor that loads the player (CH_Practice) .
so when I set the FindPlayer EQS query to CH_Practice it won't show the debug sphere
even when I drag the CH_Practice actor onto the map, it still won't show the debug sphere ... what could be causing this
I mean it traces it fine in the editor....but not when debugging in real time
hexed spade
wtf now it works...i changed radius to small figure, ran into it, and then changed it back.....what did I do differently lol...or is this just it bugging out?
this is so bizarre
when I add a cube run and then remove the cube, the debug is gone
then I have to reduce the search radius to a low number run it again, the debug sphere is still gone
and then i stop. increase the search radius of the EQS query to a large number like before and then run it, the debug sphere is back.
wtf now it doesn't happen when i run through above (adding cube deleting and then starting again)
this is a complete mystery lol
bug?
storm zephyr
hello is there a way to say that a particular AI instance uses a certain navigation query filter? i'm asking this because i want to reuse the same behavior tree but have some instances that use the filter and others dont
if that is not possible then i need to make my own move to task that takes in a blackboard filter query and set it there
twin loom
OnTargetPerceptionUpdated, I'm trying to set a blackboard value to an object. The problem is that it isn't getting set. this is how I'm setting the value GetBlackboardComponent()->SetValueAsObject("TargetObject", Actor); Actor is the actor that was sensed
Setting the object works from a BTTask tho. I'm not sure why it isn't working OnTargetPerceptionUpdated The only thing I can think of is that in the BTTask, I have a blackboard key selector. But there aren't any blackboard key selector's in AIController so I'm not sure what to do
storm zephyr
fyi AAIController has a DefaultNavigationFilterClass variable that can be used for this exact purpose
twin loom
I'm having some trouble with the behaviour tree. I want to do something if the enum is set to Passive or Neutral. That's waht the node on the left checks. If that's false, I check if it's aggressive. The problem is that when the first check fails, it doesn't seem to check if aggressive. If I put the aggressive check first, it works for aggressive creatures but not for passive/neutral. How do I fix this?
pine steeple
you are using sequences
your top one should be a selector
i suggest learning the different types of composite nodes
twin loom
ok, I'm new to AI so I'm just using tasks and sequences for now
pine steeple
well then struggle ahead
or actually read up and learn about them 🙂
you can't just use Sequence everywhere.
your top sequence is going to exit out as soon as the decorator for Is neutral or passive returns false
meaning your Aggressive will never execute.
twin loom
ok, I'll read up on the different nodes
pine steeple
selector will continue till something succeeds
so change your top node to selector
and it will work.
twin loom
ok
pine steeple
in a nutshell, sequence will execute left to right, till something returns false or there is no more tasks
selector will run a node and keep going left to right till somethiing succeeds
hexed spade
hi guys I see this on top of the EQS docs "You can try out this Experimental feature, but we do not recommend shipping projects with it." how serious is this warning will it break stuff randomly?
or has anybody shipped stuff fine with EQS?
pseudo grotto
Hey how to add combat mode
floral mango
@hexed spade it's pretty solid at this stage, I wouldn't worry too much about the experimental tag
pine steeple
well if Fortnite use EQS for nearly everything in the world... To me that means its pretty solid 😄
buoyant geyser
@simple crest did you know that Dave Mark is on the gamedev.net discord btw
pine steeple
whois Dave Mark?
thorny jay
Hi everyone, I'm having a really infuriating crash in my AI blueprints. From the stack trace it seems to be a crash in an AI service, but I can't see what function actually causes the crash. The stack trace has two "unknown function" calls right at the end
The service is in blueprint, but it does call some functions I've defined in C++
So I assume the service is trying to run some code I wrote in C++ that crashes, but I can't figure out what
I can't even see which service it is that crashes, it just has UBTService_BlueprintBase::ReceiveTickAI() in the stack trace so I assume it must be one of my AI services
Does anyone know how I can debug this a little better? The crash is really intermittent, sometimes it happens after a few seconds of starting the game, sometimes it's after 10-15 minutes
patent hornet
what build @thorny jay ?
patent hornet
i mean packaged/PIE/Standalone, what binaries?
thorny jay
Ah sorry, it's in PIE, running standalone
Windows build
I haven't tried running it with a dedicated server, but this is meant to be an offline mode so it wouldn't make much sense to do so
patent hornet
c++ ?
thorny jay
Yes, mostly C++ but the AI is mostly done in blueprint. All of my AI Services are in Blueprint, but they call C++ code that I've written
thorny jay
Ok
patent hornet
and just work normally until it crashes
when it does though, IDE will hit a breakpoint
and you'll be better informed after
thorny jay
Fantastic, thank you. I'll give it a try
patent hornet
as you'll be able to see which service, which AI... etc
thorny jay
Nice
patent hornet
in your Locals/Autos
also, if you don't have editor symbols for debugging
its time to install those now
thorny jay
Hmm, running it from the editor using the debugger gives me an error
Cannot find Engine\Intermediate\Build\Unused\UE4.exe
Does it have to be a source build?
thorny jay
Ah there we go 🙂
@patent hornet Fantastic, it actually helped me fix a separate problem, now I just need to wait for my AI crash to occur. Thank you so much for walking me through that process
patent hornet
@thorny jay thats my default working mode
i always do a round of tests on the code making sure breakpoints hit when theya re supposed to
thorny jay
@patent hornet I'll be sure to use this in future. One of the downsides to being a self-taught programmer is you often miss some of the basics
patent hornet
@thorny jay one thing worth noting: editor started via .uproject file uses DevelopmentEditor, so if you re-compile DebugGameEditor then start the editor by doubleclicking .uproject, your changes won't be there
thorny jay
@patent hornet thats good to know, thats the kind of "gotcha" that would drive me crazy xD
thorny jay
@patent hornet Just to let you know that thanks to your help, I found the issue, and it was a doozy. My AI operates in squads, and sometimes it will issue individual orders to squad members. When a player joins the server, a bot will be removed to maintain team balance, and I was forgetting to remove the destroyed AI Controller from the squad array, so if it just so happened to try and issue an order to that squad member, it would find garbage data instead. Would never have figured that out without the debugger 🙂
deft siren
Hi. Please help a poor noob, is there a way for a pawn to detect if another pawn is blocking his path? I use detour crowd manager, with or without RVO but my pawns are still clumping toghether if it happens to have the same goal.
I would like to have some way to check if a pawn's path is blocked by another pawn to change its goal.
fallow hound
I don't think easily. Not saying it is impossible but it isn't a built-in feature.
Prob not a noob kind of problem to tackle tbh
hexed spade
thats a major relief that Fornite uses EQS lool
will ignore the experimental warning
fallow hound
yeah its been experimental for a long time
twin loom
not sure if this should go in this or #legacy-physics but basically, I've got a 4-legged character that is controlled by ai. The collisions work perfectly except when I have the ai go to the player location when attacking. The player is meshed into the creature. Is there any way I can force the creature to stop going inside the player? The yellow capsule is the capsule component found inside the creature.
thorny jay
@twin loom one idea is to create a new "creature" collision channel and make the creatures capsule component use it, then add a capsule to the player which blocks only that channel
It won't interfere with player movement but will block the creature
twin loom
The collision works just fine except when the creature ai controller is moving the creature to the player location
The yellow capsule is what's being consided the creature's position
And the creature's trying to reach the player causing the player to ignore the normal creature colliders that are shown in green
@thorny jay
thorny jay
@twin loom Unfortunately, the character movement component in UE4 only takes that capsule component into consideration when moving
twin loom
I just changed the capsule component on the creature too be giant so the glitching isn't happening but theres some clear problems with this
thorny jay
So one option is to place the player and creature's capsules on separate channels, have all the capsule components for the creature block the player's channel, and add a big capsule to the player to block the creature so it can't get close enough
Or you will need to write a custom movement component
twin loom
I think I'll go with the first option
rapid ridge
I'm using AAIController::MoveToLocation/MoveToActor but the acceptance radius is wrong, the AI stops before the acceptance radius is met, not right at the radius
is there something I can do?
twin loom
@thorny jay Would I create a new channel for the player and a new channel for the creature?
thorny jay
@twin loom Hey there. Yes, you would create a new channel for both
hexed spade
With EQS I have been able to make the AI run away from the player. How do I make it favor grid locations that is close to a fixed location (ex. goal)?
My thinking is adding another distance test to the goal from the AI player should modify the grid on top of running away from the player
misty wharf
yeah if you add a distance test comparing to goal and scoring points that are closer to goal higher, it will add that score into the total score for each item
and as a result it should start favoring ones closer to the goal since their total is higher
hexed spade
@misty wharf hmmm seems like it is still giving a higher score to where the player is
the distance to test set to goal works but something is wrong with my scoring here....it is giving highest score to where the player is when it shouldn't
im gonna try fiddling with the goal distance to see if it changes things...
yes it works as it should but now the AI seems to prefer to be right under the net
it just does this forever....
I thought about putting an invisible cylinder around the goal post but then it wont pick up the ball again if it just lands inside the cylinder
(side note: EQS is powerful stuff!)
this is what I mean. it'd be nice if I could add another distance test to the area behind the backboard....AI guy thinks he MJ 😂
uneven shell
hey guys, I have a question. I would like to position enemies on radius around the player, when they approach him, so each of them has clear line for shooting and won't fire at each other. Any smart ways to achieve it?
uneven shell
thx
whole steppe
rapid ridge
wouldn't that have the same result as a regular MoveToActor? I don't know if it would be any different
charred ruin
Any one have any idea why navmesh characters get stuck here?
they get stuck on all stairs in my game, I tried disabled the stairs from affecting navmeshes and using blocking volumes but they still get stuck in the stairs
pine steeple
probably to big a capsule
(ai has a capsule too big that the one the navmesh has set)
charred ruin
nope, tried making it smaller and they still get stuck at the same spots
misty wharf
yeah I wish there was some easier way to debug navigation
I just created a new character in my game and it completely refuses to move even though it's essentially identical to my previous npc's :P
with BT's the navigation system just doesn't tell you anything, it just silently fails
I should have tried the visual logger before complaining about this...
turns out it actually does tell you what's up :P
hexed spade
how can I see the EQS grid while playing the game? I press apostrophe and toggle between numpad but I only see nav mesh being generated in real time .... I need to see what the new EQS grid values are that depends on a location that changes
btw anybody know how I can fix this bug #gameplay-ai message
like I need it to respect a certain radius around the hoop
I guess I could measure the distance between the hoop and the player and if it falls underneath the threshold have it move back outside and shoot the ball
in the behavior tree is it possible to collapse a branch? its getting quite large
floral mango
if you have the gameplay debugger open and select the pawn, you'll see the EQS results
or you can use the EQS testing pawn
hexed spade
yes! ty
slow bobcat
hello! long time no see!
We want to have areas where short enemies can go through and tall enemies can't (they will go around).
The "problem" is that we use NavWalking (which makes AI to not collide against World Static / World Dynamic) + crowd manager
Reading about how to handle this I saw that some people use NavArea_LowHeight. I can see it in my level (in editor) but I have no clue how to use this. When using it, AI that can fit under, just goes around.
So here are my 2 questions
- Does anyone use this or knows about documentation that explains how to use it? I can't find anything anywhere except mentions to it
- Does anyone know if crowdManager actually supports this?
Just so we are on the same page, having an AI that fits under the grey block, I would expect it to pick the pink arrow path, but it picks the red path.
Any clues will be appreciated!
Thanks!
opal crest
I haven't dealt with this specific problem, but have you set up your Agent for the shorter AI to be able to crouch? I think that's what the nav system uses to allow an agent to cross a Low_Height area.
Really just a wild guess on my part.
wild plover
Hello. i have a simple AI (it is waving at the player when it see it). how can i make it call functions on his own actor, ? should i create a new Bttask for each function ? or there is a way to do it other way ?
slow bobcat
@opal crest yeah, they are able to couch, couch capsule height is smaller that the gap under the grey block and I confirmed (printing on tick for debug) that is crouched
graceful saffron
I've got a voxel block world, but AI just won't walk up the blocks. They're stuck on whatever level they spawn on. No matter what I set the Recastnav settings to, they simply won't walk up. I think it's because the block is a 90 degree world like minecraft and nav only works up to 89 degrees? Not sure what to do
AI moves fine in the green, but will never move up a floor or walk down. They just get stuck :/
pine steeple
you need to set the step height
opal crest
@slow bobcat I took a moment and prototyped a way to do this, because I don't think you need LowHeight volumes to accomplish this. I set my AI Pawns to use the AIDetour controller. I created a short pawn with a capsule 96 high, and a tall pawn with a capsule 192 high. In Navigation System I set up two agents (Short and Tall) whose height matched the pawn capsule height. I made sure my nav volume was high enough to cover the areas they needed to get under. (The top down sample starts with a low navmeshvolume, so this was a brief gotcha). Once I got everything set up, short agents go under arches, tall agents walk around.
Once this is set up, you can use the RecastNavMesh-Short and RecastNavMesh-Tall to toggle the visibility of the two navmeshes independantly. to verify that there's no walkable mesh for tall underneath the low areas, and that there is a mesh in those low places for low agents.
Having collision disabled for your moving pawns should make this easier, rather than harder (since then they won't get stuck on geometry that disagrees with your what your navmesh tells your AI it can do).
slow bobcat
Ooh thanks. The only thing that doesn't add up here is that you are using 2 agents and Detour crowd control doesn't support it. If you look into the header file of the crowd control, you will find this (image), but I will try what you did anyway. Will be back with results. Thanks!
opal crest
Oh, yikes. I read about that, but it seemed to work anyway on 4.25
Maybe my setup was too simple to trigger the issue?
slow bobcat
In the movement component of your AI, is it set up to use NavWalk? If you play and look into the physics config of the root component at runtime, is it set to Override world dynamic and world static?
opal crest
It's not. I managed to add a little more complexity to my setup and you're absolutely right. Detour breaks as soon as there are multiple agents.
Maybe you could use NavLinks, conditionally enabled for the shorter agents, but that seems like a lot of trouble.
Or a custom nav modifier volume that is ignored by short agents?
I'm going to see if that second makes sense.
opal crest
Yeah. NavQueryFilter's are the trick.
My Tall Agent Uses this Query (Class Defaults)
My Short Agent uses this one
These are both subclasses of NavQueryFilter. NavArea_short is a subclass of NavArea (no implementation at all)
Short character does this:
Should work just as well with the LowHeight areas, but I wanted to try custom volumes since it looked like something I could use for a different project.
hexed spade
hi guys my character refuses to run into the wall on the left (checkered) is there a way to make this possible? adjust the grid?
robust kelp
Hi Guys, is somewhere a Tutorial or BP for the Combatreaction/System like Hellsplit or Blade and Sorcery?
lyric flint
hi, how can i move AI and make it jump in order to reach the clouds?
misty wharf
you can probably use a nav link proxy, with a smart link you should be able to trigger actions like jumps
glossy flame
is there a way to make the "Move To" node brake slowly when reaching the end and not just abruptly stop? (please ping me with answers)
pine steeple
set the braking
in the CMC
also i know in BT the moveto nodes have a braking thing
glossy flame
@pine steeple thats the move to node, none of those influence braking in any way
and i already tried setting the braking friction in the charactermovement but they get completely ignored for some reason
pine steeple
there is something somewhere for the braking
i haven't got UE4 open atm, but i am 100 percent sure there is something for braking
dawn crystal
Hello everyone! I have a problem strictly connected with Spline Line and NPC behavior. Before that I have created a patrol path and if my npc saw me, he immediately changed himself position (in the area of navmesh) to mine position (player position). As following, I wanna to create a Splite Line (done) but if my NPC sees me, he is following splite line still. He cannot go out from given splite line. My question is following: "How to force NPC's to follow me (FindPlayerPosition and then Go to this location)
low path
Hi! I am attempting to make a chase and roam AI for my game.
I follow a tutorial but it just doesn’t work. This is my first time using AI and was wondering if anyone could redirect me to a better tutorial or give me any material to help. Thanks!
tranquil reef
did you follow this one?
https://www.youtube.com/playlist?list=PL4G2bSPE_8ukuajpXPlAE47Yez7EAyKMu
@low path
low path
No, will watch that. Thanks
tranquil reef
@low path
...additionally I'd recommend reading a book regarding behavior trees because (me personally) find it very hard to understand such a complex topic when just watching stuff and replicating it. You could try "Blueprints Visual Scripting for Unreal Engine - Second Edition". I heard just positve stuff about it (I think because of Marcos Romero who seems to be a great teacher regarding blueprints etc.).
I just finished "Hands-On Artificial Intelligence with Unreal Engine". Its a good introduction to behavior trees but you should know blueprints (or C++) at least a little.
Hope that helps 😉
low path
Could you link me?
pine steeple
BT's are easy once you understand the basics
the flows are also easy once you get that core knowledge down
i can do complex BT's and understand the flow quite easily
south lynx
hey guys, I have a question. I would like to position enemies on radius around the player, when they approach him, so each of them has clear line for shooting and won't fire at each other. Any smart ways to achieve it?
@carrpenoctem#5419 Hey, did you get a solution for this? I have the same problem but my enemies don't shoot, they punch. I will try an enemy manager at gameinstance level that tells enemies if they can attack or position, etc. Still haven't all the rules figured out.
slow bobcat
@opal crest
Hey! sorry for the late reply.
Yep, that's exactly what I need. Never looked into NavFilters before. Now I only have a problem: we use the async task AIMoveTo in BT's and it doesn't allow you to pass filters because... reasons (image). But that's fine, I can make a child and override that exposing the filter. Will see if that works.
Thanks a lot! will be back with results
Actually, I can override the default when the enemy is possessed. Easier to do
slow bobcat
Ok, I did this but enemies can still get into these areas.
Unfortunately I can't show any recordings due to NDA, but I will try to explain the problem with images.
what works:
- Enemy spawns on the orange cross
- Player is on the blue cross
In this case, the enemy will go all the way around the pink area to engage the player
What doesn't work:
If the player crouches and stands where the red square is (imagine that's the crouching capsule) the enemy will get there and then it will get stuck, because it doesn't know how to move in the pink area.
I don't know why it's not considered an unreachable area.
We can see many problems if an enemy is pushed/dragged into those places.
One would say "well, the grey block would block the enemy through physx", but it will not, since it's a static mesh and we use NavWalking.
A different perspective with the working case
vagrant crescent
Hello hello! I'm not sure if this is common question, how do we put better optimization for our AI's? especially semi open world games with 50 or more AI actor inside? anyone can give some tips for that? Thank you!
patent hornet
profile, find out whats costing more then it should, fix it, repeat
vagrant crescent
Ok ok, Ty!
pine steeple
if ai are out of sight, and don't need to do anything till they are in range, simply disable stuff
one optimization i am looking into is, monsters that are far from any player, disables most of its stuff till its in range
out of sight, out of mind
tranquil reef
is there a fast way to be invisible to AI? I have a pawn with an AI-Controller that uses AI-Perception Component and I tried to deactivate the AI-Stimuli Component in the player character but it doesn't seem to work
tranquil reef
@pine steeple
That did it! Thank you very much :)
I always wondered what "deactivate" does since I had always issues with that
tranquil reef
@pine steeple
btw you said that BT's are very easy to you. Do you have any tutorial recommendations?
opal crest
@slow bobcat Glad you were able to make some progress. I see the remaining problem, but I'm not sure how to fix it. You could try modifying the Filter for the tall characters to not be excluded but instead insanely costly (the approach taken by Obstacles). This would allow it to move in the area, but only if it absolutely had to. That will have obvious drawbacks, though, since you could no longer create unreachable spaces. A few ideas: look at the behaviour that allowed the enemy into the space in the first place. You might also add a test in your BT to trigger a escape from out of bounds behaviour that uses MoveDirectlyTo or overrides the filter?
pine steeple
@tranquil reef honestly, no, i just learnt by using
Services are things that update Blackboard values/specific logic for the AI that must run whilst tasks are running
Tasks are what the AI should be doing
Decorators are like should we enter here or not, and if we are in here, shall we leave here if X condition happens
Selectors execute till something returns success
Sequences execute till something returns fail
Both composites will return when all nodes are exhausted
tranquil reef
@pine steeple
Alright thank you :)
I'll keep on doing then!
twin loom
I've got an AI that chases the player when it sees it. How would I rotate the head bone to look towards the player while the rest of the skeleton continues it's chase animation?
pine steeple
aim rotation
counter rotate the root bone
wait that TIP
just use AimOffset
and have the focus actor in the animbp
and rotate the head to the focus
would be done in AnimBP
twin loom
@pine steeple I'm sorry I don't have much time right now but is this tutorial similar to what you are talking about? https://docs.unrealengine.com/en-US/Engine/Animation/AnimHowTo/AimOffset/index.html
dry yacht
Hello guys wanted to ask questions, Nav Mesh Bounds Volume is by letting the AI to move where we wanted it to be but seems like my AI won't move after trigger box collide with my characterBP
haughty coral
How do you guys usually save behavior tree state in-game? Saving blackboard values may not be enough because there is also state which includes being at specific node of sequence.
misty wharf
I saved BB values and set up my tree with decorators and such so that it would go mostly into the expected state if it was loaded
Eg. if there was a sequence that was being done, after which the BB would be in a specific state, I would gate the sequence with a decorator that checks BB values
so this way it would just skip straight over it
lyric flint
Hi guys, for my game I want my AI's to have text floating above their head. This shouldn't be that hard I think - does anyone have a tutorial that might cover some of that area ?
Like the text in runescape
haughty coral
@misty wharf That makes sense for small trees but for bigger ones you would need decorators on every node to reach desired state and even after that you would need to save state of tasks like Wait
misty wharf
You could group your nodes using sequences so you wouldn't need to have the decorators on everything
But yeah it's not perfect.. not really sure if there's any other solution, it doesn't seem like you can really save the state of BT execution
fallen verge
@lyric flint Try parenting a Text Render Actor to your AI's and create a function that passes in a string to modify the Text Render. Could also use delays or Timelines to create the typewriter effect.
meager bobcat
is there a way to do a different player state class for AI controllers?
ive got a stealth game and i want to have like a Detection Meter that's replicated to all other players
and all my AIs use a player state and that seems like the place to put it
but I don't want it to be in the same class as the player stuff
misty wharf
You could probably store it in the AI controller too. Not sure if there's a way to have a different kind of player state for them
meager bobcat
AI controller doesn't replicate though, does it?
misty wharf
hm you might be right
meager bobcat
so it seems like I can do a different class for AIs in the AController::InitPlayerState function
yeet
lunar bone
Hey guys. I'm using a task in a behavior tree to make an enemy ai to do a simple attack. The task is basically just calling an Attack Function in the Enemy BP.
Any ideas how to let the task know that the attack is finished? The time it takes to attack can vary depending on what type of enemy is getting the task. I tried using an Event Dispatcher, but doesn't feel like a good solution to bind the event every time the task is being executed.
misty wharf
What you're describing with the dispatcher is how I've done it
I have a number of different actions that can be triggered via BT tasks, and they produce an event on the pawn which the task listens to... it seems to work just fine :)
The only thing to keep in mind is that you need to unbind the event after it has fired, and also unbind it from the abort event, otherwise weird stuff could happen
lunar bone
Oh, that might explain why I got some weird results. I'm not unbinding the events atm. Thanks @misty wharf , I'll try that right away 🙂
hard crag
Guys. I've asked to make a wolf pack AI prototype recently. I need some hint to be start with. The wolves must be able to circle around the player as in a pack.
graceful saffron
How do you guys make AI not freeze up/stop logic when the player jumps onto objects and such? Ive noticed in a lot of UE4 games you can bug out the AI by jumping onto objects. AI doesnt know what to do lol, cant reach the player so it stops
pine steeple
its not that easy
you need to keep track of there last known location
and move to it
before they got of navmesh
tranquil reef
@graceful saffron
I remember that there is a node called "is jumping" or "is falling" for pawn I believe. Maybe you can use these also for your logic
lyric flint
@fallen verge Thank you, I got it working after a bit of reasearching 🙂 funny how you need to know the name of one little thing sometimes
atomic crescent
How do you get a reference to a Player Character from within an EQS Generator?
class UBTT_GenerateCoverPoints : public UEnvQueryGenerator_BlueprintBase
This bit here turns up all nulls.
void UBTT_GenerateCoverPoints::GenerateItems(FEnvQueryInstance& QueryInstance) const
{
GEngine->AddOnScreenDebugMessage(-1, 5.0, FColor::Green, FString::Printf(TEXT("this->GetWorld() = %p"), this->GetWorld()));
GEngine->AddOnScreenDebugMessage(-1, 5.0, FColor::Green, FString::Printf(TEXT("GEngine->GetWorld() = %p"), GEngine->GetWorld()));
GEngine->AddOnScreenDebugMessage(-1, 5.0, FColor::Green, FString::Printf(
TEXT("GEngine->GetWorldContexts()[0].World() = %p"),
GEngine->GetWorldContexts()[0].World()));
ACharacter* PlayerCharacter = UGameplayStatics::GetPlayerCharacter(
/* WorldContextObject */ WorldContext,
/* PlayerIndex */ 0
);
GEngine->AddOnScreenDebugMessage(-1, 3.0, FColor::Blue, FString::Printf(TEXT("PlayerCharacter = %p"), PlayerCharacter));
}
usually by casting the querier
exotic current
hey guys, I cannot get my AI pawn to rotate with control rotation. Add Control Yaw/Pitch Input does nothing, neither does the rotation settings in CharacterMovementComponent
I've tried executing these functions using timelines, tick, and just one-offs, and nothing works. I'm not sure what I'm doing wrong as I'm pretty sure I've done it before?
Add Movement Input works, Controller Input doesn't
pine steeple
disable all of them
in the CMC, tick control rotation and disable Orient to rotation
whole fern
Maybe a dumb question but can you use anything similar to Simple Move to Location but without AI Controller?
whole fern
how?
I don't want to just interp from point a to b. I want to make use of Nav mesh to avoid obstacles but without AI Controller.
whole fern
do a pathfind query
@pine steeple Thank you. May I know how to use this in C++?
pine steeple
UNavigationSystemV1* NavSys = Cast<UNavigationSystemV1>(GetWorld()->GetNavigationSystem());
ANavigationData* NavData = NavSys->GetDefaultNavDataInstance(FNavigationSystem::DontCreate);
FPathFindingQuery Query;
Query.NavData = NavData;
Query.StartLocation = StartLoc;
Query.EndLocation = EndLoc;
Query.SetAllowPartialPaths(false);
const FPathFindingResult PathResult = NavSys->FindPathSync(Query, EPathFindingMode::Regular);
TArray<FNavPathPoint> Points = PathResult.Path->GetPathPoints();
for (const FNavPathPoint& Point : Points)
{
//Do whatever
Point.Location;
}```@whole fern
whole fern
Thank you so much @pine steeple! I will make use of this function. I can finally remove AIController class 🙂
whole fern
For my RTS game each civilization can have upto 200 units so I don't want to have 200 pawns + 200 AIControllers