#gameplay-ai

1 messages · Page 105 of 1

keen furnace
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nop

sudden drum
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what confuses me... is that it does reach the moveto task...

keen furnace
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it just kills the aitree

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(it stays there, but is waiting for an event to unlock ti that cant happen)

sudden drum
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I probably misinterpret what the yellow highlighting means then

keen furnace
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if its yellow, you still have a tree

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you mentioned it had no more flow

sudden drum
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nono the pics i posted

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are the of the game at runtime

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with the ai not moving

keen furnace
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ohhhhhhh

sudden drum
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and focusing on a dead actor

keen furnace
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thats a whole diff issue

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roit, get AIDebug on and click your AI in simulate

sudden drum
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and I need to run the S_GetTargetActor

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which doesnt tick

keen furnace
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also check your "blackboard keys" in the tree at runtime

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check the references are right

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if not, thats why

sudden drum
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checked those are all fine

keen furnace
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but yeah, click the troublesome ai in sim with AIDebug on, see if hes even pathing

sudden drum
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Let me check how to d othat

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I have no idea how to do that

shell dock
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@sudden drum did you checked that every task has a finish execute? maybe forgot a abort node?

sudden drum
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Im just using moveto task

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what confuses me... is that... there is the yellow highlighting on the Service S_GetTargetActor.... but I have some print strings in there and I can tell it is not ticking

shell dock
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hm like your whole tree/ai dont get fired anymore?

sudden drum
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what you see in the pics is the runtime freeze state of the AI

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it looks as if it is executing

shell dock
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hm

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the moveto task from epic.. continous go on the point... you should put in another task behind it

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the move to is good if you want to change the position value while he is moving

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you could add a custom task after that... what only walks to the same position

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do you have any events thats maybe deactivate the tree?

sudden drum
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yeah

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hold on

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I stop logic on death

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and star logic on possess

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what I don't understand

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...is

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shouldn't a service at the root of the BT

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always tick?

shell dock
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the bt should always tick

sudden drum
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but the answer here says it differently

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the guy says that it doesnt return to the root to tick the service

shell dock
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well, i dont use a service at the start/root

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aiperception tells your ai if you see something or not

sudden drum
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I'm probably doing this wrong then

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Yeah wasnt using the perception thing due to the type of game

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it is a fighting game

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like nidhogg

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well... This tells me i could actually

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move that logic in the AIController class directly

shell dock
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hm what do you want from your ai?

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or whats her "job"

sudden drum
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move towards the current opponent, fight, and if it kills him run towards the goal

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new enemies will spawn

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what happens

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is

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after it kills an acto

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actor

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it sometimes remains focused on that one

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while the service should refresh that

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...but... that doesnt happen

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cause it doesnt tick that service

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although it is highlighted

shell dock
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well for that you dont need a service... one selector and some sequence are enough

sudden drum
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but it might change focus

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because there can be 2 enemies

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and the closest one gets focus

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so i want that to tick

shell dock
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hm.. i would do that in the aicontroller or the charackter bp

sudden drum
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yeah I'll do that

shell dock
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keep your bt tree simple

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and control it with true or false

sudden drum
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yeah I have a hard time understanding what should and what shouldnt go in the BT

shell dock
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well the charackter is like the body... what could tell the ai controller if it killed/attacked someone succesfull... the aicontroller are the eye and the communication plattform... the b tree are the logic....

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go to goal (this is the last variable that can be true) to the left/ first thing to check

sudden drum
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yeah but for example... I coded combat logic all on the Ai controller... cause it was way to messy doing it in BT

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I feel as if this wouldnt be the correct thing to do

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but i just limited the bt to handle Generic MoveTo logic

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so it knows if it has to move towards the goal or not

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cause a lot of the combat is handled by responding to dispatched events from the target actor

shell dock
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lets keep it simple... the selector have to choice: go out to goal > kill/attack > go to target > idle/patrol

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no enemies? > goal

sudden drum
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yeah

shell dock
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or death what ever

sudden drum
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that's what it is doing

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thank you so much for your help Aldi!

shell dock
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looks cool

sudden drum
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Thanks!! 😃 I'll give you a free key for your help! I'll take a note

shell dock
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a not accurate example (dont copy that xD) but to get the logic

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greatly simplified, but i think you get the idea

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(i just pack move and attack as onces.. not totally correct.. but how someone handle animations and death are diffrent)

sudden drum
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Yeah I get the idea!

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I moved the focus actor thing

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on the AIController

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and...

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It is now working

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but

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these bots get stuck badly...

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so there has to be a problem with a MoveTo task or something

shell dock
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yeah as i said, the move to task from epic alone can be couse troubles

sudden drum
shell dock
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because it go to move to task.... and then go agian into move to task

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and it never stops

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you have to add a task that change the blackboard value after the move to task

sudden drum
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so im guessing it is stuck on that task

shell dock
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that it can enter the next stage

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because the selector basicaly select from left to right

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means > move to > go back to selector > goes back to move to

sudden drum
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ok

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so i need something that makes him break out of that system

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in case it fails

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Is there something that can tell me if it is failing_

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?

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some idk debugger

shell dock
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ah the move to task dont fails

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its works like it should

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but after that it "choice" the same task agian

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you can watch that fast... its short and helpful

sudden drum
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yeah seen them already

shell dock
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than you know your problem

sudden drum
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but

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I might have missed something

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exactly

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the selector stops

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as soon as it finds one that succeeds

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it succeeds

shell dock
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do you have a mic?

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than i can explain it to if you want

sudden drum
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nope 😃

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but hold on I'll try figuring this out a sec

sudden drum
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...mmh

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it is stuck in the moveto node

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and it wont move from there

shell dock
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yeah you need to use a sequence

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the selector goes to > move to > finish > move to agian

sudden drum
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yeah

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but i dont want a sequnce

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cause

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that means

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that after each time the player moves it needs to do something after

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My players never stop moving

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they have to constantly move while fighting

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I just cant understand why it just stays there

shell dock
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do you change the blackboard value somewhere?

sudden drum
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yeah

shell dock
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if found jump is not set its stay in that selector> the selector only execute move to > successful > dont care about the wait node > goes back

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if you need the move to task "always"

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then put it on every sequence

sudden drum
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ok i can now see it switch between the two

shell dock
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or the move to has to fail for the selector

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or the value changes and he decorator aborts thats

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and if you should want to go back to found jump the condition should aborts both

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if you have more selectors and sequence

sudden drum
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it is going in the moveTo

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with different locations

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There is something seriously wrong here

shell dock
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to you change the location?

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if you change the location while move to is running > move to goes to the changed values

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you need to make your own move to task if you want to "grab" a location and move to there and then go to a new location

sudden drum
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i think that my main problem

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is that i dont really understand services

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I thought that they ticked if a child task was being executed

calm plank
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Hey, how would i implement a 3 stage radius sound emitter for my AI, as like a terror radius, like how dead by daylight did it

shell dock
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@calm plank you player charackter need a pawn noise emitter component

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then you can use "make Noise" node

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your aicontroller needs pawnsensing or aiperception

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there is a event in the aicontroller "On Hear Noise

sudden drum
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I cant figure it out

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it is killing me

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everything is working.... it just becomes stupid and it doesnt know how to path anymore

violet notch
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ok im lost

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I've done this before multiple times but for some reason this value is not getting set

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EnemyAI says its not set

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but I can 100% confirm it is being set

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what am I missing?

patent hornet
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@violet notch can't tell from this, but there is a better way to set blackboard values

violet notch
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I'm sure there is a better way, but I've done this so many times before I just don't know what i've missed

keen hinge
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Make sure that the key name matches to one in the bb

pseudo onyx
keen furnace
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no idea - you didnt post a) your start/end logic for the trace, or b) the collision settings of the thing it is intended to hit @pseudo onyx

violet notch
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it prints properly with that test print string there

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but the behavior tree still beliuves the value is invalid

violet notch
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and whats worse is that I have the exact same setup that IS working litteraly right next to it

violet notch
keen hinge
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try to set the draw debug type to duration, expand node and set time to 10 and see what happens

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@pseudo onyx

coarse lantern
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Hey guys, quick question

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I've made a simple character(based on the ThirdPersonTemplate) that uses the "stock" AIController. I want to click and move. I've made raycasting and everything work fine, but when I try to make the character walk by using the AI MoveTo node(no BehaviorTrees) it just dont do anything. the Movement Result says "Sucess"

patent hornet
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and MoveToActor is at target location?

coarse lantern
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Yes, it passes one of the "TargetPoints" actors you see on the navmesh

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I've also tried just giving it a static location

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nothing works

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huh

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okay

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so

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I gave it a "Self" reference to the pawn and now it works... Funny thing is I did this earlier without luck

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so I must have changed something else

crisp spindle
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can someone shed some light on EPathFindingMode::Hierarchical ? hard to find anything about this finding mode

patent hornet
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can probably find the code if you start from EQS pathfinding queries

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as it offers a choice between standard, hierarchical and raycast

crisp spindle
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hm, i was trying to avoid that 😄

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time to start reading then

patent hornet
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yeah, not exactly light read

crisp spindle
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FindPathImplementation = FindPath;
FindHierarchicalPathImplementation = FindPath;

TestPathImplementation = TestPath;
TestHierarchicalPathImplementation = TestHierarchicalPath;

looks like it only matters for tests blobThink

violet notch
scenic fox
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Hey guys!... i don't know if any of you can point me in the right direction, but i'm trying to use NavMesh links to do a jump (from lower to higher point).. do any of you know of some literature that i can read to understand how i could get to do that?

pine steeple
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@violet notch is it actually updating the key in the behaviour tree blackboard

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cause my thought is, you are setting the wrong blackboard

violet notch
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I dont think its updating the key in the blackboard or it would in the behavior tree as well

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@pine steeple

pine steeple
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have you checked the blackboard you are setting is the same as in the BT?

violet notch
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yes

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@pine steeple

shadow sierra
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anyone ever implemented street traffic?

gilded tree
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Hey guys, I've been stuck on this issue for a while now. I have multiple AI of the same actor class (blacksmiths) which I want to find another actor (in this case an anvil). If they interact with the actor all other actors of the same class that's trying to interact with that object should disregard it and do another task like MoveTo a random point. Once the AI is done interacting with the actor, then other AI can take its place.

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Here's the actor (anvil) which has a collision box for overlap events:

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And the AI itself. I'm pretty sure I'm doing something stupid here haha. 🙂

tropic lily
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I know this sound retarded but how do you rename a new service node?

woven mural
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I would have aquick question what is the easyest way to make the ai first look at the location before moveing instead of haveing that instant turn something more smooth.

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Instead of the instead turning a more turn in place style turning

shadow sierra
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do you want it to move and turn or turn THEN move?

woven mural
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@shadow sierra I would prefer to do it first turn then move.

shadow sierra
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okay, easy

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so you in your tick, you need to do something like the following:

if( DistanceBetweenCurrentRotAndTargetRot < StartMoveRotDistance )
    CurrentMoveSpeed = MoveSpeed
else
    CurrentMoveSpeed  = 0
woven mural
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Welp only if i would use c++. xD

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Welll the thing is how you explain it i already have.

shadow sierra
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oh i see, one sec

woven mural
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this for example is my current setup

shadow sierra
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i think the problem is the ==

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of rotators

woven mural
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hmmm how could i work around that one ?

shadow sierra
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there is a way of measuring the distance between two rotators

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also what is the purpose of this task?

woven mural
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its to rotate the Tank Vehicle to the new rotation

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It gets the new move to logation from the blackboard normalizes it gets x rotation from vector and uses that as the interp to location

shadow sierra
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i would prefer to do this in the tick, constantly rotating and moving towards its target if it has one

woven mural
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wait where in the tick ?

shadow sierra
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anywhere in the tick of the tank

woven mural
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You mean like event recive tick ai

shadow sierra
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possibly

woven mural
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this is what im doing atm...

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welp found a solution

shadow sierra
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nice, well done

gilded tree
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Anyone that can help me out with my question a few scrolls up?

wild mortar
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Is there a way to recompile all Task BP at once?

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In my Task BP, I cast to a base BP character, and call a function from this class

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however, after a very minor change inside the function (adjusting node position, no signature changed)

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All of my BTT that was referencing this function got a yellow warning

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and I had to go through all my BTT to recompile them :\

ebon ore
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Hey guys!

Is there any way to make character's movement with steering (not sure if it's the right word)? I mean when changing a moving target, rotate movement direction smoothly, instead of instant direction change.
It's not about the pawn rotation, it's exactly about movement direction.

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top one is the default movement path
the bottom is what I'm trying to do

sorry for Paint picture xD

📎 Screenshot_227.png
magic jasper
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Not by default. Character Movement follows whatever 'RequestedVelocity' is, which by default is just the next pathpoint

ebon ore
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well, the top path is the default movement if just use MoveTo to a new target

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though thanks for the RequestedVelocity, now I think I know how to make it

magic jasper
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Characters just rotate towards whichever direction they're moving. There's a checkbox in the character for making it slowly rotate towards the direction, but it will always move directly towards the next pathpoint

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E.g. you can't really "round off" the corners along the path

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Might not be a checkbox actually... RotationRate maybe

ebon ore
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@magic jasper as I said, my question is not about the pawn rotation, rather about movement direction rotation. Anyway, I'm going just to add a lerp to the RequestedVelocity, I think it should work.

magic jasper
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Yeah, that's the bit you can't change without modifying the character movement component a fair bit.

pine steeple
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anyone here used EQS?

pine steeple
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no

tropic lily
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Hey is it possible to make custom events fire off in Service nodes which are activated from outside objects/actors?

patent hornet
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it is, but getting the reference to the Service from outside is complicated

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you should bind its events to event dispatchers in other objects instead

tropic lily
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Just so we’re on the same page, event dispatchers are these things, right?

📎 image0.jpg
patent hornet
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no, those are events

tropic lily
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Oh no I mean the blue node

patent hornet
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as BP calls it

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no

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you add them below where you add variables

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they can have inputs for any payload they are supposed to transfer when called

tropic lily
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Found it

patent hornet
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from the Service, you find a reference to an object that has a dispatcher and BindEventTo<your dispatcher name>

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from the object, you Call<dispatchername>

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result is the dispatcher will, when called, execute all events bound to it

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without having to have a reference to the object those events belong to

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(in c++ event dispatchers are called delegates, if that helps any)

tropic lily
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Sorry if I sound stupid, but the dispatchers is service node I’m trying to contact, right?

patent hornet
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that made literally no sense 😛

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example

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you have a Character with float Health

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you want your Service to execute some code whenever that Health changes

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your Character has EventDispatcher, say named HealthChanged

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and a SetHealth function that takes in a float input (dispatcher also takes a float input)

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SetHealth sets the Health variable to its input value, and calls the HealthChanged dispatcher, passing it its input value as well

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your Service has a reference to your character, and on ReceiveActivationAI, for example, it takes a Pawn reference, Casts it to your custom Character class, and from that pin you do BindEventToHealthChanged

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that node will have a small red rectangle bottom left, from which you can draw a line and add "custom event"

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that event will automatically match the dispatcher's signature

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and it will execute whenever the SetHealth function on the Character is called

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it will also have a float value, which is the new value of Health variable in the Character

south prism
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Can someone answer me why my ai is sometimes not using his AnimationBP, when I start in preview? Then the AI is just moving with his normal position

patent hornet
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that is exceptionally vague @south prism

south prism
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dont know how I could explain it better

mighty cedar
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how do decorators work, i put a decorator in a selector, and it ignores its value it executes first tree off of it

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basically i have a selector where it checks blackboard value if AI is dead or not.

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but it ignorest its value

ripe whale
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Does anybody know how to have a decorator in the behaviour tree test a value in a blackboard key? Specifically I want a decorator to check to see if a bool value in my blackboard is false and if it is false I don't want to run any of the child nodes in that branch

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@mighty cedar I think I have basically the same question as you

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It seems to me that decorators can only check for the existence of keys in the blackboard, i.e. != nil

mighty cedar
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its really weird. so they basically are used for actor type variables to see its its valid or not

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i suppose

ripe whale
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Yeah it looks to me like the the "Blackboard Based Condition" decorator can only check if a key has an associated value in the blackboard

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it looks like it can't actually check what the value is

flint trail
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you can make custom decorator

mighty cedar
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so how i actually check bool, any idea?

ripe whale
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not really, trying to figure that out myself

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@flint trail how do you make a custom one?

mighty cedar
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i am fairly new to behavior trees

flint trail
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there are literally a ton of videos on YouTube about such basics like decorators, services and tasks

mighty cedar
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yes they make a decorator unrelated to any of my questions

ripe whale
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can you briefly explain how you would check the value of a bool in the blackboard with a decorator? or should we not be using decorators for this?

mighty cedar
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they just start video saying whats a decorator

flint trail
mighty cedar
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and then print string it

flint trail
mighty cedar
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ill check it out

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thnx

ripe whale
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I haven't watched those videos specifically but I read through the quick start guide and watched live training vids and nobody ever checked the value of a bool in the blackboard unless I missed something

gilded tree
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How do I make sure that if ten AI overlaps a box, all of them should be Destroyed (they will do something else in my use case) except for the first AI to reach the overlap box?

mighty cedar
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yeah, ive seen some tuts about ai and didnt see it either, i check those vids none the less.

gilded tree
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I've got the code covered, but the AI don't behave as supposed.

mighty cedar
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welcome to the club buddy

ripe whale
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@mighty cedar The solution to our problem is to create a custom decorator

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that reads the value from the blackboard

mighty cedar
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gets it

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?

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seems easy

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😄

ripe whale
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yeah it is easy

mighty cedar
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thanks buddy

flint trail
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I strongly recommend finding good Ai videos and watching them first

mighty cedar
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i get how behavior tree works

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i just lack some basics

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i managed to make decent ai

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but that decoirator thingy

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was tough to find

flint trail
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I hardly see how can one make decent AI using BT and not using decorators 😃

mighty cedar
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i used

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the variables i used werea ctor types

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tho

ripe whale
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ctor?

flint trail
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actor

mighty cedar
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actor

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well starting 4.20

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in blackboard there is no actor

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object

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apperars

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but you can set it as actor

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anyway

pine steeple
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there has never been an Actor in blackboard

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its always been Object with Actor set as the type

mighty cedar
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i remeber seen older videos there was actor

ripe whale
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Does anybody know what the difference is between "Event Receive Tick" and "Event Receive Execute"?

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And which one should I be using for custom define BT Tasks?

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It looks like Tick is getting called more often from the prints I am doing

mighty cedar
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you should use AI events

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and tick is tick event, execute events executes when your task is called

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you have to finish it

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or it will get stuck

ripe whale
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AI Events and non-AI events are the same AFAIK

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Not sure why the AI Events are offered at all TBH, maybe somebody could tell me about that too

mighty cedar
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i use AI events cause it gives you controller and pawn, not sure if other eventss return same thing

ripe whale
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Yeah thats the only difference

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99% sure they are called at exactly the same time

mighty cedar
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yes, but i am not sure if not AI events return you pawn

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i think its only controller

ripe whale
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You do seem to get Pawn with the AI Tick and AI Execute events

mighty cedar
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yes and its pretty handy

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😄

ripe whale
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yep for sure

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I am pretty sure that you should never use Event Receive Tick / Tick AI in Behaviour Tree Tasks

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because ticks seem to happen faster than the blackboard executes (maybe per frame rather than per execution of the behaviour tree root node?)

mighty cedar
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i never use it anyway

flint trail
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why is that @ripe whale ?

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I use AI Tick in a few spots in my BT and it works fine

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now, overusing tick or doing something heavy on tick in several places is a bad idea

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but tick on its own is harmless and no one should advise not to use tick at all

mighty cedar
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i used to use it on services

ripe whale
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On services it makes sense I think

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@flint trail So for example I had a Behaviour Tree task and I was using the tick event but I was noticing that it was executed twice for each run of the sequence node

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I put a print out right after execute tick event and each time the sequence node was called the task was called twice or three times (it changed a bit)

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and then I switched it to event execute and it only ran once as expected

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This is not how services run though, services seem to be controlled by the specified tick rate and event tick gets called at that rate

flint trail
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@ripe whale There are specific AI tick events. They are not the same as Event Tick in BP.

ripe whale
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I am talking about these nodes

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and in a Behaviour Tree Task they get called at different frequencies

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They are not the same

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is that is the same as your understanding?

flint trail
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Tick AI isn't the same as Even Tick

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So, I use Tick AI in my some of my BT's Services

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didn't have any issues with it

ripe whale
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Service tick isn't the same as task tick from what I am seeing

flint trail
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Event Receive Tick AI is what I am talking about to be absolutely clear 😛

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perhaps.. What I do (in Decorator, in Task and in Service) is I go into Override Function in the Functions tab and pick Tick event from there

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this way I make sure it's the correct tick

ripe whale
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Do you use Event Receive Tick in your Tasks?

flint trail
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I don't recall right now, at work

ripe whale
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If you are using tick in your tasks I suspect that your tasks are not doing exactly what you think they are doing

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they may be executing more often than you think

flint trail
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I mean, my AI does exactly what I need it to do

ripe whale
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Yeah mine was working before as well but it is wasted resources and CPU time to be executing tasks more frequently than they need to be executed

pine steeple
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anyone here wrote a custom test for EQS?

static dew
#

Curious if anyone knows how to ok knock back and away ai. Seems they have super powers of they're moving forward at a location and you attempt to launch h them away they just go pffft and basically ignore it

viscid oasis
#

what?

lime orchid
#

Hey, adding a floating pawn moving component to a pawn makes it move as programmed but the pawn does not rotate to the direction of the movement... it will move backwards instead of rotating the pawn and move forward

patent hornet
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OrientRotationToMovement, UseControllerRotationYaw ?

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first is probably on MovementComponent itself

lime orchid
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thanks

lime orchid
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@patent hornet can't find those values, should they be in the FloatingPawnMovement properties?

patent hornet
#

second should be on Pawn

#

first is part of CMC, but i don't remember what FloatingPawnMovement has

lime orchid
#

found it, works funny... sets the pawn rotated half way

main saffron
#

Maybe not the right place for this, but I'm trying to spawn an extremely basic AI. My actor is a pawn with a static mesh (sphere) with CanEffectNavigation false, yet when placed in the level there is a hole in the navmesh around the actor just like other static meshes in the level. I cannot figure out how to resolve this!

mighty cedar
#

@ripe whale decorators have overridable function Prform condition check

#

thats what i used

#

also you have to abort things if it fails

main saffron
#

Sphere on left is a pawn containing a Static Mesh Component - nav mesh hole around it.

📎 unknown.png
icy night
#

@main saffron Do you have a collision component as well? Might have to set CanEffectNavigation to false on that as well

main saffron
#

@icy night there is no collision component on the pawn, the SM has a collision and has Has Navigation Data selected

icy night
#

Did you move or refresh the navmesh after you set CanEffectNavigation to false? Might not be updated... otherwise I don't know

main saffron
#

@icy night Thanks for the help, I've done both, and restarting the editor, as well as adding a collision to the pawn, as well as setting the value in C++

#

also deleted and rebuilt the navmesh

#

wow... but what I didn't try doing was deleting the pawn in the level and replacing it...that worked

icy night
#

Heh, yeah forgot about that one 😃

pine steeple
#

anyone alive?

viscid oasis
#

yo

pine steeple
#

channel is dead

#

dynamically injected BT's

#

aim is to have one master bt, running default behaviours, but different enemies can inject a BT to change behaviour

ocean crystal
#

Neat

viscid oasis
#

can tags be set dynamically?

elfin socket
#

@pine steeple That looks really good, but shouldn't that node at the top be a Selector instead of a Sequence?

ocean crystal
#

My implementation of that allows the behaviors to dynamically take priority tho

#

eg attack might supersede evade on some enemies

pine steeple
#

Oh

low frigate
#

Hello. Noob here. Is EQS being discarded? I remember activating it in experimental settings a while ago ago but now I can't find it at all. And it doesn't seems to be active by default either since there's no option to create a blueprint environment query and other EQS specific related assets. Any ideas? Thanks.

elfin socket
#

@low frigate it hasnt changed iirc. Maybe you need to check your project settings again?

scenic fox
#

a question though.. why is it still experimental?

#

i try not to use experimental modules if i can avoid that

south prism
#

Someone an idea how to get my AI look at me, when I'm at his range? I tried this but they are just looking at my last position. I heard that the OnSeePawn is wrong but what can I pick for that?

📎 Unbenannt.JPG
thick edge
#

@south prism You can save the Pawn reference in OnSeePawn then in tick if the pawn reference is valid run that chunk of code

south prism
#

ok thanks

lyric flint
#

I do something similar to that but I dont use tags, I used bitflags

#

with bitflags im limited to the amount of flags though

south prism
pine steeple
#

the montage slot is set to default but the animgraph only plays Upperbody slots?

rare bramble
#

I just created an AI that follows you if you’re in its field of vision, but I also want to to follow the player if you get too close. Can this be done with a collision volume?

pine steeple
#

you can do it with a collision volume, but it would do a timer with a periodic box overlap

#

so its not checking every frame

#

@rare bramble

rare bramble
#

So it would work, but wouldn’t be very consistent?

south prism
#

@pine steeple what montage slot?

pine steeple
#

your trying to play an animation, when you should be playing a montage, and the montage needs to play on a slot defined in the AnimBP

#

PlayAnim will only work if there is not an animation blueprint set

south prism
#

Ah. So i set the play animation to a play montage?

pine steeple
#

no

#

you use the play montage node

thick edge
#

@south prism Yes, you want to play a montage. Then in your anim bp you need to blend the slot which the montage runs on into the final pose. For example, if the montage runs on slot DefaultSlot, open your anim bp type in DefaultSlot, and set the input of the new node to be what you previously had connected to your final pose. Connect the output of the slot node into the final pose

dreamy surge
#

how can I make my AI walk on walls and ceilings

#

the AI still needs to use the nav mesh
and the nav mesh is just like a floor
I need the AI to be able to jump and cling to ceilings

rare bramble
#

@dreamy surge simple. Demonic possession

dreamy surge
#

so unreal doesnt have a real system to have the AI walk on walls

#

nobody knows how?

dreamy surge
#

this is heartbreaking

pine steeple
#

you could do it in a really hacky way

#

have the capsule stay on the floor and the ai rotated upside down and use the navmesh

#

but for walls, well thats a different story

cursive smelt
#

I'm encountering some problems with inheriting Blackboard values. I want to have a base class with common keys (IsDead and so forth) but If I inherit keys from a base bb, all of the keys show no value when running the behavior tree and the tree doesn't run correctly. I can create a bb with all the individual keys and everything works fine, but that means always creating common keys for each bb. What am I missing here? (In 4.20.2)

dreamy surge
#

how do I tell my AI to use another custom nav mesh???

#

the AI always uses the unreal nav mesh

south prism
#

Hey guys, I have a Turret AnimBP with including a "Aiming" variable and now I want to make a character BP for my turret. But now I dont know how to setup the Turret_BP, that he aim to the player and other AI's. Can someone help me?

timber olive
#

i have a nav proxy link and it's always enabled. how do i make it not always enabled?

#

the only solution is when the nav proxy link doesn't exist at all

#

i want to selectively turn it on and off

violet notch
patent hornet
#

switch to using BTService

pure fern
#

Hello
Did anyone use gameplay task system? I encountered a problem with simulated tasks. It doesn't tick on client. I use task inherited from UAITask with bIsSimulatedTask and bIsTickingTask set to true. It is used with GameplayTasksComponent. I found that GameplayTasksComponent bIsActive is false on client but true on server. For testing purposes actor creates task with construct object on begin play and calls RunGameplayTask on GameplayTasksComponent with created task. It successfully replicates to client but doesn't tick. Maybe someone knows how to fix this problem, or maybe I just use this system incorrectly)

glossy salmon
#

Is anyone here dealing with large numbers of AI and optimisation?

pine steeple
#

how large you talking

#

@glossy salmon

broken hearth
#

Hey guys,
I'm trying to constrait the movement area of my player character to navmesh (We use it for AI so it seems like a good idea to use same area for player controller character)
I have found that character movement component can be set to navmesh walking mode, where it uses the navmesh to calculate movement. However, I want to forbid player leaving the generated area, and if I have an blank space in navmesh, walking into it will cause the movement component to go back to default physics walking mode.
So what I'm trying to achieve is to block player from leaving navmesh like the blank space is colliding with player.

Is there a way of doing this already supported by the engine?

📎 unknown.png
glossy salmon
#

@pine steeple

Over 100

I can get 60 or so on currently at 40 FPS

But it drops steeply after say 70-80

desert cipher
#

What blocks perception hearing? Sight I understand but I've got some AI in another area that hear noise generated by a bullet impact. I want them to ignore that since there is a wall in between

#

Googled all morning and tons of resources on sight but not much on hearing

pine steeple
#

use strength of the noise

#

and do a check to see where the noise was played and how far the ai is away

#

if its out of its hearing range, ignore

#

but there is no "block" for hearing

wicked dome
#

so when I'm pressing P in blueprint I can see the green navmesh
but when I'm playing it and pressing apostrophe and num0 it's doesn't show my navmesh
so my ai doesn't move

#

hmmm this only happen when I added a new map and loaded it as 'always loaded'

pine steeple
#

weird, is it dynamic navmesh

desert cipher
#

@pine steeple Thanks. I think in my case, it's best just to try and return the area the noise came from and if it's outside their "area" then try to ignore it.

wicked dome
#

@pine steeple wait, should it be dynamic?

pine steeple
#

dont think so but can't say i have ever seen issue of navmesh being displayed in viewport but not working in game

amber sparrow
#

what do you think would be the most elaborate resource available online regarding behaviour trees? be it a big tutorial, video, or project to download?

patent hornet
#

check the pinned messages first i think

amber sparrow
#

👍

#

did not think about that

broken hearth
#

Guys, bumping previous question, do you know a good way to constrain player character movement to the area generated by navmesh? (Player pawn using character movement component, being moved by adding input to this comp)
I've been looking to find a way to do this outside of the box in engine, but it seems like I will need to write own character movement component, and change velocity when player gets close to navmesh border.

pine steeple
#

anyone know why my navmesh isnt working

desert cipher
#

are nav links (inside BP) the same thing as a nav link proxy that you can spawn in world? I've got a surface inside a blueprint that AI needs a nav link for. The Blueprint is randomly spawned though so I can't just place it and use a world nav link proxy. I notice the proxy has these nice nodes you can drag with the regular nav link doesn't..

#

basically I need to get the AI to realize these stairs are fine to walk up

desert cipher
#

woohoo.I got it, but only manually. I'm having issues spawning my nav links.

#

I'm trying to attach them to arrows, but they're behaving oddly

desert cipher
#

hmmm.. I have one last little bit of issue. I've got all 4 points spawning correctly and assigned to 2 nav links. The problem is when the game starts, it doesn't seem to initialize the points. They're there, but there is no green arrow connecting them. While the game is running if I deposses and do anything to the navmesh then it will draw the green lines between the two points, at which point the AI starts to use the bridge.

#

When my tiles are spawned I actually rebuild the navmesh, but that happens after begin play. So the points should be spawned and available when the navmesh is built.

#

move navlink node 0.05 distance (moving before play doesn't make it generate)

📎 aftermove.png
#

I even tried putting the navlink point generate in construct to make sure it was absolutely done before the cpp made the call to generate the navmesh.

desert cipher
#

As a point of interest, a different item that I spawn which also has a navlink on it, seems to work fine from the beginning of play. The bridge itself is included on the tile, but the other item is spawned in randomly in the begin play of the tile.

flint trail
#

maybe make a collision hull that is solid ramp basically connects upper and lower level when staircase is in place ?

desert cipher
#

I might try that. There was a collision mesh on it, but I think it was too steep for them to walk up. I calculated a new one in unreal, which works perfectly fine, it's just the navlin won't spawn properly. I did try removing the bridge and the navmesh and spawning them the same was the second item I have, but it didn't seem to make a difference. The other item when it spawns the navlinks work fine, but this one is being finicky.

#

I just don't understand why it suddenly works after a very tiny adjustment while the game is running, but won't start in a working state.

forest drum
#

hellos, could it be that to complicated nav mesh area crashes the map?

#

i'm getting editor crashes on my map, as soon as AI calcutaes path to goal, no crash on simple map

ivory willow
#

Hi!

#

you don't need Nav Links to do so

#

although, its about jumping, you can skip the jumping part 😃

desert cipher
#

@ivory willow thanks I'll check that out

desert cipher
#

@ivory willow By changing the step height I was able to convince the navmesh that those stairs were okay. that worked great, Thanks! I'd prefer to get the nav links working, but that's a good fix for now

slow lake
#

Something from #blueprint but it's technically AI so maybe it'll apply here as well.
I'm working on a flying AI (jet style. A constantly moving object). Trying to figure out how to get it to move and turn so it can navigate from point to point. My idea was to have it rotate left or right and then tilt up or down until it's facing towards the target point. Problem is I'm having trouble figuring out how much I would need to rotate the ship left or right in the first place depending on where the target is

ivory willow
#

@desert cipher I'm glad it helped. 😃

crisp bone
#

Man, I can get an AI to follow the player, but I cannot for the life of me get the AI to move to a vector 200 units towards the player 😢

tropic lily
#

Hey does anyone know how to make a behavior tree service node thing respond to sound?

flint trail
#

I upgraded my project from 4.19.2 to 4.20.3 and my navmesh is gone :/ How do I fix it ?

crisp spindle
#

have you tried rebuilding it ?

flint trail
#

yep

crisp spindle
#

maybe add new nav mesh volume or move old one blobThink

#

have you tried creating navmesh on a new map? i'm on 4.20.3 and it works for me

flint trail
#

that's irrelevant - I need my 4.19.2 project to work

#

new project works fine

crisp spindle
#

what is irrelevant?

flint trail
#

creating nav mesh in a new map

crisp spindle
#

just to see if it is working properly, some settings are project wide, it was just a sanity check

#

if it works with new maps, one more thing i can suggest is to delete default recast nav mesh and build paths after that blobThink

grim citrus
#

I am trying to set up a simple move to location for a "click selected" Ai character. But it always fails. Anyone who can help? (Will post screens in a sec.)

#

The nav mesh looks fine, at least to me.

crisp spindle
#

hm, have you tried drawing target destination you are passing to Go ?

grim citrus
#

As in Project Destination on Move to Location node?

crisp spindle
#

just DrawDebugSphere with To as location, just to see if you have valid location

#

i don't use bps that much and you are using location from a separate execution path, is that valid ? blobThink

grim citrus
#

Uhm. I don't know. I thought that Move to Location would try to move the character to closest point to it. All tutorials I have seen doesn't do any offset from ground or otherwise. They just click the ground and send it to the Move to Location

crisp spindle
#

it would be easy to check with c++

#

but it looks like it uses UE_VLOG to log issues

#
  1. Start the game
  2. Open visual log
  3. Start recording
  4. Select target and right click to move
  5. Look at visual log so see if anything useful was collected
grim citrus
#

Hm. Maybe.

#

LogNavigation (Warning) FPImplRecastNavMesh::InitPathfinding start point not on navmesh

crisp spindle
#

sounds useful

grim citrus
#

But... It is standing on the ground, which have NavMesh...

crisp spindle
#

maybe on edge or something

grim citrus
#

like 3 meter to closest edge.

crisp spindle
#

hm, i'm out of ideas

grim citrus
#

😦

#

Well, thank you for trying. 😃
Hopefully someone else have an idea.

patent hornet
#

one common issue is your Pawns collider being inside the ground

grim citrus
#

I tried to have it spawn in the air so it have to fall down, still same thing,

patent hornet
#

well, your movement is somewhat unusual

#

so make sure its the navigation and not your input handling

#

have it move to your location + some arbitrary vector whenever you press M

#

if it moves, your input is the problem, if it doesn't solve the simpler scenario, then plug your inputs back in

flint trail
#

so, I can't get navmesh to build at all in 4.20.3... What the Hell ?!?!?!

wild mortar
#

@flint trail when you rebuild it it's not build?

flint trail
#

nah, Showing Navigation was off

#

(I don't know why, since it was on in 4.19)

#

so, all works out of the box 😆

wild mortar
#

Cool beans

#

Also, for some reason my acceleration is always 0, even though my speed is fluctuating between 0-600
This is on an AI, and I'm grabbing accel and velocity from Character Movement

flint trail
#

fingers crossed, AI seems to be working fine

tropic lily
#

When he reaches the spot he doesn’t go back to wondering aimlessly
I know by the looks of this screenshot it should be pretty obvious as to why but I still haven’t found a way to make him go back to wandering aimlessly after seeing there’s nothing there

#

Anyone know how to make him go back to wandering aimlessly?

floral mango
#

Start menu -> type 'snip', press enter

broken hearth
#

Hey, bumping my question from before. Is there a built-in way to constrain player controlled character to make him unable to walk outside of the navmesh?
I can use NavmeshWalking mode in CharacterMovementComponent, however as soon as I walk outside of navmesh, the component detects it and switches MovementMode to Walking (which is calculated by physics).

stable void
#

I'm guessing this is a common issue but I can't make the pathfinding work properly. I've already added custom agents in the project setting but my characters keep getting stuck at corners ..... Can someone that has done this before help please ?

keen furnace
#

@stable void tried increasing the nav agent radius so the navmesh doesnt generate so close to the corner? if there are individual trouble spots though you can nav modify them to obstacle or similar though

#

@broken hearth dont believe so, may have to use a modified CMC

#

@tropic lily use a sequence for the moveto, after the moveto do the wandering. also download Gyazo or similar

broken hearth
#

Hey @keen furnace, do you have any recomendations where to start with modifying CMC?
I have tried few approaches:

  1. Using the velocity vector from CMC, predict when the player moves out of the navmesh in CMC tick. If he does so, clamp the speed vector. This however wont give me the effect of "sliding" on the edge of playable area. (When player gets to the corner he justs stops).
  2. "Carrot on a stick" movement. Move player with AI pathfinding agent, and use a small offset vector rotated by the input direction. This however behaves wildly on some thin obstacles. Player also stops on the corners instead of "sliding"
    I also had an idea that I could hook up to the build paths event in UE and maybe spawn some thin colliders around the navmesh edges? This could solve the issue but solution is rather complicated.
keen furnace
#

honestly i havent had to do this before, my delving into CMC has mostly been to extend and use the savedflags... my initial thought is maybe keep saving location of player last tick, and checking if the player is on the navmesh this tick, if not then tp back to last valid navmesh position, if yes then save current valid pos. may be expensive and/or jittery though, and still wouldnt slide - but at least wouldnt have the side effect of getting the player stuck if they are knocked off the navmesh @broken hearth
if you are able to mod recast to create physical blocks around its edges that would be a legit solution, as you say complicated/timeconsuming though

stable void
#

@keen furnace I fixed it in the end... by restarting the editor ... I have spent so long trying to figure out what was going wrong. Thank you though ! Now the nav-mesh is giving me other problems. Is like whack a mole here! If someone take a look at this wink-wink and know what's going on then please say so !

📎 Halp.jpg
#

navmesh documentation is awful

keen furnace
#

ah yeah the agents often dont update without an editor restart 😦 can you verify your character is actually using that yellow navmesh? it sounds like they are using the green one

#

try a navfilter to stop it from using that other navmesh maybe

stable void
#

how do I see that ? I'm trying to find console commands or blueprint nodes to affect the character but I can't seem to find anything relevant online .... I'd prefer to read something rather then waste peoples time. Thank you for helping me though. It's very much appreciated.

keen furnace
#

basically creating custom nav areas and using filters on each character type to set what it can and cannot use

pine steeple
#

navagents dont work for me for some reason

frigid knoll
#

Is there a "is navigable?" or Can navigate to? or Location within nav mesh? type nodes?

pine steeple
#

there is Random Navigable poins

#

points

olive garnet
#

I'm getting this message in the log what does it mean? LogEQS: Warning: Finished query EQS_FindRandomLocation_RandomBest25Pct over execution time warning. Total Execution Time: 67.47 ms
generator[0]: 5.14 ms (items:14637) (EnvQueryGenerator_PathingGrid_0)

#

a cookie to anyone that can tell me why its doing it

stable void
#

Does anyone know why my character if fine when using a custom AI controller but not fine with the same AI controller but parented to it's detour version ?

olive garnet
#

💩

patent hornet
#

looks like it took it way too long to finish the query

#

might want to try to make it cheaper

#

15k items in a pathing grid, that doesn't come free

stable void
#

So by reparenting my AI controller to a detour AI Controller the "Move To" command in the behavior tree is not doing anytrhing anymore

📎 Capture.PNG
#

*anything anymore ? but move directly towards works

olive garnet
#

@patent hornet you the amount of props on the map?

desert cipher
#

So odd behaviour here. I have my AI set to shoot at a player in range. With some intervals and what not to give a slightly fair shooting thing. One thing that happens is that they hit a cooldown and for a second don't on the player. if the player moves, they won't track the player because set focus is called as part of shooting. So I decided to duplicate the shooting behaviour, and run it without pulling the trigger alongside it. So that while the shooting part is under cool down, the AI could still focus on the player to track in range. Problem is... instead of tracking.. the ai points at the player shoots and then points to the right and down a little bit. Definitely not in the direction of the player.

#

That's the relevant part of the tree

#

That's the aim code

#

which definitely 100% works.. since that's duplicated from the shooting code

#

What's happening is that when the shooting is on cool down, he's doing this instead of pointing at the players head like he should.

📎 aim3.png
cursive vector
#

the ai perception has affiliation (enemies, neutrals, friendlies). is that something one should actually use? cant find much on that. some say just always perceive everyone and sort them out yourself later. would you recommend using that built in team system? seems to be built on GenericTeamAgentInterface

grim citrus
#

Ugh. I cannot get Show Navigation to work in PIE...

cursive vector
#

how are you trying to do it? it doesnt show while playing, you need to unposses

wild mortar
#

Is it acceptable to use the Blackboard decorator for a boolean BB Key? I.e, it's saying "unset" or "is set", it seems to me it is more appropriate for Object class where it can be set to none, versus boolean where the value is true/false but not necessary none?

pine steeple
#

yes

digital solstice
#

Does anybody know how to make car AI with collision avoidance?

tropic lily
#

Please help, for some reason the AI won’t move towards the target
Or if I should just stick with the Movs To node, can someone help me find a way to make the AI give up chasing the player after a while?

pine steeple
#

could you use a screenshot tool or something, really hard to read them

tropic lily
#

I’ll take a better picture later. My computer’s interest is ass where I am. Otherwise I would do screenshot

#

Also try zooming in

pine steeple
#

why are you not using MoveTo Nodes?

#

ChasePlayerTest2 would probably be a service, which checks to see if the player is visible, whilst player is visible, move towards him, if for some reason he is not visible, stop the moveto

#

something like that?

tropic lily
#

See, I’m having trouble making him give up chasing the player after a while

#

So I thought I should try making a custom node that would make him give up after not being able to see the player for a few seconds

pine steeple
#

yeah use services

#

and cooldowns

tropic lily
#

Wait what’s cooldowns?

pine steeple
#

a decorator for a BT node

tropic lily
#

I know it’s a decorator but what does this decorator do?

#

More importantly can it help?

floral vector
#

super newbie here.
So after a Selector, the actions are executed from left to right (from lower to higher number)?

#

just found the unreal behaviour trees playlist inthe pinned messages but that wil take a long time to watch ... so I would be grateful is someone could answer that anyway

pine steeple
#

selector and sequence execute left to right

#

difference is, if a selector suceeds it doesnt execute the next one on the left, but if a sequence succeeds it executes the next on the left, if a selector fails it runs the next one on the left, if a sequence fails, it doesnt execute the next on the left

floral vector
#

@pine steeple Thanks 😃

#

hmm, what happens if I have a MoveTo node as child of a Selector? When does a MoveTo return success or fail?

pine steeple
#

returns if it has reached the goal

#

fails if the path is invalid

#

succeeds if it has reached the goal

floral vector
#

@pine steeple Thanks again

brittle egret
#

Hey I used the NavSystemV1 to find a path between two points, the green line is how it finds it right now, but I want to change it so it uses a path more like the red line

📎 unknown.png
#

Going straight as long as possible and then diagonal

#

Does anyone know how I could achieve that?

ocean crystal
#

one might be to move directly toward, but have a service which checks for how close the agent is to a wall - if its too close, it uses regular pathing. @brittle egret

pine steeple
#

should you not switch to the PerceptionSystem ?

#

Pawnsensing is legacy

ocean crystal
#

if the pawnsensing thing suffices for your purposes, then what is exposed to BP of perception should do as well.

#

to fully use perception you do have to dip into C++ tho

#

I actually checked whether pawnsensing had been deprecated - it was my first thought when you said it broke

pine steeple
#

its not depreciated but it is legacy iirc, but Perception system is easy, all pawns who can be detected by the perception system has a stimuli source component attached to them, and all pawns who react to stimuli has a perception system component

ocean crystal
#

actually I don't even think you need the stimuli source comp

#

probs easier if you do though

pine steeple
#

it does

#

iirc

ocean crystal
#

yeah its meant to be on the controller

pine steeple
#

the stimuli goes on the character

#

oh you can do that with perception system aswell

ocean crystal
#

its tucked away into the gameplay debugger

pine steeple
#

using the ' key

ocean crystal
#

which, btw, is super op

pine steeple
#

its an AI must

#

i have a lot of eqs queries and perception system with behaviour trees, seeing everything on screen with the nav system is unreal

ocean crystal
#

Seriously though, an AI kit on the MP without perception is kinda.... eh?

#

Bet the only thing on the MP using perception for its AI is art of combat.

#

And that doesn't even use BT

#

I mean that you'd gain an edge if you used the newer system, at least I'd think so.

#

Then again, I'm not the normal customer base for BP packs... so /shrug

#

whereas with pawnsensing its more Oh another AI thing that technically works

#

it may not be worth it if it'd be that involved.

#

perhaps build another AI pack around perception

#

then you'd have two

pine steeple
#

what is the issue with it anyway

#

so its not picking up any noise?

#

4.20.3?

desert kelp
#

Am following a tutorial on the navlink proxy to get my NPC to jump on/off platforms. I'm using an AIMoveto node in BP, while he is using the moveto node in behaviour trees

#

Could that be the reason my AI starts a jump off, then turns in midair... failing the jump most of the time?

#

yeah... it keeps going out on OnFail, which has a delay then repeats..

#

durnit, ok, dont mind me.

serene pelican
#

This is a meta question regarding AI in UE:

How do Behaviour Trees execute "AI Move To" ?
Or to rephrase it: How do Behaviour Trees know how the Pawn moves?

pine steeple
#

asks the movemement component if a path exists, if the path it exists it runs the moveto, if its at the goal it returns success, if it fails to path it returns failure

lyric flint
#

My navigation mesh isn't showing up. Has anyone had this issue?

wanton oriole
#

Sometimes it does that for me. Try moving the navmesh a little 🤔

lyric flint
#

Is there a way to allow the "move to" node to be interupted

#

so we can quickly update movement

lyric flint
#

This method won't update until after it reached thre path

#

im just wondering if anyone knows how to fix this

#

i want more of a "MOBA" style movement

#

i want players to be able to cnacel movement

#

by clicking a new location

#

The movement seems way to slow

#

to be usable for any moba / rts style games

#

it doesn't respond quick enough

pine steeple
#

you probably dont want to use BT for that

#

but control it thru an AI controller

#

but you can always abort the current tree/node by using a decorator

lyric flint
#

@pine steeple it won't stop the "MOve to " node

#

until it is near "acceptable radius"

#

is there a way to just

#

instantly update this

pine steeple
#

use an actor and teleport it around and have the moveto track that ?

slow shuttle
#

Hi all, do you know why the GameplayTag condition for behavior tree can't abort tree? I read in the C++ code that it was not ready for this... but I don't know why. Is it because the container is not multithreaded? Do you have any other way to drive the BT with GameplayTag? because as long as we can't abort it, I can change my bot behavior depanding on those tags.

lyric flint
#

@pine steeple but we cant do that with a vector?

#

lol

pine steeple
#

why not?

#

its how i do it with my AI

#

they have a TargetActor, which the MoveTo uses to navigate to

#

and i simply move that actor to the new vector location

#

if i want the AI to stop, i move the target actor ontop of the AI

cunning relic
#

Hello

#

Would anyone be willing to look at where I am going wrong with the Behavior tree tutorial?

lyric flint
#

@pine steeple But why can't we just change the vector location and have it move there?

pine steeple
#

you want it to be fluid right?

#

as in if he clicks a new location he just turns and goes

lyric flint
#

I'm trying to do a right click to move setup

#

Similar to league of legends or dota 2

pine steeple
#

right

#

if you abort the moveto, the character will stop, then execute again

#

and will look crap

lyric flint
#

hmm

#

So you are just spawning an actor at the right click location?

pine steeple
#

now if you have a empty actor which you move about the map

lyric flint
#

and then moving it?

pine steeple
#

no the actor is spawned in the player control at begin play

#

want me to mock up an example project?

#

and send it?

#

its basically, you right click, you set the Move Target actor to that location, and in your move to you navigate to that move target with Goal Tracking ticked

lyric flint
#

sure

pine steeple
#

what ue version you got

lyric flint
#

4.20

cunning relic
#

In the behavior tree tutorial where does target to follow get set?

pine steeple
#

is that what you are after?

lyric flint
#

yeah but using AI

#

lol

pine steeple
#

that is ai

lyric flint
#

it doesn't work on multiplayer

#

xD

pine steeple
#

what doesnt?

lyric flint
#

at least, not well

#

the movement is jittery

pine steeple
#

im lost :/

#

ill send over this, and see what you think

lyric flint
#

ok

pine steeple
lyric flint
#

ty

pine steeple
#

thats just for a character you can move, but i am sure you can grasp what i did, if its just pure ai your moving (not a playable character) i can do it even simpler

#

what tutorial you on about>?

cunning relic
pine steeple
#

thats where it sets the target

tidal egret
#

Hey, does anyone here have any good resources on fish AI? The flocking I'm currently using works, but doesn't take meshes into account, so the fish end up swimming through objects/terrain and just stay inside the defined cube area

sterile mirage
#

Does anyone know (off the top of their head before I measure it myself) how much more expensive FindPathSync is compared to TestPathSync?

ripe whale
#

Has anybody created custom Behavior Tree Services? How do you get a set BB values from the UBTService subclass you have created? I am using stuff like: UBTFunctionLibrary::GetBlackboardValueAsFloat(this, [FBlackboardKeySelector property]) but it is always returning nothing

#

I should I be accessing the UBlackboardComponent directly and use the methods that is has to get and set values?

#

I just find that odd because I didn't have to do that when I implemented custom services in blueprints rather than cpp

sterile mirage
#

Where are you trying to set the blackboard values? Yes it should be set directly on the blackboard component.

#

In the overridden service functions you should be passed the UBehaviorTreeComponent (OwnerComp below) which you can then use to get the right blackboard component:
OwnerComp.GetBlackboardComponent();

#

And then, as you've correctly assumed, you use the SetValue/GetValue calls on the blackboard:
MyBlackboard->SetValueAsVector(LocationStorage.SelectedKeyName, RandomLocation);

#

example for getting:
MyBlackboard->GetValue<UBlackboardKeyType_Vector>(BlackboardKey.GetSelectedKeyID());

#

Although it looks like the function library you're using is just a helper function that does the above (getting the owner's blackboard component) for you, so if you're still having trouble feel free to DM me directly and I'd be happy to help troubleshoot. I've written a lot of BT services, tasks etc. and use blackboard keys extensively.

ripe whale
#

Awesome thanks! I’ll try that soon

ripe whale
#

@sterile mirage thanks that worked!

sterile mirage
#

👍

patent hornet
#

using blackboard key selectors is a better way to go

solar elbow
#

guys, what this error is about? trying to build production, but still have this:

\AIModule\Private\BehaviorTree\Decorators\BTDecorator_BlueprintBase.cpp] [Line: 67]```
found the question at the answerhub <https://answers.unrealengine.com/questions/801681/btdecorator-related-cooking-failure-ensure-observe.html> but the solution is kinda confusing
sterile mirage
#

@patent hornet that's what he's doing.

#

He's just doing it at the C++ level.

fallow gull
#

Hi guys, for big open world (made with world composition) What's the best practice?
a. place a navmesh volume in the persistent level that envelope the whole world
b. place a navmesh volume on each sublevel

#

(and why one solution is better than the other?)

sterile mirage
#

You'll want to look into NavMesh Invokers

sterile mirage
#

I think I've found a bug in Recast Nav Meshes ProjectPoint or DoesNodeContainLocation implementations. If you project a point on to the navmesh and get back a (presumably valid) point that's on the edge of an exterior poly, that retuned point fails the DoesNodeContainLocation forthe very same node that ProjectPoint said it was on.

#

There's a comment in the code that suggests it might be a rounding error due to imprecision:
// one last step required due to recast's BVTree imprecision

sterile mirage
#

Yah that's got to be it. I can work around the issue simply by nudging the result of ProjectPoint by an incredibly small amount towards the center of the poly. Hopefully I've saved someone else some time if they ever encounter the above bug. 🤷

jovial valve
#

Does everyone here exclusively use behavior trees, or do you guys use other approaches to AI as well?

sterile mirage
#

My new game is pretty much just Behavior Trees with the AI Perception system. I like that it allows me to write a language of simple blocks (usings tasks, decorators, services and composites) that my designer can then piece together. I've basically been able to offload all AI development to someone who understands what "feels" good without having to know how to code.

pine steeple
#

i use Behaviour trees for my AI, but i use Dynamic Trees, so i have one master behaviour tree for all ai, but each ai can inject a different tree for personalized behavior for some parts of the tree

ripe whale
#

@sterile mirage have you ever used AAIController::MoveToLocation? I'm trying to use it inside a BTTask subclass but how do we know when the move is complete so that we can return the appropriate EBTNodeResult?

#

Is there some callback or something I am missing?

#

I would have expected to pass a lamda or something to this method that gets called on completion

sterile mirage
#

So what's your use case? Is there a reason you aren't using the UBTTask_MoveTo?

ripe whale
#

Inside my BTTask subclass I am setting a bunch of BB key-values as well as doing the move to

#

I could put the setting of the BB values in a different task

#

but I would like them to be all in the same task if possible

sterile mirage
#

I think you'll want to avoid creating a monolithic task that does a bunch of different tasks.

#

You can take a look at UBTTask_MoveTo.cpp to see how much work is involved with handling pathing correctly in a BT task.

#

The more you break down the work into individual tasks the more you'll be able to recycle each one as well for undiscovered use cases.

ripe whale
#

Ugh yeah this looks more complicated than I thought it was going to be

sterile mirage
#

luckily MoveTo uses any Vector or Actor blackboard key selector, so it will be pretty easy to create a couple of tasks that push the data where it needs to be before running MoveTo with whatever blackboard key you've used as storage

ripe whale
#

Yeah it will be easy

sterile mirage
#

Good luck!

ripe whale
#

Thanks!

floral vector
#

It seems that trying to use "draw debug ..." functions in a BBService doesn't work (well, it doesn't complain but it is not showing the stuff). Also spawning particle systems is not doing anything.
Is that by design? I'm seeing a video were the guy is creating a debug sphere and it works for him, but maybe is an older version. Anyhelp?

pine steeple
#

@ripe whale i actually made a custom moveto task

#

without cpp, and with cpp

floral vector
#

ah, my game has multiplayer. Could that affect the behaviortree service? If so where do BTServices execute?

pine steeple
#

BTService should not be for doing things like that

#

it should be for checking states, etc

floral vector
#

ah ok, I just saw the video tutorial is from 2015 so I assume they removed that functionality

pine steeple
#

well i would not be doing anything like spawning particles from a BTService

floral vector
#

it's just for debugging of course

#

I'm using a "memory actor" and I want to see where the AI think the memory actor is.

pine steeple
#

maybe set a bool which makes the tree abort and run a different task which sends of a command to the owning ai, to spawn the particles

#

and if its multiplayer they would need to be replicated

#

ie multicast if all players need to see it

floral vector
#

@pine steeple Can try that. Thanks!

pine steeple
#

even tho i prefer to send a client rpc to each player, and have them handle the VFX

floral vector
#

ah, solved! It was because I was using dedicated server. Now I can see all that stuff 😃

pine steeple
#

yeah but like i said, Services shouldn't be for things like that

floral vector
#

@pine steeple only for debugging the vision service, I'll remove it later. Thanks!

sterile escarp
sterile escarp
#

Do I need to enable it manually somehow? Shouldn't it run by itself when the actor has an "AI Perception" component?

pine steeple
#

you enabled the affiliation to all types

#

and there is at least a stimuli on a character in the game?

uneven bison
#

Hi,

#

When I called MoveToLocation in AIController.
Not triggered RequestDirectMove function that in UNavMovementComponent.
But good working for MoveToActor.

#

What can I do for this problem?

sterile escarp
#

@pine steeple No characters have a stimuli source, no. My AI is using sight only. Is stimuli needed for that?

pine steeple
#

characters that get detected by the perception system need a stimuli

#

so AI will have perception component, Player will have a Stimuli

sterile escarp
#

@pine steeple Its AI that are supposed to detect AI. Team deathmatch style.

pine steeple
#

then the AI will need a stimuli aswell

sterile escarp
#

On its controller or the character?

pine steeple
#

character

sterile escarp
#

Still does not work tho. 😦 Must be something else as well.

pine steeple
#

affiliation checkboxes ticked?

#

they are kinda buggy

#

need all them ticked

sterile escarp
#

where do I find them?

pine steeple
#

in the perception component when you enabled the sight sense config

#

in your AI controller

sterile escarp
#

Yes! That worked! Thanks ❤

pine steeple
#

np

tropic ether
#

Can I ask C++ questions related to AI in here?

ripe whale
#

Yes

wary ivy
#

groan

#

how do I do a raycast on the navmesh?

#

I basically have a pawn and I want to do sort of walkability raycast along the mesh

#

some units forward

#

do I have to project the actor location to the navmesh first or not?

# 
UNavigationSystemV1* navSys = UNavigationSystemV1::GetCurrent(GetWorld());
if (navSys == nullptr)
{
    GEngine->AddOnScreenDebugMessage(-1, 0.f, FColor::Red, TEXT("Navsys is null"));
    return;
}
auto* NavData = navSys->GetMainNavData();
if (NavData == nullptr)
{
    GEngine->AddOnScreenDebugMessage(-1, 0.f, FColor::Red, TEXT("Navdata is null"));
    return;
}
const ARecastNavMesh* navmesh = Cast<ARecastNavMesh>(NavData);
if (navmesh == nullptr)
{
    GEngine->AddOnScreenDebugMessage(-1, 0.f, FColor::Red, TEXT("Navmesh is null"));
    return;
}
FVector hitLoc;
const FSharedConstNavQueryFilter filter = navSys->CreateDefaultQueryFilterCopy();
bool hit = ARecastNavMesh::NavMeshRaycast(navmesh, GetActorLocation(), CurrentDirection * 200.f, hitLoc, filter, this);
#

that's what I tried but I'm not sure if it's actually working

#

the hit does return true eventually but then the hit location is the position of the actor

#

and not the end of the trace

#

shieeet

#

thanks rubber ducks, I forgot to add the actor location to trace end

#

😄

dreamy surge
#

Is there anyway to have the ai randomly jump to different ledges say 10 feet to another nevmesh area not connected to the floor or do we need to use predetermined paths and jumps?

pine steeple
#

use Navlinks

#

a smart nav link will give you the end position

#

so you can jump the AI to the end position either via lerp or launch or something similar

#

i made a custom nav link component to allow AI to vault over obstacles and windows

void cloak
#

When calling simple behaviour trees like this, are they called in a "One and done" style, or do they run until you specify for them to stop?

📎 SimpleBT.PNG
wary ivy
#

they run indefinitely iirc

#

try debugging them

ocean crystal
#

if you're using a run BT node, its once.

#

though maybe you can loop it

pine steeple
#

why can't you use blackboard ant BT in multiplayer game?

pine steeple
#

it would not cause ping and fps drops

#

i use it for 150 ai, multiplayer with EQS pathing and it runs around 3ms game thread time

#

which is good

#

the bottleneck is the Character movement component

#

movement and lags is probably caused by netupdate or bad BT design/animation

stable void
#

How do I send back the signal when the pawn has reached the move to destination ?

📎 Capture.PNG
pine steeple
#

where do you want to send the signal to?

stable void
#

back to my character

pine steeple
#

cause AIController has an override (in c++ for sure not sure in blueprint) for when movement finishes.

stable void
#

or the AIcomponent

pine steeple
#

so Moveto will return true if it succeds

#

so in that sequence after move to you can have pathing succeded task to send the info back

#

i would wrap that in a selector node which executes if MoveTo fails (failed to reach goal/unable to path) which sends saying it failed pathing

stable void
#

but there is no pathing succeeded node ?

pine steeple
#

make one

stable void
#

I didn't know you could do that ha

pine steeple
#

those are good videos

stable void
#

Perfect, thank you 😃

pine steeple
tropic lily
#

Are there any tutorials that easily explain EQS that walk you through it and doesn’t show what they’ve already done? Or a tutorial that helps you easily understand EQS?

pine steeple
#

EQS is simple really

#

its just a generator (to generate actors or points (vectors) and tests to perfom on them, returning a score

#

and filtering

tropic lily
#

Someone told me that I can use it to make the AI go down twisty corridors

pine steeple
#

you can use it for whatever you like

#

it only tests things and returns the best item or random best 25 percent or all items with a score

tropic lily
#

I feel like I’m supposed to manually set certain markers to tell the AI that it means something

pine steeple
#

eqs will only test to see if points are valid

#

why wont your ai go down twisty corridors with normal navmesh?

tropic lily
#

It will. It’s just that when it’s chasing the player, it gives up partway through when it doesn’t detect sound or see them. Logically it doesn’t make sense

desert cipher
#

How do I get my AI to go up these stairs? I have a navlink showing that those two areas can be joined. The stairs are perfectly navigable. The player character can go up these stairs without any kind of issue or hitch. The stairs themselves aren't large enough to generate any kind of navmesh themselves. Do I need to somehow set a series of points from stair to stair? Do I set an array for each step like A->B, B->C, C-D all the way up?

📎 upstairs.png
latent wasp
#

What is the best way to make a simple AI for my paper2d game with blueprints?

desert cipher
#

Well, I tried the A->B->C->D thing..and it laid out all the points properly, but.. since none of the stairs are green, it didn't actually connect anything. I hoped it would have made a kind of chain to link them all together.

tropic lily
#

Can someone please help me? I want to use EQS to tell the AI to go all the way down the hallway. But it sometimes turns abruptly. This mostly happens when he reaches a sound point but I want him to keep going forward into the hall regardless. Can you help me?

pine steeple
#

@desert cipher hacky way would be to put a bound on each stair

#

all of your points have a score of 1

#

you should really have the point have a score different to each other

desert cipher
#

@pine steeple Can I put bounds on those while they are in a blueprint?

pine steeple
#

you can drop the bounds in the level

desert cipher
#

I have navmesh bounds in the level, that's all the green stuff

pine steeple
#

yeah but its not on the stairs

desert cipher
#

the problem is the stairs aren't large enough to count for that.

#

it does cover them though.

pine steeple
#

might need to change the tile size

#

or something in the project settings

desert cipher
#

cell size and cell height?

#

I might have to make it really small. Looks like default is 19, I might need to make it 1. I'm assuming that might have a performance impact?

#

Oh definitely.. I set it to 1 and massive freeze trying to start the game.

#

It's dead.. I'll have to force it closed. So don't make it 1.

#

Lowest I can set it is 4, which isn't low enough. Anything lower and the game jams up, unable to start. 4 is just starting to draw a little green on the stairs, but not enough. 2 or 3 would probably do it. So bounds is out, any other thoughts?

patent hornet
#

got just one set of stairs? got any animations on the pawn (walking...) ?

stable void
#

@pine steeple thank you for yesterday by the way I was rushing

pine steeple
#

np cant remember that far back lol

#

only had 3hours sleep

tropic lily
#

Do you hear that bump in the night?

#

Cuz it’s me!

#

Can someone please help me? I want to use EQS to tell the AI to go all the way down the hallway. But it sometimes turns abruptly. This mostly happens when he reaches a sound point but I want him to keep going forward into the hall regardless. Can you help me?

fallow gull
#

@tropic lily because you abort the lower priority task whem hearfuck is set so it abort the MoveTo task.

tropic lily
#

But once it clears hearfuck is that not the end of it?

#

It’s not like there’s a series of sounds set. To my knowledge when it hears a new sound it updates the vector to that location

#

Even when hearfuck isn’t set he stills turns abruptly in the hall

pine steeple
#

so your sequence seems weird aswell

#

if move to fails, it wont execute the second Clear Memory

#

unless thats intended

#

but i think you need to rethink your approach

#

break down exactly what is supposed to happen

tropic lily
#

Brb I’m away from my computer atm but I will when I get there

tropic lily
#

Fuck it I don’t need a computer to tell you what needs to be done

#

Basically, it’s supposed to go all the way down certain areas that Is presumed to be where the player is

#

If it’s going down the hallway, and it doesn’t detect the player through sight or sound anymore, I want it to keep going down the hall because that’s the only way to go

#

The AI I’m using is a test ai before I transfer it to the real one

fallow gull
#

And what location does the eqs return?

tropic lily
#

You mean where the test pawn is?

#

(I’ve only started using it yesterday so I dunno jack(

#

I can show you the root thing when I get back to my PC if it helps

pine steeple
#

@fallow gull the screenshot i saw earlier all points are green with a score of 1

#

@tropic lily you need to test for points in front of the ai

#

and keep him updated so he moves following them points in a forward direction

ocean crystal
#

I'm not convinced EQS is a good use here

pine steeple
#

uding some sort of DOT test

ocean crystal
#

I'd just do whisker tracing

tropic lily
#

Someone recommended it to me when I told them what I wanted to do

ocean crystal
#

You COULD do EQS

pine steeple
#

i use eqs but mine are to fine points and quite complicated

tropic lily
#

What’s whisker tracing?

#

It sounds like something I attempted before

ocean crystal
#

its pretty close to what it sounds like if you know what whiskers are

tropic lily
#

I assume when they touch something they detect it?

pine steeple
#

i mean you could just do a forward cone from the AI, and pick points?

tropic lily
#

Brb 10 minutes

ocean crystal
#

could also have something like breadcrumbs but on path branches - if you pass one while the AI knows where you are, it at least goes to it. It'd work in a more limited way.

pine steeple
#

would make him navigate in front

#

i mean you can adjust the cone to suit corridor size

#

would work

tropic lily
#

That looks like exactly what I want

#

Now how do I do that?