#gameplay-ai | Unreal Source | Page 126

pallid atlas Jun 2, 2020, 8:23 PM

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Any thoughts?

sullen escarp Jun 2, 2020, 8:28 PM

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A task that does a 8 directional trace to a fixed length and make rules to rotate towards the best (furthest) available trace

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📎 unknown.png

pallid atlas Jun 2, 2020, 8:32 PM

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Hmmm

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If I did it toward the furthest, wouldn't the kitty always walk toward the center of the room, though?

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I like the idea though

sullen escarp Jun 2, 2020, 8:33 PM

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That's why you write rules, use some fuzzy logic

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Best 5% or 25% random or something

pallid atlas Jun 2, 2020, 8:33 PM

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Oh oh... to a fixed length

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That'll be perfect. Thanks @sullen escarp, I wouldn't have thought of that

grand atlas Jun 2, 2020, 8:42 PM

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Any guides or some tips for handling player input in a BT? For example, say I can order a character to Move, or Attack. If the Move Task is left of the Attack Task, wouldn't that mean that if I gave a Move order and then Attack order, the character wouldn't start attacking until the Move was done?

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The Attack Task couldn't cancel the Move Task. And doing the other way around would just invert the problem.

pallid atlas Jun 2, 2020, 8:48 PM

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@grand atlas It sounds to me like you'll want to use a SimpleParallel node in your BT, set to FinishMode=delayed, with the move task as the main task, and attack as the background task

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With a decorator on the attack task, checking for... whatever it is you need to check for in order to allow the attack

grand atlas Jun 2, 2020, 8:52 PM

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I don't know.. what if I wanted to introduce another kind of input? Not that I can think of any right now but it doesn't feel very expandable.

misty wharf Jun 2, 2020, 9:05 PM

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I guess that would somewhat depend on if your character is doing the actions simultaneously or no

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ie. is the character attacking and moving, or if the move and attack actions are separate altogether

grand atlas Jun 2, 2020, 9:07 PM

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How does RTS units deal with player input? I guess that's what it comes down to.

patent hornet Jun 2, 2020, 9:09 PM

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service runs for finding valid targets

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move decorator aborts if one is found

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and the attack takes over

grand atlas Jun 2, 2020, 9:16 PM

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I feel like I need something like the image below, so that tasks can be cancelled no matter what their position is. And some service on the input would clear previous data.. or something. This along having the AI autonomy on another branch.

📎 BTPlayerInput.png

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Input would mean first setting the playerinput boolean to false, and have a service reset the data, followed by setting new data and finally b=true.
Am I completely off track?

sullen escarp Jun 2, 2020, 11:27 PM

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One way could be to have a BB key "NewOrderRecieved" boolean used as a Decorator on a branch from the Selector checking if it's TRUE, if so set it to FALSE. Mark the decorator to abort lower priority when it's changed. Then whenever you assign a new order set the "NewOrderRecieved" key to true and it'll interrupt any behaviors running that were lower priority / to the right of the decorator

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@grand atlas

📎 unknown.png

urban wadi Jun 3, 2020, 12:46 AM

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Anyone know how to utilize the enemy, neutral, friendly in the AI Dectection by affiliation in AI Percention?

urban wadi Jun 3, 2020, 1:04 AM

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right now I have my AI set up to find my player through the BB behavior tree without the use of EQS. Should I be using EQS for location the player?

misty wharf Jun 3, 2020, 1:47 AM

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afaik the affiliation thing has no BP api for some reason and you need to set it up on the C++ side of things

pallid atlas Jun 3, 2020, 2:03 AM

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Wow, I just switched from using OnTargetPerceptionUpdated to OnPerceptionUpdated and boom, so many bugs resolved...

unique jacinth Jun 3, 2020, 12:00 PM

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Wow, I just switched from using OnTargetPerceptionUpdated to OnPerceptionUpdated and boom, so many bugs resolved...
@pallid atlas What sorts of bugs? Your comment makes me slightly concerned because I just went the opposite direction

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For example, with OnPerception I don't get any updates when leaving an enemy's sight radius

pallid atlas Jun 3, 2020, 1:01 PM

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I just checked the SensedActors.length == 0 to act as my "lost sight of everything" logic. For some reason, I couldn't get the boolean value from OnTargetPerceptionUpdated's stimulus result to ever be false. I had the opposite problem you had

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@unique jacinth

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I probably had the AIPerception's settings too loose. I dunno. I think it also has to do with the particulars of my game. In my game, all the things I'm sensing are the same type of object so it makes sense to deal with them in an array

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now that i think about it, maybe I never get SensedActors.length == 0, I'll have to double check that. but I just know that the sensing logic works way better now. Before, I was having trouble getting them to see stuff right in front of their face. Now they see 20/20

unique jacinth Jun 3, 2020, 1:12 PM

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I just set the sight loss radius slightly higher than the sight gained, and I visualise perception so I see those radii, and when I move in and out of them I get the event, and if I've moved out the stimulus result is false and when I move in it's true

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ah well, since it's working for both of us we don't need to dwell on it I guess 😉

past stone Jun 3, 2020, 1:16 PM

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Anyone know why Run EQS Query would be hanging? It runs fine until I switch possession to a different pawn then if I run it again it never completes.

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Also, the Run EQS doesn't seem to work on the client in a deployed version, although it's fine when PIE (using geometry, not navigation).

civic flare Jun 3, 2020, 1:30 PM

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Hi. QQ. In order for an AI controller to move a pawn, does the pawn need to have a player input component or anything? I have a pawn i built in c++, blueprinted and then followed this write up to get random movement, but on play.. no movement happens at all. https://www.raywenderlich.com/238-unreal-engine-4-tutorial-artificial-intelligence

raywenderlich.com

Unreal Engine 4 Tutorial: Artificial Intelligence

In this Unreal Engine 4 tutorial, you will learn how to use behavior trees and AI Perception to create a simple AI character that roams and attacks enemies.

gritty relic Jun 3, 2020, 1:41 PM

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Does somebody know how to change the hotkey to open the standard Unreal A.I. Debugger?
It is normally the ' (apostrophe) key, but I use a QWERTZ keyboard, which doesn't have that key.

smoky summit Jun 3, 2020, 1:56 PM

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@gritty relic Project Settings -> Engine -> Gameplay Debugger -> Input -> Activation Key

gritty relic Jun 3, 2020, 1:58 PM

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That worked like a charm!
Thank you so much!!

smoky summit Jun 3, 2020, 1:58 PM

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no problem

past stone Jun 3, 2020, 2:26 PM

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After deploying it seems that all my EQS queries are now non editable. Is this because they've been cooked?

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They're now "Data Assets". Can't view them or edit them.

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Nevermind, EQS had been disabled in the options for some reason when it built. No idea how that happened :/

smoky summit Jun 3, 2020, 2:43 PM

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You built from editor?

past stone Jun 3, 2020, 3:20 PM

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@smoky summit No, I think I deleted the saved folder at some point since it was getting huge. Guessing it was that.

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Still not sure why Run EQS Query node is not working on the client though. Only seems to be in the deployed version. The OnQueryFinished event is never triggered

narrow monolith Jun 3, 2020, 3:29 PM

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ok here

solar bronze Jun 3, 2020, 3:29 PM

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ok, have you done anything yet with the ai?

narrow monolith Jun 3, 2020, 3:30 PM

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no

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I don't even have the actors tbh

solar bronze Jun 3, 2020, 3:30 PM

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start with that, i'd recommend you searching for tutorials or other things to learn some ai basics first

narrow monolith Jun 3, 2020, 3:30 PM

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alright

civic flare Jun 3, 2020, 4:03 PM

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Does anyone have experience using random move to ai and the actual character / pawn not actually moving?

static fable Jun 3, 2020, 4:44 PM

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How can I apply a nav mesh volume to a mesh so that when I press P it has a highlighted area on top of it ?
I would be greatful for any advice!

civic flare Jun 3, 2020, 4:47 PM

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I have a character which has my animation bp, my aicontroller ( which has run behavior tree in begin play with my bt ) and my bt has moveto, set random location and wait.. but he never moves....

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hmm do you have to assign a nav mesh volume to a actor bp?

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nm found it

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the magic p button to make the nav mesh show as green 😐

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@static fable not sure if it is the same thing.. but I had to move the mesh volume up then snap back down for it to be in the right spot. I guess I was like 1 off or something or they were overlapping.

static fable Jun 3, 2020, 4:56 PM

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I think my issue might be to do with collision, thank you though @civic flare

civic flare Jun 3, 2020, 4:56 PM

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Cool. I'm pretty new but trying to help. 🙂

static fable Jun 3, 2020, 5:38 PM

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I cant get this Navmesh to work so aaaany advice would be welcom XD

civic flare Jun 3, 2020, 5:50 PM

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I don't know I can help.. but.. What are you trying to accomplish with it? Expanding on that might help.

mild saddle Jun 3, 2020, 6:48 PM

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I have an AI enemy that tries to get into cover when it's "exposed" to the player (i.e. successful line trace between enemy and player's collision capsule centers). However, when the enemy loses sight of the player, it enters a "searching" mode and goes to the player's last known location. This can sometimes lead to behavior tree toggling back and forth rapidly between the Combat state and the Searching state, especially around corners. Does anyone have advice for fixing this issue? I imagine it's a relatively common problem with shooter AI.

📎 unknown.png

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This "Lock AILogic" seems promising, does anyone know what exactly it does?

📎 unknown.png

sullen escarp Jun 3, 2020, 7:05 PM

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When in cover do the line of sight check from the position they would be when they're fighting from cover.

📎 unknown.png

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If they can't see the player from cover maybe do the trace to the last known position of player that's valid for a couple seconds

mild saddle Jun 3, 2020, 7:13 PM

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Thanks for the advice. I think you're right - the enemy isn't able to see the player once in cover for some reason, even though my EQS query is supposed to generate points where the enemy should be able to see the player. I noticed that even with the Acceptance Radius set to -1, the enemy doesn't quite reach the location before finishing the execute, which could be part of the problem. I can look more into this.

smoky summit Jun 3, 2020, 8:28 PM

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I'm running into an issue sometimes where GetFocalPoint is returning the same location forever even after reaching the location, switching paths, etc. Once a bot gets in this state it just forever uses this focal point

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Has anyone seen this?

jaunty peak Jun 3, 2020, 8:33 PM

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@mild saddle there is an auto detect variable, can't recall it's proper name off the top of my head, in the AI Perception component of your AI. It allows your NPC to keep track of targets if they move out of view and are with the range you set. Note, it only works if the AI has perceived the target already and not forgotten about them.

sullen escarp Jun 3, 2020, 9:33 PM

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A good analysis of AI and perception concepts from Splinter Cell https://www.youtube.com/watch?v=1zh4CzzpGDM&t=349s

YouTube

AI and Games

How Splinter Cell: Blacklist Builds Balance for Stealth | AI and Games

Support AI and Games and help the show grow by joining my Patreon:
http://www.patreon.com/ai_and_games

--

Stealth games are one of the most challenging genres to get right. You either run the risk of making it too easy and predictable, or impenetrable for only the most ard...

▶ Play video

glossy spire Jun 4, 2020, 2:57 AM

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how would i REMOVE a dynamic subtree

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calling Set Dynamic Subtree with the same inject tag but with a null behavior asset doesnt work

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does it?

simple crest Jun 4, 2020, 3:34 AM

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amazing (and depressing) how ~20 years later people are still referencing the great things they did in games like Thief/Thief II/Splinter Cell...

clever tendon Jun 4, 2020, 10:58 AM

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What could be causing nav mesh not to be visile and navigation not working while in game?

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Nav mesh generated and is visible in editor like it should. But AI stopped moving and typin show navigation doesn't show the navigation mesh anymore while in game

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And enable drawing is enabled on on RecastNavMesh

clever tendon Jun 4, 2020, 11:15 AM

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Got it working by fully reverting defaultengine.ini to a previous version

civic flare Jun 4, 2020, 12:19 PM

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good morning discord peeps. Would someone explain to me how the nav mesh volume, a plane and my character / pawn with ai works together? It seems if the nav mesh is a little in the wrong spot with the ground and pawn my ai doesn't work. I literally got it working once, then it stopped and I'm pretty sure its the position of things and can't get my pawn walking again.

tawdry adder Jun 4, 2020, 12:48 PM

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https://www.youtube.com/watch?v=-KDazrBx6IY
Well Normaly it should just work if you have the navmesh properly setup and then call MoveToLocation...

YouTube

Tesla Dev

Unreal Engine 4 Tutorial - Basic AI Navigation

In this tutorial we will setup some basic AI that can navigate in our map. We will do this by using Navmesh volumes and also simple move to nodes within blueprint.

▶ Play video

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I am having a different problem though....
Basically i worked all day on my AI and it worked really well. But as soon as I placed two enemies in the scene they behave very wierd. It seems that only one enemy acts at a time and if one ememy sees me the other one comes. Somehow the variables are synced but i turned off sync in the blackboard...
Pleasseee some one help me👏

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No variables are set to static aswell

civic flare Jun 4, 2020, 1:23 PM

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thanks @tawdry adder

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I'll look at the video

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I think i finally got the stars aligned

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now to figure out why my pig moonwalks and warps instead of moves to location smoothely

hollow gull Jun 4, 2020, 3:20 PM

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~~Hi, can someone tell me in which config file I can set the auto register all pawns to false?~~
DefaultGame.ini
[/Script/AIModule.AISense_Sight]
bAutoRegisterAllPawnsAsSources=false

unique jacinth Jun 4, 2020, 3:33 PM

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amazing (and depressing) how ~20 years later people are still referencing the great things they did in games like Thief/Thief II/Splinter Cell...
@simple crest Blacklist is from 2013, although I get what you mean 😉

final holly Jun 4, 2020, 3:34 PM

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Back in the days they didn't have all these other fancy features to hide the poor gameplay, so gameplay had to be good. Which helps us analyze these type of games very easily and integrate their logic into our own games

smoky summit Jun 4, 2020, 3:52 PM

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Anyone have their own custom pathfollowing logic to get around the fact that GetFocalPoint appears to be bugged and sometimes gets into a state where it stops updating the focus location?

noble minnow Jun 4, 2020, 3:58 PM

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Back in the days they didn't have all these other fancy features to hide the poor gameplay, so gameplay had to be good
feel like this describes like 99% of modern technology lol

can anyone comment on whether they've found there to be an upper limit for nav mesh bounds volume size even with nav invokers? all the tutorial's / forum posts I've seen seem to indicate you can scale very big worlds with nav invokers but I'm working with 300000 UU x 300000 UU x 50000 UU and when I scale my nav mes bounds volume up too large it stops displaying any generated nav data unless I bump cell height up an order of magnitude which ruins the accuracy with respect to matching my level geometry.

static crater Jun 4, 2020, 4:33 PM

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My terrain is 6x6 km, i actually devided it into multiple navmeshes, as some parts are like ocean,water. I disabled auto update navmesh in editor so it wont regenerate all the time. I dont even use nav invokers

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Also i switch to 'dynamic' when in editor to prevent loading time when i press play (dynamic modifiers takes more time, but seems a little faster in performance)

brazen pewter Jun 4, 2020, 4:48 PM

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Hello, I'm encountering some terrible hitches on my characters from time to time and I can't really wrap my head around why it's happening, any direction what can I check for potential issues?

📎 unknown.png

brazen pewter Jun 4, 2020, 6:43 PM

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for anyone interested ^, I've asked two other people to profile the game for me and they had fine results so it seems my hardware is failing

noble minnow Jun 4, 2020, 6:46 PM

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@brazen pewter might also be related to some layer of software between your game engine and hardware like OS, drivers, etc

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@static crater yeah unfortunately I only see these problems when I scale up past 200k x 200k x 10k, and the only way to get nav to generate is to use ridiculously big cell size to the point it's unusable

brazen pewter Jun 4, 2020, 6:49 PM

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I've actually had some performance spikes when playing some games since some time, but didn't really bat an eye to that, I'' be googling around to check if I there is some explanation for that, or if it's an actual hardware failure

pallid atlas Jun 4, 2020, 7:37 PM

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As soon as I added a physics asset to my skeletal mesh, it seems to break the navigation AI. It still moves the actors around, but it doesn't seem to transition between BT tasks correctly anymore.

Anyone else ever have a similar problem?

brave shuttle Jun 4, 2020, 11:28 PM

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Would anyone know how i am meant to be able to tell the pathfinding AI that it needs x amount of space to fit though a gap. I noticed some agent size value before but it appeared to not do anything. Currently i have one set of AI that need to try and navigate around the second set. but they will just try to phase through the visuals of the second set as its only seen to be a small capsule

patent hornet Jun 5, 2020, 1:58 AM

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there is crowd avodance as long as they are on the same navmesh

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it is fairly problematic to configure

smoky summit Jun 5, 2020, 2:36 AM

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Be aware that the crowd component completely changes the path following method

glossy spire Jun 5, 2020, 2:47 AM

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is a composite decorator really the best way to do an OR check

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for several other decorators

stiff gale Jun 5, 2020, 3:28 AM

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How do you increase this dynamic nav mesh range?
https://gyazo.com/8f188f70bc3bc8063afb948a67548ee2

Gyazo

static crater Jun 5, 2020, 9:31 AM

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Hi, anyone knows how to create a pathfinding query with a custom filter?
Like:
FNavigationQueryFilter Filter; Filter.SetMaxSearchNodes(102400);

📎 unknown.png

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however Query struct takes FSharedConstNavQueryFilter , not FNavigationQueryFilter (see image)

steel bramble Jun 5, 2020, 1:46 PM

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Hey guys. I'm a newbie in terms of AI programming, and I was wondering what's the best approach to deal with AI for non-visible entities.

Imagine having a woodcutter Actor, who (guess what) chops wood when the player is near. The game keeps track of chopped wood so "it knows" that when the tree is gone, it's gone. Now imagine going far away from the woodcutter. As an optimization, I wouldn't want all actors to be still present, but I would like for the woodcutter to still chop down "imaginary" trees, in such a way that when the player does come back and the actors are actually physically present, there would be more missing trees.

So my question is, how would you approach this kind of situation?

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Also, imagine that the woodcutter uses perception components to "see" nearby trees. How would he be able to find more if no "tree actor" is spawned, when the player is far away?

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Any ideas or hint to articles or whatever that talk about these kind of issues are welcome 🙂

livid token Jun 5, 2020, 3:18 PM

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is anyone familiarized with this error log ? LogCrowdFollowing: Error: Unable to find RecastNavMesh instance while trying to create UCrowdManager instance
Every change i make to the crowdmanager logs it, and even though i have my controllers set to use UCrowdFollowingComponent it's not being applied as well

brave shuttle Jun 5, 2020, 3:28 PM

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@smoky summit @patent hornet Im using the default navigation, i just want to change how big the actors think they are

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so instead of thinking they are a tiny little capsule they actually think they are an acceptable size

patent hornet Jun 5, 2020, 3:28 PM

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it does adjust where they think they can path

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you can make a simple test by overriding nav agent radius to be less then capsule, they'll get stuck on every corner

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but they do not avoid one another by default

brave shuttle Jun 5, 2020, 3:29 PM

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dont need to avoid

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but push against

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and as a swarm, eventally spread around the blocking actor

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would it happen to be these "radius" values that you mean Zlo?

📎 unknown.png

pallid atlas Jun 5, 2020, 4:54 PM

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I have a BP with just a skeletal mesh and box collider components and a floating pawn movement. Until I added a physics asset to the mesh, everything was fine: they moved around (using AI), they animated properly, etc. After adding the physics asset, they still animate properly, as if they're moving (animation blendspace uses actor velocity), but they're just running in place.

Anyone have any insight into what is going wrong here?

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How it is possible to have a non-zero velocity when the actor isn't moving?

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Maybe I should post this in #legacy-physics, but it seems to be affecting the AI's movement, so I dunno, I just thought I'd post it here.

pallid atlas Jun 5, 2020, 5:51 PM

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I'm gonna repost this in #legacy-physics

torn ermine Jun 5, 2020, 6:01 PM

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@pallid atlas
velocity in the movement component is not the actual speed of the object
this is the force that should cause movement
it is used to calculate the movement, after which the blocking of movement due to the collider.

pallid atlas Jun 5, 2020, 6:01 PM

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The box collider?

torn ermine Jun 5, 2020, 6:01 PM

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probably yes

pallid atlas Jun 5, 2020, 6:02 PM

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Hmmmm.... I didn't think of that. Thanks

torn ermine Jun 5, 2020, 6:02 PM

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why this is happening is difficult to say without studying the code

pallid atlas Jun 5, 2020, 6:02 PM

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One question snake, just your personal experience

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I feel like I should create a new object collision channel. Do you find yourself having to create custom channels a lot or is that a sign that you're not using what is available properly?

torn ermine Jun 5, 2020, 6:05 PM

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if I need a new collision channel I create it without any doubt.
there is a fairly extensive supply for custom channels.
moreover, it may be easier for the physical engine to process fewer objects each on its channel than if all objects will be in one

pallid atlas Jun 5, 2020, 6:09 PM

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oh okay, I see. Thanks

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Still can't get it to work, though that was still a great help. If you care to enlighten me further, here are my collision settings:

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Here is the BP (a kitty cat), there is the box collider, I'm using it to determine when the kitty steps in poop 🙂

📎 unknown.png

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The settings for the skeletal mesh

📎 unknown.png

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The settings for the box collider

📎 unknown.png

torn ermine Jun 5, 2020, 6:12 PM

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oh...
the movementcomponent must work with the root object of the actor...
as it is presented on the screenshot , it should not work
similar to the character when the capsule is installed in his root component
and everything is attached to it

pallid atlas Jun 5, 2020, 6:12 PM

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I have the mesh's visibility channel set to ignore so that multiple kitties can't "see" each other when doing line traces (I use them when moving the kitty so that they don't end up facing the wall all the time)

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Oh... okay, huh. Yeah, when I was doing all this, I changed it from DefaultRootComponent > SK_Kitty > Collider | Movement

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to make SK_Kitty the root component

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Someone said that it had to be the root component, so I tried it

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How can I reattach the Movement to the root?

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Trying to drag it onto SK_Kitty, not working. No options in the right-click menu

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@torn ermine side note: what is "Can Ever Affect Navigation"? I am competely at a loss as to what the setting should be for this. It seems to be available everywhere, I have no idea what it means. I Googled for it, everyone seems to already know what it does except me.

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I duplicated the Movement component, now it's below the mesh and collider like it used to be. Still not working. Did I not do this right?

📎 unknown.png

torn ermine Jun 5, 2020, 6:23 PM

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Can Ever Affect Navigation
means exactly how it sounds - Does the component (the collision of the component in particular) have an effect on navigation (in particular the navigation mesh).

pallid atlas Jun 5, 2020, 6:25 PM

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Okay, so does that mean that if it's not checked on something important then the AI can't move the actor?

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I think you were on to something with the Movement component not being set up correctly... but now I can't seem to figure out how to fix it

torn ermine Jun 5, 2020, 6:27 PM

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if the box blocks the navigation mesh
and the dynamic navigation mesh obviously AI cannot move since it does not appear on the navigation mesh

pallid atlas Jun 5, 2020, 6:28 PM

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My nav mesh seems to be okay...

📎 unknown.png

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So, I should only have "Can Ever Affect Navigation" checked when this component should be something that blocks movement on the nav mesh?

torn ermine Jun 5, 2020, 6:30 PM

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you still have the wrong actor
https://i.imgur.com/EN6tnUY.png

I don’t think it’s a good idea to use the box for movement.
there are several fundamental problems for realizing the movement with the box at the base.
only figures symmetrical to the axis of rotation handle the trajectories well when they collide with obstacles and obtain a point of contact.
that is, to make the main movement primitive a box must be a very important reason.
that is why we have a capsule character.

Imgur

pallid atlas Jun 5, 2020, 6:33 PM

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I should make the Collider the root component?

torn ermine Jun 5, 2020, 6:34 PM

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right

pallid atlas Jun 5, 2020, 6:34 PM

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okay

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Okay, well it's moving now 🙂

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As soon as I made the collider the root component, though, this happened lol

📎 unknown.png

livid token Jun 5, 2020, 6:35 PM

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is anyone familiarized with this error log ? LogCrowdFollowing: Error: Unable to find RecastNavMesh instance while trying to create UCrowdManager instance
Every change i make to the crowdmanager logs it, and even though i have my controllers set to use UCrowdFollowingComponent it's not being applied as well
@livid token

torn ermine Jun 5, 2020, 6:36 PM

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@pallid atlas
align scale
scale is passed to components attached to them

pallid atlas Jun 5, 2020, 6:36 PM

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oh okay, thx @torn ermine

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I should use this to change the shape of the box collider?

📎 unknown.png

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Changing that doesn't seem to change the size of my kitty

torn ermine Jun 5, 2020, 6:39 PM

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@livid token
does not find the navigation mesh, why this is happening you should find in your project.
not enough information to even make any assumptions

livid token Jun 5, 2020, 6:40 PM

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@torn ermine thanks for the feedback. Right now it's happing on a factory project where i just add the nav bounds volume as well

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it kinda threw me off the loop since i already had it working and dindt do any major change regarding ai

pallid atlas Jun 5, 2020, 6:44 PM

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@torn ermine Thanks again, that got me going in the right direction at least. You were a big help.

livid token Jun 5, 2020, 7:47 PM

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what are the crowdmanager configs setup that brought you better results?

pallid atlas Jun 6, 2020, 1:51 AM

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Am I doing this line trace correctly? I am trying to check if something is in front of this actor, but it is always returning true no matter what.

📎 unknown.png

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Oh, the end needs to be the actor location plus the computed forward vector, huh?

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No, that didn't fix it.

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📎 unknown.png

woven pilot Jun 6, 2020, 6:10 AM

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@pallid atlas If I'm not mistaken, everything with the visibility channel set will return true here. You're not using a custom specific channel, and you're also not checking the hit actor for anything specific, and you also don't have an ignore actors array set. So basically everything in the level would return true.

static crater Jun 6, 2020, 7:29 AM

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Hi, anyone knows how to create a pathfinding query with a custom filter?
Like:
FNavigationQueryFilter Filter;
Filter.SetMaxSearchNodes(102400);

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magic peak Jun 6, 2020, 10:16 AM

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hi can someone help me. i set up a mixamo zombie character and applied an animation for when its follow me the player. but its still moving in a t pose. any suggestions? the animation is as follows

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slow bobcat Jun 6, 2020, 12:25 PM

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Hi! I have a question, maybe someone knows here.
When you do a build (cook + compile) and your levels use a static navmesh, is the navmesh generated during cooking time and saved in the Recast object or is it generated when you load the level?
I'm trying to figure out if it's possible to modify the navMesh during cooking time and save changes to it (flood filling cleaning) to save time.
I haven't got far with it but I can see how there are calls to DestNavMesh->OnNavMeshGenerationFinished(); when loading the levels in the build (running it in DebugGame from VS), which can mean that the navMesh is actually generated and not cooked.

Does anyone know?
Cheers!

mossy bay Jun 6, 2020, 3:49 PM

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So I've been following the official AI tutorial but when setting the Simple Move to Location using GetRadnomReachablePointInRadius, it doesn't work. Anyone know's what the problem with this tutorial is? Navmesh is build and I triple checked the blueprint suggested but still nothing.

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The breakpoint reveals that the incoming goal vector is 0,0,0...

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I've manually set the Nav Data component with a variable and now I'm getting a valid Vector. But the agent is still not moving :/

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RESOLVED: Somehow the nav mesh got broken (dissapeared in editor). After restarting Unreal I was able to see it again and the controller magically started working 😂

wind briar Jun 6, 2020, 4:23 PM

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How would I go about making a blueprint where the ai chases me for a couple of seconds then walks off and ignores me

pallid atlas Jun 6, 2020, 4:29 PM

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@wind briar check out this video series, it covers stuff exactly like that

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https://www.youtube.com/watch?v=zNJEvAGiw7w

YouTube

Ryan Laley

Unreal Engine 4 Tutorial - AI - Part 1 The Behaviour Tree

Welcome to the start of a brand new series. This time we are diving into AI for games. This episode introduces the concepts being used in AI design and in particular, the behaviour tree. In this episode we add an NPC that can randomly roam around the level.

Support me on Patr...

▶ Play video

wind briar Jun 6, 2020, 4:29 PM

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Thank you ! 😃

pallid atlas Jun 6, 2020, 4:29 PM

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yw. That video series is how I learned to use AI

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(not that I'm expert or anything... but)

wind briar Jun 6, 2020, 4:30 PM

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Basically the basics of ai then

pallid atlas Jun 6, 2020, 4:31 PM

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@woven pilot What do you mean "custom specific channel"? You mean as opposed to Visibility or Camera?

To give you a better idea of what I'm trying to do here:

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I've got a cat in a box, and it wanders around aimlessly unless it sees a lure

woven pilot Jun 6, 2020, 4:32 PM

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Yes, as opposed to visibility or camera

pallid atlas Jun 6, 2020, 4:32 PM

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While it wanders around aimlessly, it often would get stuck facing a wall

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I needed it to be able to turn around if a line trace, emitted from its face, hits anything. As of now, the only things that it can hit are walls and other cats, but for the sake of this, it really just means other walls, since I only have one cat in there atm

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But after putting in a debug print statement, I learned that the line trace hits every time it is checked

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even if the cat is nowhere near a wall

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Now, this used to work fine, up until I added a physics asset to my cat (in order to allow collision with other cats).

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But, after adding the physics asset, a shitload of things broke

woven pilot Jun 6, 2020, 4:34 PM

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Have you tried enabling Draw Debug and see what your trace is actually hitting?

pallid atlas Jun 6, 2020, 4:35 PM

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No I have not. I wasn't aware of that option

woven pilot Jun 6, 2020, 4:35 PM

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What you just said sounds like the trace might be hitting this "physics asset" you just mentioned

pallid atlas Jun 6, 2020, 4:35 PM

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I'll check it out. Under the V down arrow of the line trace node I presume

woven pilot Jun 6, 2020, 4:35 PM

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Yes

pallid atlas Jun 6, 2020, 4:35 PM

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cool. Thanks @woven pilot

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Yeah, well, the physics asset does allow collision to work, but it broke the AI movement

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The animations work fine (blendspace based on velocity), but the cat isn't going anywhere

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I learned that the velocity of an actor has to do with the forces applied to it, not the actual velocity as it's commonly thought of i.e. "speed"

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So, it can have a non-zero velocity and still be standing still (wouldn't it have to have infinite mass for that to be true?... I digress)

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So, according to this:

https://docs.unrealengine.com/en-US/Engine/Physics/Tracing/Overview/index.html

Traces Overview

Overview of the Unreal Engine 4 tracing system.

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traces use physics to do their job. It therefore makes sense that adding my physics asset broke the trace

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I just don't know where to tell it to ignore itself (Ignore Self being checked on the trace node apparently is referring to something else)

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@woven pilot I turned on the trace debug:

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The xyz coordinates being printed are from the PrintString task

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GetRandomLocation is where I perform the line trace

woven pilot Jun 6, 2020, 4:44 PM

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What kind of physics asset are you mentioning? A collision component?

pallid atlas Jun 6, 2020, 4:44 PM

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Here is GetRandomLocation

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Um. I don't know much at all about physics assets. Here it is:

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It is just two capsules

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Both of them have almost the exact same settings:

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woven pilot Jun 6, 2020, 4:47 PM

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I think the ignore self isn't working because you've put this line trace inside a Blueprint Task, which I think is a bit unusual

pallid atlas Jun 6, 2020, 4:48 PM

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That is an AI Task Blueprint

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Why is that unusual

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I don't know where else I would put it

woven pilot Jun 6, 2020, 4:48 PM

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For a quick test you can try to make an array with just the cat actor as item

pallid atlas Jun 6, 2020, 4:48 PM

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While it wanders around, I need it to check if it's facing a wall

woven pilot Jun 6, 2020, 4:48 PM

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Then pass that into "actors to ignore" of the line trace

pallid atlas Jun 6, 2020, 4:49 PM

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kk good call

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Like that, no

woven pilot Jun 6, 2020, 4:49 PM

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Should be

pallid atlas Jun 6, 2020, 4:50 PM

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Same result. No movement

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Is that 100.0 a good value? Too large?

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I figured that just meant it would trace about 100 units in front of itself

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which isn't very far

woven pilot Jun 6, 2020, 4:51 PM

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That depends on your level but it's not far at all

pallid atlas Jun 6, 2020, 4:51 PM

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The box the kitty is in is 4000x400

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4000x4000

woven pilot Jun 6, 2020, 4:51 PM

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My guess is that the line trace is hitting the PB capsules

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To see what's being hit

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You can break the hit result

pallid atlas Jun 6, 2020, 4:52 PM

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Yeah, that would make the most sense. But do you know where to tell it to ignore these?

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ok

woven pilot Jun 6, 2020, 4:52 PM

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And check what it's actually hitting

pallid atlas Jun 6, 2020, 4:52 PM

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Should I try and cast the Hit Actor to... a physics body?

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You can't just call PrintString on an object 😦

woven pilot Jun 6, 2020, 4:53 PM

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You don't have to cast anything right now, just debug print the hit actor or hit component

pallid atlas Jun 6, 2020, 4:53 PM

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I wish you could

woven pilot Jun 6, 2020, 4:53 PM

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Yes you can

pallid atlas Jun 6, 2020, 4:53 PM

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Oh really?

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I've tried before, or so I thought, and it appeared to not work

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lemme try again

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aahhhh.... it's printing "Floor"

woven pilot Jun 6, 2020, 4:54 PM

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Maybe your directions got messed up at some point then

pallid atlas Jun 6, 2020, 4:54 PM

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maybe

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thanks for all the help, btw dude

woven pilot Jun 6, 2020, 4:54 PM

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You're welcome

pallid atlas Jun 6, 2020, 4:55 PM

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I guess I was lucky you happened to be on

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Oops

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Do you see anything wrong with the way I am doing this?

woven pilot Jun 6, 2020, 4:56 PM

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I don't see the reason for that vector addition

pallid atlas Jun 6, 2020, 4:56 PM

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I originally had it as this

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woven pilot Jun 6, 2020, 4:57 PM

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Seems more correct

pallid atlas Jun 6, 2020, 4:57 PM

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Same result

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I was confused by the description of GetForwardVector

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It sounded like it produced a unit vector starting at 0,0,0, so I thought maybe I needed to add it to the current actor location in order to get my trace endpoint

woven pilot Jun 6, 2020, 4:59 PM

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Unreal considers the X direction to be "forward", so that node gives you a vector pointing in the direction the actor is rotated towards in X

pallid atlas Jun 6, 2020, 4:59 PM

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X?!

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oh, well, okay, yeah that makes sense hehe

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The XY plane is the floor

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But wouldn't I have to add that vector to its current location? In order to get a point 100 units in front of wherever the cat happens to be?

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Or does it already automatically take that into account

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Why would the line trace be hitting the floor

woven pilot Jun 6, 2020, 5:01 PM

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No, the forward vector is basically pointing in the direction the actor is facing already

pallid atlas Jun 6, 2020, 5:02 PM

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oh okay

woven pilot Jun 6, 2020, 5:02 PM

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It's length is 1, so you multiplying it by 100 gives you a line trace 100 units in the X direction of the actor

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That part is correct I would say

simple crest Jun 6, 2020, 5:02 PM

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use Draw Debug Line

pallid atlas Jun 6, 2020, 5:02 PM

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I have a floor collider, all over the floor

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Is it hitting that?

simple crest Jun 6, 2020, 5:03 PM

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also use Get Actor Forward Vector

pallid atlas Jun 6, 2020, 5:03 PM

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It's only up to the cat's knees about, though

woven pilot Jun 6, 2020, 5:03 PM

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That might be it if the actor position is inside this collider

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Then it will hit the floor right away since the start of the line trace is the actor position

pallid atlas Jun 6, 2020, 5:04 PM

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📎 unknown.png

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I'll check to see the settings on the Visibility trace channel of the floor collider

simple crest Jun 6, 2020, 5:05 PM

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now add the position (you were right about that before, you're tracing to some point in a 100 unit circle around the world origin right now)

pallid atlas Jun 6, 2020, 5:05 PM

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No, that's set to ignore Visibility

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and it's called FloorTrigger

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The debug printed out "Floor"

simple crest Jun 6, 2020, 5:05 PM

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(you can see all of this easily if you learn to use Draw Debug Line)

pallid atlas Jun 6, 2020, 5:05 PM

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@simple crest care to enlighten me?

simple crest Jun 6, 2020, 5:05 PM

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and it is normal to "lift" traces like these a few units above the floor so you don't get floor hits from z fighting

pallid atlas Jun 6, 2020, 5:06 PM

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Okay, that may be an idea

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I'll try that

simple crest Jun 6, 2020, 5:06 PM

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it's pretty simple, same as setting up a trace - you don't seem dumb I have faith in you 😄 https://i.gyazo.com/410244695b613bc2b8e53953151eadc1.png

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just replace your trace with this while you figure out the vector maffs

pallid atlas Jun 6, 2020, 5:08 PM

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That worked!

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🥳

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Thanks for the Draw Debug Line, that would've helped a lot, that didn't go to waste on me 🙂

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But just adding 50 to the z-axis value for the start and end points of the trace worked

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I guess, cuz the cat's z position is 0, it was hitting the floor?

woven pilot Jun 6, 2020, 5:09 PM

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Prolly

pallid atlas Jun 6, 2020, 5:09 PM

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Thank you both, I really appreciated your help and time on this

woven pilot Jun 6, 2020, 5:10 PM

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Meow!

pallid atlas Jun 6, 2020, 5:10 PM

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lol

simple crest Jun 6, 2020, 5:10 PM

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yep. Z fighting affects anything that uses floating point math, not just graphics

pallid atlas Jun 6, 2020, 5:11 PM

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Wow that draw debug line is awesome. I wish I knew about that for the past two months

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(That's how noob I am to this)

woven pilot Jun 6, 2020, 5:11 PM

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Welcome to game development lol

pallid atlas Jun 6, 2020, 5:11 PM

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😄

midnight scroll Jun 6, 2020, 5:23 PM

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There are a lot of those that are incredibly useful for gameplay design.

📎 unknown.png

pallid atlas Jun 6, 2020, 5:28 PM

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Oh wow

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Good to know

vast relic Jun 7, 2020, 4:01 AM

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Anyone here hooked up AI to GAS? I'm trying to figure out what's the best way to build a character that can be agnostic as to whether it's driven by a PlayerController or AIController. I heard there's a way to call input events from the AI?

patent hornet Jun 7, 2020, 4:28 AM

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it doesn't matter if its GAS or not

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you have a set of functions to handle Pawn's actions

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Attack(), ActivateAbility(), Interact() etc...

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your function handing input that activates ability lives in the PC, and calls ActivateAbility function on the Pawn/Pawn's Component

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your BT that drives AI calls ActivateAbility when it decides its time to do so

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to handle targeting agnostically, you spawn a TargetActor, iirc GAS does that already

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PC moves the TargetActor to follow the mouse, BT teleports it to wherever it decides the target is

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and your Target is TargetActor->GetActorLocation()

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all other stuff follows the same pattern

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do not put any logic about how to execute an action in either controller, keep them on the Pawn - recommending components here to encapsulate the logic

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@vast relic

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simulating input for the AIController just introduces another layer of code you need to debug and maintain

misty wharf Jun 7, 2020, 5:49 AM

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Ugh, this is annoying :\ My EQS query randomly seems to decide to return points that cannot be navigated to according to the query's own rules...

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Using the EQS Testing Pawn it of course never does that

viscid oasis Jun 7, 2020, 6:30 AM

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I tried for ages to get EQS to work. I couldn't and ended up going another route. Then today I checked and it seemed like the engine reverted to it being disabled.

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I've got an issue where I'm targeting a MoveTo against a largish actor. The AI does two things. 1) They head to the exact same point (I'm assuming the WorldLocation) 2) They run into each other due to them heading to the exact same point.

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Is there something I should look into that can help fix these issues? I was thinking I could go down the route of running a EQ to check the closest boundary for my actor but that seems heavy-handed. Same with doing a simple line trace.

vast relic Jun 7, 2020, 7:58 AM

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@patent hornet That was my planned approach. The problem is that there's no analog to "Wait input release" that could be called by AI unless I started triggering all abilities by GameplayEvents which are tags and adds a whole another layer. GAS is weird and I'm starting to think about just ditching it for now.

vestal apex Jun 7, 2020, 8:36 AM

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I have a problem with my Ai car, I implemented a behavior tree for ue4's vehicle(sedan) and i tried to connect the BT to this car's AIController. i am setting a simple task in my BT(choose a target point in the scene) and then move to node. when i observe my BT it works correctly and move to node gets executed, but car does not move at all. why is this happening? i tried this with a character and it works right, but with the car it does not.

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i also tried AI Move To node in it's BeginPlay also dose not work

static crater Jun 7, 2020, 10:49 AM

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so the max searchnodes set in recastNavMesh.h #define RECAST_MAX_SEARCH_NODES 2048 anyone knows its possible to make that bigger? ive tried it by using Filter Filter->SetMaxSearchNodes(10240); but nothing really changes?

smoky summit Jun 7, 2020, 12:44 PM

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Is there any way to search all behavior trees for the usage of a task?

misty wharf Jun 7, 2020, 4:33 PM

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Any idea how to make an EQS trace test ignore the pawn that's doing the test?

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It seems the trace test is always hitting the pawn doing the trace because it blocks on the same channel as the trace...

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I would have expected it to ignore itself by default but when I turned off the channel from itself, the query started working as I thought it should 🤔

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    {
        TraceParams.AddIgnoredActors(IgnoredActors);
    }

I can see it does this in the C++ side but it definitely does not seem to behave in this way...

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This feels like it has something to do with the way my characters are set up because it works without any fuss in every single guide I can find on this topic, but I have no freaking idea what the problem is :P

misty wharf Jun 7, 2020, 5:45 PM

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hmm I think I managed to make it work by using a different channel neither of the characters actually block on... it certainly seems to behave a bit counterintuitively

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of course now the next issue is how do I use results from one generator in another generator :) basically trying to get a set of points where the player is visible, but score them based on how far they are from actors of a certain class...

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I guess I could run the queries separately and then manually go through the results to choose but that seems to defeat the purpose of having the scoring systems in EQS 🤔

pallid atlas Jun 7, 2020, 9:40 PM

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Can anyone please clarify what this tooltip is trying to say?

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pffft it didn't capture

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It says "

If set, all decorators in branch below will be removed when execution flow leaves (decorators on this node are not affected)

"

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So, what does that mean in this context, for the Is By Lure decorator, if this box is checked?

📎 unknown.png

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Also, a more specific question... what hell is going on here? :

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📎 unknown.png

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The pink line is a line trace, ignore that. But the yellow line is drawn in here

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GetRandomLocation

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You can see the yellow line gets drawn in the lower right there. It is what BB_MoveLocation is being set to.

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Yet my kitty always seems to be moving in some other random direction that has nothing to do with the yellow line.

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What is going on?

pallid atlas Jun 8, 2020, 12:07 AM

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Okay, this may shed some light on it. Now I'm even more confused. The white point is being drawn here:

📎 unknown.png

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In GetRandomLocation

📎 unknown.png

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The kitty is moving toward the white point (which is BB_MoveLocation)

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So WHY is the value of BB_MoveLocation different than what it appears it's being set to?

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It's moving through the lower execution pin, as you can see... there is no orange arrow being drawn. The orange arrow gets drawn when the line trace (the pink arrow, supposedly) hits something.

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This illuminates the issue a bit more clearly.

📎 unknown.png

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How the hell... is it possible... that the end of the yellow arrow and the white dot are in different positions?

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And I double checked... it has nothing to do with, maybe it's the next iteration through the loop (cuz this part of the BT is in a conditional loop)... the end of the yellow arrow and the next white dot don't match up, either.

pallid atlas Jun 8, 2020, 1:17 AM

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So, at least part of it was, my line trace was being computed as:

GetActorLocation -> (GetActorForwardVector * 100)

which was wrong (the pink line's endpoint was always around the same area). I needed to change it to:

GetActorLocation -> GetActorLocation + (GetActorForwardVector * 100)

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and 100 was a little low

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Also, the line trace was hitting itself (even though "Ignore Self" was checked). Just had to plug itself into the Ignored Actors array.

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The yellow line still remains a mystery, though, but I've gotten some help from a friend who said that it probably has to do with local/world coordinates mismatching

pallid atlas Jun 8, 2020, 1:35 AM

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So, I got it resolved.

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I don't really understand it, but when I get the value from the blackboard, it works. When I use the value I set into the blackboard, it gives incorrect results.

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They should be the same... 🤔

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BROKEN:

📎 unknown.png

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WORKS:

📎 unknown.png

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Why that even produces different results is beyond me. I'd think they'd be identical

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OH!!!! Eureka!! I bet I know why

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I was assuming it was calling GetRandomPointInNavigableRadius once! It was calling it twice!

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That's gotta be it

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I figured it out 🥳

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I reposted this discovery in #blueprint, I was so amazed by its deception.

pallid atlas Jun 8, 2020, 3:58 AM

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What is going on here?

📎 unknown.png

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When I go into GetLureLocation, I see this:

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📎 unknown.png

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Ignore Restart Self?

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Oh... I get it. The one inside the task is the default value.

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When I checked it inside the task, the yellow arrow switched places (cuz the checked value at the BT level was now equal to the default)

grand atlas Jun 8, 2020, 6:56 AM

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I'm a bit amused by the Getrandompointinnavradius" because it's called once when you query the return value and then again to get the vector, at which point its return value -could- be false.. So you got to make a struct that can hold on to those two values, so it is only called once.

clever tendon Jun 8, 2020, 1:07 PM

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My character movement rotation rate is set to be 5 on the z, ortien rotation to movement is true and Use controller rotation yaw is false, but still my npc rotates instantly while changing direction. Any ideas?

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Nvm found the problem. Was still setting the use yaw to true in one place

thorny jay Jun 8, 2020, 4:00 PM

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Hi everyone, is there an up to date (for 4.24) tutorial for using Environment Queries? Every tutorial I see seems to be old and I can't follow the steps. They require you to right click and create a new "Environment Query" which apparently sits under the AI category, but I don't have that entry in the context menu. I've tried creating a new blueprint class, but I can only see an EQS context and generator classes available to extend. When I then go to the behaviour tree and want to run an EQSQuery, I don't have any templates available to assign

final holly Jun 8, 2020, 4:01 PM

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Did you go into your editor settings and enable the environmental querying system under experimental options?

thorny jay Jun 8, 2020, 4:02 PM

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There isn't an experimental option listed there. I even went to "all settings" and then searched for it

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I don't even have an "experimental" category

final holly Jun 8, 2020, 4:02 PM

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Editor Preferences, not projects settings

thorny jay Jun 8, 2020, 4:03 PM

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D'oh! I'm a dumbass. Thanks xD

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Must have misread the tutorials, I assumed the reason I didn't have the experimental option was that they were using an older version of UE4 or something

final holly Jun 8, 2020, 4:05 PM

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Understandable. No unfortunately the EQS has been in experimental for a long while and I don't think it will get out of it anytime soon either

thorny jay Jun 8, 2020, 4:08 PM

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Thanks again, time to start playing around with it 🙂

wind briar Jun 8, 2020, 9:02 PM

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How easy would it be to make it so certain music plays when ONLY the ai spots you and chases after you. Then when you lose the AI the music stops?

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Like what Outlast does.

hidden comet Jun 8, 2020, 9:56 PM

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Hey, I'm trying to give my AI abilities that require specific movement, like dodging or jump attacks. However, I can't figure out how to ensure they don't leave the navmesh and get stuck.

For example, how could I make an AI character do a side step without risking moving it out of the navmesh? I tried using raycasts to check if the target point is reachable, but that seems pretty messy and potentially expensive. Ideally, I'd like to use root motion for these abilities, which makes it even harder to check if the target point is inside the navmesh.

glossy coral Jun 8, 2020, 10:14 PM

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@hidden comet Sounds like you need the ProjectPointToNavigation which will sample the closest point on the navmesh

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Anyone know why unreal sometimes ignores my Move To node for pathfinding if I have a lot of them?

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Is there a maximum amount of navmesh queries and can that number be changed?

hidden comet Jun 8, 2020, 10:28 PM

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@glossy coral Thanks, that sounds pretty useful indeed! Will look into it

warm ibex Jun 8, 2020, 10:41 PM

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Hi peeps.
Looking a lot into AI making in unreal.
youtube videos seem very focused on using behavior trees and blackboard.
I was thinking of doing my tasking on code side but was wondering if focusing it on behavior trees was a better route?
Some forums mentioned building the code tasks and then just referencing them in the behavior trees.
But then it just seems like the only reason to really make the AI with the behavior trees and editor is for more visual designing if wanted.
Any experience with either route? or what have you guys found useful when AI building

split ravine Jun 8, 2020, 11:08 PM

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for some reason if i remove the lower most wait block my application stops responding
https://i.imgur.com/CmnALJp.png
does a sequence always need a task node?

Imgur

glossy spire Jun 8, 2020, 11:40 PM

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@split ravine I mean, it wouldn't make sense to have a sequence that doesnt have any tasks

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but i dont think it should make ur program freeze or anything

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if thats actually whats happening then that seems like a bug

split ravine Jun 8, 2020, 11:42 PM

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hmm
im suspecting
im not understanding tasks vs services and using them poorly honestly

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tasks are like
I want the unit to do an action
and services are like
sending information right?

glossy spire Jun 8, 2020, 11:43 PM

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I think its somewhat up to your personal style, but IMO tasks are things that take an amount of time, while services are things that are always happening in the background

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Personally I set targets using a task

split ravine Jun 8, 2020, 11:45 PM

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hmm ok

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i may have to move
all my services to tasks aha

glossy spire Jun 8, 2020, 11:45 PM

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Honestly for me, I use very few services

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but again that might be a style choice, who knows

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I guess another way to think about it is that Tasks can fail

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but it wouldnt make sense for a service to fail

split ravine Jun 8, 2020, 11:47 PM

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oh also
is there a way to get the units to desynchronize?
because basically I'm operating on a grid system
and at the moment if they are one tile apart they will move into the same tile simultaneously, which is not quite what i desire

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liek theyre both on the same BT

glossy spire Jun 8, 2020, 11:48 PM

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one easy way is to add wait times to your behavior tree

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with a small random deviation

split ravine Jun 8, 2020, 11:48 PM

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isn't there still an unlikely but still present chance the same thing happens?

glossy spire Jun 8, 2020, 11:48 PM

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yeah

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In my case I've made my enemies pick skills to use somewhat randomly

#

as long as they meet the reqs

split ravine Jun 8, 2020, 11:49 PM

#

o hmm
i guess i could
have it wait on bb key
and the bb key be related to the unit id

#

that way they should all have different wait times?

glossy spire Jun 8, 2020, 11:50 PM

#

yeah sure, you could set starting values on begin play

#

and access those in BT

split ravine Jun 8, 2020, 11:51 PM

#

im gonna have two teams
and not more than 10 units i think
so i could just take their array position, divide by 10
so first unit at t0, second at 0.1, etc

#

and then the waits would add up to 2 seconds total

#

i wonder if i could divide smaller, b/c 2 seconds is a bit too much i think

thorny jay Jun 9, 2020, 9:20 AM

#

Hi all, got a really weird issue. I have an AI pawn set up with an AI controller, which is running a behaviour tree in BeginPlay. I have assigned blackboard to the behaviour tree, and the tree itself is just a very simple "hello world" example (all it does is run a selector which then waits for 5 seconds). When I spawn the AI in game however, it's not running the tree. If I open the tree while PIE is running, no running instances are detected

#

It was working before, then I did some messing around with EQS queries and suddenly the behaviour tree won't execute any more even when I stripped it back to the most simple tree possible

#

The behaviour tree seems to start execution, which I confirmed by printing the boolean output of Run Behaviour Tree (came out as "true")

#

But it seems to just instantly stop execution after that

#

My AI controller and behaviour trees are so simple, that I cannot understand what might be interfering with it

thorny jay Jun 9, 2020, 9:42 AM

#

Ok never mind. My issue is that players spawn after a few seconds, so the AI controller doesn't have a pawn when it's first instantiated. Setting a delay until the pawn has been created for the controller fixed the issue

#

I'll just update the code so it only runs the behaviour tree once the pawn is created and possessed, rather than immediately in the controller's BeginPlay function

vestal apex Jun 9, 2020, 10:18 AM

#

when i load my new level, i get this massage Navmesh needs to rebulit,
how can i fix this issue?

#

i also searched project setting to see if there are anything about rebuilding but i did not find anything helpful

misty wharf Jun 9, 2020, 2:14 PM

#

@vestal apex under the Build button there is build paths

#

just pressing Build should do it as well

vestal apex Jun 9, 2020, 2:15 PM

#

@misty wharf after some search i found some stuff about static and dynamic NavMesh under project setting, do i need to tweak them too?

misty wharf Jun 9, 2020, 2:16 PM

#

no, if it says needs a rebuild it just means you need to press the build button

#

at least that's what fixed it for me every time

vestal apex Jun 9, 2020, 2:16 PM

#

aha thanks

thorny jay Jun 9, 2020, 7:05 PM

#

Hi everyone, does anyone know how I can ensure an EQS query always succeeds? I have an EQS query which keeps the AI's current target up to date, allowing it to switch targets if necessary. I run it in a sequence, the idea being that the AI always updates its target, and then runs the rest of its behaviour. However, if the EQS query fails to update the blackboard key, then the sequence aborts. I want it to always continue. How can I achieve this?

final holly Jun 9, 2020, 7:07 PM

#

you want the EQS querry to always return a result or you want to keep the sequence alive regardless?

thorny jay Jun 9, 2020, 7:07 PM

#

Keep the sequence alive regardless

final holly Jun 9, 2020, 7:08 PM

#

Force succeed

#

It's a decorator node

thorny jay Jun 9, 2020, 7:08 PM

#

Aaah ok

#

I put it on the node running the EQS query, or the sequence calling it?

final holly Jun 9, 2020, 7:09 PM

#

The EQS, it forces the node to always return a succession. It's used for optional branches in sequences. Like the tooltip says lol

thorny jay Jun 9, 2020, 7:11 PM

#

Ok thanks 🙂 Didn't know about the force succeed decorator. Thank you 🙂

final holly Jun 9, 2020, 7:12 PM

#

No problem

storm zephyr Jun 9, 2020, 10:33 PM

#

hello, when my AI is moving its MoveStatus variable (of type EPathFollowingStatus) is mostly EPathFollowingStatus::Moving, but when it gets to an intermediate point he briefly goes into EPathFollowingStatus::Idle. Is there a way to distinguish a temporary idle of a move to from an idle when there is no move to command at all?

#

i tried to check the GetPath() on the path following component, but it's nullptr when it's idle

#

so it seems to be a full idle for a few frames during that time

cyan sigil Jun 10, 2020, 1:36 AM

#

Hello, Slackers. I am doing some debug for AI and want to set up a simple test case. I'd like to have a command I can call to order the AI to pursue an actor. High level, what steps should I take?

simple musk Jun 10, 2020, 2:14 AM

#

I am confused on my character it doesnt have an ai stimuli source yet my ai still chases it when I do not want it to

#

I was under the belief that you need to have the component in order for the perception to work. Is that wrong?

urban wadi Jun 10, 2020, 5:46 AM

#

is EQS a good system to implement?

torn ermine Jun 10, 2020, 7:25 AM

#

Most systems in UE4 are pretty good, including EQS. The main thing is to determine the scope of these systems.
Difficulties arise only when we use the system for other purposes, or when the requirements for the operation of the system contradict the original design.
When choosing particular systems, you must determine whether it solves your problems.
on EQS we can say that it performs the tasks for which it is designed.
EQS is mainly useful when AI needs an understanding of a marked or unmarked environment in order to decide what to do next. And it is not designed as something that should be called on a regular basis (every tick), it should be event-oriented in the architecture of your AI
https://docs.unrealengine.com/en-US/Engine/ArtificialIntelligence/EQS/index.html
@urban wadi

Environment Query System

Documents the Environment Query System (EQS) and how it can be used to query the environment for data. That data can then be used to provide the AI with data used in the decision making process on how to proceed.

static crater Jun 10, 2020, 8:26 AM

#

So anyone knows how to properly use Partial Paths to get the expected path (right now a partial path is returned shown as green in the image)

📎 unknown.png

final holly Jun 10, 2020, 8:27 AM

#

Make sure there is a valid NavMesh from Start to Target.
If I remember correctly you tried to calculate paths over a great distance that caused this issue. Don't call paths that are too long

static crater Jun 10, 2020, 9:08 AM

#

the navmesh is valid, and indeed the path is to long

#

so i would have to split up the path in different locations ? but how to know the right direction?

final holly Jun 10, 2020, 9:09 AM

#

I'd advise making a Node Network then which uses a pahtfinding algoritm to know which nodes the AI needs to go through in order to reach it's goal

static crater Jun 10, 2020, 9:10 AM

#

yeah i was thinking something like that

#

any idea where to look for any info about how to make such a algorithm?

final holly Jun 10, 2020, 9:11 AM

#

There's a bunch of different pathfinding algorithms with A* being the most common usually

static crater Jun 10, 2020, 9:13 AM

#

its kinda odd though as the navsystem v1 is A* to right?

#

i could then aswell use the custom algorithm for the whole pathfinding part 🙃

final holly Jun 10, 2020, 9:13 AM

#

Ehm.. No

#

Your custom algoritm will be a looot simpler than the NavMesh's. As yours will only consist of waypoints in order to divide up the world, as agents traversing big distances will eventually follow the same path between these nodes. The NavMesh is there to make the AI be able to navigate anywhere in the world

torn ermine Jun 10, 2020, 9:15 AM

#

the path is considered partial
if after the search the result does not match the final goal
if (lastBestNode-> id! = endRef) status | = DT_PARTIAL_RESULT;
perhaps heuristic is guilty together with limited(64) search nodes
Engine\Source\Runtime\Navmesh\Private\Detour\DetourNavMeshQuery.cpp
dtStatus dtNavMeshQuery::findPath(...
if I found the execution code correctly

static crater Jun 10, 2020, 9:17 AM

#

i actually found out how to use Filters to alter the limit:
FNavigationQueryFilter* Filter = new FNavigationQueryFilter(); Filter->SetFilterImplementation(NavigationData->GetDefaultQueryFilterImpl()); Filter->SetMaxSearchNodes(MaxSearchNodes); NavFilter = MakeShareable(Filter);

#

MaxSearchNodes is 2048 by default

#

however it seems to heavy to calculate a path over 4km, so i'd have to make that custom node system anyhow

#

@final holly would the custom algorithm not do somehow the same ? (like checking obstacles)

final holly Jun 10, 2020, 9:21 AM

#

Kind of. You'd split up the world with these nodes. But still calculate a path between these nodes with the navmesh to get the distance from on point to another (for the A* algoritm). So yes, between the nodes there will be pathfinding and obstacle checking.

static crater Jun 10, 2020, 9:21 AM

#

right, yeah okay. Sounds reasonable.

#

Thanks for the info

final holly Jun 10, 2020, 9:22 AM

#

No problem, good luck

civic flare Jun 10, 2020, 1:42 PM

#

How does one make the rotate to face bb entry smooth?

final holly Jun 10, 2020, 1:43 PM

#

In the MovementComponent of the AI there are settings for specifiying the maximum rate of rotation which is also used by the face bb entry

civic flare Jun 10, 2020, 1:44 PM

#

Does that make it less choppy?

final holly Jun 10, 2020, 1:44 PM

#

What do you mean by choppy?

civic flare Jun 10, 2020, 1:46 PM

#

I'm trying to make a pig randomly roam around an area

#

Right now.. it picks a location, then snaps to look at it

#

no ease

#

it also walks backwards or doesn't stop sometimes.. but that feels like a different issue

final holly Jun 10, 2020, 1:46 PM

#

Right, yes playing around with those settings will make it not snap anymore.

civic flare Jun 10, 2020, 1:47 PM

#

Precision right?

#

k ill play with that

final holly Jun 10, 2020, 1:50 PM

#

📎 unknown.png

#

These settings are also used for matching the rotation of the agents during pathfollowing

civic flare Jun 10, 2020, 1:51 PM

#

k

#

just checked the controller

#

my z is 360.. does that matter

#

?

final holly Jun 10, 2020, 1:52 PM

#

That's why it snaps, there is no limit to the rotation as 360 is a full spin

#

Try lowering it and see how the Rotate to BB entry changes

civic flare Jun 10, 2020, 1:53 PM

#

ah k

#

so that is the max rotation setting basically

#

and the precision works within that

final holly Jun 10, 2020, 1:54 PM

#

More like the Rotation rate per second

civic flare Jun 10, 2020, 1:54 PM

#

hmm.

final holly Jun 10, 2020, 1:54 PM

#

Precision is basically allowing the face BB entry node to exit once the rotation is within that threshold different than the desired rotation.

civic flare Jun 10, 2020, 1:55 PM

#

Ah rotation rate

#

I get it now

#

k let me play with that

final holly Jun 10, 2020, 1:55 PM

#

Go do that, good luck

civic flare Jun 10, 2020, 1:55 PM

#

thx

civic flare Jun 10, 2020, 2:18 PM

#

k i set rotation z to like 5 and precision 10 and it still is jumping

#

I checked the character bp to make sure all the meshes etc were centered.. where does it rotate from.. center right?

final holly Jun 10, 2020, 2:26 PM

#

Yep should be the center. And that's odd, for me it slows down the rotation speed if I lower that value

civic flare Jun 10, 2020, 2:28 PM

#

📎 unknown.png

#

📎 unknown.png

#

📎 unknown.png

#

📎 unknown.png

final holly Jun 10, 2020, 2:30 PM

#

I'm not sure if you should put that service on the rotate node, as services will only start once the node is activated. And I don't know if the Rotate updates if you update the location while it is running

#

Might be better to make it a task to make sure it happens in order

civic flare Jun 10, 2020, 2:33 PM

#

K I put it back to this.. still jumpy

#

📎 unknown.png

#

This is where I started with the tutorial I found

#

📎 unknown.png

#

Service

final holly Jun 10, 2020, 2:34 PM

#

Could you make a video of the actual "jumpy" behavior

civic flare Jun 10, 2020, 2:36 PM

#

Yeah. let me figure that out. Not used to Windows LOL

#

📎 Unreal_Editor_2020-06-10_10-38-17.mp4

ruby plover Jun 10, 2020, 2:41 PM

#

Im trying to make my ai "powerup" just once in behaviour tree but i cant seem to work it out

#

i managed to get the ai into the "powerup" decorator node but it doesnt get out

final holly Jun 10, 2020, 2:41 PM

#

@civic flare Try making the SetRandomLocation into a Task, this is very weird behavior

civic flare Jun 10, 2020, 2:42 PM

#

K ill work towards that

#

See why im hitting my head on the desk LOL

final holly Jun 10, 2020, 2:43 PM

#

Yeah I've been there too

civic flare Jun 10, 2020, 2:43 PM

#

Set random location from service to task?

final holly Jun 10, 2020, 2:43 PM

#

@ruby plover I'm not sure what you mean, maybe show us your behavior tree

#

In that way you at least know that your targetlocation is set before you call a MoveTo on it

ruby plover Jun 10, 2020, 2:44 PM

#

📎 unknown.png

#

📎 unknown.png

#

i tried using a doonce node but it doesnt work

📎 unknown.png

final holly Jun 10, 2020, 2:48 PM

#

What doesn't work about it, where are you calling this DoOnce?

ruby plover Jun 10, 2020, 2:50 PM

#

ok i figured it out

#

i guess the problem was it was always going into true from that branch

civic flare Jun 10, 2020, 3:33 PM

#

Okay set it to a task.. now he goes nowwhere LOL

#

task has the same nodes as the service did

#

Does it require something else to fire it?

#

The service had intervals...

faint lark Jun 10, 2020, 4:45 PM

#

Hello, so i've been trying to create an AI in c++ that goes through all the vectors I put in an array

📎 unknown.png

#

The two first tasks seem to be working fine, the target location (which is a vector) is getting updated to the proper values

#

But for some reason "Move To" seems to be failing

#

The navigation mesh was the last thing I added, but this shouldn't be a problem

#

Any ideas why this fails ?

civic flare Jun 10, 2020, 8:14 PM

#

@final holly Okay I think I see the problem.. but unsure of how to fix it

final holly Jun 10, 2020, 8:15 PM

#

Whats the problem

civic flare Jun 10, 2020, 8:15 PM

#

📎 unknown.png

#

Do you see how I have the pig selected

#

And the NPC_Pig_BP selected

#

and notice the xyz placer

#

its way off from the mesh

#

so I think its using that as the pivot point

#

📎 unknown.png

#

But in the BP.. its not there...

final holly Jun 10, 2020, 8:17 PM

#

What if you place a new pig into the world?

civic flare Jun 10, 2020, 8:17 PM

#

📎 unknown.png

#

Way off again

final holly Jun 10, 2020, 8:18 PM

#

ehm, that's even completely somewhere else. I'd ask this in another channel if I were you.

civic flare Jun 10, 2020, 8:18 PM

#

k, probably my problem though

#

fixed LOL

#

now to see if the ai works now

#

yup

#

fixed.. still a little fast on the turn, but its not jumping

#

had an extra root component in my cpp file

#

*dough

#

thanks for the help

final holly Jun 10, 2020, 8:21 PM

#

No worries

urban wadi Jun 10, 2020, 8:38 PM

#

@torn ermine Ok for my particular use of EQS, it would involve finding a player location in game and using that location to arrive at a location that is in a particular distance from the character to utilize a Ranged attack. Is this something I should implement or just use different tasks in the BT to get there?

storm zephyr Jun 10, 2020, 9:54 PM

#

hello, how do i force the perception system to reset the sensed actors and force a full update ? I tried RequestStimuliListenerUpdate but it didn't seem to do anything? The reason for this is that i have a character that can be disabled, and when that happens i stop the behavior tree and i call SetSenseEnabled to false. when the character is enabled again, i start the behavior tree and i call SetSenseEnabled to true. The problem is that when i do that he seems to keep the sensed actors, so if he was sensing the player when he was disabled, when he gets enabled again he's still thinking he's seeing the player, when he's not.

thorny jay Jun 11, 2020, 9:30 AM

#

Hi all. I have a strange problem with adding AI sense sonfigurations to my AI perception component. I am initializing the perception component in C++ and adding a sight sense config and a damage sense config in the constructor. However, when I open the blueprint, only the sight config is added to the perception component. If I try to add a second sense config to the perception component, it won't let me. I click the drop-down menu and choose the config class, but it just immediately flicks back to "none". Weridly, if I remove the sight config from the list and then try to re-add it, it does the same thing. Basically, I cannot add ANY sense configs in blueprint, and I can only add sight config in C++

#

I tried creating a new blueprint and run into the same issue

#


    if (PerceptionComponent) {

        sightConfig = CreateDefaultSubobject<UAISenseConfig_Sight>(TEXT("Sight Config"));

        if (sightConfig) {
            sightConfig->DetectionByAffiliation.bDetectEnemies = true;
            sightConfig->DetectionByAffiliation.bDetectNeutrals = true;
            sightConfig->DetectionByAffiliation.bDetectFriendlies = true;
            sightConfig->PeripheralVisionAngleDegrees = 60.0f;
            sightConfig->SightRadius = 30000.0f;
            sightConfig->LoseSightRadius = 30000.0f;
            PerceptionComponent->ConfigureSense(*sightConfig);
        }

        damageConfig = CreateDefaultSubobject<UAISenseConfig_Damage>(TEXT("Damage Config"));

        if (damageConfig) {
            PerceptionComponent->ConfigureSense(*damageConfig);
        }
    }```

#

https://gyazo.com/f5a593912a4131f81e2421c9888052f5

Gyazo

▶ Play video

grand atlas Jun 11, 2020, 10:26 AM

#

How does the ai sense determine Detection by Affiliation? I am calling Report Noise Event and have "detect enemies" and "detect neutrals" checked and characters of the same class does not pick up the noise. Checking "Detect Friendlies" does make the other characters pick up the noise. So how is affiliation determined?

misty wharf Jun 11, 2020, 10:29 AM

#

TIL ai perception component senses still trigger "On Target Perception Updated" even if the AI Perception component has been set inactive 🤔

thorny jay Jun 11, 2020, 10:48 AM

#

@grand atlas From what I understand, you can only achieve this in C++. You need to create a child class of the AIController, and override the ETeamAttitude::Type GetTeamAttitudeTowards(const AActor& Other) const function

#

That function takes in an actor, and from there you can run any logic you like to return ETeamAttitude::Neutral, ETeamAttitude::Friendly or ETeamAttitude::Hostile depending on your custom logic

grand atlas Jun 11, 2020, 10:50 AM

#

I see, thanks. Seems like there's some default logic happening though, like a query of the same class results in a friendly attitude.

thorny jay Jun 11, 2020, 10:56 AM

#

There is yes, it uses something called a Generic Team Agent Interface. I have no idea how it works but it looks complicated and annoying. In my case I track the player (and AI's) team in the player state (my AI has a player state since it's meant to simulate human behaviour), so I just obtain the player state in the GetTeamAttitudeTowards function and do a comparison. If the actor has no player state then they're automatically neutral

#

Basically, the default logic is to look and see if the perceived actor implements a generic team agent interface and then tries to obtain the team from it and do a comparison, if there is no interface then it returns neutral

#

Which is why all perceived characters by default are neutral

grand atlas Jun 11, 2020, 10:59 AM

#

Thanks for the information, very useful when trying to figure out this perception system.

thorny jay Jun 11, 2020, 11:04 AM

#

Sorry I can't give more specifics on the default implementation, as mentioned it seems a lot less complicated in my case to just get the player state of the perceived actor, get the player state of the perceiving bot, and then compare right there and then

faint lark Jun 11, 2020, 11:23 AM

#

📎 2020-06-11_12-22-18.mp4

#

Any ideas why my AI character isn't moving ?

#

the "move to" node uses a vector right ?

#

(I used C++ for the character and AI Controller)

torn ermine Jun 11, 2020, 11:36 AM

#

Point.Z = 250
Is it reachable by navigation?

faint lark Jun 11, 2020, 11:36 AM

#

Does it have to be exactly on the ground ?

#

can it not be a little bit above it ?

torn ermine Jun 11, 2020, 11:44 AM

#

hmm...

#

I quickly checked and does not require high accuracy of coincidence with navigation

#

https://i.imgur.com/vCRQHrt.png

Imgur

#

what is your variable value acceptable radius ?

faint lark Jun 11, 2020, 12:02 PM

#

📎 unknown.png

#

I'm using the move to task provided by the engine

#

I didn't use blueprints or c++

torn ermine Jun 11, 2020, 12:03 PM

#

📎 BTMoveTO.gif

faint lark Jun 11, 2020, 12:04 PM

#

tell me, what happens if you double click your "move to" task ?

torn ermine Jun 11, 2020, 12:04 PM

#

https://i.imgur.com/XmpDLpY.png

Imgur

faint lark Jun 11, 2020, 12:05 PM

#

This is essentially what i'm doing in C++ when the game starts

torn ermine Jun 11, 2020, 12:05 PM

#

tell me, what happens if you double click your "move to" task ?```
nothing

faint lark Jun 11, 2020, 12:05 PM

#

https://i.imgur.com/vCRQHrt.png
@torn ermine Where did you put this ?

Imgur

torn ermine Jun 11, 2020, 12:06 PM

#

Where did you put this ?
it was just a check without BTTask

#

in character

#

@faint lark
check you filter class settings in MoveTo BT Node

faint lark Jun 11, 2020, 12:09 PM

#

its set to none

#

I gotta go for now, I will try a couple things when I get back : using the "move to location or actor" BP node instead of the default task
debug the code for the default go to task in c++

#

Thank you for the help

torn ermine Jun 11, 2020, 12:12 PM

#

need to select a filter

torn ermine Jun 11, 2020, 12:50 PM

#

async nodes - this is a custom blueprint node, in the editor module, transitions when clicking on them never led to its source code
but they can be found by search by solution.

civic flare Jun 11, 2020, 12:57 PM

#

Good morning

#

Is there a tutorial for AI roaming for birds

#

I'm hoping for flight.. but also something maybe a tad more complicated where a bird lands on branches or chooses branches

#

is the best option to use a bunch of target points in the mesh nav area

#

?

#

and maybe use a basic roam but add some Y to it

#

though it would be weird to have a bird stop mid air LOL

smoky summit Jun 11, 2020, 1:08 PM

#

I would use steering behaviors for birds

#

https://gamedevelopment.tutsplus.com/series/understanding-steering-behaviors--gamedev-12732

Game Development Envato Tuts+

Understanding Steering Behaviors - Envato Tuts+ Game Development Tu...

civic flare Jun 11, 2020, 1:11 PM

#

Thanks

#

I'll take a look

smoky summit Jun 11, 2020, 1:11 PM

#

np

misty wharf Jun 11, 2020, 1:54 PM

#

hmm the gameplay tag cooldown decorator doesn't seem to actually work correctly if several actors try to perform the action simultaneously 🤔 I was hoping to use that as a sort of global cooldown but I guess not...

#

oh wait it's not even a global thing is it, it probably just saves the tag in the controller's tag container or something 🤦

faint lark Jun 11, 2020, 1:59 PM

#

need to select a filter
@torn ermine What filter ?

#

📎 unknown.png

#

i've got these ones and none of them make a difference :/

autumn pecan Jun 11, 2020, 2:14 PM

#

🤔 PathFollowingComponent exists on AI controllers, correct?

faint lark Jun 11, 2020, 2:25 PM

#

📎 unknown.png

#

looks like it @autumn pecan

autumn pecan Jun 11, 2020, 2:26 PM

#

hm, this becomes very problematic then

#

trying to integrate my custom movement component(which is actorcomponent baseclass, not a movementcomponent) but Im trying to figure out at what point of the chain do I start implementing my own stuff

#

so I probably have to replace PathfollowingComponent with a custom code too, since it seems to rely on registering movement component

faint lark Jun 11, 2020, 2:29 PM

#

Can't help you there, i'm stuck on making a freaking basic AI move...

#

This is driving me nuts, I did the hardest part and now I can't get it to just move

lyric flint Jun 11, 2020, 2:41 PM

#

@faint lark If your point is at z -250, check the navmesh projection height. Should be somewhere in project settings/navigation. It's possible the point can't be projected to navmesh because 250 is higher than the max allowed projection.

#

aka query extents

📎 unknown.png

ruby plover Jun 11, 2020, 3:56 PM

#

Can i change a variable in an ai service bp from another bp?

sullen escarp Jun 11, 2020, 3:58 PM

#

Make it a BB key that you can change

ruby plover Jun 11, 2020, 4:25 PM

#

Thanks for the advice, it worked 🙂

urban wadi Jun 11, 2020, 6:25 PM

#

Ok for my particular use of EQS, it would involve finding a player location in game and using that location to arrive at a location that is in a particular distance from the character to utilize a Ranged attack. Is this something I should implement or just use different BB tasks in the BT to get there?

urban wadi Jun 11, 2020, 6:40 PM

#

When using the perception component on an AI, does the character need to have the AI Perception Stimuli Source on it to be able to interact with the character (chasing, Attacking, etc....)?

#

Anyone?

fresh copper Jun 11, 2020, 9:58 PM

#

What can I do to fix my behavior tree. The whole tree is flashing rapidly between the steps, and none of them are running

#

📎 DvoO46K1K8.gif

#

None of these are actually happening, The npc is just standing still

sullen escarp Jun 11, 2020, 10:06 PM

#

TargetActor key probably isn't defined? And on the second branch the EQS is probably not returning any valid points.

#

Can use Visual Logger to see what's going on under the hood

fresh copper Jun 11, 2020, 10:06 PM

#

What is visual logger?

#

It is flashing between this and nothing

📎 unknown.png

#

📎 unknown.png

sullen escarp Jun 11, 2020, 10:23 PM

#

VisLog captures what's going on in the game, you can check there why the behavior tree steps are failing https://docs.unrealengine.com/en-US/Gameplay/Tools/VisualLogger/index.html

Visual Logger

Tool that captures state from actors and then displays it visually in game or editor.

fresh copper Jun 11, 2020, 10:47 PM

#

It is looping between these two parts of the log in VisLog

📎 unknown.png

#

📎 unknown.png

pine steeple Jun 11, 2020, 11:08 PM

#

your EQS is returning no valid items

fresh copper Jun 11, 2020, 11:24 PM

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How can I fix that?

pallid atlas Jun 11, 2020, 11:50 PM

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How do I abort (with failure, causing the BT to reevaluate back up the tree) from a task using a node within the task?

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Actually, nevermind. I know how to do that in a task. I'm actually in a service, which is the wrong place to do this anyway.

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Okay, better question:

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Can anyone explain to me what exactly is the difference between these two nodes?:

#

📎 unknown.png

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I tried Googling for it, but not much out there.

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I've used both in the past to accomplish the same thing (got better results from OnPerceptionUpdated), but in both cases (especially OnPerceptionUpdated), I wasn't 100% sure why it worked the way it did.

I am using sight in my examples.

For example, for OnPerceptionUpdated:

What changes in the actors trigger it being called? Any change to its location? rotation? Anything at all???
Does losing sight of everything trigger it (with UpdatedActors.length == 0)?

For OnTargetPerceptionUpdated:

How does this get triggered if more than one stimulus is in range?
When it loses sight of everything?

Thanks. The documentation is... non-existent.

misty wharf Jun 12, 2020, 11:23 AM

#

As far as I can tell the difference is the target variant is called only when that specific perception component updates.

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And yeah sight sense updates when losing LOS - at least in the target variant, the stimulus will have "successfully sensed" as false in that scenario.

vast relic Jun 12, 2020, 4:35 PM

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Anyone here tied together AI and GAS? Specifically I'm trying to figure out how to make a character completely agnostic as to whether it's being driven by AI or player controller. The sticking point is that GAS works best when directly bound to input. Is there a way to have an AI controller call input actions?

urban wadi Jun 12, 2020, 5:38 PM

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When trying to create a ranged AI is the best implementation EQS for finding and attacking at range? Or should i use a mixture of BB tasks and services? Please anyone give me an answer, because I don't want to use EQS if it is indeed experimental and or causes slower execution in game.

patent hornet Jun 12, 2020, 5:50 PM

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its technically experimental, stable since 4.15 or so, and unchanged

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and it doesn't "cause slower execution"

urban wadi Jun 12, 2020, 5:59 PM

#

Okay i guess worst case scenario i can use the EQS for ranged AI, and in the event it does not work i can use BTT, services and decoratros

#

decorators

ruby plover Jun 12, 2020, 6:18 PM

#

Im having this exact problem: https://answers.unrealengine.com/questions/102662/my-navmesh-needs-to-get-rebuild-after-i-reload-a-m.html
My navmesh is dynamic and i force rebuild at load

This effects packaging too, ai doesnt move in a packaged game
The tickbox named "can be main nav data" in project settings -> navigation mesh and in the recastnavmesh actor in the world outliner keeps getting turned off too
This is starting to drive me mad, i dont have any clue why this is happening and its been a problem for like a month

patent hornet Jun 12, 2020, 6:19 PM

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@urban wadi EQS usually goes into a BT Service

#

its not one or the other

ruby plover Jun 12, 2020, 6:27 PM

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Well, ive put a navmeshbounds volume to the first map i start at just to try what would happen, the "navigation needs to be rebuilt" error is gone now and it looks fine in editor but when i play a build version of the game ai still doesnt move

pallid atlas Jun 12, 2020, 6:59 PM

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@misty wharf what about when multiple stimulus are visible? How does the target variant respond? In what order would it process them? I'm having a difficult time trying to debug it/figure that one out.

misty wharf Jun 12, 2020, 7:00 PM

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Hard to say tbh, they'll all come in but I wouldn't have any idea what the order will be :) Would you know what order they are in the array? Probably not

pallid atlas Jun 12, 2020, 7:00 PM

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True

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Since I have your attention, would you mind offering your knowledge on another perception-related question?

misty wharf Jun 12, 2020, 7:02 PM

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I'll try but no promises because I'm not super experienced on that :D

pallid atlas Jun 12, 2020, 7:02 PM

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I need to be able to have different visual stimuli have a strength modifier, so that either:

A) The stronger stimuli will be noticed first, or at least will I'll be able to filter them by strength or something like that.
or
B) A weaker stimuli won't have a 100% chance of being noticed.

#

Do you know how to accomplish this?

#

Either one would work for my scenario

misty wharf Jun 12, 2020, 7:04 PM

#

I can think of two possible ways... You could compare distance to actor, or have two separate sight senses, one with a lower distance, the other with a higher distance

pallid atlas Jun 12, 2020, 7:04 PM

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I suppose I could just add a variable Strength in the BP containing the stimuli, then run a random bool on it

misty wharf Jun 12, 2020, 7:04 PM

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although the two senses method probably wouldn't work if you need to define "weak sight" by some other factor besides distance

pallid atlas Jun 12, 2020, 7:04 PM

#

when it does get noticed.

#

That is a good idea. Two sight stimuli

#

Interesting idea, at least

#

I wouldn't have thought of that

#

thx

misty wharf Jun 12, 2020, 7:05 PM

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Distance to actor is probably better tbh, less complicated to handle since you'd just get one set of sight stimulus events, and more flexible if you want to make it say based on if you're crouched or something

pallid atlas Jun 12, 2020, 7:06 PM

#

cool. thx @misty wharf

#

One last question, @misty wharf:

Just in your personal experience, when is it preferable to choose the target variant over the generic one, or vice-versa?

It seems to me that both could accomplish the same tasks for just about anything... there must be a gotcha that I'm not thinking of; a case where it is plainly better to use one over the other.

#

I suppose the stimulus result on the target variant gives you more information

misty wharf Jun 12, 2020, 7:12 PM

#

The target is probably better if you need to react to individual stimulus events, while the other one could be better if you need to react to groups of stimulus

#

You can use get latest stimulus or whatever it was called on the AI Perception to get the stimulus data for any actor

pallid atlas Jun 12, 2020, 7:14 PM

#

Yeah. So, in my case, I need to be doingone of two things based on either ZERO or MORE THAN ZERO stimuli are sensed. In my case, the generic would be better, no? Because with the target variant, a result of false tells me that some particular stimulus went out of sight, but I'd have no way of knowing if it no longer sees any stimuli, right? For that, I'd be better off checking SensedActors.length in the generic version, no?

misty wharf Jun 12, 2020, 7:15 PM

#

There is a method on the ai perception that you can use to get all sensed actors or something like this iirc

pallid atlas Jun 12, 2020, 7:15 PM

#

You know the name of that node? For getting the latest stimulus?

#

Nothing is coming up in the context menu as far as I can find

misty wharf Jun 12, 2020, 7:15 PM

#

uhh I wonder what was it called..

pallid atlas Jun 12, 2020, 7:16 PM

#

oh, nice. you are being very helpful, thank you. all kinds of new info

#

They really need to make the docs better

misty wharf Jun 12, 2020, 7:16 PM

#

"get actors perception"

#

the naming is a bit confusing tbh but that should do it

pallid atlas Jun 12, 2020, 7:17 PM

#

cool, thx

📎 unknown.png

ruby plover Jun 12, 2020, 8:13 PM

#

OK. I guess i fixed it. Im not 100% exactly certain what specifically fixed it but im positive that it got fixed after i changed these :

📎 unknown.png

#

Idk why that fixed it for sure but its fixed for NOW. I hope im right and it doesnt brake again since this is really important.

#

Well, now i see that when i close the editor and open it up again, those settings reset to default. Idk why. At least they carry over to the build of the game but its still stupid.

glass falcon Jun 13, 2020, 3:01 AM

#

I'm getting an error while packaging because of my custom decorators

#

https://pastebin.com/rpU34uLM

Pastebin

packaging error - Pastebin.com

#

By custom I just mean I made bp decorators

sullen escarp Jun 13, 2020, 5:56 AM

#

@glass falcon Originally posted by mieszko This means you have a BP-implemented BT decorator, that uses BB keys, its instance is set to abort lower priority or self or both, but the BB key is not set. Go through your BT decorators and validate the setup.

neat condor Jun 13, 2020, 1:41 PM

#

Does anyone here have any idea about NLP in general? To give more context.

I started working on my thesis, for now I am in the documentation period where I just read a lot of things to come to a decent idea.

My plan is the following:

Let there be a chat (the most basic stuff ever).
Let there be a BOT that is the player's "assistant" (or moving wiki 🙂 )
The player will query, using the chat, the bot. For example
- Where can I heal myself?
- Where can I get drop X?
- Guide me to Healing Fountain.
etc.
The bot will take the use input, process it, and take the desired action.

Now, how I thought it would look like:

User Input goes to BOT
Bot does a http call to a local server (yes, won't bother implementing NLP things in UE, will use, most likely, python for this because it already has a lot of useful libraries)
The text is being processed (i don't know yet how, documenting on this)
The server sends the response back to the bot.
The response will then go through a "service manager" which I think would be cool to be a Decision Tree.
The bot will take the desired action (either chat answer or "follow me" action etc.)

Why NLP? => Want to reduce the decision tree complexity

Now, there are unknowns to me in terms of NLP.

The question for anyone: Do you know of any place where I can read more in depth things about NLP that may be useful for what I need to do? Or, any idea of what I can try? That would be really helpful.

Thanks a lot.

lyric flint Jun 13, 2020, 1:55 PM

#

Does someone know how i can make it so the ai only plays the anim the first time it sees you?Since right now it starts chasing you and it keeps playing the anim over and over again.

📎 unknown.png

#

@neat condor You didn't find anything on Udemy related to natural language processing? I vaguely recall I've seen something. I usually browse Udemy for all my intellectual needs, so to speak 😄

#

from your list of steps, step 3. Is the one you need to worry about. "The text is being processed" Is as generic as "let's go to Mars" 😄 Here is where you need to train your AI, throw enough quantity of data so that an accurate model emerges

#

your thesis supervisor may be a better partner for brainstorming though...

#

I feel everything I said is too fuzzy to even be relevant, So I guess I'm gonna shut up now 😄

neat condor Jun 13, 2020, 2:02 PM

#

Yes, mainly the problem is that step, the "unknown" let's say.

The problem is not that I can't find papers / courses etc. related to NLP (or to be more exact, NLU), but that i need to lower the search radius a bit, as there is a ton of stuff on the internet, deep diving in all of them will just lead to nothing, I think 🤔 I may be wrong tho

#

nah it makes sense 😄

lyric flint Jun 13, 2020, 2:03 PM

#

Your criteria is to find relevant sample of data, the keyword is relevant

glass falcon Jun 13, 2020, 2:04 PM

#

@sullen escarp I've seen that but I don't understand. How am I supposed to validate the setup

#

In the by decoratior I already have an is valid node to check if the bb key is valid

lyric flint Jun 13, 2020, 2:04 PM

#

It hurts my brain every time I use fuzzy notions, such as relevant or enough 😄

neat condor Jun 13, 2020, 2:05 PM

#

To be fair, from the readings I did until now, I think that what I actually need to do is simply take the relevant information out of a text, not really predict an "action".

Also, i know what you are talking about, I need to read things about NLP here 😄 all is hard to understand, especially when it gets to math 🙂

lyric flint Jun 13, 2020, 2:06 PM

#

I mean, hopefully Bell and Markov stuff would be taken care of by your Python libraries already

#

The fact that I heard of Bell and Markov, does not mean I understand them 😄

neat condor Jun 13, 2020, 2:07 PM

#

Basic stuff should be fine 😄 I am ok even with implementing.

The problem here is directions. Consider me at a crossroad with 100 possible directions. Which ones should I consider taking? 🙂

lyric flint Jun 13, 2020, 2:08 PM

#

This is where you need accurate Emergent behavior, that comes exclusively out of training your AI

#

I mean I can also close my eyes and play darts blindfolded, but my accuracy would suffer 😄

#

see, the AI's problem is that it doesn't understand blow some snow

#

It can mean do cocaine or clean your driveway

#

unless you guide explicitly your AI with contextual relevance that you manually tag and veto, your poor AI would not know who is who and why 🙂

#

I feel out of my depth but with this conversation, so I would rather quietly bow out, as I don't intend to confuse you 😄

#

it was nice to pretend I'm smart for five minutes though....

neat condor Jun 13, 2020, 2:13 PM

#

yeah, you see, the AI should "understand" what the player meant. Take, for example, Alexa / Siri / Cortana / Google Assistan. So, there is a text that it gets from you (in their case, more complicated, speech, but let's say it's text). Now, they try to break that text into relevant information. Let's say you ask "How will the weather be tomorrow in Berlin".
Information it extracts is:

what -> weather
where -> Berlin
when -> tomorrow

My AI should be somewhere in the same place right?
But yeah, many unknowns for now

#

To be fair, i feel like discussions are useful, as they tend to lead to something, compared to blindlessly trying to find something 🙂

lyric flint Jun 13, 2020, 2:13 PM

#

I was working with some guys in San Francisco many years ago, they were doing exactly this

#

their business model was targeted for litigation

#

so they used a server farm for AI, the use of actual linguists for contextual relevance and they use lawyers for vetoing

#

these three ingredients together made their system highly accurate

#

Especially at that time this was 15 years ago

#

with 30% of their workforce was actually linguists, highly trained with a lot of degrees

neat condor Jun 13, 2020, 2:18 PM

#

It's complicated, not gonna lie. Second thesis I do, I chose, AGAIN, something that I don't know that well 🙂 Fun times

sullen escarp Jun 13, 2020, 2:20 PM

#

@glass falcon Sounds like there might be a BT node that has an exposed BB key selector but it's null for whatever reason, maybe go through and re-select the keys from the dropdown list.

glass falcon Jun 13, 2020, 3:38 PM

#

Ok

#

I'll try @sullen escarp

cerulean girder Jun 13, 2020, 8:37 PM

#

the 2 hardest things i experienced learning the ai in ue4 was when you should be aborting a branch, and remembering that a branch aborted in a sequence either on purpose or from a failed condition aborts the entire sequence, it doesnt go on to the next step in sequence it cancels the entire thing out.

#

other than that its pretty straight forward

true gazelle Jun 14, 2020, 2:38 AM

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Evening all. Is there any way to use the AI Perception debugging without numpad keys?

#

i have tenkeyless keyboard arggg

delicate pivot Jun 14, 2020, 1:07 PM

#

Hello, i am making RPG game and i can't solve one problem. I have created unit-bear(Character), that just goes to Player and attacks him and I have made spell blueprint that i called Ice Aery. It cycles around player and when it sees Bear it should fly to him and explodes. It is character because I used PawnSensing, but its not working. Event On See Pawn isn't functioning. Anyone help ?

#

I have reacreated IceAery as pawn and still not working

tidal void Jun 14, 2020, 7:38 PM

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@delicate pivot Do you have your "Detection by Affiliation" set up properly?

digital cairn Jun 14, 2020, 9:17 PM

#

I am trying to modify a navmesh a bit... I need the default cost to be higher than 1. I created a custom recastnavmesh and am trying to set the default area to a custom created NavArea with higher default cost. Sadly this does not seem to work, anyone tried to do this?

(What I am trying to do as a end result is a road system where the AI would prefer to walk on the road due to the lower path cost, trying to avoid having to manually navigate the AI to reach to road and travel along a spline or such)

lyric flint Jun 15, 2020, 12:01 AM

#

@humble apex Absolutely, for example have a flag that sets NPC as of party member. Then have a method that checks to see if party member and the game mode is not combat ( but instead explore mode, metaphorically ) if the distance between the NPC and the player is bigger than xxx, start a quick AImoveto Toward the player and abort when the distance is acceptable

#

When the distance is acceptable, set the NPC to idle state, Which should take care of the animation and such 🙂

glass falcon Jun 15, 2020, 1:30 AM

#

@sullen escarp it didn't work

smoky summit Jun 15, 2020, 4:51 AM

#

Has anyone seen an issue where EQS queries get stuck and never return a result when they definitely should be?

delicate pivot Jun 15, 2020, 5:10 AM

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@tidal void i dont know what it is, so probably no

hidden comet Jun 15, 2020, 3:33 PM

#

Hey, I'm using the Navigation Invoker system for an open world AI, but am getting the error message that my navmesh bounds volume is too large.

"Error: Navmesh bounds are too large! Limiting requested tiles count (1225224) to: (1048576)"

Wasn't this system implemented specifically for large worlds? Is there anything I can do to raise the tile count limit or work around the limitation?

pallid atlas Jun 15, 2020, 3:50 PM

#

I have a question about nav meshes:

I have different types of flooring that must react differently to certain collisions, and so I thought I'd turn my static floor mesh into an abstract BP class, and subclass it for the different type of flooring.

I went to add the nav mesh to the abstract base class (figuring it would sum up the pieces of the nav meshes?), and discovered that was not an option.

So, if I want to procedurally generate a floor map, I would first generate the floor, compute the total bounds size, and then add a nav mesh to its entirety? There is no way to just "have the nav mesh be part of the flooring"?

rocky bison Jun 15, 2020, 5:51 PM

#

hey all, is there a way to extend an EQS SimpleGrid in a specific direction so I can get something like in the image?

📎 unknown.png

inland umbra Jun 15, 2020, 5:53 PM

#

you could add custom EQS generator https://www.orfeasel.com/creating-custom-eqs-generators-in-c/

Orfeas Eleftheriou

Οrfeas

Creating Custom EQS Generators in C++ | Orfeas Eleftheriou

In this post we're going to create our own EQS Generator in Unreal Engine 4. This post assumes you're familiar with the Environment Query System that resides in UE4. In case you don't q

rocky bison Jun 15, 2020, 6:05 PM

#

ill check that out, thanks

#

oof, i'm not too sure about C++ though

sullen escarp Jun 15, 2020, 6:15 PM

#

You can make generators in BP too. Though they intermittently crashed for me when compiling / using EQS testing pawn to preview but that was also back on 4.23 so might have been fixed

rocky bison Jun 15, 2020, 6:55 PM

#

ah

#

okay

#

also, whenever i try to get the forward vector of my ai character to do a line trace it just goes back to the world origin?

📎 unknown.png

#

📎 unknown.png

#

is there another node I'm missing or something? this setup usually works, though ive never tried with AI before

pine steeple Jun 15, 2020, 7:10 PM

#

@rocky bison ofc it would

#

where is your end?

#

probably 0,10, 0

#

or something

rocky bison Jun 15, 2020, 7:10 PM

#

Hmm

#

True

pine steeple Jun 15, 2020, 7:10 PM

#

right

#

so what should your end be

#

10 units in front of player right?

rocky bison Jun 15, 2020, 7:11 PM

#

Well, I'd like it 10 units in front of the ai character

pine steeple Jun 15, 2020, 7:11 PM

#

right

#

so what must you do

#

?

rocky bison Jun 15, 2020, 7:12 PM

#

I'm feeling stupid right now

pine steeple Jun 15, 2020, 7:12 PM

#

Add the ActorLocation to it

rocky bison Jun 15, 2020, 7:12 PM

#

Well shit

#

That makes more sense

#

Yeah I'm stupid

#

This will probably work, but I just got off my pc, so I'll have to test it out later

#

Thanks mate!

magic jasper Jun 15, 2020, 7:24 PM

#

Just putting feelers out - I don't suppose anybody has any ideas how Deep Rock Galactic does it's 3D surface pathfinding do they?

#

I've looked at the SVON plugin which is pretty nice, but that's more about avoiding surfaces than moving across them..

#

found a thing:
https://www.gdcvault.com/browse/gdc-18/play/1025151/Hierarchical-Dynamic-Pathfinding-for-Large

urban wadi Jun 15, 2020, 7:37 PM

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Just some advice

pine steeple Jun 15, 2020, 7:38 PM

#

so i have a weird bug, Launcher Engine Shipping build - Navmesh works fines, Source engine Shipping Build - Navmesh doesnt generate

urban wadi Jun 15, 2020, 7:38 PM

#

Is it better to use on tick focus actor for a Ranged AI to update and attack my character, or is it better to Utilized EQS to do so?

pine steeple Jun 15, 2020, 7:38 PM

#

anyone else experienced this?

true gazelle Jun 15, 2020, 8:11 PM

#

Hey All, I'm used to sending a add movement input a vector to move a character without a physical controller, but i noticed that doesn't work at all if you have an aicontroller on the character

#

is there any node i can use to add movement input with an ai controller?

dusk kelp Jun 15, 2020, 8:14 PM

#

Hey, guys, cant find EQS in 4.25 version. Where to enable it now?

pine steeple Jun 15, 2020, 8:21 PM

#

in the same spot it always is

#

Editor Preferences

#

EQS..

dusk kelp Jun 15, 2020, 8:21 PM

#

:/

📎 unknown.png

#

Seems like its not experimental. I can run EQS in my Decorators. But! I cant find where to create Query Template

true gazelle Jun 15, 2020, 8:52 PM

#

damn can't you just use an ai controller with a character bp to move in a world direction?

#

not to a specific location, just to keep moving!?

#

i dunno why i can't find anything : /

high summit Jun 15, 2020, 9:51 PM

#

@true gazelle https://www.youtube.com/watch?v=Il7WMwPd-qw use this to move your ai character dynamically without movement input

YouTube

Techno Nerd

How to use AI MOVE TO node in UE4 || BLUEPRINTS || UE4 TUTORIALS

Check out my Patreon: http://bit.ly/TechnoNerd_Patreon

DON'T CLICK THIS: bit.ly/2vBhU2s

PLEASE LIKE AND SUBSCRIBE

And feel free to request Tutorials.

#UnrealEngineTutorials
#AiMoveTo

How to use AI MOVE TO node in UE4

▶ Play video

olive garnet Jun 15, 2020, 10:56 PM

#

Is any one else having issue with nav in shipping builds on 4.25 for tiled landscapes? these no issues with AI working in the editor and in dev builds but just doesn't work for shipping?

true gazelle Jun 16, 2020, 1:04 AM

#

@high summit thanks but that node is still a Move TO node which seems to require a destination. I'm just trying to move my character in a circular fashion

#

and just loop in a pure circle

#

so there's no end destination

glass falcon Jun 16, 2020, 1:27 AM

#

@pine steeple am I allowed to dm you with a problem

#

It's on ai and packaging and I can't find a solution anywhere

thorny jay Jun 16, 2020, 10:24 AM

#

Hi everyone, does anyone know how, when running an EQS query, I can extract and store the score of the chosen result?

#

I have created a Behaviour Tree which runs a custom EQS query to determine a good cover point when engaging an enemy. I want the AI to continually re-evaluate it and if it finds a better one then it should go to the new one instead

#

The EQS query works great, but I have no idea how to save the score of the "winning" cover point so that I can compare it when it runs the query again

#

I only want it to switch cover if the new point is significantly better than the previous one, otherwise it will keep shifting up and down a piece of cover for no actual reason

torn ermine Jun 16, 2020, 12:19 PM

#

@thorny jay
https://i.imgur.com/KPsoVp4.png

#

just run it inside custom BTTask

thorny jay Jun 16, 2020, 12:41 PM

#

@torn ermine That's brilliant, thanks! 🙂

slow bobcat Jun 16, 2020, 2:20 PM

#

Quick question: when you retrieve a call for the event Receive Abort AI in a task, do you need to call Finish Execute there too?
I'm having a nasty bug and, after a lot of debugging, adding this (green circle) fixed it. That doesn't make sense to me and, before I jump into the rabbit hole of code again, I thought it might be worth to ask here.

BTW, the bug is that the Tree seems to be stuck running nothing. Debugging code throws hints of the current task being a inactive one. I only have seen something similar when forgetting to add Finish Execute to a task, so I tried and... bam

📎 unknown.png

#

Looks like you have to always call one of this 2?

📎 unknown.png

paper sparrow Jun 16, 2020, 2:53 PM

#

@slow bobcat Use the Gameplay debugger and see what the AI is actually doing. If its stuck on that task, then yes. I would also do a print string check to make sure it is receiving its abort properly

#

SphereTrace vs. AI Perception / What's the performance like? Does anyone know any summaries from any talks from Epic?

slow bobcat Jun 16, 2020, 2:59 PM

#

@paper sparrow yeah that's what I did. Took a while to understand what was really going on. Thanks!
I'm still unclear about calling finish abort, but that seems to fix it.

About perception system: depends.

Are you doing a massive sphere and checking overlaps within it against many things? -> Perception will be probably cheaper

Are you doinc a lot of time-sliced checks using small speheres-> that would probably be cheaper that the perception system (depends a lot on your implementation of it and how many actors are in consideraton)

#

There's a thread in this channel talking about this.
The perception system time-slices its checks so it's always equally expensive.

Pros:

it's already in the engine
It's easy to override
Usually Sight and Damage are more than enough for everything
It's performance friendly in terms of how much costs to cpu every frame
Nice debug tools

Cons:

it can be very limiting when you base your logic in things like "I can see target vs I don't see the target"
If you override CanBeSeenFrom (the function that checks visibility for Sight) and you make something more or less expensive + you have a lot of perception stimuli to check against, it can take a lot to process all of them. We had a problem where 40 enemies checked against 1 player. The 1st ones will react immediately but, the longer the list (40) the longer it will take for the last ones because of the time-slicing
CanBeSeenFrom (and I guess any other detection function for the other senses) do not support Async Tasks. The system would be better if you could use EQS IMHO.
The whole "perceived target" + "lost target" thing is too limited in terms of information provided back to code.

#

As I mentioned about cost: depends on what do you compare against

paper sparrow Jun 16, 2020, 3:27 PM

#

Thanks @slow bobcat ! I did my prototype using sphere trace, but I now understand how to use the AI. I wanted to use sight as well as sound, but really keen to keep performance in a good shape

slow bobcat Jun 16, 2020, 3:34 PM

#

something that fixed many problems for me was to implement logic to optimize AI based on how far from the closest player it is.
We have 2 timers that run an EQS.

Timer1 runs a EQS that loops all the enemies (we have them in an array in an enemy manager) and checks distances against the closes player. If they are closer than X units, we set them as "CloseRange" and we enable everything in them
Timer2 runs the same EQS (less often) and does the same process but checking if they are further than X units from the closest player. If they are, we mark them as FarRange and we disable as many things as we can.

One of the things we enable/disable is the Perception System. That way, only enemies in CloseRange to a player check for visibility. The rest are just shut down.

In this process there's also what we do with enemies that are > Close && < Far, but you get the idea.

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There's the Significance Manager to do this things. At the time of implementing this system, I didn't know about it. I recommend you to use it (we do know for other similar optimizations) since it's more generic and multi threaded. You have to be careful locking down object due multithread, but it's a nice system

paper sparrow Jun 16, 2020, 3:38 PM

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Yeah not a bad idea, unfortunately I'm running a multiplayer game x) Makes everything 100x harder. Have to do everything to reasonable efficiency or it all goes to shit

slow bobcat Jun 16, 2020, 3:39 PM

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We are running a multiplayer game too. It's actually not a problem since AI is server only.

paper sparrow Jun 16, 2020, 3:39 PM

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with 40 players per server?

slow bobcat Jun 16, 2020, 3:39 PM

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On top of that: we don't use dedicated server, it's host/client

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no no, up to 4 players, but a lot of enemies. The ones doing the visibility check is the AI.
40 enemies checking if they can see the player

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so yeah, it can be done and designing things using the Significance Manager you can keep performance. Biggest problem we see is the Character Movement Component. That shit is expensive as fuck, so we disable tick as soon as we can

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anyway, whether you have few enemies checking against many players or the other way around, you will have to do optimizations

paper sparrow Jun 16, 2020, 3:43 PM

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Yeah CMC is hard 😂

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Makes sense if you only have 4 players, then you will always have more enemies so that's a good optimisation

raw estuary Jun 16, 2020, 4:13 PM

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hi guys, I made a Move To node in the behavior Tree but I can't select the Blackboard Key in the details panel. In the Blackboard I created an Object Key. Any Ideas?

pine steeple Jun 16, 2020, 4:31 PM

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need to set class to Actor

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if you expand the key

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@raw estuary

raw estuary Jun 16, 2020, 6:01 PM

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got it, thank you my saviour

cerulean girder Jun 16, 2020, 8:16 PM

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@slow bobcat you ALWAYS have to finishexecute...yes...other wise it never ever completes

slow bobcat Jun 16, 2020, 8:18 PM

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Yeah, but I wasn't expecting to actually need that for abort too. In my head I was assuming that, since the engine is the one aborting the task, it will know about it finishing. I added FinishAbort to couple Tasks. I guess we have been lucky until now

past dragon Jun 16, 2020, 8:39 PM

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Hi guys
Suddenly my Perception isn't giving me the false Sensed. I get true when sensing enemy but no false update when leaving the range!
What did I break?

cerulean girder Jun 16, 2020, 8:54 PM

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@slow bobcat it is strange since its always needed why doesnt the engine just automatically handle it...theres no case where i can think that it isnt used

slow bobcat Jun 16, 2020, 8:57 PM

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I think we were just very lucky with interruptions and dynamic bt injections

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Hi guys
Suddenly my Perception isn't giving me the false Sensed. I get true when sensing enemy but no false update when leaving the range!
What did I break?
@past dragon

check that your ranges make sense in the sense. For sight there a close and far ranges (sense/green and loose/pink). make sure the pink is bigger than the green. Silly common mistake

past dragon Jun 16, 2020, 9:05 PM

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@slow bobcat Yeah, that's all good. I'm doing this on the controller.

faint tendon Jun 16, 2020, 10:06 PM

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hey can someone help me understand the basics of editing pawns?

fresh remnant Jun 16, 2020, 11:33 PM

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Anyone work on customizing Unreal's crowd manager to work with multiple nav meshes? I'm wondering if that's something I should try to do or is that a lost cause depending on how rigidly it is coded for a single nav mesh. I haven't dived too deep yet, but I need multiple nav meshes because of my agent sizes but I also need all agents to follow the same crowd manager.

glossy spire Jun 17, 2020, 4:32 AM

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Is there any way to have something like a selector or a sequence as the primary execution on a Simple Parallel?

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maybe that is what a Service is for?

steel dragon Jun 17, 2020, 4:55 AM

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Heyo, I'm relatively new to working with UE4 (worked with Unity/etc for several years), so maybe I'm missing something obvious, but...
Has anyone here worked much with the HTNPlanner plugin yet? Since it's experimental and undocumented, I'll mostly just be experimenting in C++ before I try to make it actually do anything in a game.
I know https://github.com/bullyleo/UnrealHTNGraphEditor exists, but it's been a while since it last got changed, and it seems closer to a behavior tree than HTN/GOAP.... it'll be a nice reference but that's about it.

tulip shale Jun 17, 2020, 6:50 AM

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is there a semi-effective AI pathfinding method to prevent AI clumping up that works for networking? wondering if i should try to make my own setup that will probably be just awful

patent hornet Jun 17, 2020, 10:24 AM

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there are 2 of them

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crowd avoidance - AI will use the corridors instead of paths, does not work for agents of different navmeshes, it has pretty bad glitches with dynamic navmesh gneeration

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and RVO - a force is added to push the AI out of each other's way - this one can push them into nav area nulls

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off the map, if you have any holes, etc...

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some of that might had been fixed on 4.25

static fable Jun 17, 2020, 3:17 PM

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I got a message saying my navmesh needs to be rebuilt.
can that be built in the same way lighting does

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please @ me

sinful steeple Jun 17, 2020, 4:30 PM

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Ok cool. So I'm not at home right now, but here's my issue I'm having.. so in my game setup, I have an AI charger character, set up with the on see pawn blueprint. It was working before, now it's not, and I've looked through everything and can't figure out what changed in order for it to stop working.

quasi trench Jun 17, 2020, 6:20 PM

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Did somebody know a good tutorial for creating a IA for a action oriented third person game?

sinful steeple Jun 17, 2020, 6:27 PM

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What kind of AI are you trying to implement?

runic zinc Jun 17, 2020, 6:54 PM

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Hi im trying to get my ai to keep a distance but it only runs to me and i don't know what to do so it ceeps the distance. anyone know what i need to do

📎 unknown.png

quasi trench Jun 17, 2020, 6:58 PM

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An IA for normal enemy, that follows and attack, with smooth transition between

runic zinc Jun 17, 2020, 7:01 PM

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something like that yes im just starting with keeping a distance, rn he runs to me but not away if i get to close, its supose to be an ranged unit

solar bronze Jun 17, 2020, 7:11 PM

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Hi im trying to get my ai to keep a distance but it only runs to me and i don't know what to do so it ceeps the distance. anyone know what i need to do
@runic zinc the 'run from player' and 'follow player' events are the same thing

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it only really changes the radius but thats not gonna help you much

runic zinc Jun 17, 2020, 7:19 PM

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@solar bronze ok do you have a video or something that can show me how i should do it?

solar bronze Jun 17, 2020, 7:20 PM

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a video to that specific case, i don't know any

runic zinc Jun 17, 2020, 7:26 PM

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damn hmm

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ty anyway ^^

solar bronze Jun 17, 2020, 7:29 PM

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np

buoyant geyser Jun 17, 2020, 7:32 PM

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is there a difference between navmesh settings in Test/Shipping and Development? both are cooked builds

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I'm not getting the complete navmesh generated in Test mode and looking at the logs it seems like it's just generating a smaller amount of nav tiles

sudden drum Jun 17, 2020, 8:29 PM

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Hey guys, I'm facing a horrible issue. Every time I build the game, I can't rely on the navmesh getting lost. If I then open the map in editor the navmesh isn't there anymore and I have to rebuild paths manually so it regenerates it.

glass falcon Jun 17, 2020, 11:03 PM

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I can't abort from the does path exist decorator

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The only option is none

pine steeple Jun 18, 2020, 12:39 AM

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there is a pull request

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eek delayed

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@buoyant geyser what engine version?

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i was having the exact same issue in 4.24.3 source engine

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works fine in Launcher engine!

buoyant geyser Jun 18, 2020, 12:46 AM

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4.22

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@pine steeple do you have the PR link

pine steeple Jun 18, 2020, 12:47 AM

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PR link for?

buoyant geyser Jun 18, 2020, 12:47 AM

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didn't you say there was a pull request

pine steeple Jun 18, 2020, 12:47 AM

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no that was for a old post, i was delayed in discord

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i only realised on monday that 4.24.3 source build doesn't generate navmeshs in shipping

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but the launcher build does it just fine

buoyant geyser Jun 18, 2020, 12:48 AM

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can't use launcher build and can't upgrade either

pine steeple Jun 18, 2020, 12:48 AM

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so i want to find out what is different

buoyant geyser Jun 18, 2020, 12:48 AM

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it might be an issue with the RMC

pine steeple Jun 18, 2020, 12:49 AM

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both same versions tho

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just one in source and one is launcher

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that is what i want to actually find out

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is there something missing to do in source engine to allow it?

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compared to launcher build?

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going to put a UDN post to find out

worldly flame Jun 18, 2020, 4:01 AM

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anyone tried nativizing their AI?

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i got it to compile fine but in the actual game... the AIs seem rubber-band and glitch all over the place

lyric flint Jun 18, 2020, 4:57 AM

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What do you mean by nativizing their AI? I want to make sure that what I think it means matches your definition 🙂

worldly flame Jun 18, 2020, 4:58 AM

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@lyric flint nativize bp and exclusively adding their AI classes to be nativized

lyric flint Jun 18, 2020, 4:59 AM

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I do C++ only 😄

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Or should I say exclusively

worldly flame Jun 18, 2020, 5:00 AM

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😂

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no need to optimize further then

urban wadi Jun 18, 2020, 6:37 AM

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As far as AI I am using a weapon class for my melee attacks against my character. Should i create a separate class for projectiles instead of using a weapon class? Any suggestions

winged stag Jun 18, 2020, 7:56 AM

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Is there a way to automatically generate nav links during navmesh generation like in Unity?

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crowd avoidance - AI will use the corridors instead of paths, does not work for agents of different navmeshes, it has pretty bad glitches with dynamic navmesh gneeration
@patent hornet you mean that the crowd/detour avoidance system doesn't work if you have to do a rebuild at runtime?

patent hornet Jun 18, 2020, 8:02 AM

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it works, just glitches

winged stag Jun 18, 2020, 8:02 AM

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glitches how?

thorny jay Jun 18, 2020, 9:33 AM

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Hi everyone, is there a way that I can manually add walkable areas to a navmesh? I have a sloped ladder which players can run up like a regular ramp, but the navmesh thinks it's inaccessible I think because of the gaps between the rungs. Is there a way I can add a volume which doesn't have any collision at all, but the navmesh generation treats it like geometry?

patent hornet Jun 18, 2020, 10:16 AM

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mostly AI get stuck, worst are slopes and stuff like lampposts

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also they sometimes change their idea where to go each frame, and that results in horrible jitter

slow bobcat Jun 18, 2020, 11:49 AM

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@patent hornet we use crowd avoidance and I'm right now dealing with a bug where, sometimes, for some unknown reason, they will not move returning a "Blocked" from the AIMoveTo. It's driving me nuts

slow bobcat Jun 18, 2020, 1:07 PM

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turns out we were not restoring the NavWalking physics on the AI agent after exiting a custom movement mode. They were getting stuck because they were colliding against static and dynamic

robust frost Jun 18, 2020, 2:38 PM

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Hello, I have a question, on an AI character I have set bUseControllerDesiredRotation to true and bOrientRotationToMovement to false, then I set the control rotation by code but the AI ignores it while it moves from place to place with MoveToLocation.

In the end I made it work by using SetFocus but is this correct? Shouldnt it just look to the control rotation when the bUseControllerDesiredRotation is set to true?

Thanks in advance!

paper sparrow Jun 18, 2020, 4:03 PM

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@robust frost Same thing happened to me recently, I wanted to make the AI rotate smoothly to a direction without invoking any tick just using the CMCs rotation speed. If you find out the answer please share 🙂

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Stupid question - How do I change the Blackboard associated with a Behaviour Tree.... I want to use a different set of variables

📎 unknown.png

sullen escarp Jun 18, 2020, 4:18 PM

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When you open a Behavior Tree there is a dropdown in the details pane for what Blackboard is associated

paper sparrow Jun 18, 2020, 4:52 PM

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@sullen escarp thanks 🙂 Knew it was somewhere

winged stag Jun 18, 2020, 9:28 PM

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I have... useControlDesiredRotation = true, and orientrotationtomovement = false, usecontrollerrotationYaw = false and my ai is rotating semi-smoothly using the crowd ai controller

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@robust frost

glass falcon Jun 18, 2020, 9:41 PM

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Does the nave link proxy have a distance limit

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Because every time I go above a certain distance or try to put it in a specific place the green navigation line disappears

true gazelle Jun 19, 2020, 12:32 AM

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Is it totally fine to have multiple nav mesh bounds volumes partially overlapping?

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in order to create pathways for examples

glass falcon Jun 19, 2020, 5:04 AM

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How do I go about making my ai look up and down at the player in multiplayer

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If it was single player I could just use some look at stuff

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Also I'm using an aim offset

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I just don't know how to drive the pitch and yaw values

paper hazel Jun 19, 2020, 8:34 AM

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@glass falcon I assume all of your AI run on the server and as such you should really not need to do anything different from how you would in a single player game. If the look ats are not critical and can be different on each client I would move the functionality to be per client like small glances and such so that you do not need to send that through the network.

thorny jay Jun 19, 2020, 9:41 AM

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Ok, I have a really bizarre problem I'm struggling to explain. All of a sudden my AI can only see an enemy if the enemy is facing away from them (i.e. the dot product of their forward vectors is > 0)

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I have not touched ANYTHING to do with sight for about a week. Then I boot up the editor today and bam, my AI can't see anyone unless they're facing away from them

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I have gone through the controller blueprint and the sight config, nothing in there that could do this. I checked the code I'd overridden in CanBeSeenFrom:

{
    static const FName NAME_AILineOfSight = FName(TEXT("TestPawnLineOfSight"));

    FHitResult HitResult;

    const bool bHeadHit = GetWorld()->LineTraceTestByChannel(ObserverLocation, GetPawnViewLocation(), ECollisionChannel::ECC_Visibility, FCollisionQueryParams(NAME_AILineOfSight, true, IgnoreActor));

    NumberOfLoSChecksPerformed++;

    if (!bHeadHit) {
        OutSeenLocation = GetPawnViewLocation();
        OutSightStrength = 1;
        return true;
    }

    const bool bBodyHit = GetWorld()->LineTraceTestByChannel(ObserverLocation, GetActorLocation(), ECollisionChannel::ECC_Visibility, FCollisionQueryParams(NAME_AILineOfSight, true, IgnoreActor));
    
    NumberOfLoSChecksPerformed++;

    if (!bBodyHit) {
        OutSeenLocation = GetActorLocation();
        OutSightStrength = 1;
        return true;
    }

    OutSightStrength = 0;
    return false;
}```

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Nothing in there to check for the rotation of the actor

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I have deleted my binaries, intermediate and everything and rebuilt. Problem persists

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Can someone explain what could have possibly caused this before I lose my mind? It seems impossible

thorny jay Jun 19, 2020, 10:24 AM

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Ok never mind, I figured it out. My trace is to the pawn's view location but doesn't ignore the actor, so presumably it was hitting the pawn itself and failing to complete the trace. That doesn't explain why the issue didn't start occuring the moment I overrode the CanBeSeenFrom function though.... One of life's mysteries

glass falcon Jun 19, 2020, 1:26 PM

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@paper hazel the ai camera needs to face the player in order for the ai to correctly shoot at the player

frail kindle Jun 19, 2020, 4:39 PM

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hello i have a quick question, im using a nav mesh but I cant seem to make it go under certain objects. For example I have a desk I would like my AI to go under. Any suggestions?

paper hazel Jun 19, 2020, 7:06 PM

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@glass falcon you should still be able to use the "look at stuff" as the player still has a representation on the server.

glass falcon Jun 19, 2020, 7:46 PM

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@@paper hazel so it there no way to replicate the pitch of the player camera

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Because to spectate players I use set view target

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Is there a better way to do it ?

hoary vortex Jun 19, 2020, 8:11 PM

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hello, I have an AI who follows the flying player and when I put in a 3rd person player from the start template, it works with that too, but when I put in a car player I have, it only follows the spawn point instead of the car and the AI just gathers around the spawn point even if my car isnt there

glass falcon Jun 19, 2020, 8:19 PM

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Is there a better way to do it ?

hoary vortex Jun 19, 2020, 8:22 PM

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to make the car or the AI?

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AI uses pawn sensing target

glass falcon Jun 19, 2020, 8:44 PM

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Oh sorry the message sent late

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I was talking about my question

alpine path Jun 20, 2020, 7:05 PM

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Is there a way to increase pathfind cost based on slope step?

unborn jungle Jun 20, 2020, 10:50 PM

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If using a dynamic navmesh, does the game use the previously built navmesh in editor in packaged builds unless something new forces it to update?

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I don't want players to have to rebuild it every time but there are some situations in my game where I need the navmesh to update, so it would be great if it functioned similarly to static other than in situations where it detects a newly spawned obstacle and needs to update

lyric flint Jun 21, 2020, 12:07 AM

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can someone help me make my ai aim worse?Because its really op that each shot goes straight for you

warm dagger Jun 21, 2020, 12:47 AM

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@lyric flint Check out the response about bullet spread. https://www.reddit.com/r/unrealengine/comments/9dsyit/how_to_make_ai_less_accurate/

r/unrealengine - How to make AI less accurate?

1 vote and 12 comments so far on Reddit

cerulean girder Jun 21, 2020, 5:11 AM

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@lyric flint i do it by having an offset on projectiles spawn rotation...random in range -1.5 to 1.5 added to the x y z rot of the spawned bullet...it keeps it pretty accurate up close but further away that 3* variation means the difference between hit or miss...

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You can go even more like -2.5 to 2.5...but then at about 800 units they might seem like they cant aim for shit...

soft zealot Jun 21, 2020, 8:57 AM

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Question about Behaviour Tree Tasks:
Calling "Set Blackboard Value as Bool" won't actually change the blackboards value. With "Set Value as Bool" and hooking up the blackboard as the target ,that is used in the Behaviour tree, then it works.

Do I need to set the tasks blackboard value to my blackboard to get "Set Blackboard Value as Bool" working? If yes, how can I set it?