Unreal Engine 4 Tutorial - AI Behaviour Tree

[@mdarrow26]

If you are using a later version of ue4 and don't have the get ai controller function do this. Instead of starting with "Event Receive Execute" start with "Event Receive Execute AI" then you can skip the "get AI controller" and "get controlled pawn" nodes. All you have to do is pull off the Controlled Pawn pin on the "Event Receive Execute AI" node and plug that into the "get actor location". The rest of it should be the same.

[@carlos321698]

Thank you.

[@TheiLame]

Thank you!!

[@j.j.a.baileystudios3347]

Thanks, I was so Confused!!!

[@evilrabbit2009]

Thank you!

[@billyfunt61]

Peeps like you are AWESOME! Thanks for that.

[@arsinwellz5021]

I watch a lot of tutorials, not just Unreal. You by far do the best tutorials I've found. Keep up the good work. I also never comment on youtube, but I've watched the majority of your videos and felt the need to let you know how great of a job you do. Thanks for your gift to the world.

[@TeslaUE4]

Thank you for the kind words! :)

[@pengchengpan7401]

I second that. Tesla's tutorials are always consise, on point, and easy to reproduce.

[@NanoCryptoCurrency]

Mathew Wadstein is also pretty great, he creates a bunch of videos that don't get much attention on all different aspects of unreal 4, some of his videos explained information that I couldn't find anywhere else. Though video tutorials aren't normally the best for learning, try to use them simply as a reference.

[@erikm9768]

Agree, Tesla Dev's tutorials is the gold standard on youtube. Amazing guy

[@Tarkonian]

Bum bum bum bum.... Tomatoes?

[@JustAGuyProduction]

Great video, very helpful. For those of you with newer versions of Unreal Engine: you have to set the "BT Asset" from the drop-down when you create the "Run Behavior" node in the "AI Controller". It does not automatically select the behavior tree in newer versions of Unreal. Also, you can just ignore not having an execution pin for "Get AI Controller".

[@philipyouds3031]

Your tutorial was the only one I've tried on this subject out of a dozen or so that actually worked. It made sense, was easy to follow, had no extraneous waffle, and it was pleasant to listen to. Well done! Please keep up the good work!

[@DuaneForkner]

I'm actually using the most recent release of the Engine, but thanks to many amazing online courses and videos of yours, have become extremely comfortable with understanding how to connect things correctly. Actually thanks to your tutorials and a few others, I got this working for a side scroller start to finish without an error... You are an incredible instructor. Thank You!

[@x1xNoisEx1x]

In 22 minutes I actually understood more of the BT basics and usage concepts than from hours of the Unreal Engine original AI series. Great one!

[@xTGTECHNIQUE]

I am doing an Unreal level for an assignment in college, and I shot myself in the foot with asperations of making a fps and I have been working on an AI with various tutorials all were dated for over a month, and they either didnt work, or they missed something I needed. This tutorial has everything, you sir are a legend and you have saved me. Thank you!

[@J0hnux]

The last video I watched from other tutorial videos of other youtubers were not clear. So, I thought of Tesla Dev's video about behavior tree and it looks really good and clear. Thanks for the clear tutorial.

[@chap1400]

Really great tutorial here. So simple to follow and you explain things that most people just don't, even super important reasons for things. Going to use this as my base - Adding patrol routes, melee attacks and a move to last known player location task which times out if the player isn't found again. Thanks for this - Great stuff :)

[@PsyCoCinematics]

4:12 Minor thing, but make sure to update the Move To with the variable/blackboard key you just made as it did not autofill like the tutorial showed. And again at 7:10.

[@a79z15]

Anyone who is having issues with the behavior tree and blackboard with their ai not moving around, make sure you check that the FIND LOCATION and MOVE TO task nodes in the blueprint have the blackboard key on the right set to MoveLocation. If you are using a newer version of Unreal, it might have defaulted to either none of SelfActor.

[@yersaltycaptain8167]

In case someone is having a problem where the enemy executes the first sequence even though he should be focusing the player (thus walking away), I set the "Auto success range from last seen location" to 100 and works fine for me. It's right under detect friendlies in the AIPerception component (go to 8:50 in the video)

[@primestyleproduction1799]

One of the most useful lessons for me, at least has two things i've been looking for a very long time! Thank you very much!

[@DuaneForkner]

same here learning the engine the last 6 months or so... AI was one of the hardest to find. also agreed Tesla-Dev is one of the very best!!

[@psynema]

These are great as refreshers as I'm used to re doing the same 2-4 hour tutorial over and over...this is much better memory enforcement w/ speed runs etc.

[@mettymoo6945]

You're the only person on youtube who managed to help me understand this, thanks!

[@TheEightshot]

Just spent half an hour trying to figure out why the character wouldnt move, going through the blueprints, behaviour trees etc REPEATEDLY, finally thought, "I'll just watch the tutorial again." So ye, no Nav mesh. that's what i get for putting a flat green material on the ground

[@Andili76]

Hi Tesla, This was one of the best tutorials i have seen so far! It was perfectly explained and I finally have an idea on how AI works, thank you for that. I might contact you regarding a project I am working on due to me being stuck and there is no tutorial on youtube explaining what it is that I need to be doing. Thanks again

[@prophet7247]

Wow, I was intimidated by behavior trees but this helped a ton. Thank you.

[@anamtakhan1744]

One of the best tutorial available on internet

[@MauriceChavez353]

theres a cool event for tasks and decorators called "receive execute ai" which automatically gives you the controller reference.

[@Arkakaman]

Thank you this helped a lot! I would just like to note that I wish your fonts where slightly bigger

[@Giaour]

Another your great tutorial, well done and easy to create custom Ai on it!

[@Blimkat]

This was awesome. Can't wait to implement this later. Thanks Tesla.

[@taleofvalor2094]

You're tutorials are perfect. AI seemed daunting before this. Would you ever consider doing a tutorial on the environment query system?

[@fkmarketing1475]

seriously..you are a GOD in explaining stuff like this! Liked and subbed you are awesome, keep it up!

[@samson2342]

Tesla Dev, in later versions of unreal what do i use in substitute to the function "Get AiController" Since i can't connect the event to the green Get Ai Controller node. Iam using unreal ver:4.16.3.

[@dastTHZ]

Hi, I tried to do this with my project (Currently using 4.12.5) but it doesn't seems to work, my AI character just stand still. I did everything again from scratch and nothing, I don't know if I'm missing something or what could be wrong.

[@fkmarketing1475]

same issue :(

[@GroundbreakGames]

Nav Mesh

[@GroundbreakGames]

. Ill be on discord soon if you need some help. its on my vids pages

[@LyricStudiosLLC]

To everyone with this issue: add a "Nav Mesh Bounds Volume" to your scene, wait for it to build, and everything should be good to go

[@LyricStudiosLLC]

Glad to hear!

[@hiQer]

The ****** updates make all these tutorial obsolete.. I did all you did but when you add the Event Recieve Execute node @ 5:10 I'm stuck.. such a simple thing I did 100 times. But when I type in Get AIController I only get a green float and not a blue note with the pin connector. Can someone tell me what I am doing wrong?

[@NebiCarax]

Same question for you, hah.

[@sqwert654]

Go to the "Move to" task and change the BB Key under the Backboard menu to "MoveLocation" from default SelfActor. Also change "Event Receive Execute" to "Event Receive Execute AI" I believe it is.

[@Takomuhra]

It's because you no longer need the event chain there. It does it without the pins connected. Same as "Calculate direction" in animation blueprints, it no longer has that pin either. Just use the new function, there's no issue with it.

[@denno445]

When is the Behaviour tree connected to the character? My character is not moving and I'm trying to figure out why

[@ryanb2505]

Step 1: Set playback speed to 0.5 Step 2: Play video on large monitor Step 3: Profit

[@chocochipcookiealert]

black board/behavior tree not interconnecting :(

[@KaliMero138]

hello Tesla, Thanks for this awesome tutorial. i would like to know how to add hearing with aiperception ? in stimulus break there isn't separate successful sight or hearing...

[@mcf924]

I know this message is too old, but the answer is using the node "get sense class for stimulus", then from return value pin, drag a "get display name" node

[@tech-ii5sh]

How did you make or get the Event On Possess Node? I have none in my listing or able to figure how to make a custom node to make that one. I am totally stuck on the first node. :(

[@vinnybonato3718]

If I'm trying to create multiples of these would I duplicate the AI character or would I have to make separate copies of everything?

[@demetriusdukes9277]

Hey Tesla great videos. I just have a question, I'm not able to get my AI Perception to work. I've been able to get the AI to randomly navigate the level, just as you did in the video. However, my AI cant sense my first person controller. Is there something that i'm missing? I have made sure to enable detect enemies, neutrals and friends. And still nothing. I even went into my first person blueprint and created a register perception stimuli source and still nothing. Any help you could offer would be great.

[@n3m3s1s360]

Same problem Im having

[@acalindigital]

Followed tutorial and it did not work first time.There has been some changes in v4.17-4.18 blueprint,but it is working now. First in Finish Execute be sure to check Success and connect Event Receive Execute(white node) to Set Blackboard Value as Vector. Working fine now

[@ANGUSWW]

Hey Telsa I was just wondering how to do something. If the character had a flashlight and say the flashlight flashed an object/character how would I make that object/character play an animation when it is flashed?

[@erikm9768]

How do you cancel the Move To ?? if the AI Character sees the player then we dont want him to first run to a random location but immediately jump into the move towards player behavior

[@erikm9768]

nevermind, very easy just change to "observer aborts: self"

[@davidhan88]

I've followed this tutorial, but I'm getting some strange results when the AI perception component is added. The AI controller seems to be losing perception of the player immediately after perceiving the player. This is resulting in constant "I see the player" and "I no longer see the player" messages. I'm using the default sense config values for "sight radius" and "lose sight radius" and "peripheral vision angle degrees" so I'm not sure why the AI seems to lose sight of the player immediately. Any thoughts?

[@manndeswaldes7574]

I had the problem with my ai not moving i found out that in my ai controller just putting the Event On Possess directly to the run behavior tree fixed the problem

[@bloodprince87]

Tesla, my AI apparently only move to random location but does not the other commands. Any suggestion where I've overlooked?

[@bloodprince87]

nevermind resolved. I put your link as reference in my solution at unreal answerhub. hope you don't mind.

[@nmills3]

Can you show how to get an ai to teleport when pathfinding by using nav link proxys and trigger boxes

[@vincentfallen]

You just got yourself a new subscriber bro

[@ktbsupremo]

Hi, how could this be modified for a multiplayer environment where there are multiple character at one time, I'm trying but it always goes to the "Main" player Thanks

[@alperenakyuz]

It's because of the get player controller node. Player controller 0 is always the local player on either the client or the server.

[@dastTHZ]

Hey, thanks for your tutorial. I'm having a problem, the AI character doesn't rotate correctly. It walks diagonaly and when it lose track of the player it begin to move erratically until it faces the player's position.

[@PierrePutter]

Try check Checking Orient Rotation to movement in the AICharacter BP in the charactermovement component.

[@Raidbollen]

How can i tell to the enemy of attack only when he's near me? Because i have some problem with Focus.. when its activate, the enemy sometime go backward with forward movement (like a moonwalk xD), and what can i use for melee attack? Because the linetrace is good for range attack

[@Theanagamer1]

When I create the FindRandomLocation and when I try to get AIController its not the same, it gets a green box instead of a blue, and I cant conect the exec.

[@mrchilled85]

do it like this :) prntscr.com/kiyzdm

[@yaboyconnor2240]

Hey Tesla, how are ya?? I have a question for you & am kinda struggling to find an answer... How do you make ai make a sound when it spots the player?? Sorry I’m kinda new to UE4. Cheers!!🍺👍🏻👍🏻👍🏻 Edit: Also, can anyone else help?? Any guidance is HIGHLY appreciated👍🏻👍🏻👍🏻

[@daryl0063]

Easy. If you are doing the blackboard just like this tutorial hen I would plug the sound into your Focus on Player task. after the execute and when you set the focus, right after that search for play sound 2d and select your sound. There is a better way to do it but that is the rough and dirty way. You can also go to the construction tab in your ai controller and create sound 2d, pick your sound then promote it to a variable then just like above right after your set focus, you will cast to your ai controller get your sound variable and right click and type play.

[@KiwiHawk-downunder-nz]

Kia ora Thanks a heap for ALL you effort,.. any chance you can do a wee tut on setting up a third person char so they can take armour, weapons from a chest to equip, along the lines of how Skyrim works if thats a better way to put it

[@eatthesky0]

There are actually a decent amount of tutorials on making a skyrim like inventory out there. Here's one to get you started: shootertutorial.com/2015/12/15/complete-skyrim-like-inventory-tutorialThe website name is misleading, I know.

[@KiwiHawk-downunder-nz]

LOL page is the most missleading I seen "opps page can't be found" roflmao

[@eatthesky0]

Kiwi Hawk I don't know why it didn't go to the tutorial... But it is on the site. And it works. But feel free to not believe me. Just google skyrim inventory in UE4 you'll find plenty of stuff. And good luck with whatever you're trying to make.

[@OscarPullin]

I learnt a lot from this video, thank you.

[@MrShaggy24]

anyone knows the different between build the logic in ,,AI Controller'' or in ,,New Service'' what is better?

[@cristiangambadori220]

if it doesn't work you should check the radius in the "get random point in navigable radius", i've tried this in 4.15 and event receive execute doesn't work, you have to use event receive execute AI and drag the controlled pawn into get AI controller

[@nmills3]

Thanks for this tutorial cause other tutorials on blackboards and a.i are just in one ear and out the other cause they are so complicated

[@VValkyr]

Hey tesla, maybe some speed tree tutorials? You are doing the bests for unreal engine sooo

[@OoJxCorrey]

Hey, great tutorials But what if u could try this on multiplayer? Ive tryed it and if the host and a client are in the map, the ai alwas follows/ attacking the host. How could that be and what i have to change?

[@the_faminist]

It could be Get Player Character with a Player Index set to 0. I haven't tried multiplayer yet, but I'm assuming it will assign 0 to host, 1 to next player, 2 to third player, etc. You'd probably have to write some routine to attack the nearest player character instead of just Player 0.

[@AmranSidek]

you said " as first person character" break stimuli...but if im using a "third person character" whats the workaround?

[@sumitdebbarma1443]

How to disable movement when AI is dead. My ai keeps moving even after he is dead. Looks like a lying dead body is being drag by itself after being killed by me. How to fix it ? I still dont know how to solve this in behaviour tree.

[@Mijdax]

My problem: I have a plane and it has a move function that allows it to move in a direction, doesnt matter if player or not player. If the player uses right than the plane moves right, if the behaviourtree uses right, than the plane moves right. So far, so good. Problem is that this is called on tick. So when player presses right, plane moves right on tick by a speedvalue but the behaviourtree ticks are not called as frequently as the player controller ticks... why? this forces me to make functions only made for behaviourtree but a well programmed object oriented idea shouldnt force you to do different functions for the same things

[@illpoet13]

hey we have the same ringtones! good work, your tutorials do me a world of good in my quest to fulfill my lifelong dream of making video games. so much value. Do you have one on spawning ai? I can't figure it out, i can get an ai to spawn when i destory his house but then he just sits there.

[@demonitgames]

Hey @Tesla Dev can u make AI go build and get resources

[@GonxoAS]

Hi. How could I get damage from the enemy with a distance attack or with melee attack? I want that the enemy can be able to kill me. Does anybody know some link to any tutorial to learn this? Please, Thanks!

[@Windblownlmp]

Telsa,. keep up the good work

[@seanhomar5945]

Hi, Great video, however, when testing my AI movement it did not work, my AI character does not move.

[@GroundbreakGames]

Did you add a navmesh to your level?

[@yuchenmei7011]

Thanks for the great tutorial.

[@ION1234ASDASD]

you are the best. how can i play a matinee after "ai move to" ( on success )? something like an animation to kill the first person character. sory for my English thank you

[@warnpeace2008]

My AI was just chillin' and reffused to move too... I think there's perhaps been some change since Tesla's (Brilliant) tutorial: the GetAIController @ 5:16 on my UE is green and doesn't have an execute input. I got the AI going by just connecting the Event Receive Exectue to GetActorLocation. figured it out by watching this vid on same subject. kzbin.info/www/bejne/nmGuk2dopKiij8k though Tesla's gives me a much better understanding of what's going on. Thanks mate.x

[@josephlemons]

Where are more videos!!!!

[@Stbodsies]

Very helpful, Thank you.

[@klausbdl]

the tutorial is so good that I'm afraid I wont learn everything as I get to the end of the video. Help.

[@BitchesLoveGoodra]

I like the tutorials you do so this isn't aimed at you personally Tesla, but why does every AI tutorial cover the same type of AI- either a shambling zombie or a guy with a gun? Why are there so few tutorials on other enemy types- like animals, creatures and monsters? I would love to learn how to create an enemy that wanders around to pre-selected patrol points at random- occasionally stopping or looking around, then chasing down a player when alerted to their presence and doing some melee attacking. Something more interesting with a touch of randomness that isn't a soldier/guard with a gun or a zombie standing still until the player walks into it, y'know? Still though, great tutorial- I know it's harder for you to find time to do these tutorials so I greatly appreciate it whenever you do :)

[@ByterunnersGS]

Tutorials like this are for You to understand the basics and cocept of making an AI respond to the world. Basic and common exaples like that are used just to show on how the game AI logic is designed. You have to sit down and think Your AI action logic on Your own, using the tutorial as a technical exaple, but thinking of Your logic. You have to think of things like: What does Your AI do on Idle? When should it stop the idle action? What conditions should there be to change the action? What data does the AI need to perform the action? Example - let's say a cat running from hostile players: Can I see the player? NO - Walk around or lick my back. YES - Stop licking, check if player is hostile. Is he Hostile? When is he hostile (let's say he has a team int set to 2 and the cat has 1. You check if the teams missmatch) NO - Continue walking around YES - Run. Am I running away? NO - Back to Idle YES - Where should I run? What location would be safe for a cat? - Call a Function finding a location (let's say a BP Actor named "CatSafeLocations"). You find a closest CatSafeLocation and go to it. Have I made it to the location? NO - continue running YES - check if hostile player still in sight. YES - Run to another spot. NO - Lick my back.

[@ahuman_4617]

When ever i gt ai controller its grenn how to change it

[@Palexite]

lol I was complaining when I watch someone else’s video and it did not work. BUT I FORGOT TOO PUT THE PLAYER CONTROLLER, the only way it functions lol

[@Darknesslayer]

you go really fast

[@naivesometimes4494]

That's what i'm thinking, if he doesn't prepare for this and do it such clearly and fast , he must be quite smart.

[@eaal8387]

Dude I sent like few messages for tutoring, can help me out?

[@clebo99]

Dumb question.....why didn't the AI character actually fire at the player?

[@OnVentUK]

Worked perfectly!

[@mhnoni]

Thanks a lot Tesla .

[@blakegt.7326]

Hi, can you please make a Flying AI Tutorial? The idea is having an AI space ship that follows uour ship and attack us when we are at sight, cero tutorials for this right now at youtube, please!

[@warnpeace2008]

There's a pretty good Plug-in called Don's 3D pathindinf for flying AI. Good doccumentation and I think it's free too.

[@blakegt.7326]

Yes, thanks, i already found it and install it, i had a few problems with it...for example when the flying AI gets out from the path range it crashes Unreal... and the creator of this plugin never answers questions, But i think overall it works Ok.

[@shannonervin1306]

I can't get AI to work. I have followed multiple tutorials and it wont work. The AI won't even move!!!

[@ByterunnersGS]

1. Check if You have a proper AI class (If You want it to walk around You need it to be a character class). 2. Check if the NavMesh bounds volume is properly set 3. check if the AI character has a controller, and a CharacterMovement component, then check the component settings 4. For test create a new BP class of type character -> add anything to the components to make You see it in the scene (like a Cube mesh) -> place it in the scene and add a navmesh bounds volume to generate navmesh in the scene. 5. In the newly created BP character on Event Begin play set a delay of say 2s and then a node named "Simple Move to location". Put in some location, or pick it from another actor in the scene. Check if it walks there. Often errors like this occur when You miss something in the basic setup.

[@RascalCase]

OMG SAME PROFILE PICTURE

[@Condetg]

Hi Tesla, or anyone who can give me a hand. I'm trying to do a simple task : Tell to the AI : Go there. And that's it. Using this tutorial, I can't figure how to do it. I don't want the AI move randomly... Just go on a precise location... Thanks.

[@PierrePutter]

Use Interp Nodes to achieve this.

[@keltar2007]

vERY aWESOME tUT!!!

[@danstark8156]

thank you

[@gvm4817]

thanks!

[@raiden58237]

Tesla, I beg you. Do not create Skynet!

[@goonythedon]

agreed

[@darkmagiciansels5833]

wth camera shake in unreal its that simple i watched 30min, video in unity and write 10 lines of code to make camera shake lol you can create AI that do damage and patrol and strafing and all in 20min ...

[@trkWIN]

blackboard system in ue4 is fucking tooo overcomplicated! more and more and more and more blueprints and variables! does developers heard about Ockham's razor? all that stuff can be done more simplier way. hate it

[@AGCreationsflorida]

yea u would think by now they would have more preset stuff... I mean how many ways can you make a game you know.. most fps are about the same... 3rd persons are all the same.. should be a little easier, but then again I feel maybe they do that on purpose so not everyone can do it?? idk lol

[@AGCreationsflorida]

and then people can focus on whats important, creating the worlds and fun gameplay and all that =P

[@estergym5083]

Yes. The greatest issue to me is they keep changing each version also.

[@OGPatriot03]

They get more money the more people use and publish games on the engine, huge steps have already been made to be more user friendly then you could imagine compared to years ago. I'm not saying they shouldn't continue improving it anywhere they can but they have to maintain giving the end user total control of their project (So no limitations). For instance, the nice "Move to" task that's default in the behavior tree doesn't work without a nav mesh so vertical 2D is out of the picture. So making it more user friendly in the sense of pre-built configurations can actually make it much less user friendly to anyone trying to work outside the bounds.

[@ljiljankocurcic8893]

More presets creates generic asset flipping games like we can see with game guru , game maker etc whatever they called. Even free unity assets are being used by every non-programmer. And the reason AI seems the same in all games is AAA devs dumbing down their games so they can get larger player base. UE4 AI system is good if you know what you're looking for. Good AI should immitate human behaviour, not other games.

[@michaelm.8545]

How would I make a squad based AI?

[@guilherme-da-fonseca]

hey when i create on target perception node the cast to first person character doesnt appear

[@guilherme-da-fonseca]

ups i was in third person template...