gameplay-ai

[celest python]

It wont be in range of 0-1

It will be in range of -1 and +1

[kindred moss]

Right that makes sense I figured that

[celest python]

Your values should be in range of -1 and 1 in blend space

[kindred moss]

Thank you so much

[celest python]

Dots in the bottom are backwards animations

[kindred moss]

That's all very clear now. Thank you so much. Then for Character Movement Component Max Walk Speed, I can just play with the Max Walk Speed and it will always correspond to my 1 value for speed in the Blend Space?

[ocean wren]

The problem with that of course, is that you'll get foot skate unless you work out the foot plant frequency vs the speed of movement

[celest python]

Yes, your max walk speed is always going to be equal to 1 in blend space

[kindred moss]

Is there an automated way of ensuring this doesn't happen? Or what does this involve?

[celest python]

half of your max walk speed will be 0.5 (for walking animations etc)

[kindred moss]

Cheers thank you so much, it all makes sense now that you've said that. It makes sense to unitize these values and I'm not sure why in the tutorials I've watched their always manually changing them...

[celest python]

What is 'foot skate'? 🤔

or 'foot plant frequency'

[kindred moss]

I think they mean sliding?

[ocean wren]

there are ways to make it better, like raycasting the feet and planting them via physics bone solvers and the like.. but its far better to actually work out how far you travel vs where feet plans are and animate the two values at the same speed

you can work out the speed by taking the difference between pelvis location and origin for any given anim

assuming no root motion of course

yeah, sliding = skating

[kindred moss]

Is there a reference you could point me towards where you learned that process? I don't fully understand. Sorry, I'm new to animating. That sounds really interesting though.

[ocean wren]

hmm, not one thing.. I've just seen hundreds of presentations about animation at this point 🙂

[kindred moss]

In my project, I'm just creating two realistic pedestrians that are controlled by an AI...

[ocean wren]

I assume there's some good discussion on GDC for the animation of Uncharted

[kindred moss]

Ahaha no worries I feel

[celest python]

Anything about Uncharted in GDCs is recommended btw

[dense halo]

is there a way that you can pass a param to a UEnvQueryContext from UEnvQueryTest?

[ocean wren]

the TLDR is basically, that you need to compute your character move speed based on your target animation framerate by taking the distance travelled by the pelvis for your movement clip (i.e. how far do they move from the start position)

[kindred moss]

This applies to animations in place or root animations?

[ocean wren]

well, if you think about it, in place motion to be "correct" needs to move the in-place character by the same amount that a root motion root would move for the same animation right?

so calculating the root motion offset and applying that to the in-place character would make them match perfectly

The further you get away from that value, the more likely you'll get foot skate/sliding

Now you can partially fix it by using IK to plant the feet to the floor near when the foot would start to move to the floor, but that will get funky if you're speeds aren't within a reasonable window

Thinking about it, pretty sure I've seen some Epic sessions on animation that talked about this kind of thing.. but it was a while back

Your best bet is to work out your character speeds early and then animate to those

[kindred moss]

No that makes a ton of sense. I want to do that! For instance, I have 36 FPS walk cycle for a 30 FPS frame rate. How do I calculate the distance it would travel if in theory, it was a root animation?

I basically guess how far it steps?

Because if I know the distance I can work backwards to get the Max Walk Speed quite easily...

[ocean wren]

Yeah, you can just take your pelvis location as the point.. animate it and then the distance it travels is how fast you should be moving

Now ideally, you can worth from there or the other way round 😉

work from there even

its simple maths for the most part

[kindred moss]

Yeah it is just understanding the reasoning was the hard part but it all makes sense now

Thanks a million

[ocean wren]

Hehehe.. it gets worse when you start doing motion warping and all that 🙂

and trying to blend animations that have different rates

[kindred moss]

I saw that...is that new for UE5, the motion warping?

[ocean wren]

Its worth checking out some GDC animation talks, there's always new stuff to learn

[kindred moss]

I have to learn because I have these two AIs moving around a sort of archviz scene that will be interacting with so many different objects. I want to use motion warping so that I can adapt generic animations to these objects. Does that make sense?

[ocean wren]

motion warping has been around for a while.. pretty sure they had it in 4.24 ish?

Yeah, that makes sense.. you might want to check out origin shifting too

[kindred moss]

Oh okay! I just saw in a recent Inside Unreal that their dev team made some changes...

[ocean wren]

Yeah, I think they added some new techniques in UE5

But I saw a presentation about warping from before the UE5 announce, pretty sure it was an Epic guy

[kindred moss]

https://www.youtube.com/watch?v=SM_AR-oZ-1k&t=2411s

[ocean wren]

We've been doing it for soccer games for a while

[kindred moss]

32:23ish

[ocean wren]

pretty sure that was where I first saw it discussed.. PES

or maybe FIFA, can't recall, was at an aiGameDev.com conference

They do mad stuff with warping, so that feet hit footballs properly

And weight shifting and stride lengthening/shortening and all that 🙂

[kindred moss]

Awesome! I'm an outsider to all this stuff so I'm just learning and it's a steep ass curve. I'm an architectural design assistant but working on an immersive project for an exhibition next year. We're showing a pretty crazy architectural project that people will be able to explore and they'll be these two AIs walking around doing stuff. That's the really really boring and basic gist as to why I'm asking all these dumb questions.

[ocean wren]

If you want some fun anim stuff, check out motion matching from Ubisoft guys

[kindred moss]

That makes sense. I've played all the games but when I see how it works on the back end I just get so interested!

[ocean wren]

I've got a few VR/AR scenes to throw together for some training over summer

trying to think what to do as a demo for the heritage sector

and some demo's for UK Navy training

[kindred moss]

Oh wow that's great. Please keep me posted ahah 😀

[ocean wren]

Its weird how much work you can get if you're prepared to do VR in the military training sector, there's whole conferences that are basically just VR sims

ITEC in the UK has TONS of VR/AR stuff

[lyric flint]

@charred lava One of the most informational gems about AI navigation scenarios in unreal
https://youtu.be/yqZE5O8VPAU?t=2931

You can actually use Navigation System V1's Find Path to Location Synchronously, and use the Path Points (Array of vectors) field of the return values as spline points. Before doing that, tune the spline with how you want it to behave/bend, etc.

[celest python]

Can we actually do that? Never had find enough time to mess with navigation system yet

[harsh snow]

Hello, is it okay that my character can be detected by AIPerception even if it doesn't have AIPerceptionStimuliSourceComponent? It was added before as a component in blueprint but i deleted it and the behavior of AI didn't change

[misty wharf]

pawns have this behavior by default, they don't need a stimuli comp

(iirc)

[harsh snow]

Is there any possibility to disable their inherited stimuli comp?

[misty wharf]

I think it might be an option on the ai perception component itself, or on the senses you have configured

auto register pawns as sources or something

[prisma arrow]

Is it possible to give objects ai? I'm looking to have dolls that are able to be picked up however they run away when the player gets near. Not sure how i can do this though.

[obsidian igloo]

so im having an issue with navigation. my AI work fine in other levels, and they worked just fine in the level that recently has been having issues, ive made no changes to ai or pawns and im absolutely sure that my navmesh is in the level. the issue is, my AI just stop doing anything at all on begin play. ive scoured the internet for fixes but i just cannot get the AI to move anymore on my map, would anyone have any idea what this could be?

ive tried auto possess which is setup for spawned and placed as well

[harsh snow]

You were right, thanks! In my DefaultGame.ini bAutoRegisterAllPawnsAsSource was set to true. I've set it to false but the AI still sees my character 😭

[misty wharf]

hm unfortunately I've never tried turning it off so not sure 🤔 You should be able to manually unregister things from the perception system though, maybe give that a try?

[misty wharf]

Yes, just make the pawns and have them possessed by an AI controller

(or characters since it sounds like they are characters)

[haughty pelican]

Just a quick question is there an AI MoveTo c++ function equivalent to the one in bp?

[pure crest]

AAIController::MoveTo

[ocean wren]

Whooo! today is speechmachine day! finally got time to work on my speech plugin

[charred lava]

Thanks for that!

[harsh snow]

As far as i know I can only unregister their stimulisource component, but it doesn't work because for some reason even though i've set bAutoRegisterAllPawnsAsSource to false it still registers my character

[misty wharf]

Yeah might be the case. Have you verified it's actually loading the value from your config correctly? This feels like it should work 🤔

[gray sail]

Does anyone here know how to use UE5s MassSchematic?

[celest python]

You can get better help for UE5 related things at #ue5-general

I doubt anyone knows MassGameplay in depth though, most of the people waiting for matrix demo

[harsh snow]

I don't know how to check it. I thought it might be in UAI_Sense constructor but I cant debug it

[normal mist]

Hi folks! I have generated a metric bazillion spline components from imported GIS road data. Over the past 2 years of working in UE, I've gained a healthy familiarity of systems within the engine, but AI is unexplored territory for me. What would be the sensible way of having AI path-find using only the roads that I've created?

Also of note - it is not 1 giant spline spanning the entire road network, but rather 400+ different splines that intersect

hehe

[ocean wren]

You'd likely just be better using your own A* pathfinder on the splines, assuming you've connected them somehow?

A* is super easy to implement and pretty much the industry standard go-to for simple pathing stuff

there are variants like HPA* if performance is too bad, but only 400 splines normal A* should be fine

[normal mist]

Thank you so much @ocean wren!

I have not connected them and it kind of intimidates me on if its possible

[ocean wren]

Well, first order of business is connecting them then 🙂

[normal mist]

https://tenor.com/view/simpsons-nervous-what-to-do-gif-12774075

[ocean wren]

https://tenor.com/view/everything-is-connected-neil-degrasse-tyson-startalk-everything-is-related-everything-is-linked-gif-20161060

[normal mist]

LOL

thanks for that

[normal mist]

@buoyant geyser am I going to have to write a compute shader for this? 😱

[ocean wren]

Naah, you don't need anything that complex

its basically just a graph you need to traverse

A* is a graph search algorithm

Don't get it mixed up.. A* works on arbitrary graphs, not just regular grids

[normal mist]

ooo

Is it possible to build a navmesh along a specific landscape layer?

I could paint the roads to the landscape via a layer..

However I'm looking up tutorials on how to do A* in UE and how to think in terms of graphs

thank you very much @ocean wren for pointing me in the right direction

[ocean wren]

There might even be an implementation in Unreal you could use thinking about it, pretty sure they had one for Paragon that they had in fortnite, but can't remember if it was a regular grid or not

You could use it for reference at least

[normal mist]

I am searching around but having trouble finding anything dealing with multi-spline pathing

[ocean wren]

well, splines are just line segments

[halcyon moon]

People, hello) Help with a trifle, I'm still poorly oriented myself (

There is a function by which I destroy trees, activation, as you can see, goes through an overlap, that is, a Persian, or rather, I have it ai, went up to a tree, cut it down, found another tree, cut it down, etc., what I want. Since I have trees in a separate spawn blueprint, there are a lot of them, and ai goes in order, sometimes crossing those trees that do not need to be cut, but the trigger is launched. Question!) How to add a time limit with such a function at the beginning, like if the Persian or the Persian trigger is in the activator for less than half a second, then we don’t turn on the function, if we turn it on more, I’ll be glad to help)

[misty wharf]

If you use a timer instead of delay you can cancel it if the overlap ends

[ocean wren]

Seems like a bad way to do it anyway, having a trigger for every tree is likely overkill, better to have trees register with some central system and simply keep a list of trees that each agent is due to cut

[misty gale]

Create nodes at intersections and a spline for each edge in a graph

[dense halo]

hey, is the NodeRef in FNavLocation, the same as the tile index?

[ocean wren]

From what I remember yes pretty sure it is

[ocean wren]

Well, its the polygon rather than the tile if I think about it

you can obviously look up the tile from the noderef though

[celest python]

iirc there is a built in abstract A* implementation in UE btw

You can hook it up to your system easily

FGraphAStar

Woah can you look at that documentation

I'm surprised

[ocean wren]

Documentayshun? whats that?

[misty gale]

Sweet, thanks!

[celest python]

Something we can eat? 😄

[ocean wren]

Covered in chocolate?

[celest python]

How did this went? Any progress?

[ocean wren]

No, I had to review a paper for a journal

Will be working on it today

[celest python]

Nice

[ocean wren]

Interesting to see how nobody has done any real microphone stuff in UE

in fact, there's a ton of people trying to figure it out and getting no responses 🙂

[celest python]

Like for commanding AI with microphone?

[ocean wren]

Well, getting the microphone data is the issue really, I need to pass it as packets to the cloud

there's an audiocapturecomponent since 4.19, but not obvious how to ensure you can easily grab the raw data from it.. the interface is a bit weird

[celest python]

Yeah, I can imagine

My gut says Unity has a more straightforward way* at this though

[ocean wren]

Shouldn't really make any difference, given its just buffered data

apparently people who've tried have found that the data stream stops being recieved.. I guess you need to poll something or signal buffer release or something

of course, not documented properly 🙂

[celest python]

I guess thats when UDN comes into play

but... 😄

[ocean wren]

Not really needed, I can figure it out myself, just takes longer

[ocean wren]

hmm, so audio capture component seems to be the wrong thing.. although I can capture the mic with it

the latency is insane

[ocean wren]

I guess using an external mic access approach is better for my use-case, kind of weird though

[normal mist]

@misty gale @celest python thank you! I can't wrap my head around how to heuristically detect an intersection so I'm going the route of generating an entire grid 😱

Following Sebastian Lague's a* tutorial

I set my roads to a specific object channel and am doing collision checks on just that channel to detect if the location is "walkable"

Build an entire grid from that...8x8km

Kinda worried it might eat up all my ram lol

[misty gale]

Sounds expensive 🍍

[normal mist]

Literally drinking coffee in bed right now delaying getting up and trying it out

[misty gale]

🤣

I have yet to try my own graph setup

Still got other things to iron out before i can try implementing a*

[normal mist]

I have built a graph like once or twice...years ago

[misty gale]

I've never done it before 😅

[normal mist]

I don't know how I'll be able to detect an intersection

[misty gale]

Currently saving a bunch of refs

You dont detect them, they are nodes

And the roads are splines

[normal mist]

I imagined that the control points in the splines are the nodes?

[misty gale]

As long as theres no intersection to it, why would it be?

[normal mist]

Sorry, I don't understand that last statement

[misty gale]

What is a control point exactly?

A spline point?

[normal mist]

Yes, thanks for correction

[misty gale]

Spline point is just part of singular spline

An edge in a graph

The path between two nodes

A node in your case would be an intersection

In my case its an intersection or a building

[normal mist]

Two questions coming to mind:

• how to heuristically create intersections
• how to path find between two nodes - I guess I'd just have a reference to the current spline component and follow that? Following a spline component is trivial, done it many times before

[misty gale]

heuristic is a word that still scares me lol

[normal mist]

First part is challenging because my road network is like 400 spline components, each one a road, that may or may not physically intersect

[misty gale]

2 sec let me snippet

[normal mist]

Like do I traverse along a spline and do a distance check for every spline and if the distance is below N then I assume it's an intersection?

[misty gale]

the spline has its length,

so you just ask the edges from a node of their length (cost)

[normal mist]

Is length a property of spline component ?

And is it the distance of the entire spline or the distance btwn two spline points?

[misty gale]

yes, it is ^^

entire

all the red rings

would be intersections,

or "nodes" in a graph

the roads would be individual splines

so between each node there's atleast one spline

depending on the graphing setup you want. With a directional multigraph there could be several (good for highways i suppose)

graphs are still way above my head tbh

[normal mist]

Directional will be v2, gotta walk before I can run 😂

Right now I don't have a way to automatically detect an intersection,that's a big challenge

[misty gale]

https://www.javatpoint.com/graph-algorithms

this one is the one i use for reference

[normal mist]

Because a spline component doesn't have a reference to a nearby spline component (that it may be intersecting with)

[misty gale]

Wherever two or more splines meet would be intersection

[normal mist]

OH

I do a collision check at the ends of spline components

OMG

[misty gale]

well, yes 😄

thats what im doing xD

[normal mist]

and if it detects another, it's an intersection!

[misty gale]

currently atleast

[normal mist]

OMG YES

Alrighty. Time to leave the bed. Thank you for your wisdom @misty gale

[misty gale]

Best of luck!

[normal mist]

However it isn't to the computer. It's coffee related, the after effects

Computer will come later

[misty gale]

coffee is important!

[normal mist]

i am become 'puter

I'm scratching my head on how to include the references to the USplineComponent in the Node (intersection)

Looking into FGraphAStar because it looks like it has its own graph implementation (TGraph)

[misty gale]

Currently i have an adjecencylist and a edgeSet

Not sure if i meed both, or if they're even needed together

Sorta have to try it put before i grasp it 😂

[vale adder]

Hey there, I have a problem with AI
I have followed the official Unreal Engine tutorial yesterday and it worked perfectly
I have opened the engine now and it doesn't
More specifically, the sight sense does not work: the AI is blind, when the player goes in front of it the event On Target Perception Updated does not fire, and I have no idea why
I have checked the AIPerception, the AI Stimuli Source and everything seems in place
Honestly it feels like if my calculator suddenly started saying that 1+1 = 3...
What should I do?

Even if I tried deleting the Hearing Sense it still doesn't work

[vale adder]

Even after I created another controller and set it it does not work
There must be something wrong with the AI Perception Stimuli Source, but I cannot find anything
Guess the gods hate me

I'm starting to think this is an engine bug
I have been searching through the internet and it seems like no one had my problem before

EDIT: It cannot see other actors either, I am so confused!

[dense halo]

is it possible to do the opposite? given a location and a tile index or do you have to use NavigationData->ProjectPoint() with an extent like FVector(0.1f)?

[ocean wren]

Can't remember to be honest.. You can get the tile, because you can dirty it. You can get connected noderef's from a given poly. I'd probably avoid tiles altogether and worry about polygons.

[dense halo]

I'm creating cover points on nav mesh updated, so I'm starting from the tiles, and I store the location of the cover point along side the tile index, I'm just dividing up the nav tile edge, so not sure how I can get the noderef

[ocean wren]

Yeah, I did the same thing using noderefs, didn't use tiles because you can change the tile size, what you really want is the polygon edges anyway

[vale adder]

It works now
What the actual hell?!

I am not complaining about the fact that it works but I am confused

Like... eh? The same identical code worked yesterday, didn't work one hour ago and now works again...?

[dense halo]

how did you do it? I'm doing (or the person that created it)

    NavGeo.bGatherNavMeshEdges = true;

    // get the navigation vertices from recast via a batch query
    NavRef->BeginBatchQuery();
    NavRef->GetDebugGeometry(NavGeo, NavmeshTileIndex);
    NavRef->FinishBatchQuery();

    // process the navmesh vertices (called nav mesh edges for some occult reason)
    TArray<FVector>& Vertices = NavGeo.NavMeshEdges;

and then

        //const FVector LastEdgeDir = GetEdgeDir(Vertices[nVertices - 2], Vertices[nVertices - 1]);
        // ReSharper disable once CppUE4CodingStandardNamingViolationWarning
        for (int iVertex = 0; iVertex < nVertices; iVertex += 2)
        {
            const FVector EdgeStartVertex = Vertices[iVertex];
            const FVector EdgeEndVertex = Vertices[iVertex + 1];
            const FVector Edge = EdgeEndVertex - EdgeStartVertex;
            const FVector EdgeDir = Edge.GetUnsafeNormal();

[ocean wren]

I walked the polygons and looked for edges where there were no other polygons, so basically external edges. I stored those in a list of edges.. then generated along them

[dense halo]

can you tell me how you did this edges where there were no other polygons do you have to manually check? for the tile you can just set bGatherNavMeshEdges, look at the code for that, hoping there's an easier way

[lunar grove]

this code not working for debugging sphere ?

does any one have idea ?

[pure crest]

Are the callback functions being called?

[misty gale]

did you come up with a clever solution ?

This is my current structs , updated whenever a road (spline (TunnelRef)) is placed

[lunar grove]

We r passing pawn as args in func and dont think it need to be called in beginpaly

[pure crest]

I don't think I understand you. OnPawnSeen, and OnPawnHear. Are they getting called/executed?

[lunar grove]

Sry, @pure crest Im new Ai programing in ue4.
I have just build Project in tuts it wirked fine.

Not for me.

[pure crest]

That's TomLooman AI tutorial I know. You'll probably find the solution to your problem there in the comments under the video

But I would debug the code and see what is executing and what not. Because you don't seem to have an idea of what's running and what's not

[lunar grove]

Ok i will check debug log

Log is not showing

[pure crest]

Also make sure OnPawnSeen, and OnPawnHear have UFUNCTTION() specifier above them in your .h file

[lunar grove]

Ufunc present

[pure crest]

Do you know how to debug?

[lunar grove]

Yeah, put break points on onpawnseen ,

Its not stopping on break points put on functions

[pure crest]

Are you using hot reload?

Just in case: http://hotreloadsucks.com/

[lunar grove]

Ok i will try

OTHER mention i have included "AIModule" in build file too.

[pure crest]

Without AIModule you would be getting linking errors

[lunar grove]

Ok

What msg im seeing first time.

[pure crest]

It's ok

[lunar grove]

Should close this msg

[pure crest]

You can

Live Coding you can use it when you make changes only to .cpp files(So you simply press the compile button in editor)

For changes in .h file or the constructor you need to close the ue4 editor, build from rider, and relaunch your ue4 editor

[lunar grove]

Did

Ok, got it .cpp mistake /change Small rectify in live coding

No results debug sphere not showing still

[pure crest]

Although this shouldn't be the issue but try moving the AddDynamic from Constructor to BeginPlay

Lines 17&18

[pure crest]

@lunar grove This 100% the solution due to BP corruption from hot reload probably. Also if you don't have a NavMesh placed in your level, add one.

[lunar grove]

thanks alot @pure crest you are ue4 superhero of the day. 😋
Forgot to put Nav mesh vol.

[spiral berry]

Hi everyone I'm having a problem with spawning an array of actors and then getting the array to move to another actors location. Do all the actors in my array need to be controlled using ai to get them to move? My BP prints but my array of actors don't do anything. Any help would be much appreciated!!! Thanks, Emma

(it's for some virtual drone visualisations)

[hidden river]

I believe the AI MoveTo node should work well in your case, @spiral berry

I am currently struggling with an issue of my own though. I'm streaming levels with AI enemies in them, each level has a navmesh in it but the enemies won't move at all, even though they worked fine when put in a persistant level

I'm assuming something isn't updating correctly with the NavMesh when the level streams in at a new location

[spiral berry]

I did try that one too but It didn’t work I’ve never used any ai before :0

[hidden river]

Basically, you'll need an "AIPerception" component in your drones. In this component you can specify how far they should be able to detect their "targets" and then you can run your AI MoveTo node from an "On Target Perception Updated" node, which runs every time the AIPerception detects something new

You can make sure that the actor they spot is your target cube by using a tag and a branch node, for example.

Though I am honestly not sure if this is the right move when it comes to flying characters

[normal mist]

I have not. I'm feeling overwhelmed with the graph implementation, so I am starting with a more simple Grid implementation thats straight from the Sebastian Lague implemention. If I'm able to do this successfully, I'm hoping it will give me a foundation to transfer over to the more simple graph method

thanks for sharing yours

[misty gale]

I'll see if i can share some more in not to long. Gonna experiment with it for fluid and electric transportation

[normal mist]

🙏 thank you @misty gale

[normal mist]

Is it possible to have a nashmesh bounds volume only paint to a specific collision channel?

or landscape layer?

[ocean wren]

Well, I mean its possible if you code it to 🙂

[normal mist]

teehee

[stray violet]

I've got a door that is opening when a character walks up to it.
It then plays an animation to raise the door.
Currently, the nav mesh isn't updating when the door raises, is there something extra I need to do to support this?

[dawn loom]

is there any way to have a shared cooldown without making my own cooldown BTD? I used the Tag Cooldown thinking it'd be on the tag itself and not related to the BT with that tag

and now I just realized that's not how it works

(because the thing I thought would be put on a global cooldown just got entered another time by another BT while it was supposed to be on cooldown)

[celest python]

Not out of the box afaik

AI manager subsystem calls you 😄

[dawn loom]

https://media.discordapp.net/attachments/603649974042886296/804409299517571092/image0-19.gif

it's funny because I put a tag cooldown on a suicide attack

so there's no way it's going to be called twice by the same AI 😂

[lyric flint]

If you use dynamic one, it shouldn't be a problem. If you use a static one, the solution, as always is to trick the eye :D meaning, have a marker on the other side right at the edge of the generated nav mesh, and just lerp your character through the door while faking walking animation. Hopefully it makes sense 😆

[dense halo]

hey, is there a better way of drawing debug shapes from inside an EnvQueryTest?

[misty wharf]

I usually use the eqs testing pawn

it gives a very handy visualization of what the generator did and how the items scored/filtered

[dense halo]

yeah I'm using that too, but I'm doing some line traces inside the query test that I want to visualise, so I was thinking that there might be a better way to draw it other than DrawDebugLines

[misty wharf]

I guess the visual logger is the other option?

[dense halo]

ok thanks

[normal mist]

road pathfinding...IT LIVES!!

so beautiful

[normal mist]

@misty gale are you doing an implementation of FGraphAStar?

I am now starting to look at how to implement it. The only example I can find, FNavLocalGridData, implements TSimpleCellGrid. If I have intersections as nodes, I am having trouble visualizing in my head how that fits within a 2D grid

This forum post has been a big help (https://www.reddit.com/r/unrealengine/comments/8pnpaw/unreal_didnt_have_proper_point_graph_navigation/e0dgm8h/?utm_source=reddit&utm_medium=web2x&context=3) but there are some statements in there that I don't understand

Declare FNodeRef to by the type of something you can identify your nodes by, could be an index in an array, a pointer, etc (typedef MyNodeRefType FNodeRef)

Create a TGraph which is what stores the information about how your nodes are laid out in the graph, and has 3 functions, one to get how many neighbours a node has, another to check if a NodeRef is a valid node and the last to get a specific neighbour based on the index.
The only reference I can find to what a TGraph is is here:

template<typename TGraph, typename Policy = FGraphAStarDefaultPolicy, typename TSearchNode = FGraphAStarDefaultNode<TGraph>, bool DoRangeCheck = false >
struct FGraphAStar

Not sure what a TGraph is from reading that

[misty gale]

My FNodeRef is pure references currently. Its a bit unclear to me if Graph is ment to be several lists or just one with helper functions yet. Sounds like several lists would be the faster (but more memory intensive) way to go but dunno yet

Like, I think i need several lists, but havnt avtually implemented the A* or djikstra yet (this is way beyond my knowledge) so dunno untill i get there sorta

Gonna check out TGraph in a few minutes , walking the dog 😅

[normal mist]

hows the pupper doing today?

[misty gale]

https://docs.unrealengine.com/5.0/en-US/API/Runtime/AIModule/FGraphAStar/

[normal mist]

I'm getting acquainted with some c++ specific terms

• template<typename TGraph, [...]> is just referring to the generic. TIL that's how you define generics in c++
• typedef seems to be purely to reduce verbosity - creates an alias for another type. please correct me if I'm wrong

[misty gale]

Same, I'm very new to c++ aswell, coming from bp's and plc programming.. but that sounds about right yes

Templates seem incredibly usefull

Was under the impression that templates needed to implement all the different function inputs you wanted to support in some obscure way 😅

[normal mist]

I think I figured out how to implement FGraphAStar, but I am not sure how to represent intersections as nodes in a graph. like if it can fit within the data structure of a 2D grid

[misty gale]

Like a matrix?

[normal mist]

Sorry for the confusing way of saying it. I'm familiar with how to perform A* a 2D array, or grid. I do not know how to perform A* on a tree. I can visualize how to organize a set of nodes of intersections as a tree, but I can't visualize how to organize that as a 2D array

so if I chunk the world into equal partitions, that maps very cleanly to a 2D array. But if I chunk the world into intersections that are unevenly spaced apart, I can't visualize how to map that to a grid

I think it boils down to the cost function. All examples of a cost function I'm finding are of grids that are evenly partitioned

that isn't the case with a tree of intersections that are unevenly spaced

I wouldnt know how to compute the cost btwn two nodes that arent directly connected in that case

[misty gale]

im not sure how that is relevant for this tho

like

all you need from node to node to determine cost

is distance

(and if you're actually doing roads, you'd factor in traffic density and speed limits)

so the algo would just traverse the nodes and combine the costs , if im not mistaken

[lyric flint]

Guys how do i approach a enemy manager that tells a list of enemy behaviour tree to do stuff so the enemy does one stuff at a time?

Like only one enemy should go to a player out of the 3

[ocean wren]

A* basically uses heuristics to represent cost.. so you can basically give it whatever costs you want. Usually for something like a road network, you'd give it spline length as cost

For things like terrain, you could also scale that cost by terrain type.. so a dirt road would be more costly than a paved one for example

[ocean wren]

I created a Squad actor that controls a squad of soldiers.. the squadmanager had things like detected enemies (i.e. ones a squad member had seen/heard) squad actor used MessageEndpoint to communicate data with Squad members (squad members were also actors)

So each squadmember had a squad

squad had any number of squadmembers that could register with them

squad also had functions for selecting squad members and determining stuff like enemy/friendly statuses

When a squad member pecieved a threat (enemy or unknown) it sent a message to the squad it was registered with "Hey, I've just sensed a threat!"

the squad then propagated that to the other squad members registered with it

For things like which squad member engaged an enemy, the squad actor has its own BT that does things like task assignments for squad members

Bearing in mind, my use case for this was a Full Spectrum Warrior style game

which I aim to ressurect at some point 🙂

Fully recommend MessageEndpoint's btw chaps.. very useful class to understand

pub/sub messaging in general is a great pattern to apply to stuff, so handy dandy understandy 🙂

[misty gale]

Yeah i mentioned that in the post above ^ factoring in speed limit and traffic density would aslo be part of tje cost

[ocean wren]

Yarp

I wonder if Mikko has done most of this kind of thing for the MassAI stuff?

I mean it has traffic and whatnot right?

[celest python]

@ocean wren Do you think this is enough (or even correct) for normalizing scores for utility system? -- if we dont have negative values

const float NormalizedScore = FMath::GetMappedRangeValueClamped(FVector2D(MinRange, MaxRange), FVector2D(0.f, 1.f), Value);

[ocean wren]

That depends a lot on what you're scoring, normally I'd use something like a UCurveFloat? (might be UFloatCurve)

the basic idea is to have your score elements normalized so you don't overpower one with another

[lyric flint]

Interesting, Tysm zoom. So its better to tell a squad member what to do than it its determining what to do in a BT huh

[celest python]

Arent curves used as 'function'?

[ocean wren]

Well, the curves are just data you can use to bias values.. I used them for scaling perception closer to enemies and to bias perception closer to the front

so used two curves with angles to return the perception scaled value

so feed the cos of the angle into the curve.. curve biases the "front" and "near" parts etc.

[ocean wren]

I think of it as a chain of command.. squad commands squad members.. you can add a "team" on top of squads, a battle on top of teams etc..

I've used the same architecture for controlling the parts of a tank 🙂

[celest python]

Like mutable curves with static 'tangents'?

(<#gameplay-ai message>) (similar to HoJo's)

[ocean wren]

i.e. tank commander, gunner, loader, driver etc.

[ocean wren]

Well, curves are just a normal part of UE, I didn't do anything special for them

right, off to work for a bit.. back laters!

[lyric flint]

Like a master-slave architecture huh

[ocean wren]

Yeah, basically. Based on publisher/subscriber messaging (via the MessageEndpoint class in UE)

I've used it in a ton of AI for coordination stuff

[lyric flint]

I see

[ocean wren]

bbl

[normal mist]

I do the same

[strange spoke]

Can some help me with my behaviour tree

https://gyazo.com/ffe519dee643dcf37f35d29692624c59

its skipping the wait sequence for some reason

[misty wharf]

Your MoveTo is likely to be failing

This, or the decorator aborting it would be the only reasons why the sequence would not run the remainder of the nodes

[strange spoke]

https://gyazo.com/4da4b4aabd04f3b49d3fca250bda2619

thats the has seen

condition

[misty wharf]

If you use the BT debugger you should be able to see why it aborts

[strange spoke]

how do i debug it

iv pressed the ' symbol

and 4 for behaviour tree

[misty wharf]

Pause the game when in PIE

Then you can use the arrow buttons in the toolbar of the BT editor to move backwards and forwards in the execution history

If you go backwards to the point where it fails to go into the Wait node, it should show parts of it in red to indicate what caused it to abort

You can also look at the BB values and hover over the red bits and such to get some more info

[normal mist]

@misty gale sorry for going unresponsive last night. was late and was succumbed to the bed. I am having difficulty conceptualizing how to map a series of intersections to a 2d grid. With a 2D grid, every cell has 8 neighbors. With intersections, it might have 0 neighbors, 20 neighbors, or any amount inbetween

[misty gale]

Im just not getting why it should be a 2d grid, a graph can have as many connections as it needs to each node

[normal mist]

It doesn't have to be - I would love for it not to be a grid 😆 I have only seen examples of FGraphAStar (or just A* in general) be used with a 2D grid, so I am having trouble conceptualizing how to use it with a tree

so for example - to get the travel cost between two nodes. With a grid, it just does some operation on the distance between the nodes in the 2D array. I don't know the equivalent with a graph/tree. I know how to calculate the cost between two neighbors - that is just data I can get from the spline component. But I don't know how to get the cost between two non-neighbors without already knowing the path to sum up the individual neighbor costs

[spiral bone]

Does the MoveTo have some sort of "Stop Movement immediately"? I'm trying to make an enemy strafe it looks kind of funky. Like, once he reaches to location it will stop immediately.

[celest python]

It zeroes velocity

Once new path data received

You gotta override a function in CMC in C++ (afaik its not exposed to BP)

[spiral bone]

Thanks! I'll see what I can do then!

[celest python]

bool UYourCustomCharacterMovement::ShouldComputeAccelerationToReachRequestedVelocity(const float RequestedSpeed) const
{
    /*return Super::ShouldComputeAccelerationToReachRequestedVelocity(RequestedSpeed);*/

    // always return false so CMC will snap to the velocity instead of braking for calculating friction. 
    return false;
}

[misty gale]

Hm im not sure how it would be any different really. It just logically woris its way through the nodes moving closer to the target and picks the cheapest combination (or shortest, fastest etc)

[real arrow]

Is it possible for the GetCurrentlyPerceivedActors() function to return actors without a stimulus source?

[real arrow]

assuming bregisterAllPawnsAsSources is false

[normal mist]

Did you do that? Beautiful animation

I think I'm just going to calculate the cost using Euclidean distance 🙂

[normal mist]

Inching closer towards building a graph of my roads and intersectionsssss

[mossy nexus]

interesting, never seen percolation be used visually in tandem with shortest path

[strange spoke]

https://gyazo.com/fa85802d3dbc771d1ad0f952b29467e8

does this mean that canknifeattack can only be true if start logic is true?

[pure crest]

Well yes

It means that at that specific moment, CanKnifeAttack is equal to the value of StartLogic

It's not bound to it though

[surreal jolt]

Hi everyone, new to AI this week so hopefully this isn't too noob but I'm wondering the best practices for organising BT code.
I've ended up in a situation where I have a service to update the last known location of a player while my zombie can "sense" the player. I had other nodes below the sequence but now I don't and it's stopped working because the sequence has no children.

I can see a few ways to do this:

• Having a task that does the updates but then I have to pass in the CanSense bool instead of just using a decorator.
• I could have a dummy type node to let the services and decorators work.
• I could have a service that runs on the top sequence which gets CanSense and just runs the boolean check and all the service logic inside one service without using a decorator
• The stuff I haven't thought of yet.

So is there a best practice here? What do you think is the best way to do this?

[ocean wren]

Why would you want to update the position if you're not going to do anything with it?

If you have no child nodes, then there's no point in updating the position

If the intention is to chase the player, then it makes sense and your sequence should have children to do that

so the sequence/selector has conditions under which it runs, the children actually do the tasks to run it

so in your chase player example, it makes sense to have a condition for if the player is sensed, if that is true, then the sequence should contain a moveto node with the player actor as its blackboard value

you don't really need the update last position or run speed services.. those would be better as BT Tasks (i.e. children)

If you pass an actor reference for the MoveTo, it should automatically follow the player btw.. unless you want something specific like going to a slightly outdated "known" location

[surreal jolt]

I do, on the right. But I want them separated so I update the known location as long as the zombie can sense the player and if the player gets out of range then the location will stop updating but the zombie will keep moving towards the location

[surreal jolt]

Why are those better as tasks? I don't really know when you'd choose each.

[haughty pelican]

Hi guys would anyone be able to help me with this issue. Ive got a choice widget setup to spawn in two types of AI I have implemented however when I select one of my AI i get a "EXCEPTION_ACCESS_VIOLATION" at line 19 any idea why this could be causing an issue. Ive got the nav bounds setup and stuff within the world

[misty wharf]

Result from GetPawn is probably nullptr

Depending on where this function is called from, it's possible the AI controller doesn't have a pawn yet

[haughty pelican]

Yeah its called in begin play so that could be the issue

[misty wharf]

Yep that's most likely it, BeginPlay does sometimes get called before the controller possesses a pawn

(or maybe always, not 100% sure but it definitely happens)

[noble shadow]

Hi, I am trying to tweak a pid controller for a vehicle but it's difficult to tweak because of sharp pathing corners. Navigating around edges is also troublesome. Is there a way to change it from shortest to fastest path or something or would I be looking at generating my own path points?

[haughty pelican]

Yeah that seemed to have fixed the issue cheers for that 🙂

[ocean wren]

You might want to look at where it does the string pulling (using funnel algorithm) and maybe make a variation on that?

[dense halo]

hey, I'm trying to get my ai working but I'm running into a weird issue, my EQS query test isn't running on my AI

the generator is creating the items fine but RunTest never gets called, but it works fine with my testing pawn

[ocean wren]

wrong query context?

[dense halo]

I think I found the issue, my nav mesh isn't being rebuilt on start, is there a reason for this? I selected dynamic instead of static under the nav mesh project settings

[ocean wren]

dynamic is where it rebuilds when you load the level

you might also find a tick box on the navmeshboundsvolume or recastnavmesh actors in your level. cant remember its been a while 🙂

[dense halo]

found it, need to disable Auto Create Navigation Data, enabling it spawns missing navigation data actors but doesn't call rebuild on existing ones

[normal mist]

@misty gale its happening!!

Built a graph of intersections and roads

[misty gale]

Ohh nice !well done😄

Looks very web-like

[half aurora]

anyone has good example of an AI following spline, I try to make one but the character moves a bit jittery at different points of the spline

[misty gale]

How are you moving it ?

Done on tick, interpolation of the distance should be pretty smooth

[half aurora]

I'm currently using a timer and passing the next point's location after the AI reaches it previous destination. If I do it over tick would I use SetActorLocation or something else? Because I want to animate the character walking

[normal mist]

@misty gale my extension of FGraphAStar is not going so well so far 😆

The two green circles are the start and end. The red circles are the nodes inbetween. Doesn't go towards the destination lol

I notice that the path always starts at the bottom left of the map and goes towards the top right, regarldess of where the start & end are

it does have a little variation if I move the start and end around

I also notice that Traversal Cost within GraphAStar::FindPath is always returning a value of 3.40282347E+38

whereas the traversal cost function I made does return the correct value

For some reason my breakpoints arent working in the function where the magic is happening

[misty gale]

Distance between nodes may vary so youd atleast need to factor that in

Tick would be set actorlocation yes

Location being lixation at distance along spline

Distance = current distance + speed*deltaTime

[half aurora]

Doing over tick is the right direciton, but I don't think SetActorLocation over Tick on a Character is the way to go, I'll end up with this:

[outer wolf]

How would I do this?

[normal mist]

@misty gale IT WORKS

lines are just debug lines from graph vertex (intersection) to vertex. I can get reference to specific road (USplineComponent) and follow it in detail upon reaching intersection

the graph was procedurally generated from imported GIS road data

had to detect intersections dynamically. 🙂

[misty gale]

Wwll depends on what you need really. For this wirh animation youd need ro calculate custom velocity during this movement and feed that to your anim bp

[misty gale]

oh my! Well done!! 😄 You've made far more progress than I have!

[ocean wren]

Does it need to override a class, or does it use some kind of delegate functions?

[ocean wren]

Now you should try and make it usable and user-friendly 🙂

Funnily enough, I've got to do some spline graphs myself 🙂 for a game prototype for my SteamDeck game idea

Although to be fair, I've got to pathfind jump locations across and between splines as well as follow connections

Probably need to find the nearest spline segment to the target location and be able to do a distance from spline to spline check

cos I want my enemies to jump across splines

[acoustic apex]

Hi!
Is there a way to make NavMesh ignore agent radius for edges?

[misty wharf]

no, the navmesh is considered from the center of the agent

so the agent can walk to the edge so that its center is right at the edge, thus if the radius would not be included, it would be able to walk too far into geometry

[acoustic apex]

so the agent can walk to the edge so that its center is right at the edge
Are you sure? As I can see the edge of the capsule will align with the edge of geometry. So a bot won't be able get closer to the edge to the point when part of a capsule exceeds the edge of a geometry.
Anyway, if there's no way to process edges without obstacles differently, then my question is off

[misty wharf]

As far as I know they should be able to walk all the way where their center is right at the edge

You may be able to get slightly different results by tweaking the navmesh settings, but I don't know if it'll do exactly what you want

[vivid drift]

Trying to make a dumb ai pattern that simply moves towards a target enemy endlessly and attacks while close. Attacking is a separate action that can happen in parallel with moving.

This works at a high level but seems to be rapidly restarting the task when it's reached the target, which has consequences for the attack node.

There's also issues with the attack node triggering many times in rapid succession if the target goes in and out of attack range.

Should I switch these two nodes around so that attacking is the main thread, and the move to is the thing that happens in parallel? Maybe make it "Attack while near", and the move to can be "Move to, if far away"?

Seems like it would work but conceptually the move feels like it should be the main thread task to me

[misty wharf]

I've never really used simple parallel much... It seems this behavior would be easy to achieve by moving the attacking logic into the controller or pawn, where it doesn't need any interaction from the BT

I guess you could alternatively have a "follow player" task which doesn't exit and just keep chasing until it gets aborted by something else

[vivid drift]

I want it to be in the BT because all of the enemies are running their own sub trees for attack behaviors on top of a larger, general behavior scheme. This is just the dumbest one.

I ended going for this:

^^ Zombie Attack

I guess it works. Feels a bit odd but I suppose its fine

[ocean wren]

So your logic is a bit weird.. you want some logic that moves to the enemy, then other logic that performs the attack when in range to do it right?

so the attack behaviour should be higher priority than the move, but only if you are in range

[tardy wolf]

So probably a bit of an odd one but is there an easy way to enable/disable an AI controller on a character?
My game puts the player in control of a squad where they can swap between characters, any not directly controlled is taken over by an AI.

[dense halo]

you can just call unpossess/destroy on the ai controller and make the player controller possess that character?

[tardy wolf]

Trying that but the issue is when a character gets unselected and should fall back under the AI's control, it doesn't do that.

Or at least it doesn't appear to be.

So I've just run a print test and apparently the controller is possessing correctly. Not sure why its not doing anything after it does so.

It can see the enemy but doesn't fire.

[vivid drift]

@ocean wren no. I want to move to the enemy and, while in range, attack. They're parallel tasks. No priority.

[dense halo]

are you using bt? if so do you initialize it again?

[normal mist]

Happy to share more when I get home

It's way way easier than I thought

The hardest part is generating the graph that will be used, which may or may not be hard depending on your needs

[tardy wolf]

I do and I did not. Wasn't aware that was a thing I had to do.

[dense halo]

I mean just calling the run behavior tree node again

[tardy wolf]

Oh right, I completely forgot to even do that.

It was something in the AI controller itself handling firing directly rather than through the tree.

What does the Restart Logic do? Target is Brain Component?

[misty wharf]

it restarts behavior tree

if your brain comp is a behavior tree comp (it is by default)

[tardy wolf]

So in this case Run Behavior Tree and Restart Logic are functionally the same?

[misty wharf]

if the tree isn't running then probably yeah

[winged pasture]

is it possible to change this value from the controller?

[quick current]

Hello everyone, I wonder if it's possible to modify a AI Perception / senses config in game.

I have an AI controller for all my turret and i want to change in game the sight radius (long range, mid range or short range). But i don't see any options to do that.

I already try to use the "add AI perception component and set the result to the old one but it's doesn't work.

[dense halo]

I had to create my own decorator, using a blackboard key for the test value as well

[ocean wren]

Why don't you just get the distance when you get a sensed agent? Then do the AI behaviour based on that?

Rather than modifying the perception system?

[quick current]

I already try that, i think it's the best indeed. I would prefer the sights radius because this is better with perception update. I will try to join a screen of I will try to join a screen of my AI controller.

[dense halo]

hey, I want to check my item against multiple contexts so I'm calling
It.SetScore(TestPurpose, FilterType, 1.0f, MinThresholdValue, MaxThresholdValue); multiple for each Item Iterator but it seems to only show the highest value

I set the Multiple Context Score Op to be average score, but it doesn't work

anyone know what could be going wrong? I tried just putting

    {
        It.SetScore(TestPurpose, FilterType, 0.5f, MinThresholdValue, MaxThresholdValue);

        continue;
``` but it still just shows up as 1.0f in the score

[wintry flint]

I solved this by using Spawn Default Controller and applying it to the pawn that was previously possessed by my Player Controller

[tardy wolf]

Would this not spawn a brand new controller each time?

[wintry flint]

It appears to be that Unpossess clears the pawn of both a Player and AI controller - I can swap to a character that had a working AI controller, demonstrated by it following me, swap back to my original character, and watching the character stare mindlessly into space.

As far as I can tell there's no way around this purely in BP, so spawning a new AI controller is required.

Oh, just read up a bit further

I have functionality that runs on Event Tick (bad practice, but just a placeholder) and the AI Controller still fails like you mentioned despite not having any Behavior Trees to run

[wintry flint]

Looked at the world outliner a bit more closely and your assumption was correct

I pretty much always get "Accessed None" errors when I try to get the AI Controller of the previously controlled Pawn

That's why I assumed that Un Possess just outright destroyed the formerly possessed pawn's AI Controller

[surreal jolt]

I'm trying to understand why a MoveTo node keeps running even when a decorator is false. I assume it's because of this Observer Abort field which i'm still learning about. However this node doesn't have an ObserverAborts field so when will it actually update and how can I get it to interrupt a current task?

[outer wolf]

curious how to make this work with the nav system

[misty wharf]

what exactly are you referring to with "this"?

Navigation should work with stairs if they are not too steep (set in navmesh config iirc)

[dense halo]

hey, does anyone have any ideas on how to implement AI flanking? is there a way to make the navigation area inside of the players view/or just the general direction the player is looking at cost more?

[normal mist]

I was thinking about this the other day. Could you, at runtime, place a navmesh modifier volume and increase the cost of the navmesh directly btwn the ai and the player?

[ocean wren]

Use an EQS query to pick positions with weights that favour points at the sides of the enemy (i.e. given a vector from them to you, you want your troops to take positions that are perpendicular to that vector from the enemy position but with line of sight to them). Its basically what EQS is for. See Matthew Jack's thing in one of the GameAIPro books about environment query systems for info.

[dark warren]

Hey, I'm running into and issue with my behaviour tree I can't understand why its happening.
It's going down the tree correctly but at some point it always reactivates the first node of a sequence and does never get past it. No matter which node I place.

Why?

[misty wharf]

You're using selectors

A selector will execute its children until one of them succeeds, after which it will exit

as opposed to a Sequence, which will execute children until one of them fails

[dark warren]

Oh my god. Should have just take a short break and then it should have been obviously. Just got blind by working 😂 thanks!

[misty wharf]

It's easy to mix those up :)

[normal mist]

@dense halo direct link: http://www.gameaipro.com/GameAIPro/GameAIPro_Chapter26_Tactical_Position_Selection.pdf

Thanks @ocean wren for referring Game AI Pro. Never heard of it before

[dense halo]

thanks

[normal mist]

looks like it is referring to the query system in cryengine

[finite parrot]

hi, is there a reason why nav mesh shows boundary on an area for no obvious reason?

volume covers the entire map

no blocking volumes there

it's missing an entire rectangular area

[normal mist]

@ocean wren @misty gale starting to reap the fruits of my FGraphAStar labour 🙂
The magic here is the LAV knowing to turn at the intersection to get to its destination. Obv it didn't react quick enough to make the turn, but thats a simple fix 🙂

[celest python]

hey looks nice

[normal mist]

thanks 🙂

[normal mist]

spent all of 10 minutes cleaning up the vehicle handling for pre-emptively slowing down for intersections

nowthisispodracing.gif

[strange spoke]

https://gyazo.com/2ac826dd00fe6ac313bf48a3c8d31aef?token=e76740868bad6dc09e2c7a2f723e8333

how would i set has seen to false if the ai loses sight?

[misty wharf]

There seems to be some kind of timeout that occurs if an AI Controller can't follow a path - anyone have any idea where that is?

I'd like to make the timeout shorter since it's taking a bit too long for it to decide it's not able to move currently

Ah, looks like it might be in UPathFollowingComponent

another random useful feature that's just hidden from BP 🤔

[celest python]

Have you found it?

[misty wharf]

Yeah you can set the blocked detection settings using PathFollowingComp->SetBlockDetection

[normal mist]

TIL of the existence of UPathFollowingComponent. Surprised theres no mention of a USplineComponent in there

can't think of anything more path-like than a spline : D

[misty wharf]

well the path following comp concerns itself with following navigation paths so it's a bit different from a spline

the nav paths are just a series of waypoints essentially, I guess you could create your own spline based path following comp tho

[latent coral]

Hey guys, quick question. I am spawning my AI but the character is not possessing the AI controller. Any tip?

[misty wharf]

If you're spawning it at runtime and not via placing in level, check that you have the correct auto possess by ai setting

It defaults to placed in level but not spawned

[latent coral]

It was "placed in world" I've changed it. Thank you mate, its working now.

[misty gale]

Eey, nicely done !

[normal mist]

Thank you 🙏

[ocean wren]

Yeah, Matthew Jack designed that system (now CEO of Kythera AI I believe) for CryTek, then Mieszko (Epic AI guy) basically took Matthew's talk and implemented it in UE, so the concepts are very similar

[ocean wren]

Nice. Yeah you need to predict intersections for sure 🙂

You need to fix your road intersections though, those are triggering me hard 🙂

[misty gale]

Should be fairly straight forward should it not ? Having a second predictor, further ahead oor smth ?

[ocean wren]

Yeah, its basically just a pathfind, you already know the next spline segment you're going to traverse, so you just need to calculate the stopping/slowing distance for your current velocity

and start when youre that distance away from the intersection to the next segment

[misty gale]

But you dont know if it straight or not

[ocean wren]

yeah, you could modify it based on angle to the road for sure

[misty gale]

So youd need to check that aswell

Probably easiest to just 'splice' segments that goes straight

In the pathfinding setup

[ocean wren]

Just talking about that use case where you want to do a perpendicular road 🙂

[misty gale]

Yeah

[ocean wren]

if you've got essentially parallel input/output roads, then you can maintain current velocity.. although I'd probably have a velocity value for the segment endpoints and try and match that

usually for roads, they have a target speed value when they're built, same with trains

[misty gale]

Yeah thats true

Depending on their classification / standard and their surroundings

[ocean wren]

and the camber of the road and whatnot

[lusty nebula]

does anyone know in UE, when the config refers to "range" and "radius" - is that measured in cm? i.e. so if I do a "range = 1000" for the AI sight - does that mean 10m of sight?

[misty wharf]

Yeah, all distances in UE are measured in unreal units (ie. cm) unless otherwise specified

[misty wharf]

Hmm, really need a better integration of LOS checks and such into my behavior tree... it's getting a bit complicated with custom decorators because I need custom LOS checks and such 🤔

And setting my custom LOS check decorator to abort self seems to cause it to not really work as desired because it's aborting even if the value from it isn't changing...

It's a bit complicated because I need two separate types of LOS checks... one for perception, ie. can the enemy see you... and another different more complex one for can the enemy actually shoot at you

[hidden river]

Hello everyone, quick question! Can NavMeshBounds Volumes move? I am trying to stream in levels and move them to locations by moving a point that the entire level is parented to and it works perfectly, however my NavMesh seems to be left behind, even though it is set to movable

Nevermind, it seems the volume does move, however the navmesh refuses to update correctly

If I manually hop out of my character and back into the editor and move the NavMesh Volume around, it updates and everything works, the AI starts moving.
Any ideas on why it would not update on its own even after being moved through blueprints? Or any ideas on how to fix this?
The NavMesh is set to Dynamic rebuilding

[misty wharf]

You may need to enable runtime generation for it to work when the bounds are moved

The mesh probably is generated for specific coordinates

Oh nvm you said it's already set to dynamic 🤔

There might be some function you can call to have it rebuild, but not sure

Most likely not BP-exposed

[hidden river]

Yeah it's weird, it's like it's not considered update worthy

Maybe I need custom code that "wiggles every navmesh around" every time a new level spawns 🤔 hopefully forcefully updating it

[normal mist]

bwuaha that honestly is a challenge that I don't know how to solve. Generating spline meshes from GIS data. Not sure how to generate clean intersection meshes

also check out the second video where they slow down for intersections 🙂

[normal mist]

very happy with how things are progressing

[celest python]

lol, nice

[normal mist]

thanks 😄

[stone walrus]

anyone know how to make an ai (car) for endless runner game

or link u know please give me thanks

[ocean wren]

Hmm, I suspect once you've got the spline intersections, the easiest way would be to generate the road meshes procedurally and deal with the whole thing as a PCG problem

Could probably do it pretty easy in Houdini

actually, thinking about it, they added CSG to the mesh editing tools, so you could probably do it using those

That rendering without any shadows definitely gives me an operation flashpoint vibe, but the audio 🙂

[normal mist]

what is PCG/CSG @ocean wren ? thanks for the response 🙂

[normal mist]

OFP/ArmA is a huge inspiration

[prime barn]

Hello, I managed to move and rebuild nav mesh bounds in one of my projects. I explain it here: https://forums.unrealengine.com/t/moving-navmesh-volume/338023/6

[rapid ridge]

I have a Nav Mesh Bounds Volume, and the pawn is possessed by an AIController, but when calling AIController::MoveToLocation nothing happens

    if (PC == nullptr)
    {
        checkNoEntry();
        return;
    }

    PC->MoveToLocation(FVector::ZeroVector);

well calling it on PossessedBy with a delay works

[hidden river]

Thank you for your response, I actually stumbled upon that very thread when looking for answers. For some reason that didn't work for me, I think I couldn't seem to find that command or something, I'll look into it again tomorrow

[ocean wren]

PCG = procedural content generation - CSG = constructive solid geometry. Basically, you can generate the meshes for the roads by intersecting the road meshes using the new geometry tools.

[hidden river]

Are you sure the command is exactly "RebuildNavigation"? when I start typing that, no auto complete suggestions come up

[prime barn]

As far as I observed, it doesn't auto complete in the debug command console, but it works when used via code/BP. Weird, I know. 🙂

[prime barn]

Yup, just confirmed, it's working, despite Output Log throwing "Command not recognized: RebuildNavigation".

[hidden river]

Alright, weird 🤔 but thanks! I'll give it a shot

It works great! Cheers

[prime barn]

Yes, strange, ain't it? 😄

[prime barn]

I don't get it. But well...

[ruby bluff]

Does anybody knows if it is possible to temporarily override player's pawn with an AI agent?
I need a way to make player's character do stuff while in a cutscene - for instance, to go to the defined spot, while player's locked out of the controls.

[misty wharf]

Sure, many ways to go about it

You can for example have a flag which you check before reading inputs and just use it to turn off control while you move the character using Move To or some other method

Or possess it with an AI controller to do stuff

[ocean wren]

Typically, you'd do that with a sequencer sequence

just trigger the sequence and disable player input

[ebon lagoon]

Why is my AI refusing to move?

I have tried to printString the PlayerController/Pawn, which worked successfully

yet for some reason it is refusing to move and keeps getting check on the MoveTo node (the key is set, so the decorator is not failing afaik)

ok after further testing it works on characters but not on pawns....

How can I make pawns controlled by AI?

[misty gale]

Is there a way to pick up the player char instance there , dynamically?

Assuming sequence = level sequence

[dawn loom]

nav filtering is giving me a headache can someone help?

I have setup a navlink that uses NavArea_Hover that I setup

and I also made a NavFilter_Default that all AI controllers use except the Hovering one (AIC_Drone) which initially just excluded NavArea_Hover but it didn't change anything

so I marked it with a very very big travel cost and on the NavFilter_Hover (used by the AIC_Drone) I set it back to 0

so before I changed the travel cost override (when it was excluded in the default and not excluded in the hover filter) ALL my AIs were trying to take the proxy

and now none of them are

not even the drones which should be using the hover NavFilter (which should make the cost back to 1)

I'm so confused

[normal mist]

I'd love someone's input on this. I have a convoy managing the throttle and steering of many vehicles. Is it in best practice for the convoy to invoke commands on the vehicle pawns or the ai controllers of the vehicles?

[misty wharf]

it probably depends on which of those has the sort of control over it

ie. if telling the pawn to go somewhere would make the ai controller get confused or give conflicting instruction then it seems it should probably go to ai controller in the first place

[dawn loom]

nobody has an idea about the issue I'm having? I still didn't find a solution btw

[dawn loom]

ok I think there was some kind of offset with the proxies locations that's why it was never taking it, I still have the issue of ALL AI trying to take it even though they have a filter that shouldn't allow that

and most importantly this is never getting triggered they just stand on it and watch

[ocean wren]

I'd use the vehicle itself to set the throttle, given the player might want to do the same. Controller would then use that same interface (so AIController or PlayerController would use the same function).

[dawn loom]

btw I still can't find a fix for this

if anyone has any idea 🥲

[ocean wren]

Its a bitwise filter isn't it? You should have the bits for both area types on so that it sums the costs?

[dawn loom]

is it? I just marked it as excluded for the default NavFilter and not exlucded for the Hover NavFilter

[unkempt breach]

Do you have an idea where I can find the Foliage settings? It's supposed to be there where the red circle is.

[unkempt breach]

I use the 4.26.2 version

[dawn loom]

#ue4-general @unkempt breach

btw I just tried more stuff to fix my issue I added the regular areas to my filter but it still decides to always takes the NavLinkProxy that has a NavArea that is excluded

😭

I stg forcing me to use navlinks is worse than torture

like, adding a modifier on top of the proxy means they never take it

but if I just keep the area on the proxy it doesn't care about the filter anymore for some reason

[ocean wren]

You'll just have to debug it.. put a breakpoint in where it evaluates the navlink and see where it calculates the path cost.. pretty sure its when its traversing the edges between noderef's in the path generation step

[unkempt breach]

Thanks for the answer. Unfortunately, I'm still a beginner and don't know exactly where to start

[ocean wren]

Unfortunately if you want to get the most out of Unreal Engine and AI in particular, you're going to have to dig into C++ code to really understand what's going on

[misty gale]

Ai can be a fairly complex subject, so its not surprising really

[ocean wren]

Something that struck me recently, in case anyone is interested. Is that making the hard tech stuff that other people use, has a lot of value. By that I mean in terms of career and opportunity. So if you're inclined to work on AI technology, I urge you to pursue it.

Just don't do the exact same pathfinding stuff that everyone else is 😉

[dense halo]

hey, is it a bad idea to not have a player state for the ai?

I want to have a lot of ai and having the player state is just another replicated actor

[ocean wren]

what do you want it for?

and generally, you don't want to replicate AI stuff, it needs to run on your server end

[dense halo]

I don't want it, just wanted to know if it's a bad idea to not have it

[ocean wren]

Player state is generally for replicating player state info.. given AI isn't a player, I can't see why you'd use it

[celest python]

Bots in CSGO could appreciate a playerstate

Because having a single playerstate for both AI and players could help the workflow

since they use shared values like score, damage count, overall performance etc.

[ocean wren]

Yeah, i guess you could do that if you wanted them to fake being players

[dense halo]

ok, I guess I'll be fine without, I just have the ai for a coop game and they don't really need to track score/dmg

[misty wharf]

none of my AI's have playerstates in either of my games

they can hold their state on the pawn or controller just fine I think, so unless you need replication or something prolly unnecessary

[ocean wren]

Yeah, the use case of sort of player-like bots is probably the only reason.. so you can use the same playerstate presentation logic

[dense halo]

is there a better way to have the ai always know about the player team? I basically spawn the ai at the start of the round and they hunt down the player, so every time the ai need to get a new target (initial or check if any are closer), I iterate through the controllers and check if they are in a different team

[misty wharf]

I guess you could keep an array of all players in a specific team so you can just pick one from there

but it probably wouldn't make much of a difference

[glass pilot]

I'm having issues with moving my AI, I'm using simple MoveTo Actor/Location nodes.. It works more often than not, but sometimes I get this FPathFollowingResult Blocked[Blocked] for 10-20seconds straight and I can't figure out why.
Currently trying to move the AI Agent about 400uu in a straight line with no obstacles, checking the NavMesh with P shows everything green..
Any input would be greatly appreciated!

[ocean wren]

Going out on a limb here.. I'd say that something was blocking it

[glass pilot]

You're correct, was an object in players hand with CanAffectNavigation enabled. First MoveTo call returns blocked still though, and I can't figure out why

[misty wharf]

there are some functions you can override to get info on hits

and for when CMC's move is blocked

[glass pilot]

Any examples of those? Sounds just like what I need!

[misty wharf]

https://docs.unrealengine.com/4.26/en-US/API/Runtime/Engine/GameFramework/ACharacter/MoveBlockedBy/

not sure if it's available in BP's but this gets called by the CMC when movement is blocked

The other option would be to enable hit events and use the actor hit thing from regular collision detection, but the MoveBlockedBy gets called in some circumstances where the hit might not

[glass pilot]

Awesome, thanks for the info! This should be enough to get me through this issue for sure

[celest python]

This never gets called on me 😦

[misty wharf]

No idea, it was definitely getting called a lot while I was implementing some movement logic to deal with sliding :)

[ocean wren]

Anything in the logs?

[wooden jolt]

hello everyone

Could anyone help me out I have an issue and cant find the solution to it: I have a very large map, with a nav mesh on it, but in order to stop it from building every time i make a change, i used navigation invokers as per the UE4 tutorial on their site. It works just fine when the navmesh encompases half the map, but when I increase the size to cover all of it, it stops working. I cant find a solution to this

this is how my map looks

[lone stump]

Not sure why it stops working when you increase size, maybe fixed tile pool or something, but you can disable automatic build in editor preferences, search for update navigation automatically

[wooden jolt]

i played with this a bit, i checked the "fixed tile pool size" and increased to 2048 ? didnt seem to do anything, but I was just eyeballing things..

[lone stump]

that would make it stop working, yes

personally I've had it crash, but that was with level streaming

I would leave it off

[wooden jolt]

yeah its off

but I still dont have a fix to my problem 😦

[tame pebble]

Hi all, I'm beginning to develop a project that utilizes ai image recognition (input from an NDI, AWS or similar for analysis) and am considering using UE - has this been done before? If so, can someone point me in the right direction toward any projects ideally w/ documentation or discussion of process/challanges?

[lone stump]

@wooden jolt check visual logger, there might be some message regarding why it's failing

[wooden jolt]

how do I do that ?

[lone stump]

you go to Windows > Developer Tools > Visual Logger, it'll open new window

https://docs.unrealengine.com/4.27/en-US/TestingAndOptimization/VisualLogger/

[ocean wren]

What exactly is it you want to do? There are a number of different angles depending on what that is.

[tame pebble]

At its most basic form - i want to be able to take a real world object (say an apple) and place it infront of the camera - after identifying an apple is within the camera frame, a HUD would be triggered displaying information on the apple.

[wooden jolt]

Thanks!

[wooden jolt]

I made it work tho

i just increased the scale of the navmesh volume by a lot

no idea why it was like this. maybe because my whole encompassed landscape is on a 25 angle

[ocean wren]

So you want unreal engine to display some UI based on some computer vision input is that it?

In which case, maybe the OpenCV plugin would be what you want

But I don't understand why you would do that with Unreal Engine?

[tame pebble]

Thanks!

[tame pebble]

UE only for the realtime/rendering built into the engine

[ocean wren]

Am I misunderstanding? the apple is just a real apple shown to a camera right?

not an apple in the UE world?

[tame pebble]

thats correct! Real world apple shown to the camera - identified as an apple and triggeres and event

HUD, Model displayed, Etc

[ocean wren]

Ok... weird, but ok 🙂

[tame pebble]

hahahaha im hoping its easy! 😛

[ocean wren]

Yeah, OpenCV plugin would work for that

pretty sure OpenCV supports image classifiers

If you wanted to get a bit more fancy, you could do the image classification externally and then use a Web api to send commands to Unreal. So do the image classification using something like tensorflow lite in a browser and then send web commands to the running Unreal instance

But at that point, I'm definitely not sure what value the Unreal Engine would have 🙂

[tame pebble]

i need to look into open CV more to understand what it is but the idea is that when an item is identified it displays the info on that item - so show the camera an apple, display the name of the object, maybe a 3d model of the apple. Show the camera a banana and get a 3d model of a banana 🙂

really its just about triggering the proper event in UE based on the element shown - UE would be dealing with a pretty visual thats all

[ocean wren]

Right, its just a bit of a sledgehammer to crack a nut really

I'd do the same kind of thing for instance, using a WebGL engine like babylon.js

Would make it easier to demonstrate

[main heart]

Yeah dig in all its glory

[tame pebble]

Its just familiarity of tools for me - i know UE pretty well from the content creation side. I haven't programmed for web in almost 20 years.

[ocean wren]

I'm sure there's a few hundred tutorials and demos on using OpenCV with UE, so I guess its not a bad option. Its just in terms of overkill its on the upper end 🙂

Guess it depends on your intended audience though

[tame pebble]

Just yesterday i used a bench vise to open a beer bottle - so maybe its in my DNA 😛 Thanks so much for pointing me in the right direction! its much appreciated!

[ocean wren]

Random conversation on twitter today gave me a bunch of ideas for ML based product features! yay!

[ocean wren]

Goddam faceware is expensive.. wow

[normal mist]

I'm getting WAY too wrapped up in my head and tripping over the details with implementing an AI Squad. Should it be an actor, pawn, or just a disembodied AI controller? Ideally it could benefit from a behaviour tree as it would have complex decision making similar to any singular AI pawn

the responsibilites of the "squad" class is that it tells multiple AI pawns what to do

[misty wharf]

It should be an AI controller if you want to use BT's

At least that's going to be the most straightforward way to be able to use them, since there are several assumptions in a number of places that BT is ran in an AI controller

[lyric flint]

hey guys

which one is better AI perception or pawn sensing ?

just trying to make a simple AI that chases after the player and also he looses him from sight the AI will return to original patrol point

[misty wharf]

AI perception

Pawn Sensing is an older system which is more or less superseded by ai perception

[ocean wren]

I never used a behaviour tree in my squad actors.. which were just regular actors. I opted for a utility approach for those, but yeah, have an actor in the world per squad, have the squad members register with the squad (use some ID to denote which squad member belongs to which squad). Other than that, its mostly just choosing which entity is responsible for which behaviour. I had a three level structure, of team, squad and squadmember. I'm sure there are some examples in GameAIPro etc.

my squads basically had responsibility for 1) who is in the squad or not 2) selection of squad members 3) choosing squad members for tasks and stuff like coordinating target selections and unit movements

as I've said before, I recommend using messagendpoint for them so you can inject commands up and down the chain and debug without having all the logic in place

makes unit testing a bit easier because you can mock up commands for test purposes

[normal mist]

Thanks so much, I have never heard of messagendpoint before 👍

[dense halo]

hey, I created a custom decorator which inherits from UBTDecorator however I'm having an issue where it returns true but doesn't run the move to node below it (move to might be failing although the actor is set) and it doesn't seem to check the condition every tick, I created a blueprint decorator and it seems to check the condition every tick

is there something I'm missing?

https://codeshare.io/gLpwmy

https://codeshare.io/qPykwM

[dense halo]

does anyone know why when the Move To fails (right at the start since the nav mesh still seems to be getting built), it will jump to the wait? instead of trying the Move To again?

it seems to run my decorator check once, try the move to and when that fails, it goes to the wait.

should it not keep trying the move to since my decorator is returning true

[vivid drift]

@dense halo Sequences tries nodes left to right until something fails. Selector tries nodes left to right until something succeeds. Your first node fails, so it tries the next node.

[haughty edge]

Hi guys! What exactly does bSweepWhileNavWalking in the CMC do?

[vale adder]

Quick question, how do I mark the player as enemy to the AIPerception in the controller?

If I mark detect Neutrals and friendlies in the sight sense, the AI will see and follow the player, but will do the same with every other pawn, including pawns of the same class, so I wanted to know how could I mark the player pawn or any other pawn as enemy or friendly or neutral, this will be also useful for infighting and ally systems

[misty wharf]

This has to be done in C++ using IGenericTeamAgentInterface on your player class

[vale adder]

Oh ok

I am willing to do that

I guess I'll have to do that with every other pawn as well, right?
Since I also need and infighting system like in Doom

Will this work?

Or probably I need UCLASS()

I'll write in #cpp

[ocean wren]

I really don't understand why they made that interface.. especially not AIController centric. What do you do for a player? What team are they on?

It should be a component

Or a tag

[misty wharf]

well it does work on controllers I think

I think the problem with components is that you would have to do GetComponentByTag to determine if an actor has it, which is not exactly fast

I guess a tag would in theory work but the interface offers more functionality with less implementation than a tag based system would I think, especially when gameplay tag containers are not on things by default

so I'd say it's part legacy part because it's faster :D

[ocean wren]

Yeah, but its not possible to determine what team a human player is on using it.. because its on AIController

if it were on the base controller class.. that'd be no issue

And honestly, I think a proper tag system would be fine for this (its the basis for the GAS right?)

[spiral bone]

On Decorators, should I use Event Receive Tick AI at the start?

[misty wharf]

I mean you could just create a custom controller class and put it on there, I don't think it prevents you from doing that

[misty wharf]

If you need it to tick. If it's just a condition check you can override Perform Condition Check AI

[spiral bone]

I'll stick with tick for now I guess.

Thanks!

[misty wharf]

Keep in mind tick can't choose whether the decorator passes or fails, but depending on how it's intended to work tick can be used

[elder perch]

For a side scroller with a world that gets generated at the start, but you want to have ai moving around, what would be the best way to do this?

[misty wharf]

Runtime navmesh generation should work I think

although you might not even need navmesh for sidescroller, depends on how you want the AI move around it

[spiral bone]

I want to switch the branch once I hit the enemy, but unless the enemy reaches to target location (finishes task), it won't switch. Is there anyway to interrupt the current task?

[elder perch]

@misty wharf Thank you. What would be the best method for doing this in c++? An AI controller, on the pawns own tick event, or something else?

[misty wharf]

kinda depends on what you're looking to do... you can do movement without navigation via ticking ai controllers or such for example

[elder perch]

Would be move left and right. If come across enemy, perform attack. Move to resource, pick it up, move it to needed location

[misty wharf]

Yeah you could just tick the movement I guess and use something like a collision box or linetrace to test for enemy etc.

[latent coral]

Hey guys, I am with a huge problem here on my project. I hope someone have a answer. My project its a planet. I apply gravity to my character it world fine. I can walk around jump ETC. But being a planet I cant use a NavMesh for AI. And the simple walk to Actor works but it dont create the best path due not having a NavMesh. Also applying force works but again, no path. Any ideas?

Tried also EQS, but even on trace for grid it just trace half of the world. The another half it dont work.

[misty wharf]

Could be a kind of complicated thing tbh

You would need to generate some kind of custom navigation system for it

One thing that comes to mind is you could create a custom EQS generator which can generate points on the planet surface in some fashion, and then do a custom A* pathfinder through the points to your goal

I'd imagine there would be some way to actually generate a navmesh for it too, but no idea how you'd go about that :D

[latent coral]

I was even using DonNav for the flyable npc but, it is being expensive for long paths. Also looking for a alternative.

Will try and see if I can generate a custom navigation. I tried a custom EQS generator but I guess I am too suck for it, I couldnt do it right.

[misty wharf]

Depending on how your planet surface looks, you could use the planet radius and just generate points using it

kind of like generating points on a circle, you'd take the center point and then the radius and step through a set of angles and use basic trig to calculate where the point lands based on the radius

but if your planet geometry is more complex it might need to be a bit more elaborate

[latent coral]

my test world is just a big sphere, but the real world is a complex landscape that generates sometimes. It depends.

[misty wharf]

I think the basic approach would still be same, but you'd need to find some way of determining where the surface is for each angle instead of just using a hardcoded radius

[latent coral]

I have no idea how to. Doing a search for it for days. For EQS there leak information about generation custom grids. I am looking now the nav one, didnt knew I could do this.

[dense halo]

hey, is it possible to have default values for floats/ints variables on the blackboard? or do I have to initialize them on the controller when I run the behavior tree?

[misty wharf]

you could probably determine terrain height by comparing to your terrain mesh, or by doing a linetrace to see when it hits the terrain, or something like that

[misty wharf]

afaik this needs to be initialized by the controller or some other actor

[misty gale]

Isnt a planet really just a 2d plane, warped and looped?

So a regular navmesh with some tweaks should work on it assuming theres no caves and whatnot

[misty wharf]

Assuming you find a way to generate it that is

If the planet in this case is actually sphere-shaped, the navmesh generator ain't gonna behave

[ocean wren]

yeah, forget the navmesh, it won't work

you'd have to generate your own

[misty wharf]

I guess in theory you could have the planet terrain as a flat plane and project it as a sphere

then you could use the same projection on the navmesh data

but I get the feeling the navmesh stuff just in general aren't going to work very well with it still

[ocean wren]

a spherical projection wouldn't work because you'd get pinching at the poles

[lyric flint]

hey guys

need some advice

should I do a behavior tree for my ennemy AI or just a blueprint with AI perception

[main heart]

Depends on the complexity. If you have multiple objectives (patrolling, attacking, and leeway management) use behavior trees. On the other had if you have specific function in mind a simple enough blueprint would go long way.

[wooden jolt]

hey

does anyone know why the navmesh only gets built on a single part of the map ?

if I scale it down (a lot) it gets built anywhere, but if i enlarge it, it only builds that

or parts of it

[haughty edge]

@wooden jolt Do you have a very large navmesh bounds? I think they don't function correctly when it's too big :P

[wooden jolt]

yeah its huge

its scaled 2000x

[haughty edge]

I had to split it into smaller ones

[wooden jolt]

and I actually need it to be even larger - about 5000x

[haughty edge]

I have multiple smaller ones maybe you can try that and see if it works

also if the map is massive, you might want to try out navmesh invokers so they don't build everywhere

[wooden jolt]

smaller ones give similarly bad results - I even made a post on the unreal forum with no answer..

you can check out some screenshots there, from a test map

https://forums.unrealengine.com/t/navmesh-is-not-building-properly-on-all-the-landscape/510994

its super weird

look in the screenshots where i've had multiple nav meshes

[haughty edge]

I have mine like this

they're not massive and I have 2 of them testing, they work fairly well

[wooden jolt]

im lost in words

[haughty edge]

Does your log say that your navmesh bounds are too big

[wooden jolt]

i dont understand why it isnt working

no

i get no errors

hang on

[haughty edge]

I'm not using UE5 so I'm not sure what's going on, so having multiple smaller ones doesn't work as well?

[wooden jolt]

i dont use mine with brush settings

just normal scaling

could that be it?

i dont think so

but worth a try

[haughty edge]

yeah give it a go

[wooden jolt]

no, that's not it

[haughty edge]

so you don't have this

[wooden jolt]

no

wait

where am i supposed to see that ? in the message log?

[haughty edge]

Output Log

[wooden jolt]

nothing

I also have these set like this

but it doesnt do anything

even if its 1 or 8 million

[haughty edge]

I don't know then, sorry, multiple small ones is working for me

[wooden jolt]

if I make smaller ones, it just draws them like this:

see ? the upper ones are incomplete

[haughty edge]

are they covered by the terrain?

[wooden jolt]

no

here is a better view

whats even funnier i built a navmesh on this cube here :

and ofc it didnt get built

or so you would think, till you move the cube

[haughty edge]

so it was built in the wrong place?

[wooden jolt]

on the cube yes

why ? I dont know

but on the landscape itself it just stops there, it doesnt get built under

[haughty edge]

what if you try one with my brush size settings

but I gotta say, generating navmesh for the whole map is not ideal :P

[ocean wren]

Yeah, its basically not designed for large terrains like this. I'm sure it'll be an issue until they make a fix for UE5 later. but the current navmesh generation system just isn't the right choice for this scale of terrain.

You might want to check out some of the commercial navmesh generation middleware if you need that sort of size

but its $$$$ 🙂

Kythera and the like

[wooden jolt]

any idea whats it called on the marketplace?

[wooden jolt]

doesnt work

[ocean wren]

KytheraAI I think? you can search for their website

There are a bunch of pathfinding middleware companies though

Navpower etc

[wooden jolt]

i think its a little bit too compicated for my level tho

[ocean wren]

HavokAI also has a pathing thing

[haughty edge]

if it doesn't build anything then something is probably broken :P

[ocean wren]

Well, yeah, so there's the thing. You're trying to build a game that isn't a good fit for the engine currently. If you don't have the budget or skill, then I suggest you rethink the game.

Or pay the $$$ if you have the budget 🙂

[misty wharf]

I wonder if this is why the bots in fortnite and pubg are so dum

[sudden citrus]

they dum cause they don't have to be smort

[slender holly]

Is Unreal's "Run Behavior" task with decorator currently bugged in UE5?

Despite having a decorator on BT that's run by "Run Behavior" and "Observer Aborts" set to "Both", it doesn't seem to evaluate the branch that calls "Run Behavior" again when the blackboard variable is set (using Vector here). Removing call to "Run Behavior" and just replacing with that BT content works fine.

[sudden citrus]

Can you post a screenshot

of the branch asset and the calling asset both

[slender holly]

Here's Main BT.

And subtree ran by Run Behavior.

They are both using the same blackboard. The problem is, when NoiseLocation is set, and executing MoveTo, setting the value TargetLocation (changing the notify observer to On Value/Result Change makes no difference) does not cause it to abort current branch (executing Move To) and execute other branch RunBehavior.

And the weird thing is this behavior does not happen when I directly paste that subtree into main tree. So, I think somehow Run Behavior is causing the decorator observer abort to be ignored.

@sudden citrus

[lyric flint]

the enemy will just patrol from specfic points and some are idle

when they see the player they will run after them

if they loose sight of the player for 10 seconds they go back to original patrol points

[ruby reef]

Hey everyone. So I'm looking for some ideas on how to approach this. I currently have doors that work for the player. I want the ai to use the door if its in the way to the next point they want to move to. Whats the best way to approach this so the ai only needs to open doors it needs and not every single door it goes near.

They can pass through the door fine if its open using navlink proxies

[misty wharf]

if by "ones they need to" you mean they should prefer a path where they don't need to open doors, you could give the navlinks for doors a nav area which has a higher cost

This should make the pathfinding prefer not opening doors if a path that doesn't require opening them is available

[ruby reef]

My map levels will mostly consist of office type buildings so there are a lot of doors

Rooms with more than one door and hall ways with doors they will pass by

[misty wharf]

So what was the specific issue with it?

They won't actually open the doors and just pass through them instead?

[ruby reef]

They can only pass through open doors. The issue is having them open the door. I tried using a box collision on the door which worked. When the npc passed into the collision it would trigger the door opening. But with this method the npc was opening every door it was walking by. What I'm trying to achieve is have it only open the door blocking its path.

I appreciate you taking the time to hear me out btw.

[misty wharf]

You can use a smart link which can perform actions when it's being traversed, which could be used to trigger the door to open/close

Or you could set it up so that when the npc actually collides with the door it would trigger the door to open

[ruby reef]

So you are saying I can call the proxy navlink the door already uses in a blueprint when its being used?

If true that sounds like a great solution

[misty wharf]

yeah you'd need to create what's called a smart nav link instead of a "regular" nav link for it

you'll probably find some info on how to do that if you google for ue4 smart nav link

[ruby reef]

Thanks so much, Ill give that a go!

[lyric flint]

how can I increase the maximum walking speed of my AI

[wooden jolt]

in the character's bp movement component

@lyric flint

[lyric flint]

ok well Im in the masterAI rn

idk where to plug in

I saw this in a forum

but It wont work

@wooden jolt

[lyric flint]

forgot to mention he walks to wander but runs after the player when detected

so it obviously cant be the same speed

[wooden jolt]

print a string after set

see if it gets triggered

@lyric flint

[lyric flint]

@wooden jolt

this is becoming spaguetti

it just bugs out now

check this out

[wooden jolt]

I have no idea

truth be told 😄

[lyric flint]

idk what to plug in self

[lyric flint]

can somebody pls help me

[ocean wren]

maybe you should try doing some tutorials first?

plenty of those on learn.unrealengine.com

[lyric flint]

but what im asking for is simple

its just not working for some reason

trying to increase the speed of my AI when hes running

to 300

and then 150 when walking