multiplayer

[odd hamlet]

But how am i suppose to know how a connection string looks like tho:(

[chrome bay]

Well you're not really - but that's why Chat GPT is a useful as a box of dead frogs

Only way you're going to get correct info is by looking at the source code

Keep in mind Chat GPT is just feeding you harvested info from the internet, most of which is either wrong or out of date.

[odd hamlet]

May I ask how did you get in there?

how did u find the cpp?

[upbeat basin]

You can use your IDE's search action/tool. If there is a log, then it should be typed in somewhere (excluding the parameterized stuff ofc). If you include the engine files on the search, you can locate where the log is coming from

[magic hazel]

Hello! Does anyone know how to fix or avoid this?
Multiplayer. Host can easily travel from menu to gameworld and vice versa. But Client is stuck when tries to open menu.
I use LoadingScreen through FLoadingScreenAttributes and need to use bAllowEngineTick for properly shown loading screen.
Without bAllowEngineTick client works normally but loading screen works on it weirdly.

[chrome bay]

Just CTRL+F'd the error you posted over the entire solution

specifically the Failed to parse connection URL part

[halcyon gorge]

Hi everyone! I decided to make a multiplayer game for a jam. I set it up using the Steam subsystem with App ID 480 following a tutorial. I tested it on two PCs with different Steam accounts, one of which was connected via mobile data. The session was created successfully, and everything worked. However, when I shared it with my jam teammates, they couldn't connect.

I then decided to switch to EOS. I set it up following another tutorial, but when launching the game, the PersistentAuth login fails. I added a login button for AccountPortal, but it doesn't work either—the login window doesn't even open. I double-checked all the IDs.

Does anyone know what could be causing this issue or have a simple solution for implementing a Relay? I don’t have time to set up a dedicated server, and hosting my own relay server seems too complex at the moment.

[odd hamlet]

could you explain like an idiot because i dont know where to ctrl + F over the entire solution,

I got this one and i canno`t find it 😦
LogSockets: Warning: Could not serialize 76561198867930852, got error code SE_NO_ERROR [0]

[chrome bay]

just open any code file and pres CTRL + F, switch to search "Entire Solution"

sometimes you need to search just parts of the message because the rest will be formatted arguments

It's just a starting point to get you in the right place

[odd hamlet]

SteamConnectIP=76561198867930852:7777

I tried it this way but still doesn`t work

LogSockets: Warning: Could not serialize 76561198867930852, got error code SE_NO_ERROR [0]

I get this error from the image

i simply can't understand it anymroe

[lost inlet]

then you're not using steam sockets

[upbeat basin]

Is it coming from the Steam net driver?

If that's the case then +NetDriverDefinitions=(DefName="GameNetDriver",DriverClassName="OnlineSubsystemSteam.SteamNetDriver",DriverClassNameFallback="OnlineSubsystemUtils.IpNetDriver") on DefaultEngine.ini could help, if missing

[odd hamlet]

this is coming from SocketSubsystemBSD.cpp, the error

bool bInviteSent = SteamFriends()->InviteUserToGame(FriendSteamId, TCHAR_TO_ANSI(*SteamConnectString));

and this is how i am inviting my friend

[upbeat basin]

I meant the steam sockets, what sswires said, not the error

[odd hamlet]

this is in my DefaultEngine.ini

[odd hamlet]

how the fuck am i suppose to use them?
"

I want to cry

[chrome bay]

There are two steam-relevant socket types. FSocketSubsystemSteam and FSteamSocketsSubsystem.

GetAddressFromString in both cases doesn't take a string in the format you're providing. The regular steam subsystem takes an ID only, no port - in the format of steam.#### The Steam Sockets Subsystem takes the steam.ipaddress:port format.

Put a breakpoint in, see where it's going wrong. You don't need to add SteamConnectIP= to the start to begin with, that's for something else

It also wouldn't shock me in the slightest to find out that the Online Steam Subsystem is massively out of date, because Epic don't maintain it at all anymore and the Steam API has changed a lot

The GameRichPresenceJoinRequested_t callback data you get from Steam is what contains the connection string. Solid chance it's not what Epic thinks it is which is why the friend invite fails.

Should be a very easy fix, but you'll need to start debugging

[ornate moat]

As a Romanian friend, I would suggest you, stop using chatgpt.

You are not using it as a source of documentation, you just get random code from it.. Wich is bad.

@odd hamlet

Instead of asking chatgpt :

How I add multiplayer to my game, give me code.

Ask : hey, I want the new unreal engine 5.5 documentation about steam sockets. And so on

Don t ask for something "precooked "

[lost inlet]

or just don't ask chatgpt because its knowledge about unreal engine is extremely limited

[agile basin]

Hi, I have this issue where player0 will autoposess the actor set to player0, but player1 just spawns at the default location instead of autoposessing player1. Any ideas?

[hollow frigate]

Im confuse... (and probably not doing the best approach). This is a logic to display health bar above enemy head when in range. I can confirm the check if enemy work perfectly, but instead of showing the bar above the enemy head, it show above my own character head?

[dark edge]

If you and enemy are both PSW_CharacterBase, then you're both telling each other to unhide hp bar

[hollow frigate]

so I should run it on client only?

[dark edge]

Just think about the rules

[hollow frigate]

I'm confuse now ! not sure what you mean by think about the rules... if by default I set the hp bar to visible and do a logic for each character to hide their own bar it work, and they only see the other players bar, not their own. I though I was specifically picking up the WB I wanted to hide/show for to the requested player

[dark edge]

"Show HP Bar when near another character and that character is your enemy" is obviously not the correct rule.

It should be "Show HP bar when near the PLAYERS character and that character is your enemy"

I would do it all from the POV of the players pawn, simplest way to do it. Is the players pawn special? like, is there a class for just the players character?

[hollow frigate]

the logic is casting to a base class but its built in a player only class. So my issue is between player (pvp)

[hollow frigate]

So the structure I have to make it simple
Base Class is the parent for player and monster, the logic works almost perfectly for monster, but for some reason it's replicating to all player, so if player 1 is close to a monster, he sees the bar but if player 2 is too far, he shouldn't see it but he will because if player 1 been close. but PVP, its just a mess for some weird reason

[dark edge]

Just do it in player classes, like this:
Overlap -> if self is locally controlled -> cast otheractor to character -> if otheractor is on enemy team -> tell them to show their hp bar.

or just enable the overlap collider for locally controlled characters

or in some other way filter it to end up with the same result, which is that a characters hp bar is visible if they overlap a LOCALLY CONTROLLED characters overlap collider, and they are enemies

[hollow frigate]

great adding the locally controlled on self did fix the monster bar showing to all player at any distance, but the pvp still not working. Ill try to dig more to figure out why its making that restriction on player

[dark edge]

show your current code

[ornate moat]

Did someone tried to do a RogueLike type game?

I can't find a good Wave system

and i was thinkin' maybe someone can help me out

[dark edge]

wfc?

[ornate moat]

With a ideea

[ornate moat]

wfc?

[hollow frigate]

checked Owner No See on the Widget Component

Ok I think its working fine now

[hot scroll]

Hey, I'm having an unusual bug with Client behavior.
I have a UX element that has text based on the IsServer node. It'll say Client or Server.
I'm seeing my TargetRules with the TargetType.Client think it is the Server.

This happens in Cooked .exe as well as Packaged .exe
The editor will correctly be a Client when I set it to use as a Client.

I'm rather perplexed about how to diagnose this further. Any suggestions/common gotchas?

[dark edge]

what do you mean by Wave system?

[ornate moat]

Imagine the game Brotato as example

where you start the game

and bunch of enemy spawns

at the beggining

after clearing the stage, you go to next stage [wave] and there are more powerfull enemies

etc.

Shortly, i need a system where per level / wave / stage enemies to become more hardfully to beat, and more powerfully / more to spawn

[dark edge]

ok that sort of wave

[ornate moat]

yessir

[dark edge]

just make it

make an actor that spawns dudes, get it to spawn 3 dudes at begin play

[ornate moat]

i did that, the problem comes after it

I kinda want to make it inifnite until you die

i don't really want to do a switch on int, check if level 1/2/3/4.../50/51

to change Hp / Dmg multiplier manually

That's where i fwk things up

[short arrow]

You don't really gotta do all that, just need a few starting variables like... how many enemies to spawn at level 1, and a few multipliers to increase their strengths each round, when the round ends, increment the level, spawn the zombies and apply the multipliers

[dark edge]

math

[silent grotto]

Uhm hi, I am kinda confused right now. I put my viewport into a new window, 2 clients and put it at "Play as Client" but for some reason but send they have authority. Even when I put it as Listen Server both still have authority. How is that? One says server when printing while the other does not and still both think they have authority.
Am I doing something wrong? I just print at begin play the GetAUthority BP function

[dark edge]

EnemyStrength = 1.2 ^ Level

that'll make them 20 percent stronger per level forever

whatever that means

[short arrow]

For example if you have 5 starting enemies, and you're on round 2 now, it would be 5 * (2 * multiplier) or something

Each round you'd end up with more and more enemies

You'd do the same with their stats

[ornate moat]

Some sort like

BeginPlay -> CurrentHealth = 100 -> OnWaveClear ->SetUpSettings
SetUpSettings -> get current health * HealthMultiplier [1.2] -> SpawnZombies -> StartNewWave

Hope i got it

Som' like that?

[short arrow]

Sounds like you got it

[ornate moat]

Saw some dudes / even the AI chat, told me to use data structs, enums, and it's blown me away

I lost it at that part

[silent grotto]

Why is this true for both clients?

I call this from HUD at BeginPlay, "Play as Client"

[short arrow]

It shouldn't be, you sure you got the game set as listen server mode or client mode?

[silent grotto]

Gives me the same result

[grand kestrel]

@thin stratus @pallid mesa it appears that moves that don't get combined can still get delayed which still results in de-sync
This didn't happen on my predicted movement dev project, but it happened in production, and when I went back to the dev project it was happening there too lol...
In ReplicateMoveToServer() it handles move combining (CanCombineWith(), CombineWith()) and regardless of the outcoming, then factors delaying the move based on ClientNetSendMoveDeltaTime

We need to stop it from delaying moves where time-critical events occur, i.e. a change to velocity in OnStartMyModifier()
Therefore, CanDelaySendingMove() needs to be overridden, which basically tells us exactly this:

    // Don't delay moves that change movement mode over the course of the move.
    if (NewMove->StartPackedMovementMode != NewMove->EndPackedMovementMode)
    {
        return false;
    }

Do you guys agree with my approach, to override this and check NewMove->StartMyModifer != NewMove->EndMyModifier ?
Or is there some sort of oversight on my part?
I suppose I could achieve the same by setting bForceNoCombine on the saved move elsewhere, and possibly avoid requiring Start/End modifiers?

[short arrow]

You sure the actor is replicating?

[silent grotto]

Does it need to be replicated for the result to be false?

So in other words, if it's not being replicated, I always have authority?

[short arrow]

Whatever spawns it will have authority over the actor

So multiple things will say they have authority of it yes

It's checking authority against the actor, if you want to know if you are authority over the game you can check "Is Server"

[silent grotto]

Looks like HUD has no replication at all, which kinda makes sense

[short arrow]

Or you can check your own role against the server

I believe it's in the controller

"Remote role" i believe is how you can check what you are

https://dev.epicgames.com/documentation/en-us/unreal-engine/actor-role-and-remote-role-in-unreal-engine

[short arrow]

No widgets have replication, indeed

[silent grotto]

I said HUD, not widgets.

[short arrow]

HUD Class

Yes it's got no replication

[silent grotto]

and is Server seems to be the thing I was looking for

[silent grotto]

but this is a good idea tbh

so thank you very much!

[short arrow]

👍

[silent grotto]

hhm maybe one more thing which I do not understand

I basically have this setup right now

but changing the resolution with this widget, changes only one window no matter in what window I hit apply

like one window never changes its resolution

and I am not sure why that is

I basically do this:

but even when doing Get Player Controller (the one that requires an index) it aint working properly

[short arrow]

There are lots of small bugs related to graphics settings in PIE, try doing it in standalone

[dark edge]

because HUD isn't a replicated thing

every HUD has "authority"

[silent grotto]

yeah we figured that out already ^^ thank you

[silent grotto]

okay

but I think remember trying this already and having the same result

oh nvm

standalone does the thing

crazy

[short arrow]

Yeah, never rely on PIE for settings

Or most things for that matter

Always test final code in standalone if you're having unexplainable issues

There are also things that will work in pie but won't work in standalone

That'll be fun

Those ones must be fixed

[silent grotto]

okay, but the issue I had in standalone was that my framegrabber was just recording black frames, which wasn't the case for PIE and idk why, I just followed this as much as possible when implementing the framegrabber :
https://github.com/pafuhana1213/FrameGrabberSample/tree/master

[silent grotto]

yeah exactly xd

[short arrow]

I'm not gonna get all into plugins and stuff sorry bud 😅

[silent grotto]

its not a plugin but nah nah dw, I just wanted to mention, cause I don't quite understand but I'll come up with some solution I guess

[ornate moat]

Do Functions calls themselfs on servers too? rpcs?

i can't set them to run on server / multicast it

tho

[quiet yarrow]

Sure you can run them on server / multicast

run on server custom event > multicast > Function

though if server and client will need the relavant info to run the function

[ornate moat]

nah

i mean

the functions

I see no ros / multicast

[quiet yarrow]

yeah no you cant just run a function on server without a custom event

you also cant run rpc inside functions

but you can call rpc from inside functions

and send the data from within out

[ornate moat]

i see, so if a function is inside a custom event with run on server on, it's gonna work

that function as an c.event

[quiet yarrow]

correct

[ornate moat]

I see

[thin stratus]

Makes sense to me

[ornate moat]

ty

Yo, @quiet yarrow Mind if i send you a dm?

i have one question, and it's off the subject, don't really wanna fwk the discord flow here

[quiet yarrow]

sure

[split siren]

I set up simple Iris project, but I can't see any part of Iris processing happening on a separate thread/worker, which I assume is the main benefit. What am I missing?

[quiet yarrow]

Im having a tough time finding a working replicatable solution to having Physics arms/hands + procedural animations.

I figured I could replicate a ball and move that and have the arm attached to it, but since its not the parent I cant move it? So im out of ideas

chatgpt is saying do IK for the hands, but its instructions suck. Could someone help point me in the right direction?

[grand kestrel]

I would have thought moves marked as important (IsImportantMove) would inherently not be delayed
But nope
I'm almost tempted to add that though...

[grand kestrel]

@thin stratus @pallid mesa
Updated: https://github.com/Vaei/PredictedMovement/wiki/Move-Containers#delayed-moves
Might get updated again soon tho lol...

[tacit furnace]

I'm trying to replicate the functionality shown in the blueprint. However, when I execute it as 'Run on Server,' the spawned actors don't appear on the client side, and the server spawns 6 actors instead of 3. How can I fix this so that only 3 actors spawn on the server and properly replicate to the clients?

[haughty ingot]

Need more context

[tacit furnace]

this is a combinaiton from this video https://youtu.be/XxtfP3hpopo?feature=shared lock puzzle and this codes spawn dials

[haughty ingot]

Sorry I'm not going to watch a video, but if you want to show more of your project I can look at pictures. There isn't enough context in your message to help you without much trouble

[lost inlet]

Feeling a bit of deja vu

Since I'm sure that tutorial does not cover multiplayer at all

And Unreal RPC 101: you can only call server RPCs on actors the client owns

I also wonder about the test methodology here and what the actual logic looks like in more detail

And any actors spawned by the server must be replicated to appear on other clients

[tacit furnace]

I'll use rpc in player controller

[tacit furnace]

actor and components are replicated

[tacit furnace]

what information do you need?

[bright summit]

it should return null? What GetOwner should return if actor is owned by the server? I thought I understand the basics of multiplayer but then comes ownership and everything collapses 😄

[short arrow]

you still need to set the owner if you plan to that node

https://i.gyazo.com/f35aff397b0a58c5765c46437af3de42.png

[bright summit]

I'm confused because pre-placed in scene objects do not return owner so I assume the owner is the server, right? When I spawn the same actor but through server rpc (for testing purposes only) by level bluebrint, it also do not return owner (I didn't set it in spawn node), so it should be server-owned, right?

(route of spawning by level bp):
player pawn interact server rpc->OnInteract Event on object->Spawn Actor

I have an actor with physics simulation, player can grab it, throw etc. Actors can damage players also based on phys impact. With objects pre-placed in scene everything works correctly, but when I spawn this as I mentioned it is not. Wondering why, both objects should behave the same

Damage RPC is executed by object (OnHit event) it self on the player's pawn damageable component

[short arrow]

if you have it pre placed, with "Net Load on Client" enabled, then that's why

[bright summit]

yes it has ticked this box

[short arrow]

untick it and see if it stops working

personally, I always leave that option off, I think it should be off by default

[bright summit]

it even didn't spawn

on client ofc

[short arrow]

what you're seeing now is what's happening when you try to spawn the actor at runtime

when the client loads the game it's spawning those actors

with "net load on client" on, they keep their own copy of those actors pre placed in the world

so there's like literally 2 copies

a client owned copy, and a server owned one

[bright summit]

ok but spawned runtime client see this actor as well

I assume my approach with running these RPC's are bad but I want to understand what is happening

[short arrow]

need more information to be more helpful

so there's an event that doesn't fire when you spawn an actor?

if you're experiencing that problem on a client it's because it does not have ownership of the actor

[bright summit]

That's right, the runtime spawned actor isn't working as intended but the placed in scene it is.

[short arrow]

are you sure the actor that's placed in scene is actually replicating?

if the server calls the event, everyone will probably see it

but if the client calls it, I imagine that only the client that called it will see it

net load on client is a little complicated

[bright summit]

It must be replicated because it's physics simulated actor and position is synced

[short arrow]

right but are you testing from the perspective of both client and server?

[bright summit]

yes

[short arrow]

and also calling the event from both client and server?

[bright summit]

spawn event actually I have called only from server

[short arrow]

either way, if you are trying to do an RPC from a client that isn't set as the owner of the actor then it won't work

that's the issue

Net Load on Client is complicated

[bright summit]

so with net load on client, client has owning connection of this actor to be able to sent rpc?

[short arrow]

it has ownership of it's own actor that it spawned

I don't believe it's actually working 100% properly the way you say it is with Net Load on Client, I think issues would present themselves with further testing

[bright summit]

with object that is pre-placed on scene I can grab the object, throw it into player and he is being damaged. Damage is applied from throwed actor in OnHit event calling the server rpc on player's damageable comonent. And it works, from client perspective and the server. There is no any warnings about not owning connection.

But if I do the same for run-time spawned actor there are warnings about it

[sinful tree]

RPCs are only meant to be executed on client owned replicated actors. You probably shouldn't be sending an RPC with the OnHit event as the server can detect the hit event itself without the client telling it to happen. If I rememberr right, if you're using "NetLoadOnClient" then the client would be spawning its own copy of that actor, and then it's just executing its own logic client side, not replicating anything to the server.

[bright summit]

yeah about hit event you're right, it's meaningless rpc I will fix this. So what should I do when spawning actors run-time to have the same behaviour as that with "net load on client"?

[sinful tree]

You should not be RPCing in actors that aren't owned by clients, period.

If you want the client to be able to tell the server to do something on that actor, then you must make it owned by a client first before allowing the RPC to be sent.

So when spawning it at runtime, you could set the owner of it at that point.... If someone else can end up interacting with it and you want them to send RPCs, then you'd have to change the ownership to them on the server first.

The other consideration here is that some events trigger on all machines, like the OnHit event - that means all clients could ultimately detect the OnHit and then be attempting to call the RPC. You need to gate the logic so that only the appropriate machine is executing what you need it to execute, like checking authority before proceeding with your code.

[bright summit]

if actros have unticked "net load on client" and are placed in scene, they should be visible on client if it is replicated actor?

ok it should

[bright summit]

Changing ownership should be done by server. So I am doing it via Interact function Server RPC while picking up object. Still same problem. Also moved the damage rpc to the object itself to be sure it will be executed. What is strange client can call RPC, listen server no. On in-scene placed actors there is no problem even without "net load on client"

what is more strange - when testing on client1, client2, client3 - eachother can damage themselves via phys object

[tardy fossil]

aint multiplayer logic fun?!

[bright summit]

yeah. still do not know why placed in scene actors are able to call rpc's 😄

[chrome bay]

They're net addressable, so calling RPC's is fine

Client/Server RPCs won't go anywhere, but Multicasts will

In the same sense, you can add components to actors which have RPC's but are not explicitly replicated. Works fine

[bright summit]

you are talking about in-scene placed actors, right?

[chrome bay]

Yeah, you can call Multicasts on them (possibly only reliable) and they will work

But Server/Client won't, unless somebody is set as the net owner

Not something I've ever done mind you

[bright summit]

ok ok

my func applying damage is server rpc, not multicast and it still works 😄

on scene placed actors

there is no any message about no owning connection

I think I am not fully understaing how RPCs should be routed. The basics one like interact I know, but what about such this case, when I want to apply damage from the falling world object, or maybe.. door stuck?

where the RPC should be implemented and what should call it?

[chrome bay]

It shouldn't be. If the client calls a Server RPC on an actor they don't explicitly own it should fail straight away

And if the client doesn't reject it the Server should

The answer is you don't

The Server deals the damage and the effects of that replicate back to clients naturally

[bright summit]

I removed the RPC property tag and made it as normal function and it works as previously. So In-scene placed actor is owning connection of all the player because it can call on the player applydamage function?

[chrome bay]

Okay, so I'm assuming the actor isn't replicated? In which case that's why you can call an "RPC" - you are the local authority over that actor.

So no RPC is actually being done, you're just running it locally.

And no - an actor can only have one owning connection at once.

You can do whatever you want to stuff placed in the level as a client if those actors aren't replicated, but obviously that will only happen on your local machine

So if you destroy a wall and try to walk through it, then the server would "correct" you back

[bright summit]

It has bReplicates = true, I unchecked in placed actors also "net load on client" and it is still spawning on clients so it should be replicated

their local role is simulated proxy

[chrome bay]

Yeah, so they are replicated then. The RPC should be failing

There's no way that RPC is actually running server-side

[bright summit]

let me double check

so I don't know, unchecked run one process to have reliable print strings, as you can see implementation is executed on server, but not on client

[dark parcel]

Like what?

Damage is server side only

The thing that client receive is the effects and the replicated variable

If I'm client and I hit something, tell server I hit something and send any neccesary data. Server check if the damage valid then subtract the hit point.

The client can then get the updated hit point.

[bright summit]

this is not the case, I am wondering how is it possible that inscene placed actor is able to call server rpc on player without owning connection

it shouldn't be

rpc should be dropped

but it is not

[dark parcel]

Ownership shouldn't even be in this picture

Sounds like quiet a shit show if you have to pass ownership around

Not to mention delay existing

Everything client do, can be routed to things they controlled from the get go

The controller or the character they possess

[bright summit]

oh really? I was previously told that I should change ownerships in that case

[dark parcel]

Like what example?

[bright summit]

picking up physics object which is able to damage players on impact or other world objects

[dark parcel]

So you gonna tell server, hwy I hit something. Give me the ownership of this actor.

Then you ask server to calculate the damage after you get the ownership?

Then what happend if another client hit the same thing?

[dark parcel]

The object can have reference to the character that owns it.

You route the rpc from the character

You don't send server rpc from the physic object.

Physic object on hit -> get owner -> cast to my character-> client_ihitsomething(server rpc)

[chrome bay]

I woudln't even bring networking into it, all of that should just be handled server side

Otherwise it's an instant exploit

A server RPC that asks it to just apply damage is asking for trouble

[bright summit]

HasAuthority should work here well, but still don't know why calling rpc is possible from worldspawned actors and it is not dropped

[dark parcel]

Client wouldn't be able to call rpc on actor they don't own.

I'm not sure the context, if you doing like a goal post overlap and the like then you can just use rely on the server world with switch has authority.

But I think it gets tricky when you are doing shooting, or simmiliar mechanic

Because the server and the client don't neccesarily see the same thing

@chrome bay can I ask for 2 cent. For a melee combat, should I just deal with it server side?

I was gonna let client have a degree of authority so they don't feel cheated.

Like shooting a slow moving fire ball. If the client don't have High ping and the fireball hit an enemy. Then the server will just check if the hit is possible by doing simple calculation. Then just explode the ball in the server and deal damage.

With no experience I don't know the approach with the best trade off.

[bright summit]

Ok converted it to just OnHit event, without any rpcs as @chrome bay suggested. Problem is with spawned in run-time actors. HasAuthority check is just failing and events are not executing

[chrome bay]

You'd probably do it similar to how you would validate client hits for bullets I imagine. Notify the server you hit something, but don't take is as gospel, server should verify

[bright summit]

eh

I started wondering why I done the RPCs and not just the HasAuthority thing. That was propably damage was not applied so I thought it was necessary

but it wasn't and @chrome bay was right. The problem was in damage calculation which damage alwas was 0

because spawned object had 5kg of mass which was out of bounds

sorry for wasting your time

[dark parcel]

Thx.

[split siren]

I have a weird setup. I want to test how good Iris is, so I have dedicated server running on workstation and 500+ clients on Kubernetes cluster.
When client attempts to connect, the server sees it and tries for 20 seconds

LogHandshake: SendConnectChallenge. Timestamp: 344.449866, 

Which never reaches the client in a pod on a Kuberentes cluster.
There shouln't be any firewall in between them.
I wonder, what is the StatelessConnectHandlerComponent::SendToClient function actually using to send the connect challenge? At that point, is there a tunnel/websocket already created?

[bright summit]

Ok I have another issue. I was searching on this discord for similar and I found but it wasn't my case because I need replicated mesh component(phys simulation sync). The problem are these warnings:

FNetGUIDCache::SupportsObject: AudioComponent /Game/FirstPerson/Maps/UEDPIE_0_FirstPersonMap3.FirstPersonMap3:PersistentLevel.BasePhysicsEntity_UAID_74563C6386EE1B4502_2145970111.AudioComponent_5 NOT Supported.```

I need to play these sounds/particles in this actor class, is there any way to get rid of it?

[exotic wasp]

are you replicating the audio component?

[bright summit]

nope

just spawning via gameplaystatics inside the actor where replicated static mesh is

[thin stratus]

So what are you doing with it that triggers that?

I assume you aren't calling an RPC inside of it, so are you replicating it via a variable or passing it along in an RPC?

Either of those only work if the Object is stably named, which a Subobject usually is.
If you created this runtime, then you need to ensure that the Object has the same name on Server and Client. And you also need to ensure that the Object exists on the Client before trying to replicate anything with it.
Better idea would be not passing it along, but just assuming that the receiving end of the RPC has such a Component too.

Or just not spawning it runtime.

[bright summit]

actually its function called from tick which updates the "scraping" sounds and decides if it should play or not. It spawns sound if it do not exists (there is no need to hold it whole time), same things are with niagara - OnHit, Overlap etc. I can get rid of it just slapping !HasAuthority but on listen server it just stopping working

none of audiocomponent or niagara are replicated, they are just created runtime

only thing replicated in this actor is static mesh

[thin stratus]

I didn't ask if the Component is replicated.

I asked if you are passing the Component through a Variable or RPC

Spawning it and calling functions on it wouldn't cause the warning you get.

Somewhere you are trying to send the pointer to that Component through the net.

[bright summit]

I have second static class which has bound events from this actor (OnHit, Overlap etc.) to handle them there. For example static function ProcessImpactDamage

If it matters my actor is child of AStaticMeshActor and I am getting staticmeshcomp from there via GetStaticMeshComponent()

[bright summit]

I have SpawnSoundAttached also and it is attached to rootcomponent, but I do not know if it can be the case

[thin stratus]

@bright summit None of this matters. I already told you where the warning usually comes from.

[bright summit]

Ok thank you, this is a good hint I think

[nocturne quail]

I have little extended the VehicleReset system in the default vehicle template to get smooth Decelleration effect if the character jumps from the vehicle while it was moving
but the issue is now the velocity never reach Zero so the timer is always running

void AVehicle::SmoothDecellerate() //called by server
{
    FVector CurrentLinearVelocity = GetMesh()->GetPhysicsLinearVelocity();
    FVector CurrentAngularVelocity = GetMesh()->GetPhysicsAngularVelocityInDegrees();

    float LinearDamping = 0.1f;
    float AngularDamping = 1.0f;

    FVector NewLinearVelocity = FMath::Lerp(CurrentLinearVelocity, FVector::ZeroVector, LinearDamping);
    FVector NewAngularVelocity = FMath::Lerp(CurrentAngularVelocity, FVector::ZeroVector, AngularDamping);

    GetMesh()->SetPhysicsLinearVelocity(NewLinearVelocity);
    GetMesh()->SetPhysicsAngularVelocityInDegrees(NewAngularVelocity);

    UE_LOG(LogTemp, Warning, TEXT("Current Linear Velocity: %s"), *CurrentLinearVelocity.ToString());
    UE_LOG(LogTemp, Warning, TEXT("Current Angular Velocity: %s"), *CurrentAngularVelocity.ToString());
    UE_LOG(LogTemp, Warning, TEXT("New Linear Velocity: %s"), *NewLinearVelocity.ToString());
    UE_LOG(LogTemp, Warning, TEXT("New Angular Velocity: %s"), *NewAngularVelocity.ToString());

    if (NewLinearVelocity.SizeSquared() > KINDA_SMALL_NUMBER || NewAngularVelocity.SizeSquared() > KINDA_SMALL_NUMBER)
    {
        GetWorld()->GetTimerManager().SetTimer(SmoothStopTimerHandle, this, &AVehicle::SmoothDecellerate, 0.1f, false);
    }
    else
    {
        ResetVehicle(); //Immediately stop vehicle movements etc
    }
}

Logs:

LogTemp: Warning: Current Linear Velocity: X=96.161 Y=-0.016 Z=0.705
LogTemp: Warning: Current Angular Velocity: X=-0.002 Y=0.016 Z=0.000
LogTemp: Warning: New Linear Velocity: X=86.545 Y=-0.015 Z=0.634
LogTemp: Warning: New Angular Velocity: X=0.000 Y=0.000 Z=0.000

is there any other reliable way to achieve this?

also the vehicle is decreasing velocities which is fine

but it drops from 500 to 100 smoothly and then keeps 100

[split siren]

If I understand your problem correctly, the solution might be to use
FMath::FInterpTo()
Or if you need something more smooth
FMath::InterpEaseInOut

Basically you need to keep track of the start value/time and use the current time to see where you currently are on the curve (from StartTime/Value to EndTime/Value)
For example, if your start time is at 1.0 with speed of 1000 and your end time is at 6.0 with speed 0.0, if you are at second 3.5 you can calculate exactly what the value should be.

At least that would be my take on it

[split siren]

But even so, your code shouldn't stop at 100 velocity... If it really does that, there might be something else changing the speed

[nocturne quail]

yeah this is what i am trying to find, it seems like when i start to decrease the current velocity, when it reach 100, something start to increasing it

so decrease, increase starts in cycle

[split siren]

What movement component does it have?

[nocturne quail]

ChaosVehicleMovement = CastChecked<UChaosWheeledVehicleMovementComponent>(GetVehicleMovement());

[split siren]

You should not externally change the physics without going through the movement component. Dumb question, but can't you just apply breaks when player exits the vehicle?

[nocturne quail]

it stops the vehicle immediately which is only the case if the character jumps when not holding the throttle input

like a vehicle current speed is 15000 and a character jumps, so the vehicle should move forward and smoothly stops

what i achieve is the velocity drops to 100 and then it locked on it 😄

from 15000 to 100 smoothly

i can put hard value like if this is 100 put brake

but NewLinearVelocity.SizeSquared() > KINDA_SMALL_NUMBER should do the trick to stop the timer, but it don''t

[split siren]

I find it weird that the vehicle stops instantly when player exits the vehicle. The momentum should be kept, is it possible by any chance that the vehicle collides with the character mesh on the same tick as exiting the vehicle, thus stopping the car instantly?

[nocturne quail]

currently compiling with Finterp, lets see what we will get 😄

[nocturne quail]

no, my character don't block vehicle

it is ignored temporary

just for this case to be sure it was not colliding

[split siren]

I am gonna try it on the car example...

So your car is the a pawn you possess and then you posses your human character when exiting right?

[nocturne quail]

i am also doing it on car template

[nocturne quail]

yes

i am using

UCLASS(abstract)
class ATP_VehicleAdvPawn : public AWheeledVehiclePawn

default C++ vehicle template

[mellow stag]

Hello! I was wondering if anyone is familiar with CheatEngine and the speed cheat whcih changes the tick rate I was wondering how to setup a block for that?

[split siren]

You can take a look at CMC, there is some time discrepancy allowed but client needs to pay it back at some point.

[mellow stag]

Where would I change the time discrepency?

[split siren]

Hey, so I tested it and the template works normally. Once you possess something else, the car is put into neutral and continues normally

[split siren]

https://youtu.be/6SQtAfyu8ts

[nocturne quail]

continues and never stops, right?

[mellow stag]

Right now on my dedicated server you can pull up cheat engine and enable SpeedHack and the client has full control over the speed

[split siren]

It's put into neutral, it will stop eventually but it takes a while. But it doesnt' stop instantly as you described

[split siren]

Over the speed of what?

[mellow stag]

Movement. everything else is server side so they cant control that

[split siren]

Even movement is server side

[dark parcel]

Like what exactly? Changing things like Max walk speed won't do anything

Client will just get corrected by the server

[nocturne quail]

You called the reset vehicle function when unpossess?

[split siren]

It has client side prediction but speed hack shouldnt effect the server location too much

[mellow stag]

https://www.youtube.com/watch?v=KPXLA5re6xc i was trying to correct this by making my own check for player location etc. here's what it looks like

Ignore how the character disappears thats just my check

[nocturne quail]

void ATP_VehicleAdvPawn::ResetVehicle(const FInputActionValue& Value)
{
    // reset to a location slightly above our current one
    FVector ResetLocation = GetActorLocation() + FVector(0.0f, 0.0f, 50.0f);

    // reset to our yaw. Ignore pitch and roll
    FRotator ResetRotation = GetActorRotation();
    ResetRotation.Pitch = 0.0f;
    ResetRotation.Roll = 0.0f;
    
    // teleport the actor to the reset spot and reset physics
    SetActorTransform(FTransform(ResetRotation, ResetLocation, FVector::OneVector), false, nullptr, ETeleportType::TeleportPhysics);

    GetMesh()->SetPhysicsAngularVelocityInDegrees(FVector::ZeroVector);
    GetMesh()->SetPhysicsLinearVelocity(FVector::ZeroVector);

    UE_LOG(LogTemplateVehicle, Error, TEXT("Reset Vehicle"));
}

this is what they used when we exit vehicle by default which stops the vehicle instantly

[mellow stag]

The speedhack has full control, I might have disabled some sort of check

[split siren]

Why do you want to reset the vehicle upon exiting?

[split siren]

Are you running client-server? Or is it a standalone

[mellow stag]

On my packaged game in the dedicated server on steam, you can do the exact same thing.

I am running Client Server in PIE

[nocturne quail]

many reasons because this is important.

void AVehicle::ResetVehicleState()
{
    // Reset the vehicle to a new position and state
    if (AAIControllerBase* TempAIController = GetWorld()->SpawnActor<AAIControllerBase>())
    {
        // Reset location slightly above current position
        FVector ResetLocation = GetActorLocation() + FVector(0.0f, 0.0f, 50.0f);

        // Reset to yaw, ignoring pitch and roll
        FRotator ResetRotation = GetActorRotation();
        ResetRotation.Pitch = 0.0f;
        ResetRotation.Roll = 0.0f;

        // Teleport the actor to the reset spot and reset physics
        SetActorTransform(FTransform(ResetRotation, ResetLocation, FVector::OneVector), false, nullptr, ETeleportType::TeleportPhysics);

        // Directly stop the vehicle if it was not moving
        GetMesh()->SetPhysicsAngularVelocityInDegrees(FVector::ZeroVector);
        GetMesh()->SetPhysicsLinearVelocity(FVector::ZeroVector);

        // If there is no valid driver, possess an AI controller and reset throttle input
        if (!IsValid(Driver))
        {
            TempAIController->Possess(this);
            GetVehicleMovementComponent()->SetThrottleInput(0.0f);
            TempAIController->UnPossess();
        }

        // Cleanup AI controller and reset interaction
        TempAIController->Destroy();
        VehicleInteractionComponent->SetActive(true);
    }
}

if not reset, it will never stop untill it hits something

[mellow stag]

Velocity is staying the same with hacks on/off so cheatengine is just altering the tick which allows the player to move faster

[split siren]

https://github.com/EpicGames/UnrealEngine/blob/585df42eb3a391efd295abd231333df20cddbcf3/Engine/Source/Runtime/Engine/Classes/GameFramework/GameNetworkManager.h#L198-L200
This value is responsible for the discrepancy resolution

[mellow stag]

Found my issue I had both of these disabled

I mean enabled

Now is there a value I can change for how frequent this check or how much the discrepency is?

[split siren]

Yeah, there is a tone of options
https://github.com/EpicGames/UnrealEngine/blob/585df42eb3a391efd295abd231333df20cddbcf3/Engine/Source/Runtime/Engine/Classes/GameFramework/GameNetworkManager.h#L202-L245

MovementTimeDiscrepancyDriftAllowance

[mellow stag]

Are these thru C+ or BP?

[split siren]

/** 
     * Accepted drift in clocks between client and server as a percent per second allowed. 
     *
     * 0.0 is "no forgiveness" and all logic would run on raw values, no tampering on the server side.
     * 0.02 would be a 2% per second difference "forgiven" - if the time discrepancy in a given second was less than 2%,
     * the error handling/detection code effectively ignores it.
     * 
     * Increasing this value above 0% lessens the chance of false positives on time discrepancy (burst packet loss, performance
     * hitches), but also means anyone tampering with their client time below that percent will not be detected and no resolution
     * action will be taken, and anyone above that threshold will still gain the advantage of this % of time boost (if running at 
     * 10% speed-up and this value is 0.05 or 5% allowance, they would only be resolved down to a 5% speed boost).
     *
     * Time discrepancy detection code DOES keep track of LifetimeRawTimeDiscrepancy, which is unaffected by this drift allowance,
     * so cheating below DriftAllowance percent could be tracked and acted on outside of an individual game. For example, if DriftAllowance
     * was 0.05 (meaning we're not going to actively prevent any cheating below 5% boosts to ensure less false positives for normal players),
     * we could still post-process analytics of the game showing that Player X regularly runs at 4% speed boost and take action.
     */
    UPROPERTY(GlobalConfig)
    float MovementTimeDiscrepancyDriftAllowance;

They are globalconfig

[mellow stag]

Perfect thank you ❤️

[mellow stag]

Sorry to bug again, but can't seem to find global config

[split siren]

https://github.com/EpicGames/UnrealEngine/blob/ue5-main/Engine/Config/BaseGame.ini#L42-L45

[mellow stag]

Ty!

[steep orbit]

Hey everyone, I assume that the "Play as Client" option launches a dedicated server in the background if the correct settings are configured, but I was wondering if there's a second dedicated server launched behind the scenes when we switch levels. I don't think there is, but I just wanted to ask. When my player travels to another map, it seems like the PreLoginAsync() event doesn't get triggered at all, unlike PostLogin(), which is triggered during map transitions. PreLoginAsync() only seems to fire the first time I play the game. This might be due to the limitations of the editor and would likely be more relevant in tests on actual built servers, but it would be a nightmare to dev like this since the players should (normally) be authenticated with an id and token to access the maps lol

I just can't get why the PostLogin() event will be fired with map travels but not the PreLoginAsync()

[twin juniper]

Kindly check out my recent work

[dark edge]

What's this got to do with #multiplayer ?

[twin juniper]

I make those character in unreal engine 5

[nocturne quail]

u are on the wrong place , check #work-in-progress to post your work

[twin juniper]

Okay

[twin juniper]

IF YOU'RE INTERESTED KINDLY INBOX ME AM AVAILABLE

[dark parcel]

did it added you?

[nocturne quail]

not yet 😄

[mellow stag]

Do you by chance know the best settings, i've been fine tuning them for the past couple hours can't seem to get them right

[nocturne quail]

@split siren
finally it works: 😄

void AVehicle::SmoothDecellerate()
{
    FVector CurrentLinearVelocity = GetMesh()->GetPhysicsLinearVelocity();
    const float StopThreshold = 10.0f;
    const float MaxDeceleration = 1000.0f;
    const float StoppingCoefficient = 0.1f;

    FVector NewLinearVelocity = FVector::ZeroVector;

    if (CurrentLinearVelocity.Size() > StopThreshold)
    {
        FVector Direction = CurrentLinearVelocity.GetSafeNormal();
        float DecelerationAmount = MaxDeceleration * GetWorld()->GetDeltaSeconds();
        NewLinearVelocity = CurrentLinearVelocity - (Direction * DecelerationAmount);

        if (NewLinearVelocity.Size() < StopThreshold)
        {
            NewLinearVelocity = FVector::ZeroVector;
        }
    }

    GetMesh()->SetPhysicsLinearVelocity(NewLinearVelocity);

    if (NewLinearVelocity.SizeSquared() > FMath::Square(StopThreshold))
    {
        GetWorld()->GetTimerManager().SetTimer(SmoothDecellerateTimer, this, &AVehicle::SmoothDecellerate, 0.1f, false);
    }
    else
    {
        ResetVehicleState();
    }
}

[silent grotto]

Hey, not sure if people still awake (it is 2 am over here) but I was being confused - i have one PC creating a session with a print, that should print the PlayerController's display name and "has joined" but for some reason when my other computer joins the session (and it seems be successful) there is no message that says a playercontroller has joined and I do not see 2 pawns in the map hirarchy either but just one.
But it said it joined which means it has found sessions and joined session at index 0
Why is OnPostLogin not being triggered then=?

this seems to fire up when a session is created but not when others join

[quiet yarrow]

how does world partitioning work in multiplayer?

does the server/host have all cells loaded?

[dark edge]

It probably at least has all cells that all clients have loaded or something to that effect

[grand kestrel]

I can just do a role check on CMC TickComponent and make the client do DeltaTime *= 2.f and bam speed hacked lol. CMC does have speed hack detection but it's disabled by default. You can enable it in the config ini

[bright summit]

Sorry to bother you, just wanna be sure, you was talking about sending pointer to audiocomponent/Niagara right? Or staticmesh?

[bright summit]

ok I see that it complains only about audio and niagara which is spawned attatched to the static'mesh

[bright summit]

made another component for attatching these things and it is fixed now. I thought that StaticMeshActor has another rootcomponent than the staticmeshcomp itself

[sly dirge]

Hello, Im trying to replicate the grabbing functionality from VRGK which acts on a physics constraint attached to the hand and the object a player tries to grab. My current setup is as follows: Player has a hand actor with physics constraints, when player grabs an object it attaches that object to the physics constraint on the hand actor.

The method I went with (and correct me if I need to change it) is I spawn the hand actors only locally on owning client, when client grabs an object, I am calling a Server RPC that sets the owner of the object to the player pawn and then calls an interface function on that object. In that interface function I am setting the replicate movement to false if grabbed and true if released, a replicated variable Grabbed to start the event tick, and I set the owning pawn and replicated transform variable.In event tick I check if locally controlled I am setting the replicated variables of the velocities and transform and sending them to the server with a server RPC, If not owning client I simply just set the objects velocities and transforms to the replicated values.
This method works great untill I introcude some lag, on pktLag=250 its smooth until the player throws the object and the replicate movement is enabled again. Im assuming this is happening because the server state is behind the client state when it switches back to replicate movement enabled.(video showcasees it)

I am trying to avoid having to have physics constraints on the server and have the server handle all physics since its a physics heavy game, any suggestions on how to fix this ? I am open to changing how I handle the Hand actors if its necessary to replicate.

Sorry for the long detailed message, first time working on multiplayer so dont want to miss any important info.

[upbeat basin]

Joining to a session doesn't automatically connects you to the server, although I feel like I read someone said it should somewhere around here, it might be an option I am missing as well.

So what I do, and what I can recommmend for the time being, is after joining session you can use IOnlineSessionPtr::GetResolvedConnectString() to get the connection string and travel to the server giving connection string as the URL argument

For additional information, OnPostLogin is called whenever a player tries to connect to a server and gets approved, nothing to do with sessions. After you create the session I believe you travel to the desired level, that's why you get the PostLogin. You get associated with a new world with a new controller, so the server is being notified about that, not because you create a session

[split siren]

Before starting yet another project, I wanted to ask for a sanity check.
From my profiling the main reason limiting allowing more players to join the game is the time to iterate over and tick all UDataStreamChannels.
Since I am using iris, all game data should be already collected at that point.
How difficult would it be to make the DataStreamChannels to tick in parallel?

[nova wasp]

You would need to make replication reading thread safe which seems difficult given it triggers onreps and creates objects (only reading but this screenshot is writing...)

But perhaps some earlier pieces are less prone to mutation

Ah you left out this is writing

This I'm not so sure about

[split siren]

I was thinking about the reading thread as well.. It mainly runs the CMC, which I can make run in parallel under several conditions. But the out seems to be several times more expensive

[nova wasp]

It reads literally all rpcs and onreps from clients (well, onreps only on clients)

You could maybe filter out incoming data by type but it will require engine changes

And is not trivial to split without sending extra metadata in the packet

[split siren]

Doesn't the scope also include the CMC replay?

[nova wasp]

I do think this is kind of possible but it will be mutex spam in the reader at the very least

[nova wasp]

What?

CMC replay?

[tardy fossil]

pretty sure CMC sends all its data over RPCs

[split siren]

ServerMovePacked runs the CMC inputs from the client on the server no?

[nova wasp]

That's saved moves

I have never heard them referred to as a replay... That is a very general term to use in this context lol

[split siren]

Yeah, my bad.

[nova wasp]

Rollback would be a more direct term to me at least... I could be wrong

Replay does make sense as that's effectively what it does

[split siren]

I just saw the term in the cmc quite a lot

[bright summit]

If I noticed correctly when I am replicating static mesh every other aprameters like physmaterials are not being syncronized (what is is reasonable), but I need this info. Tried to get on the server PhysicalMaterial but it seems to be too early at BeginPlay because it returns me default one, but OnHit it seems applied correclty (phys mat is assigned on material which static mesh is using)

It seems beginplay is the latest initialization point of actor where I can bring this information. Any ideas how to get it? Or am I missing something again? 😄

[nova wasp]

Said alone i was thinking you meant actual replays which Iris does not support

So I was confused

I'm more familiar with the sim proxy side of the CMC

You may as well just breakpoint the read

Curious how much of the CMC can be threaded

Threading sweeps is trivial but the scene component moves is less so

This is a great example of why making an MMO in unreal is a bit difficult lol

Work done per connection is fine at low counts

[chrome bay]

Usually pointless because most dedicated servers are single threaded

However, Epic are supposedly thinking long-term about supporting some amount of parrellism for this in case you do want a MT server.

[split siren]

That is the motiovation, I am happy to have fewer server instances hosting more players.

[pale hazel]

Can I replicate a Struct that contains a TObjectPtr<UObject>?
So my structure is:

AActor:
  -TObjectPtr<UObject>:
    -TArray<FArrayEntry>

FArrayEntry looks like this:
FArrayEntry:
  - TObjectPtr<UObject>   <- THIS DOESNT REPLICATE

I know how to make UObjects replicatable, and the array of structs is correctly replicated, except for the UObjectPtr's, those are not replicated.
Trying to mark the TObjectPtr in FArrayEntry doesnt work, UnrealHeaderTool tells me "Struct Members cannot be replicated"
So does this just not work? Do I have to make a UObject class out of my FArrayEntry struct?

[chrome bay]

struct members already are replicated by default

the only meta that works on them is NotReplicated

You're only replicating a reference to that object remember, not the actual object itself.

[stable aspen]

Hey all, what can cause this? Im running my game via "run as listen server" with two players, the server works fine, but the client doesnt take input and doesnt seem to replicate where the server is at
(Being in T-pose is expected as i broke animations)

Server to the right and client to the left

Seems to be with my game state as changing it in the gamemode fixes this issue...

What did i forget to do in it? Its quite litteraly nothing

UCLASS()
class SHINOBIPROJECT_API AGameGameState : public AGameStateBase
{
    GENERATED_BODY()
};

[pale hazel]

Right, that makes sense. But how would I go about replicating an uobject then?

Do I have to create the object on the client manually somehow?

[chrome bay]

https://dev.epicgames.com/community/learning/knowledge-base/7y39/unreal-engine-using-the-replicated-subobjects-list

[pale hazel]

Right, this is for subobjects of actors, but what about subobjects of uobjects?
or do I have to register the referenced UObject in my uobject, as a subobject of the overarching actor?

I think I have a bit of reading and experimenting to do, thanks

[pale hazel]

But still if anyone knows how to properly replicate this structure, please let me know

[chrome bay]

Any replicated UObject has to be outered by an actor at some point

If you want to replicate an object you spawned/created at runtime, it has to be replicated via an actor

[pale hazel]

That would be via calling AddReplicatedSubObject right?
I do this with my UObject (the one that contains the Array of Structs, which then contain another UObject Ref)

So if I have a setup like this:

class AMyActor
{
    TObjectPtr<UHighlevelObject> HighlevelObj;
}

class UHighlevelObject
{
    TArray<FArrayEntry> MyArray;
}

struct FArrayEntry
{
    TObjectPtr<ULowlevelObject> LowlevelObj;
}

class ULowlevelObject
{
    int MyFunInt;
}

I need to call AddReplicatedSubObject() when I instantiate my HighlevelObj, to make it replicated

And to replicate the LowlevelObj values, which are kept in the MyArray inside the HighlevelObj, I also need to call AddReplicatedSubObject() for each of the LowlevelObject instances

Am I understanding this right?

[chrome bay]

yeah pretty much

[pale hazel]

Alright, I'll give this a shot and see if i can make it work, thanks a lot for the help, appreciate it

But that's for monday, the weekend calls, thanks again

[grizzled stirrup]

In C++ will an OnRep function be called automatically on client (but not the server) when a property replicates down?

[winter pollen]

How do you guys usally test replication in editor? Both on listen server and client options? I usally test with like 2 clients idk if thats enough to be sure

[little pumice]

to test what exactly?

[winter pollen]

that is correctly replicated

just talking in general

[little pumice]

listen server(first player) can be fine if your goal is to inspect only the second player (client).

though codebase may contain strict checks like IsDedicatedServer

keep that in mind

[quiet yarrow]

is there no proper way to set owner real time on physic objects? Seems if this is done sometimes weird location mismatch happens for a brief moment

[undone magnet]

Hey all! I'm following an online tutorial for an inventory system, and I've added the ability for player characters to hold items in their hand using ChildActorComponents. However, I'm using both a first person mesh (for the owning client) and third person mesh (for all other clients). Therefore, I've had to change things to create two hand ChildActorComponents - one for each mesh - and set them up so there are two of the held item when an item is equipped. However, I now run into the problem of two items being visible to every client when an item is being held. I would like to make it so the first person mesh's ChildActorComponent is only visible to the client that owns the player character and the third person mesh's ChildActorComponent is visible only to all other clients. What would be the best way to go about this?

[exotic wasp]

is there an option to set visible only for owner?

should be a property, might be specific to the mesh on the item

[tender olive]

wait, I got lost on client to server calls.
So if I have an actor (blue print actor) that was spawn from the client, so it doesn't exists on the server, so far that is fine.
But on this client actor, I want to call the server to run a server action.

but as far as I understand, since this actor only exists on the client, having a custom event set to run on server (reliable), doesn't do anything, it runs, but from the client.

From reading I was supposed to call the server from the player controller, but in this random actor, one can't get the a valid player reference.
what am I missing?

I don't want to call an action on the actor itself, I want to reach to the game mode, and ask it to spawn some more actors

[nova wasp]

if the client spawns it why is it difficult to just send an rpc from the client that spawns it? no context for the actual thing you want to do here doens't help

I'm not sure if bp supports replicated sub objects but that might help reduce the amount of rpc boilerplate if that is the issue

[tender olive]

? no context? what else would I say, i have an actor that lives on the client, and I want to call a function on the game mode in the server, but I can't find a way to reach it, that is all

[nova wasp]

what creates the actor on the client?

[tender olive]

pcg spawn the actor

[nova wasp]

so the client is sending an rpc indicating pcg has finished doing something? I guess I can see how that would be useful

I would say the simple thing is to have the player controller listen for some event this creates locally or just get the local player controller on the client if this is not a splitscreen game

that way the player controller pointer is present to send an rpc from to the server

[tender olive]

" local player controller on the client"

that is exactly what I have in the blueprint screenshot, it doesn't work

and that is where I'm stuck

[nova wasp]

the RPC must be created in the event graph of the player controller as it has the required setup to communicate with the server via rpc

that's why you want the player controller or their pawn

[tender olive]

all google answer point to get a player controller reference and call the server from there,

great, get player controller doesn't work from the actor

[nova wasp]

it's not just about having the pointer. the EVENT ITSELF as an RPC must be in the player controller or a sub object of it

[nova wasp]

If you mean this part... which player is this for? you don't connect anything to this pin

[tender olive]

wasn't that supposed to be the local player reference id, so you don't have to "guess" the indext for the "get player controller"?

[nova wasp]

so you are passing in a player controller to get their platform id... to get a player controller by local index?

int32 UGameplayStatics::GetPlayerControllerID(APlayerController* PlayerController)
{
    FPlatformUserId UserID = PlayerController ? PlayerController->GetPlatformUserId() : PLATFORMUSERID_NONE;
    return FGenericPlatformMisc::GetUserIndexForPlatformUser(UserID);
}

this looks like it will always return -1

https://wizardcell.com/unreal/multiplayer-tips-and-tricks/#2-beware-of-getplayerxxx0-static-functions

BP really kind of leaves you hanging with this kind of thing lol

[tender olive]

yah, but how do I figure out the index? it requires the player controller, so that is a loop

[nova wasp]

My dumb idea to get this in BP easily would be to get the HUD and call GetOwningPlayerController

that is something that should always be the local player controller (which is the ONLY player controller on clients)

listen servers and dedicates an authority (or split screen standalone) could have multiple local player controllers

[tender olive]

get hud requires the player controller 😢

can I just use "Get player Controller" at index 0 on all clients? if I get this correctly, each index is the player logged in sequence, so one need to know which index it has

[nova wasp]

UGameInstance::GetFirstLocalPlayerController not being exposed to BP is so evil lol

Multiplayer in BP seems like tilting at windmills

a local player subsystem perhaps could get the local player?

[nova wasp]

for non listen servers or dedicates this is fine

but of course you need to know what that is (when to not do this and instead iterate over the player controllers to find the first local one)

One insane spaghetti way you could do this would be to to make an single manager actor

that the BP player tells about itself when it logs in / begins play etc

and then have other actors just GetActorOfClass -> mycontroller

GetActorOfClass should use an acceleration structure by class so it won't iterate over every actor in existance but I'm not sure about bp classes

[tender olive]

wait, so if I have one dummy actor placed on the level, the server will own it right?
can I from the client actor call a function on this dummy actor then?

[nova wasp]

doesn't matter who owns it

that's besides the point

the server owning it would mean the client can't rpc it to server anyways

the client must own the object to invoke a server rpc

and the server must have sent it to them to be aware of it

the idea here is to make it easy for any actor in the world to figure out who the local client player controller is

to call a server rpc (client -> server)

I'm too used to the C++ side of multiplayer so this might be off, there might be a less complicated way

https://dev.epicgames.com/documentation/en-us/unreal-engine/remote-procedure-calls-in-unreal-engine#serverrpc

[tender olive]

so, this works
but what am I losing having that fixed 0 index?

[nova wasp]

Like I said... if the machine has multiple local players it might get the wrong one (listen servers, dedicated)

the server will have every player controller

clients (net mode client) will have only one local player controller assuming no splitscreen

read the article I linked I guess

<https://wizardcell.com/unreal/multiplayer-tips-and-tricks/#2-beware-of-getplayerxxx0-static-functions

[tender olive]

• These functions will do you more harm than good, unless you know what you’re doing (which, in most cases, sadly ends up not being the case)
  ouch 🫠

[nova wasp]

I will say honestly it's kind of unreal's fault for blueprint MP being so barebones

honestly so many things only available in the C++ api that have no real good reason for not being exposed

[tender olive]

I guess I'll make c++ class to expose that client id you mention "UGameInstance::GetFirstLocalPlayerController"

one would assume the client knows its own index id, at least I was thinking that would be the case

[sinful tree]

In online multiplayer games you shouldn't be using the ID at all. It's meant for use in local multiplayer games (like couch co-ops and the like).

This also doesn't seem like it's the right way to go about handling what you want to be doing here... If you're wanting to have a client tell the server the seed number, then this actor shouldn't be doing so in the first place. You'd probably want some kind of replicated component on the player controller that can facilitate the communication between the server and the locally spawned actor.

[nova wasp]

yeah the ID is not the issue here

the issue is just... getting the local player lol

[dark parcel]

You are already in the character blueprint

[nova wasp]

which on the listen server could change as the array changes
and on the client is always going to be the first element

[dark parcel]

Just use get controller

[nova wasp]

no they are not, they are in some actor spawned by PCG

[dark parcel]

Ohh opps

I see

[nova wasp]

which ideally has some handle to being spawned

I don't know how PCG in-world things work in terms of bp or runtime

[hybrid meteor]

i want help with my game ,i am having a problem. Its only a two player game which i run as a listen server, I want that the character who wins the game will spawn a widget component above his head (just like a health bar) but i want to spawn widget having his name on top of his head . But the problem i am having that when the client wins and i spawn the widget over his head the server is not able to see the widget but the client can, but when the server wins and then i spawn the widget over his name both the client and server can see the widget . I just cant figure out why on spawning the widget over the client the server is not able to see . Also what i am doing is when i game ends i check in the game mode which character wins i call its player controller and from that player controller i call the events which spawns the widget over the character that is in the characters blueprint

[fiery bolt]

Hi everyone.
Is there anyway to know when actors dormancy state changes or becomes relevant ?

[jade igloo]

How come my output for EventOnPostLogin in the GameMode is PC_0 and PC_1, but in the Event Beginplay in the actual player controller I only get Client 0 (and not Client 1). I'm using Play as Client with 2 players and I got my PC Replicates and Net Load on Client checked. The gamemode also has the correct Player Controller Class. If I need to provide any more details let me know.

[dark parcel]

Who's calling on the begin play? Client only know their own controller

Where server have copy of everyone controller

Look up exi compendium pinned in this channel

[hybrid meteor]

can someone please help me with this

[dark parcel]

Show me your widget component on the character

[hybrid meteor]

the cube is the character

[dark parcel]

On the detail panel type replicate and look for component replicates

[hybrid meteor]

i did that

[dark parcel]

Make sure it's ticked. Do that and show

[hybrid meteor]

its alreeady ticked

[dark parcel]

Post that here

I don't want to miss any step

[dark parcel]

Is the vissibility set to false here?

[hybrid meteor]

also when i am drawing the widget on screen then the problem arises when i am drawing it on world then the problem is gone

[hybrid meteor]

no

[dark parcel]

Well that's not network related..

[hybrid meteor]

but it somehow solves the problem

idk why

what do you think

[dark parcel]

I think it's the offset perhaps

Personally I have no issue with either one

If you can't see the widget with screen space work your way from there.

[hybrid meteor]

is there anyway that i draw it in world and still it always parrellel to screen

[dark parcel]

You have to rotate the plane to face your camera

I personally just use screen space and resize based on distance

Because I can't get text to render nicely with world space

[hybrid meteor]

how can i rotate it so that is always shows on screen'

[dark parcel]

use the Find look at rotation

but why not just use screen space

My name tag is only a border and a text

[hybrid meteor]

because of the above problem

[dark parcel]

try it at the simplest form

[hybrid meteor]

mine also is just a text but the server is not seeing the clients widget

idk why thats happening

[dark parcel]

construct a widget per character and have that display first on every machine

if you can't do that then I can't help you, there's seems to be more problems that you have yet solve

[hybrid meteor]

ok i somehow made it worked

[bright summit]

After reading your advice on this discord, watching many tutorials, reading many blogs I noticed I'm still doing things wrong. I want to have heavy customizable level interactions in my game. I was doing it in I think bad way(Screen 1) because I was using NetMulticast on almost everything on server-owned actor which was placed in-scene.

Yesterday I watched NotGDC talk where guy talked about that in some games he shipped** he didn't use any of netmulticast/client rpc**. I am still wondering how to properly do the **"interaction chain" **showed on screens.

I am attaching them to illustrate you want I wanna achieve, on first screen I showed my current way of doing things but I want to do it properly, so after watching/reading these things I prepared new way how can I approach this. But I want you to advise me if it will be proper way or should I change something (in the networking, not the way of opening doors if it should be an animation or playing sounds etc.)

[dark parcel]

why are you multicasting playing audio?

you don't need to tell others to play a sound, the sound plays when the sound plays.
For a door it play sound when the door is being opened or closed

and I wouldn't use a single multicast for a stateful entities, a door is stateful

CLient -> Hey I want to Open this door (Server RPC)
Server -> Checks if interacting client have a key -> Yes? bOpenDoor = true

OnRep bOpenDoor -> Play timeline / anim -> Play sound

[bright summit]

I wrote that I realized this is the wrong way of doing things

[dark parcel]

95% of the time you don't want to use multicast. 100% for stateful behavior

mc is good for fire and forget actions

[bright summit]

like playing sounds

[dark parcel]

not really

Why should sound be networked?

[bright summit]

it shouldn't

[dark parcel]

I seen people trying to replicate foot step sounds

like why

just play it locally when the foot hit the floor

0 networking

you can network the nike if you like

so sound can be played depending on the shoes type

[bright summit]

so idea to route these things like on second screen tagged "new way" is correct?

[dark parcel]

I haven't work on a door yet but your the designer so it can be elaborate as you want.

though I would probably just start simple for my own game and see if it work just fine

bOnRep -> Open door
bOnRep-> Close door

i probably wouldn't track if the door is fully close or not

is there a purpose on doing that?

well I guess for late joiners...

[bright summit]

yes, because I can extend this simple "doors" for moving platforms/elevators

[dark parcel]

if it really matter

If you need to sync multiple fields (e.g bDoorOpen and bDoorFullyOpen), I would probably pack them to a struct

OnRep->bDoorFullyOpen -> Don't play the time line, open the door instantly

so late joiners don't have to see the door slowly being opened

[bright summit]

yes

but what about door stop moving sound when it is complete open, without this variable I do not have a really way to play this sound without onrep

[dark parcel]

for a moving platform, you probably need different approach

you probably need to track the platform location and replicate it

[bright summit]

this is how I have doors made

[dark parcel]

that won't matter for a door but your platform will require different solution

[bright summit]

but I don't asked about it, I asked about proper routing executions

[dark parcel]

CLient -> Hey I want to Open this door (Server RPC)
Server -> Checks if interacting client have a key -> Yes? bOpenDoor = true

OnRep bOpenDoor -> Play timeline / anim -> Play sound

is probably how I would do it

[bright summit]

how about later events

[dark parcel]

like?

[bright summit]

like I showed them on screen

[dark parcel]

I can't read / understand other people code

too brain dead

You can try writing down psudo code first before diagram

just talk about what happends game play wise

E.g Interacting with a door
As client -> Ask server I want to open this door
Server checks if client have required item -> If yes, Door -> bOpen = true (replicate)

Client bOpen OnRep-> Open door

[bright summit]

I literally showed the example with button->door->light etc

you even didn't look at the images I sent

but thank you anyway

[dark parcel]

I did but can't form a comment, again because I don't understand other people code.

like what is Change location while opening

it's a bit abstract to me

not saying it's wrong, Im just saying I don't understand

[nocturne quail]

Why is OnRep_SeatOne(); not called on clients correctly?
on Server: character attach to vehicle correctly to socket
on Client: character attach to vehicle correctly not on socket

UPROPERTY(Replicated) ACharacter* Driver;
DOREPLIFETIME(ACharacter, Driver);

UPROPERTY(ReplicatedUsing = OnRep_SeatOne) bool IsSeatOneAvailable;
DOREPLIFETIME_CONDITION_NOTIFY(ACharacter, IsSeatOneAvailable, COND_None, REPNOTIFY_Always);
UFUNCTION() void OnRep_SeatOne();

void AVehicle::BeginPlay()
{
    Super::BeginPlay();
    
    VehicleInteractionComponent->OnInteract.AddDynamic(this, &AVehicle::OnInteract);
    IsSeatOneAvailable = true;
}

void AVehicle::OnInteract(ACharacter* Character)
{
    if (HasAuthority())
    {
        if (IsSeatOneAvailable)
        {
            if (APlayerController* PC = Cast<APlayerController>(Character->GetController()))
            {
                PC->Possess(this);
                SetOwner(PC);
                Driver = Character;

                IsSeatOneAvailable = false;
                OnRep_SeatOne();
            }
        }
    }
}

void AVehicle::OnRep_SeatOne()
{
    if (!IsSeatOneAvailable)
    {
        HandleAttachment(Driver, FName("SocketSeatOne"));
    }
}

void AVehicle::HandleAttachment(class ACharacter* Target, const FName Socket)
{
    if (Target && GetMesh())
    {
        Target->GetMesh()->SetCollisionProfileName(TEXT("InVehicleCharacterPreset"));
        Target->AttachToComponent(GetMesh(), { EAttachmentRule::SnapToTarget, true }, Socket);
    }
}

[tender olive]

well, would help if you tell how to get the player controller from a random actor, this is not the player character...
interesting how no one reads the original post where I clearly state it

[dark parcel]

Whos controller are you trying to reach though?

calling it from a random actor or not is kinda irrelevant

[tender olive]

it is relevant, there is no way to get the current local player controller from a random actor spawn on the client, and that is the issue.
I'm using get player controller (index 0) which is the point of the argument, since this isn't the best way, can cause other issues

[dark parcel]

Didn't they link you the article?

Use the function from GameInstance

[tender olive]

exactly, which explicitly say it is not possible, on blueprints only*

[dark parcel]

Say what?

You can get the local controller from anywhere, use the function from game Instance like the artcle showed

Multiplayer blueprint is limited

a little bit of C++ goes long way

[tender olive]

ah, try first, once you get the player controller from an actor without using the index, then you tell me, if you were so kind

[dark parcel]

well I was commenting before you said blueprint only restriction

[tender olive]

yah, problem with c++, is not c++, when I add c++ to any project, a brand new project, it restart, fine, and never open again

[dark parcel]

AAGController* UAGLibrary::GetLocalAGController(const UObject* UWorld)
{
    auto World = GEngine->GetWorldFromContextObject(UWorld, EGetWorldErrorMode::LogAndReturnNull);
    if (auto GameInstance = World->GetGameInstance())
    {
        if (auto AGController = Cast<AAGController>(GameInstance->GetFirstLocalPlayerController()))
        {
            return AGController;
        }
    }
    return nullptr;
}

This is how I get my local controller

[dark parcel]

You have to build the project 🤷‍♂️

bp multiplayer is very limited if you are not biting the bullet you will be building a house with your bare hand

[tender olive]

if it would built... it doesn't, spend like 3 days re-doing the steps for c++

[dark parcel]

nothing that can't be solved

[bright summit]

I am rewriting my project 4th time xD

this is normal you are doing things like that

when you do something for the second time it will almost always turn out better

[tender olive]

well a clean new project shouldn't just break without doing anything, that is not normal you won't find a single thread about the game just not recompiling anymore after adding the c++ from the editor

[dark parcel]

Converting the project to C++ (Adding a C++ class)
Means you have to open your project from IDE

[tender olive]

editor just create an empty class, header and imp.

it doesn't compile

[dark parcel]

and build for development editor if you want to open the uproject instead running it from the IDE

[tender olive]

and it shouldn't need to go from the vs, unreal compiles by itself, but it can't, same reason the vs can't either, why? that is a good question

[dark parcel]

you are not doing the steps that's why

it's frankly skill issue

which you can fix

[tender olive]

jezz, of course people will say, "you are not doing the steps" ,after I redo the entire steps on unreal official page 20x

[dark parcel]

Yeah you are missing something

ask in #cpp they are happy to help

or are you implying it's engine issue?

[dark parcel]

Read build out put and fix. Ask questions

[tender olive]

engine has a lot of issue, but it is not engine issue.
But then, explain me this.
it was working, I have another project with c++ enabled, so I wanted to test something, create a new third person project, as normal, add c++ from the editor, it ask to restart, then never open again. How would I be missing a step in the first place if it was already working before.

[dark parcel]

it never opened because you didn't build for development editor

I will re-iterate this again

[tender olive]

nothing else that has c++ opens

[dark parcel]

After you add a new C++ class

you will need to open your project from your IDE. Set config to development build then Build the solution.

[tender olive]

skip that, its implied I try, that is the part that just doesn't work

[dark parcel]

you can't open your project after adding C++ class because you have not build the solution.

[tender olive]

even the other project doesn't open anymore
ah, nvm, you just don't get the part that the thing don't compile

[dark parcel]

lol

[tender olive]

and keep repeating, you need to compile, like if I just didn't try the first thing

[dark parcel]

maybe you can ask questions and post the issue

instead giving up and saying C++ just doesn't work in my computer

[tender olive]

I did all that for quite some time, don't assume it didn't compile and I left, as I said, spend some days only on this

just happens to be one of the limbos unreal have, that will probably require to clean the entire system to make it work, which I just won't do it for now

[dark parcel]

You are assuming you done things correctly

and can't get the same result where others could

So I don't know what else to say at this point

you can try again and then this time ask questions when you hit the wall

[tender olive]

You assume I just gave up in 5 seconds, but I did ask alot and as usual, this is the kind of ansewer, you need to compile

[dark parcel]

I didn't say that

but you are implying you have given up

so I don't know what else to say

[tender olive]

nvm, once I have a good free time, I just clean up the entire system, and it should work, even without the holly compile from the ide, since you don't need to.
adding the cpp restart, unreal recompiles for you

[dark parcel]

no you still have to build

you actually need to

[bright summit]

once you add the cpp, just open the solution and build the project

[dark parcel]

Not sure why you are fighting it with your own believe when you don't have it work on your end...

[bright summit]

then open it

[dark parcel]

just ask #cpp 🤷‍♂️

Build the god damn project

or you can't open it which is what happend in your end

open sln , ctrl B

[tender olive]

It doesn't build the god damm project, foking sake, why you keep repeating it

jezz

[dark parcel]

Read the build output

and figure out why

I am repeating it because that's the way to build the project

if it doesn't build then fix the error which is can be read in the build output

[tender olive]

yah, again, like I didn't try that

[dark parcel]

again probably skill issue

which can be fix

[bright summit]

show us compile log

[dark parcel]

I can only repeat until I see the build output log

Repeating "but I did everything" isn't gonna correct it either

I mean you are already making a false assumption in the last few minute.

just accept that you have not done what is required, figure out what and solve the issue

and if what you said is true "It didn't build" then no shit you can't open your project again. Read the error from the output log and address it.

[tender olive]

I'm not, go your self and do it.
Create new prject with BP, click add c++, restart, unreal will ask to recompile, and it recompiles for you without a need for the ide, if you just add a class and didn't do anything.

Try it on your end first.
you telling me this is a false positive, is a false positive

[dark parcel]

Build from your IDE

for the 20X times

[tender olive]

I TRIED, for 50x time

[dark parcel]

I don't see it

[bright summit]

SHOW COMPILE LOG THEN

[dark parcel]

all I see is the result of someone not building their project

Clicking yes is not rebuilding the project from IDE

you are not worth the stress. I give up

gave you the answer but you keep on fighting me instead

[dark parcel]

Of course I tried it on my end many times 🤦‍♂️

[tender olive]

gave me nothing besides, "click compile", I was not even ask for c++ you mention it, I'm here on multiplayer asking how to get the reference from the player controller from a random actor. The answer is you can't. Done there is no continuantion on this

[dark parcel]

you can

GameInstance->GetLocalPlayerController

done

[tender olive]

in a blueprint, if you insist

[dark parcel]

self imposed restriction

wcyd

you would have ended up with a built project

instead arguing here

if you just COMPILE AND BUILD FROM THE IDE

[tender olive]

again, gave me nothing, this answer I already had, and even said, I'll expose this function later to blueprint

so far you only repeat what other already said

[dark parcel]

Yeah

that blueprint multiplayer is limited

I can't change that fact

[dark parcel]

It seems like you are handling attachment both on the server and client?

I don't know attaching business in mp but what if you just let the server do the attachment

[torpid crest]

Can anyone point to docs how to implement Steam 'Join game' which would join to already running session?
Right now it's only starting the game

nevermind found it - https://dev.epicgames.com/community/learning/tutorials/0JMY/unreal-engine-how-to-join-friends-via-steam-overlays-using-advanced-sessions?utm_source=chatgpt.com

[nocturne quail]

same issue, but if i use multicast it works fine

i mean attaching just on server changed nothing

but if i delay attachment for .5sec, it woks fine

[dark parcel]

attaching on server attached it for the clients right?

i tested just now and it does

But I can't tell if things work "correctly" since I am attaching a character and the gravity kinda fight the attachment

[nocturne quail]

yes it attached but not on the socket defined

[dark parcel]

not sure if this is related, but did you tick component replicate to the component you are attaching?

[nocturne quail]

both are replicated ofcourse

LogTemp: OnRep  Client at: 2025.10.15-19.13.50
LogTemp: OnRep  Server at: 2025.10.15-19.13.50

[thin stratus]

@nocturne quail Keep in mind Attachment doesn't need to be replicated.

Attachment is already replicated.

If the Server attaches an Actor that is replicated (which your Character will be) to something, the AttachmentInfo is gonna be gathered and replicated, and the Client will then automatically attach.

[thin stratus]

GetPlayerController node is a thing.

The OnRep wouldn't be needed anyway.

[nocturne quail]

netmulticast works fine

[thin stratus]

Also not needed though

void AActor::OnRep_AttachmentReplication() is already handling attachment

if (AttachmentReplication.AttachParent)
    {
        if (RootComponent)
        {
            USceneComponent* AttachParentComponent = (AttachmentReplication.AttachComponent ? ToRawPtr(AttachmentReplication.AttachComponent) : AttachmentReplication.AttachParent->GetRootComponent());

            if (AttachParentComponent)
            {
                RootComponent->SetRelativeLocation_Direct(AttachmentReplication.LocationOffset);
                RootComponent->SetRelativeRotation_Direct(AttachmentReplication.RotationOffset);
                RootComponent->SetRelativeScale3D_Direct(AttachmentReplication.RelativeScale3D);

                // If we're already attached to the correct Parent and Socket, then the update must be position only.
                // AttachToComponent would early out in this case.
                // Note, we ignore the special case for simulated bodies in AttachToComponent as AttachmentReplication shouldn't get updated
                // if the body is simulated (see AActor::GatherMovement).
                const bool bAlreadyAttached = (AttachParentComponent == RootComponent->GetAttachParent() && AttachmentReplication.AttachSocket == RootComponent->GetAttachSocketName() && AttachParentComponent->GetAttachChildren().Contains(RootComponent));
                if (bAlreadyAttached)
                {
                    // Note, this doesn't match AttachToComponent, but we're assuming it's safe to skip physics (see comment above).
                    RootComponent->UpdateComponentToWorld(EUpdateTransformFlags::SkipPhysicsUpdate, ETeleportType::None);
                }
                else
                {
                    RootComponent->AttachToComponent(AttachParentComponent, FAttachmentTransformRules::KeepRelativeTransform, AttachmentReplication.AttachSocket);
                }
            }
        }
    }
    else

[nocturne quail]

this my new code

void AVehicle::OnRep_SeatOne()
{
    const FDateTime CurrentTime = FDateTime::Now();

    if (HasAuthority())
    {
        UE_LOG(LogTemp, Log, TEXT("OnRep_SeatOne called on Server at: %s"), *CurrentTime.ToString());
    }
    else
    {
        UE_LOG(LogTemp, Log, TEXT("OnRep_SeatOne called on Client at: %s"), *CurrentTime.ToString());
    }
    if (HasAuthority())
    {
        HandleAttachment(Driver, FName("SocketSeatOne"));
    }
}

[thin stratus]

What do you need the OnRep for

Just call HandleAttachment in the function that sets the boolean

And get rid of the OnRep setup

[nocturne quail]

trying now

[tender olive]

oh boy, it doesn't work on a random actor that is not the current character. Plenty of discussion about it already,
its only doable trough c++ where you can actually get it anywhere.

[thin stratus]

GetPlayerController returns the local PlayerController, with the Index in it providing you with the local splitscreen/couch coop PlayerControllers if you have any.

If you only have a client with a local player index 0 would be enough.

From inside a Character you wouldn't use that node, cause there you could use GetController.
But they would both return the same fwiw (if the Character is possessed by that and you are using it locally of course)

[tender olive]

that is the thing right, index 0 will work on certain situations only, other case it will return the wrong reference.
you can't from a random actor that lives on the client side, get a valid reference to the current local player controller without c++, that is the hole point of the discussion.

I'm using "get player controller index 0", and knowing the issues it might cause

[thin stratus]

Yeah, not true what you are stating there.

I've been working with this Engine for over 10 years.

You can either trust me on that or run around with false info

Up to you

[tender olive]

So please, show me from a random actor how you get the current local player controller so you can call a server function

[dark parcel]

@thin stratus this one quiet a fighter, just saying

[thin stratus]

GetPlayerController(0) will do that.

In fact, it does the same as GetWorld()->GetFirstLocalPlayerController()

Same code in the end.

[dark parcel]

Isn't it different if you are calling it as server

[thin stratus]

Both of these will grab the LocalPlayers array of the GameInstance and return the first entry.

[latent heart]

The server's local player will be index 0 as well... if it has a player.

[thin stratus]

So GetPlayerController(0) returns the first local PlayerController

[dark parcel]

the source code even says the iterator order not to be trusted

[thin stratus]

Well we are talking about Client wanting its local PlayerController.

So GetPlayerController(0) does indeed do that.

[latent heart]

You can access the ULocalPlayer (somewhere) and find its associated player controller if you want to make sure?

[thin stratus]

The Code doesn't even use the Iterator anymore..

[dark parcel]

yeah but I think he want it as listen server too

[thin stratus]

ListenServer will also return its own local one first

[tender olive]

so the hole point on this page is "wrong": https://wizardcell.com/unreal/multiplayer-tips-and-tricks/#2-beware-of-getplayerxxx0-static-functions
if that is the case then I can use it, that was my initial question and since people said this won't work, well here we are

[thin stratus]

APlayerController* UGameInstance::GetFirstLocalPlayerController(const UWorld* World) const
{
    // Use the consistent local players order if possible
    if (World == nullptr || World == GetWorld())
    {
        for (ULocalPlayer* Player : LocalPlayers)
        {
            // Returns the first non-null UPlayer::PlayerController without filtering by UWorld.
            if (Player && Player->PlayerController)
            {
                // return first non-null entry
                return Player->PlayerController;
            }
        }
    }

class APlayerController* UGameplayStatics::GetPlayerController(const UObject* WorldContextObject, int32 PlayerIndex) 
{
    UWorld* World = GEngine->GetWorldFromContextObject(WorldContextObject, EGetWorldErrorMode::LogAndReturnNull);

    if (!World)
    {
        return nullptr;
    }

    // Don't use the game instance if the passed in world isn't the primary active world
    UGameInstance* GameInstance = World->GetGameInstance();
    const bool bUseGameInstance = GameInstance && GameInstance->GetWorld() == World;

    int32 Index = 0;
    if (bUseGameInstance)
    {        
        const TArray<ULocalPlayer*>& LocalPlayers = GameInstance->GetLocalPlayers();
        for (ULocalPlayer* LocalPlayer : LocalPlayers)
        {
            // Only count local players with an actual PC as part of the indexing
            if (APlayerController* PC = LocalPlayer->PlayerController)
            {
                if (Index == PlayerIndex)
                {
                    return PC;
                }
                Index++;
            }
        }
    }

[latent heart]

This seems correct.

[tender olive]

so let me ask again,
can I just use "get player controller 0" from a random actor that lives in the client so I can reach the server side? From blueprint**

[thin stratus]

Yeah, why wouldn't you? GetPlayerController(0)->CastToYourController()->CallServerRPC.

That being "BP" code.

Can't draw a node here

[latent heart]

You could try! Ascii art 😄

[dark parcel]

Calling that as dedicated server will return the first client controller?

[tender olive]

Yah that is what I did, so now a different answer to the same question.
So in that case you are saing that this is fine, then I don't actually have a question ,it is working

[thin stratus]

@fathom aspen The page talking about GetPlayerController(0) and GetFirstLocalPlayerController is wrong, right?

Both methods use the GameInstance LocalPlayers Array and return the first entry.

If the Client's PlayerController can end up first in the Array of the ListenServer, then both methods would do the wrong thing.

[dark parcel]

Client loading world faster than server would also change the order number based on what I read

[thin stratus]

Yeah I mean, GetPlayerController(0) returns the first entry from the GameInstance's LocalPlayer Array.
Should you use that everywhere and at all times? Probably not. In a lot of cases you have a "relative" reference to it.

• Possessed Character has the "relative" Controller available.
• PlayerState has the "relative" Controller as the "Owner" (can be cast)
• Most UserWidgets have the Controller available via "GetOwningPlayer"

In a lot of cases, this won't really make a difference if you need the local one on the Client.
If you have a Splitscreen Game where you can just a Server with multiple local Clients, then it starts making sense to fall back to those instead of the GetPlayerController node (or similar).
And if you are on the Server you (especially DedicatedServer) you often need to talk to the "relative" Controller.
E.g. if a Character dies and you want to respawn it, you want the Controller of that Character.

[thin stratus]

Sure, but they use the same array. So GetFirstLocalPlayerController would have the same issue.

[nocturne quail]

still same behaviour
now i am calling handleattachment directly on server when interacted

if i play as server, it attach correctly to the seat

else it will stay at the location from where i interact with vehicle

but will be attached to vehicle

[dark parcel]

I think it does IsLocalController check?

[thin stratus]

It's a ULocalPlayer Array.

What would that check do

[nocturne quail]

all i can guess the socket is invalid on client

[dark parcel]

I think if Netmode is dedicated, it will return false. So at least it will return a null ptr instead of the first client player controller if called from dedi server

[tender olive]

so now, even with c++ impl version of it, it would still result in the same problem 🤯 ...
On this case in particular, I just want some of the client actors to signal to the server they want to spawn, already have a control in the server to prevent multiple clients spawning the same thing, so get player controller 0 on this situation works, I just need to reach to the server.

But if I got what you said, making this a c++ call to the first player controller, wouldn't change anything compare to get player controller at index 0 node

[thin stratus]

Correct. Both would do what you want just fine.

[tender olive]

right, so If I need to know which client actually calls that, would there be any other way?

[thin stratus]

No, there is also no reason, given the RPC call is inside the PlayerController of the Client that calls.

[tender olive]

lol hahha right, so a random actor on client is doomed 🫠 , well I don't need a owning client for now, but I was planning to having it know who spawn it, which I guess I'll have to work around it

well thanks, that clarify a lot

[thin stratus]

Random Actor is doomed?

Why would it be?

[tender olive]

In my context, it spawn trough pcg, pcg doesn't asign any owner, or at least I don't know how to set a owner to a pcg spawned actor.
after the actor is done doing its thing on the client, it calls the server to spaw it, or just get destroy locally and do nothing.

currently I'm using this get player controller 0, and it works just fine, what I was trying to confirm is, ok, it has spawned, now it needs to know who spawn it, which is not possible if I got this right. Since index 0 might not be the right index

so that is why I said, "its doomed", like it will never have a owner

[thin stratus]

Right, you seem to misunderstand something.

The Index you pass in is for the LocalPlayer Array. The Client that calls the RPC doesn't have more than one entry in that.

It can't get PlayerControllers of other Clients.

[nocturne quail]

doing this atleast works to attach to the correct spot but then character falls down like som egravity is messing around with it

[thin stratus]

If you do GetPlayerController(1) on a Client in a Game that has no Splitscreen stuff, you will get a Nullptr.

[nocturne quail]

even disabled gravity still issue presists

[thin stratus]

So there is only one PlayerController you can logically retrieve for the Client anyway

So if you RPC with that one, the PlayerController instance on the Server is the one linked to that Client.

[fathom aspen]

Totally agreed. That was totally based on past personal experience, so unless something changed afterwards I can't explain what was that behavior I experienced. I'll correct it, but I would strongly advise people against using these statics getters when possible since you can shoot yourself in the foot once that gets called on a dedicated server. @tender olive
Another reason why I would not use it, is say you sometimes want to do something with the controller from the pawn, if the connection between the two breaks for whatever reason, using that function wouldn't tell you that the connection has broke, and go figure that yourself... you would end up doing things on the controller thinking it's still relevant for that pawn etc. when in fact it's not

[thin stratus]

You know who called the RPC cause that's their PlayerController it calls in.

[tender olive]

Yah that is the part I get confused, so if it will have only itself, then there is no issue, so why would the function not work well like that article describe

[thin stratus]

DedicatedServer and LocalSplitscreen can be an issue, yeah.

But only cause the people who would use the Node don't know what they are doing.
It's not even the nodes fault at that point.

[thin stratus]

The article clearly points out that it can have different results than you might expect if you use it wrong.

[fathom aspen]

Literally... been here enough to realize why these functions are cursed... people been ranting over them for long enough

[thin stratus]

Using it on the Local Player to retrieve the LocalPlayerController is totally fine.

It would only become a problem if you use it with Splitscreen Players that are connected to a Server.

Cause then the Client has more than one PlayerController.

Like 2 people in front of the same Xbox joining an online Server

And in that case you could still use the Node fwiw, but you'd need to keep track of who has what index.

On the Client, not on the Server fwiw

[fathom aspen]

Indeed, so you end up killing local multiplayer without you realizing it... you may don't want splitscreen for your game and its totally fine, but it's good to make your game scale well, because who knows

[lament flax]

imo using the static getters could influence and trigger bad design choices

MP or not

[fathom aspen]

Same goes for dedicated server. Ever heard about games that are listen server, and then unable to support dedicated, this might be one of the reasons

On a listen server you can say GetPlayerController(0) and almost be sure it's your local PC
On dedicated that is totally false

[thin stratus]

@tender olive

There, works just fine.

Actor is just dragged into the scene. 2 Player ListenServer.

The big thing is that you learn what GetPlayerController(0) can return on Client, ListenServer and DedicatedServer.
That way you know when to use it and when not.

At least imo. That's better than being scared away from it.

[dark parcel]

// Only return a local PlayerController from the given World.
        for (FConstPlayerControllerIterator Iterator = World->GetPlayerControllerIterator(); Iterator; ++Iterator)
        {
            APlayerController* PC = Iterator->Get();
            if (PC && PC->IsLocalController())
            {
                return PC;
            }
        }

This should always return the local controller? Since it's checking if the NetMode

if dedicated it will just return null

[tender olive]

yah it works, I'm using it, just want to understand why not to use since the alternative c++ reference get first would endput in the same issue

[lament flax]

whats your system

[tender olive]

thanks for all the info, I'll start a split screen project to test this out, but for now it will work

[lament flax]

there is a ton of ways to directly get your controller by caching it somewhere

[thin stratus]

ListenServer LocalPlayer array, 10 Seconds after the Client connected.

It's not possible for the ListenServer to grab the Client's PlayerController.

It has no LocalPlayer of the Client in its Array.

GetPlayerController(0) on the ListenServer will only return the ListenServer's PlayerController, as if it was a Client.

So there is nothing to be scared about.

[tender olive]

in very simplified way, pcg will spawn some actor, those actor will then do some local validation and either destroy itsel or ask to be actually spawn in the server. This is already working, we are just discussing the situation of getting to the server trough "get player controller index 0"

[dark parcel]

will this stay true on ServerTravel?

[fathom aspen]

up until you want to support dedicated servers one day

[thin stratus]

DedicatedServer will also try to use that Array, but it's empty on a DedicatedServer, as hopefully expected.
It will then go on to grab it via something else. And that something else will be the PlayerArray (PlayerStates) in the GameState.

So here you get whatever connected first as a Client, which makes sense to me, as it's index 0

[dark parcel]

it might grab the first client controller instead of returning empty

[thin stratus]

It will 100% return the first Client PlayerController

[lament flax]

• server get seeds
• server runs PCG
• each actor is replicated and runs its checks
• if they stay/destroyed client would have the same

[thin stratus]

The first Client that connected. the function is coded that way after all.

[lament flax]

not 100% sure since i never played with networked PCG

[tender olive]

pcg runs on the client

[lament flax]

why ?

[thin stratus]

If you run GetPlayerController(Index) on a DedicatedServer, you will get the PlayerController based on the PlayerArray order.

Pretty straight forward imo

[dark parcel]

// Only return a local PlayerController from the given World.
        for (FConstPlayerControllerIterator Iterator = World->GetPlayerControllerIterator(); Iterator; ++Iterator)
        {
            APlayerController* PC = Iterator->Get();
            if (PC && PC->IsLocalController())
            {
                return PC;
            }
        }

this check for Netmode so it will return null if dedi

[tender olive]

ask unreal 🤣

[lament flax]

if the server runs the PCG and the spawned actors are replicated, no need to run anything on client

[lament flax]

i think you are just talking about the default behavior, it runs locally

[fathom aspen]

right but people that use the function don't realize that... my whole point about these functions is that they are context-less and it can lead to bad design, and potentially issues as well

[tender olive]

well if you know how to make it run on the server, I'm all ears

[thin stratus]

I'm just correcting some false statements.

while sometimes in a listen-server environment for example, the client connects fast enough (through seamless travel) that it ends up as index 0 on the listen-server, so you end up with an undesired PlayerController, while expecting the listen-server’s PlayerController.

[lament flax]

run the PCG by code i guess, on server at beginplay or something

[thin stratus]

Imo, that's not the case, cause the LocalPlayer Array will NOT contain the Client's LocalPlayer either way.

[fathom aspen]

right, that's what I'm going to remove

thanks for the correction btw

[thin stratus]

The function will fall back to use the GameState's PlayerArray ,and then the Iterator afterwards.

[fathom aspen]

Cedric always there for the save

[tender olive]

Yah thanks @thin stratus loads of nice info there

[thin stratus]

Now, fun fact.

UWorld::GetFirstLocalPlayerController() is shittier than GetPlayerController(0), as that function uses the Iterator :D

[fathom aspen]

lol

so it doesn't use the game state array

[thin stratus]

And then we have UGameInstance::GetFirstLocalPlayerController, which will use the LocalPlayer Array first, and then the Iterator.

So that is again, actually shittier than GetPlayerController(0)

Could be argued if the PlayerArray order has any more worth

[fathom aspen]

in what sense? I wonder how does the iterator behave in comparison the game state PlayerArray

in terms of order and shit

[thin stratus]

But in theory one is better off using the BP node's function in C++ even

[thin stratus]

Could be that it's the same order in the end.

The Iterator is not an GetAllActorsOfClass node iterator

[fathom aspen]

-10 points for including the GameplayStatics Library, doesn't get my vote

[thin stratus]

It's just an Iterator over a PlayerController List that sits in the UWorld

[thin stratus]

Yeah, sure, but the sad truth is that it would cover more cases.

In most cases you'd never use the Node or Function anyway, but in the cases that you need it, it's good to know.

[fathom aspen]

indeed, it will travel cosmos to bring you one no matter what lol

[thin stratus]

Might want to write that down on your page :D

If you use the Iterator, then what you wrote might actually be true

[fathom aspen]

yeah, i'm getting lots of info out of this chat, so taking notes heh

[thin stratus]

Because the Iterator goes over the List that is filled via SeamlessTravel stuff

But that would mean that your sentence is actually inverted then

Although you ref the GameInstance one

The UWorld one would return a different order, and potentially even grab the Client's PlayerController

The Iterator in general would

[fathom aspen]

lol, i'm so evil

[thin stratus]

Cause it's a list of PlayerControllers.

While the GameInstance LocalPlayers array is a list of ULocalPlayer, and the Client won't nbe in there on the Server

[fathom aspen]

I assume what happened was this, the client loaded first, so there was no local PC to get on the server, and checking the GameState PlayerArray it found the client's

I mean yeah it might make sense in some situations, but this is pure evil

So in such senario both versions would behave the same

[nocturne quail]

same behaviour, nothing changes if i use attach to actor
i'm tired of it now, i am gonna redesign my own attachment system now and will not use the default attachment from AActor.. not worth it to debug it anymore 😄

[thin stratus]

So tl;dr about "GetPlayerController(0)" and similar C++ methods:

• UGameplayStatics::GetPlayerController(Index)

  • Checks the LocalPlayers Array of the GameInstance first
  • Then checks the PlayerState Array of the GameStateBase
  • Then uses the UWorld PlayerControllerList (iterator)

• UGameInstance::GetFirstLocalPlayerController()

  • Checks the LocalPlayers Array of the GameInstance first
  • Then uses the UWorld PlayerControllerList (iterator)

• UWorld::GetFirstLocalPlayerController()

  • Uses the UWorld PlayerControllerList (iterator)

• UGameInstance::LocalPlayers

  • Contains ULocalPlayer
  • Only contains entries for the Local Player, so ListenServer will only have a entry per its own Local Players

• AGameStateBase::PlayerArray

  • Contains APlayerState
  • Contains all PlayerStates of all Players, so Index 0 can return any (valid) PlayerController
    • ListenServer could return a Client one by mistake
    • DedicatedServer will always use this for UGameplayStatics
    • Client would still return the correct one as the only PlayerState with a valid PlayerController is their own

• UWorld::PlayerControllerList

  • Contains APlayerController
  • Contains all PlayerControllers, so Index 0 can return any (valid) PlayerController
    • ListenServer could return a Client one by mistake
    • DedicatedServer will always use this for UWorld and UGameInstance calls
    • Client would still return the correct one as their would only be one entry in there
  • Is filled by AController::PostInitializeComponents and FSeamlessTravelHandler::Tick()

• Splitscreen/Local Coop Players

  • Will cause UGameInstance::LocalPlayers to have more than one ULocalPlayer in it for the given Client/ListenServer
    • Not sure about the order here, but usually you add the second ULocalPlayer "later" anyway

[fathom aspen]

Wow what a huge beautiful wall of text

[fathom aspen]

Think i'm gonna steal it for my article

nooo

[thin stratus]

Credit me or I sue you. ❤️

[fathom aspen]

lost ™️ there

[thin stratus]

I will leave now though. Gotta get ready to visit a friend. Read ya all later.

[mystic estuary]

Hello, I need to bypass simulation delay for PIE debug purposes. Is there a way to somehow magically send an RPC or somehow pass the data (in my case a struct) ignoring it?

[knotty frost]

I’m making a multiplayer third-person shooter, and I can’t get my client to shoot for whatever reason. The server seems to work just fine.

My BP_Weaponbase https://blueprintue.com/blueprint/x_peg2rj/

My Spawnmanger https://blueprintue.com/blueprint/3ar0vc_b/

My Shoot Logic https://blueprintue.com/blueprint/sxgo8u9o/

[nocturne quail]

guess i found the issue, my AC was expecting disabled movement of character before it tries to attach to vehicle

else it will not be attached

but it attached and not correctly attached 😄

so found two bugs, one in AC and the other is in the handleattachment

[latent heart]

AC?

[nocturne quail]

        Target->GetCharacterMovement()->StopMovementImmediately();
        Target->GetCharacterMovement()->SetMovementMode(EMovementMode::MOVE_None);

this will do the trick i guess, compiling now will see what we will get

[nocturne quail]

Anti Cheat

[latent heart]

Ah ha.

[sinful tree]

I told you how you can properly "get" the controller - you force the actor to have a relationship with the controller. Make the contoller tell the actor itself its reference, or have a component on the controller that does the communication between the two.

[tender olive]

You lost the whole discussion about it, in summary the question and doubts was related to
"get player controller at index 0", would actually work well, and the answer is depends on what kind of multiplayer one have.
and Cedric gave a lot of explanations on how it actually works
#multiplayer message

" you force the actor to have a relationship with the controller." there is no way to do this when pcg spaw the actor. If I was spawining with an action event, that would not even be a question. The question is when one have an actor on the client and have no link to the current local player, how to get a valid one.

[ornate moat]

why tf is doing that

[bright summit]

code?

[ornate moat]

Monster Logic First photo

Adjust the Health, secnd photo.

Master logic 3th photo :

[dark parcel]

da faq...

Why are you spawning like that?

You should have the server and only the server spawn the monsters.
If the actor being spawned is set to replicate, client will eventually receive a copy

[subtle kernel]

guys, I'm kinda being a lil slow.. How can I replicate character rotation? When I have CMC and use SetActorRotation, it's not being replicated, what is the proper way to do it?

[ornate moat]

that's a good damn question

[dark parcel]

Spawner Manager Begin Play -> Switch has Authority -> Spawn things

that's it, client doesn't need to do anything, it just wait to receive a copy

[ornate moat]

By some odd reason, i tough i need to also replicate the fact that servers spawned the mobs

aswell

And yet, there's still no updated widget

Any ideea on dat'? @dark parcel

[dark parcel]

I am not getting any useful info

try posting your new spawning logic first

[ornate moat]

.

[dark parcel]

you don't need server RPC, you are already the server

[ornate moat]

oke

[dark parcel]

Authority -> Spawn Monster

[ornate moat]

done

[dark parcel]

#multiplayer message
You should just use for loop instead of calling the function again, that is pretty cursed

but that's not really your problem atm

[ornate moat]

imma gonna use Loop instead, but for now, i want to know

what's happening with the Client 1

why dosen't get the replicated health

[dark parcel]

show your widget

how does it read health

[ornate moat]

the BPI, it's setted to all the enemys, yea

[dark parcel]

interface here is utterly pointless imo