multiplayer

[vital inlet]

when the game starts its closed

[dark edge]

What bit of data in the door BP represents if it's open or not?

a bool? A float? Just the orientation of a door mesh?

[vital inlet]

a bool

[vital inlet]

heres the code for it

[dark edge]

ok so the onrep of your bool Open? is where you should do the code that should run based on Open?

show the onrep function

[vital inlet]

ok

[vital inlet]

?

onrep?

[dark edge]

onrep / repnotify

i dont remember what bp calls it

anyway its the function that runs when Open? changes

[vital inlet]

ok

[vital inlet]

i think what yr talking abt is here

[dark edge]

it'll be a function

show the functions for this class

you'll have one that's automatically called when Open? is changed

[vital inlet]

its this one

[dark edge]

ok that looks correct

put a breakpoint on ChangeDoorState, make sure it's firing

[vital inlet]

...how do i do that...

[vital inlet]

nvm i added one lol

so it shouldnt do that now, right

[dark edge]

So far your code looks correct, it appears that everything that happens after ChangeDoorState is correct (IDK why you have a flush net dormancy there though)

so you need to make sure ChangeDoorState is being called when and where it should be

[glossy wigeon]

I'm still trying to figure this out, so it's working fine most of the time but then sometimes I get it into a state where it just causes the corrections.

I've root motion for everything enabled, so the animations should drive the forward motion, I' disabling Use Controller Rotation Yaw so that this can't be an issue.

But Why does it even cause corrections, since the client is also limited to the animations root motion same as the server. (The animations come from motion matching, if this might be of any relevance)

[pulsar pond]

Hello, im using UE5.5, and currently im encountering an issue when hosting a lobby using the steamsubsystem and steam sockets.
when i make a lobby on my first boot up, for some reason, when my host server travels to the lobby of the session it made using ServerTravel(TravelURL)
the travel URL gets modified to include ?Name=Player, before the ?listen. as you can see on the second line of the log, and then due to that, clients cant find the session. HOWEVER, if i back out of the lobby, and create a new lobby as that same host, it works correctly, and clients can find the lobby and join it. The second block of logs is from the second lobby made. Any further lobbies made by that host during that gameinstance work correctly.
any insights?

[2025.08.07-17.46.22:522][706]LogGameMode: ProcessServerTravel: /Game/Maps/Menu/LobbyMenu_Map?listen //<------ correct url
[2025.08.07-17.46.22:522][706]LogEngine: Server switch level: /Game/Maps/Menu/LobbyMenu_Map?Name=Player?listen //<<<-------- externally modified i think
[2025.08.07-17.46.22:522][706]LogGlobalStatus: UEngine::Browse Started Browse: "/Game/Maps/Menu/LobbyMenu_Map?Name=Player?listen"
[2025.08.07-17.46.22:522][706]LogNet: Browse: /Game/Maps/Menu/LobbyMenu_Map?Name=Player?listen
[2025.08.07-17.46.22:522][706]LogLoad: LoadMap: /Game/Maps/Menu/LobbyMenu_Map?Name=Player?listen

[2025.08.07-17.46.33:075][982]LogGameMode: ProcessServerTravel: /Game/Maps/Menu/LobbyMenu_Map?listen
[2025.08.07-17.46.33:075][982]LogEngine: Server switch level: /Game/Maps/Menu/LobbyMenu_Map?listen
[2025.08.07-17.46.33:075][982]LogGlobalStatus: UEngine::Browse Started Browse: "/Game/Maps/Menu/LobbyMenu_Map?listen"
[2025.08.07-17.46.33:075][982]LogNet: Browse: /Game/Maps/Menu/LobbyMenu_Map?listen
[2025.08.07-17.46.33:075][982]LogLoad: LoadMap: /Game/Maps/Menu/LobbyMenu_Map?listen```

[fossil spoke]

The host should move to the lobby before it creates the session.

Not the other way around

[pulsar pond]

so i should be, as host, already in the lobby map, before i create the session?

[fossil spoke]

Yes

[thin stratus]

You sure about that statement? Most cases show CreateSession into OpenLevel.

[pulsar pond]

doesnt seem to have solved the problem, i looked online and it also doesnt seem to matter if your in the map before you start the session or if you start the session then travel to it. as the session exists with the gameinstance not a map

[thin stratus]

Honestly, I would even say all cases, but nothing stops you from creating a session after opening the lobby fwiw

[thin stratus]

What you write there is a lot of mixed up stuff.

• ServerTravel is not used to start listening, usually. You do that via OpenLevel or fwiw ClientTravel in C++, and the ?listen flag. ServerTravel is used to travel from e.g. the Lobby to Gameplay and Gameplay back to Lobby or other Gameplay maps etc. ServerTravel ensures that Clients are moved with them (seamless if possible!).

• The order of the options, so ?listen?name or ?name?listen doesn't matter at all. The URL is queried for them. It doesn't check them in order.

• Sessions and you opening a level with ?listen are two different concepts.
  • ?listen causes the local player to start listen on port 7777 (by default) for incoming connections. You can actually even do that without changing level fwiw, but that's C++ only iirc. You don't need to create a Session for players to join that "ListenServer". If you know the IP and you are using Subsystem NULL in the Editor or generally, players can simply connect via open <ipaddress:port>. The whole connections process is usually not tied to Sessions. The only exception is that some Subsystems (like Steam) remove the option of joinin directly via IP to hide the IP from others.
  • Sessions are just a set of information that points to a game that can or can't be joined. You can create a Session without having a ListenServer active, which people can join fwiw. But if they try to connect to the Server behind that Session, it would fail, cause the Server isn't listening yet. If you use the builtin BP nodes for JoinSession you might think it's one an the same, but Epic is actually doing the "Travel to Server" after "Joining the Session" for you all in one step. It isn't a requirement though.

And that means, you can Create a Session and do the OpenLevel(?listen) stuff in whatever order and with whatever delay between them that makes sense for your game.

MOST tutorials and games probably do CreateSession -> OnSuccess -> OpenLevel(?listen)

Mainly cause CreateSession can fail.

[pulsar pond]

i turned on seamless travel, and now the "Name=Player" isnt being injected into the url, so clients do find the session, however, now clients cant join and i get this log in the host log
when a client trys to join
[2025.08.08-11.13.22:222][496]LogSteamSocketsAPI: Warning: SteamSockets API: Warning Ignoring P2P signal from 'steamid:76561198183756341', unknown remote connection #3532827115

in the clients log now it says that
the FOnlineSessionSearchResult is 0, boots the client back to main menu, and get this log

[2025.08.08-11.10.45:794][701]LogSockets: SteamSockets: Now tracking socket 1930157348 for addr 76561198183756341:7777, has parent? 0
[2025.08.08-11.10.45:794][701]LogNet: Game client on port 7777, rate 100000
[2025.08.08-11.10.55:787][558]LogSteamSocketsAPI: Verbose: SteamSockets API: Log [#1930157348 P2P steamid:76561198183756341 vport 7777] problem detected locally (5003): Timed out attempting to connect
[2025.08.08-11.10.55:798][564]LogNet: Error: UEngine::BroadcastNetworkFailure: FailureType = PendingConnectionFailure, ErrorString = Your connection to the host has been lost., Driver = Name:PendingNetDriver Def:GameNetDriver SteamSocketsNetDriver_2147482085
[2025.08.08-11.10.55:798][564]LogNet: Warning: Network Failure: PendingNetDriver[PendingConnectionFailure]: Your connection to the host has been lost.

[thin stratus]

Are you trying that with two different PCs across the internet?

[pulsar pond]

yes this is in packaged builds

[thin stratus]

SeamlessTravel is only relevant when the Server travels from Lobby to Gameplay Map and back.

It has nothing to do with the connection process.

[pulsar pond]

well it def affected it, as the only thing i changed between my first issue and second attemp was setting seamlesstravel to true in the gamemode.
without it, i have that initial problem, where the first time i host a lobby, its unfindable, then if i leave it and try to create a new one, it is findable and joinable.

with seamless travel, now its findable off the bat, but not joinable

[thin stratus]

was setting seamlesstravel to true in the gamemode
You only set that to true in Lobby/Gameplay maps. Not e.g. MainMenu.

And you should not use ServerTravel to start hosting.

And that is only used when you ServerTravel AWAY from a Level, not to it.

It will probably drop the ?name cause why keep it if SeamlessTravel keeps everyone connected.

But that should only be a thing for Clients, not for the Server. Please use the OpenLevel/ClientTravel code for hosting.

The error you get is a Steam related warning as far as I can tell.

Relay candidates enabled by P2P_Transport_ICE_Enable, but P2P_TURN_ServerList is empty
That's Steam throwing a warning, not UE.

Is this even a ListenServer setup? Or are you using a DedicatedServer?

[pulsar pond]

listenserver

[thin stratus]

But the whole connection error you get seems to be Steam P2P related.

Might be an ini file setup that is wrong.

Can you show what you've changed in DefaultEngine.ini regarding OnlineSubsystem, OnlineSubsystemSteam, NetDriverDefinitions and NetConnectionClass?

[pulsar pond]

ye

!NetDriverDefinitions=ClearArray

+NetDriverDefinitions=(DefName="GameNetDriver",DriverClassName="/Script/SteamSockets.SteamSocketsNetDriver",DriverClassNameFallback="OnlineSubsystemUtils.IpNetDriver")

[OnlineSubsystem]
DefaultPlatformService=Steam

[OnlineSubsystemSteam]
bEnabled=true
SteamDevAppId=480

bInitServerOnClient=true

[/Script/OnlineSubsystemSteam.SteamNetDriver]
NetConnectionClassName="OnlineSubsystemSteam.SteamNetConnection"

[thin stratus]

Hm I would suggest removing this bInitServerOnClient=true

[pulsar pond]

mind you these are changes i made after upgrading to 5.5 from 5.4
in 5.4 everything was working, when i went 5.5 it was busted,
and this ini file is after finding what to change and add for 5.5

[thin stratus]

That boolean will cause Steam to init a Server locally.

const bool bIsServer = IsRunningDedicatedServer();
bool bInitServerOnClient = false;
GConfig->GetBool(TEXT("OnlineSubsystemSteam"), TEXT("bInitServerOnClient"), bInitServerOnClient, GEngineIni);
bool bAttemptServerInit = bIsServer || !!OSSConsoleVariables::CVarSteamInitServerOnClient.GetValueOnGameThread() || bInitServerOnClient;

UE_LOG_ONLINE(Verbose, TEXT("Steam: Starting SteamWorks. Client [%d] Server [%d]"), !bIsServer, bAttemptServerInit);
    
// Don't initialize the Steam Client API if we are launching as a server
bool bClientInitSuccess = !bIsServer ? InitSteamworksClient(bRelaunchInSteam, RelaunchAppId) : true;

// Initialize the Steam Server API if this is a dedicated server or servers should initialize on clients
bool bServerInitSuccess = bAttemptServerInit ? (InitSteamworksServer()) : true;

GConfig->GetBool(TEXT("OnlineSubsystemSteam"), TEXT("bInitServerOnClient"), bInitServerOnClient, GEngineIni); that is your config boolean.

And that causes bAttemptServerInit to be true.

That will cause Steam to do InitSteamworksServer

Can't promise that fixes anything, but that shouldn't be there

[honest bloom]

Input variables not being used is sus
maybe it's about backward compatibility though

[thin stratus]

It's also cause the method is probably virtual so you can override it.

And then you might be interested in those properties.

[honest bloom]

ooh I see !

[unkempt lodge]

Hey i am creating a basic fireball ability, everything is working fine but on the client the projectile (with a projectile movement component) is kind of shaky. I checked on lyra how they did to have a smooth grenade for example but i didn't find anything related to this. The only thing is that they enabled the interpolation of the projectile movement (which i also did) but on my side there's no improvement. So my question is: "is there a way to interpolate the projectile movement easily, or should i create a custom system for that.

[exotic wasp]

Shaky or stuttery?

Shaky might be the position precision

Stuttery is probably net update frequency and can definitely be fixed by interpolation

[fossil spoke]

Ive not had an issue with it. Perhaps it doesn’t really matter 🤷‍♂️

[kindred widget]

When you create the session doesn't matter. Most just do it before travel to determine if they should use the listen parameter. It's also more common to create the session first so that you can error out easier on like connection issues and such, they don't have to load a map just to get booted back to the main menu.

[unkempt lodge]

I tried to use the interpolation of the projectile movement component but i can't find any doc about it so its hard to understand how to use it

[unkempt lodge]

Actually it is shaky not stuttery, its like shaking even if i put the projectile speed to be really slow

[dark parcel]

is the Projectile movement component even networked at all?

afaik everyone is running their own locally

[ashen plume]

any cmc experts know if the physics volume that cmc stores in itself is properly predicted? though im not even sure if should use physics volume, but i do require some predictive way for characters to detect that they're in specific areas

[unkempt lodge]

Well i figured that after disabling replicate movements, it is smooth. For this projectile its not a problem for the clients to run their own projectile (which is only for visual as the logic is running on the server) but i was wondering one day if i have a more complex projectile how could i make it smooth for everyone

[dark parcel]

You need to implement your own smoothing. Turning on replicate movement will just override the location and fighting the pmc

[unkempt lodge]

Okay i understand, thanks !

[dark parcel]

Btw i am also doing a fire ball. Havent test with big latency, but rn i am just spawning locally on client using GAS.

Client will receive the server copy but it will be hidden.

So basically the client fire its own proxy projectile but it only serve as visual component. The real hit will only account for projectile in server instance.

There's a plan to smooth it, so when client receive the server fireball it will interpolate to servers projectile location.

But if without that and the test seems fine then i may just hold that off.

[unkempt lodge]

Yeah that's what i was thinking to do if i couldn't find a good solution. So you spawn a local version of the fireball on every client (multicast) ? Also, how do you trigger an event when you receive the location of the server ?

[dark parcel]

You are not using GAS?

[unkempt lodge]

Yes i am using GAS

[dark parcel]

If you are doing anything involving ability or attributes (e.g rpg) you should.

Yea i just execute the ability with prediction.

Client spawn first then send the direction of where the fireball is going.

The server then will spawn on its end and replicate the projectile to everyone including the caster.

But on the caster world its hidden.

No multicast. Just use GAS activate ability.

[unkempt lodge]

yeah ok i see

[unkempt lodge]

But then how do you check when the server send new location to interpolate ?

If we were on a more complex projectile for example

[dark parcel]

Like how complex? my fireball shoot straight.

Caster will receive the server's copy. I can just have a FGuid to indentify projectile that belong to the same ability.

So the caster will have 2 projectile on it's machine. It's own and the server's (when the server replicate it's copy back to client).

and when that happend, I can just simply interpolate the caster's projectile to the server's projectile.

effectively rubber band the projectile but with fine tune I can probably find the middle ground.

pretty sure this is what Unreal Tournament does as well.

[pliant cypress]

BlasterAnimInstance.cpp

bWeaponEquip = Character->IsWeaponEquipped();

Returning false for the client. It was working before but now it's broken.

Source code is here

GitHub.com/Iprabhsidhu/BlasterMultiplayerGame

[kindred widget]

Did you debug it? Is Combat null, or is equipped weapon null?

[pliant cypress]

Combat is not null neither is the weapon as you can see but I don't understand why the client can't run an equip animation.

[kindred widget]

One of those have to be null or you wouldn't get a false return.

[pliant cypress]

I'm using RPC for this

https://github.com/iprabhsidhu/BlasterMultiplayerGame/blob/master/Source/Blaster/BlasterComponents/CombatComponent.cpp

[pliant cypress]

& Replicated Property, OnRep_EquipWeapon()

[nocturne quail]

this actor exists in the world and it spawns vehicle when a character sends requests to it.

void ABP_VehicleSpawner::RegisterVehicle()
{
    if (!HasAuthority()) {
        return;
    }

    if (ASurviveGameStateBase* GameState = GetWorld()->GetGameState<ASurviveGameStateBase>())
    {
        GameState->RegisterVehicle(this, server, VehicleCount);
    }
    else
    {
        UE_LOG(LogTemp, Warning, TEXT("Failed To RegisterVehicle..."));
    }
}

why it fails to get the game state? and prints Failed To RegisterVehicle

I think i'm using a C++ game state instead of a bp parent.... making it sure now loading the editor 😄 to test

yeah, in a demo level i was using a different gamestate, issue not exists anymore

[versed tiger]

I am customizing a struct container that uses TMap to store massive amounts of data. I want this container to be network-synchronized. How can I distinguish whether a player is attempting to synchronize this container for the first time? I need to send all data during the first synchronization, but only send incremental information in subsequent synchronizations.

[unkempt lodge]

A player guided projectile for example such as the skye's flash in valorant if you know it

[dark parcel]

Can't comment unless I go further with my own game.

For my self, I will just simulate locally. Interpolation can be added on top in the future if required. Game need to be tested first.

[unkempt lodge]

Yeah that makes sense, thanks for your time and responses !

[dark edge]

How is this unwound on prediction miss?

[kindred widget]

Usually the common way to handle "replicated" tmaps, is to make a FastArray with a struct that has the key and data. Server constructs elements for this from it's own map. Client gets each fast array element addition or removal and will and add or remove them to their local version of the map.

[glad escarp]

Quick question for someone smarter than me: if I wanted to make a simple project where several different players control different parts of a spaceship, with no need for split screen, do I need to spawn a player controller for each or can one player controller use multiple controller input?

[kindred widget]

Debatable. Multiplayer?

I mean obviously. But like local or networked?

[glad escarp]

Local. If you've ever seen or played Lovers In a Dangerous Spacetime, the concept is similar but no little players running around inside the ship. Just each controller does something different in the ship. Ie, one pilot, one controls shields, several others control turrets etc.

[kindred widget]

I'm inclined to say just add players for them to begin with. Because if you ever go to consoles or anything you're already set up for it. Each set of controls can be a possessed pawn or something that handles inputs differently maybe.

[glad escarp]

That makes sense. Sometimes as you're asking questions you start to answer them yourself as well and this is where I was starting to lean before you answered. I guess the simple answer would be to make player 0 the pilot and then each of the controllable ship parts would be the subsequent players. And their pawns would be attached to the main ship pawn with attach actor to actor.

[glossy wigeon]

What could I do, to move a character to a location, so that the locomotion animations are still triggering, that will work in multiplayer?

[fossil spoke]

You mean without Player input?

You could use the navigation functions.

MoveTo for exmaple.

It would then path along navmesh as if it was walking

[glossy wigeon]

Yea I tried that, but the issue was, that the nav mesh is not synced by default and it said that this will add quite some overhead to networking if one does.

Also I can only use simple move to for player controllered characters right?

I'm also curently trying ApplyRootMotionMoveToForce, but it appears to not work well with motion matching or something

[exotic wasp]

does SpawnActor async load the actor class on the client before spawning and calling beginplay?

assuming the actor is replicated

[nocturne quail]

I am using this helper to attach characters to vehicle. it is working for the driver perfectly but other clients glitching very badly... feels like the server is correcting their location.

void AVehicleBase::ServerHandleAttachment_Implementation(class ACharacter* Target, const FName Socket)
{
    if (Target && GetMesh())
    {
        Target->GetMesh()->SetSimulatePhysics(false);
        Target->GetCharacterMovement()->StopMovementImmediately();
        Target->GetCharacterMovement()->SetMovementMode(EMovementMode::MOVE_None);
        Target->AttachToComponent(GetMesh(), { EAttachmentRule::SnapToTarget, true }, Socket);
    }
}

[fossil spoke]

Make sure you handle collisions between them properly.

You likely want to disable collisions for the Vehicle and the Meshes so they dont try and force each other out.

[nocturne quail]

Character is ignoring vehicle/physics bodies in the collision preset

and the vehicle Body mesh is also blocking only ground

their collisions has no interactions at all with each other

[nocturne quail]

These are collision presets for character, pawn, vehicle

[fossil spoke]

Can you show whats happening exactly?

"glitching very badly" isn't a helpful description.

[nocturne quail]

I can now record a short clip yes

[nova wasp]

You might need to override some parts of the character/cmc to know to not correct when in this state?

mesh interpolation will always be trying to mess with the mesh relative location unless stopped afaik

so make sure you reason about the actual actor location and the mesh separately

[nocturne quail]

I'm not exactly sure if this is the correction

the passenger is attached by server

and the driver also

for the driver it works fine, there is no glitches

for the other client want to sit with me in the vehicle have lots of glitches

[nova wasp]

separate the mesh and the root component when visualizing this

just debug draw it

[nocturne quail]

vehicle mesh is the root component

[nova wasp]

of the character

Target->AttachToComponent(GetMesh(), { EAttachmentRule::SnapToTarget, true }, Socket);

you are attaching the character to the car

what I mean here is the skeletal mesh and the character capsule are seperate

do you attach the camera to the mesh (or a child of them) or the capsule component of the character?

[nocturne quail]

mesh->springarm->camera

[nova wasp]

okay, then like I said you need to consider the offset of the mesh

also as a side note that is a scary number of skeletal meshes... ideally they are merged at runtime

[nocturne quail]

they are my custom, no ticks or physics .. they just follow the animation of the parent

[nova wasp]

still extra draw calls but perhaps that works

would be curious to see a real profile of it (no I do not mean an fps number, I mean the actual cost of each one)

Debug draw the character capsule or just quickly attach a mesh to it to visualize where it is

[nocturne quail]

I will use the merge method once time comes in future

[nova wasp]

yeah... definitely scary to set up

basically what we are trying to see here is if the character AND the mesh are moving in this jittery way or if it's just the mesh relative to the character capsule

if they are separate you want to turn off mesh smoothing when this is attached (which should be off already? I would just debug what is setting relative transform)

if they are together something else is moving the actual character relative xform

[nocturne quail]

Editor just restarted after a change build, testing it now

[nova wasp]

could make the debug draw in bp or add the mesh in bp

for something like this at least

[nocturne quail]

I tested using listen server, and found that if the driver is client and the passenger is server everything works fine both sides

if the driver is server and the client is passenger, the passenger client glitch

if the driver is client and the passenger is client, the passenger client glitch

[nova wasp]

what moves the car?

yeah you are going to have to debug the set relative transform

like I said

[open wave]

I have a rep Notify that does a lerp that's being applied every 10seconds for an aging system I'm adjusting half height and radius to keep the bounds same size as my character. But because I'm adjusting the capsule the mesh needs to have a relative offset. When applying this relative location to move down it doesn't apply on multiplayer. When doing print string test of the values its saying its being applied on server and client but visually its not working

[nova wasp]

mesh relative location will be affected by mesh interpolation

for a cmc (for sim proxies)

see UCharacterMovementComponent::SmoothClientPosition_UpdateVisuals

I guess there is BaseTranslationOffset

[nocturne quail]

driver client possess the car and moves it using input keys f/b/l/r

[nova wasp]

I think you misunderstood what I meant

I don't see how the buttons are relevant here... I mean if it's a physics object, locally predicted etc

I should have been more specific with examples I suppose

[nocturne quail]

void AVehicleBase::Throttle(const float Val)
{
    const bool bIsForward = Val > 0.1;
    const float Throttle = bIsForward ? Val : -Val;

    ChaosVehicleMovement->SetThrottleInput(bIsForward ? Throttle : 0.0f);
    ChaosVehicleMovement->SetBrakeInput(bIsForward ? 0.0f : Throttle);
}

class AVehicleBase : public AWheeledVehiclePawn
ChaosVehicleMovement = CastChecked<UChaosWheeledVehicleMovementComponent>(GetVehicleMovement());

[nocturne quail]

this is from a default vehicle template

i just changed the vehicle mesh

[nova wasp]

Oh I should probably say

I wonder if replication is coming in for the person in the vehicle still

Debug the actor transform onrep

I can't guess what is happening here, you need to debug what moves the client locally

[nocturne quail]

One thing to be noticed, if i add child actor components in the vehicle and set it to the character that want to attach to the vehicle and make it visible, everything works fine

I have to take some rest 😄 brb later

[hollow adder]

I wonder if it would be possible to reimplemt CMC jump to make it work similar to crouch or how we implement custom stuff like sprint.
I mean to make it go through the UpdateCharacterStateBefore/AfterMovement functions. I checked how jump is handled and it and it's called from ControlledCharacterMove
which also eventually calls the UpdateState functions. Comment says jump needs to be checked before adjusting input acceleration so I'm not sure if I can change this.
I'm asking because I'm working on a generic ability container that handles the abilities similar way to default CMC crouch. Works nicely with crouch/prone/sprint/dash so far but jump default implementation is just spread all over the place so not sure how to go about it

[exotic wasp]

definitely is

[scarlet mountain]

Hi everyone,
I’ve been a dev for a few years now, mainly for singleplayer, but I’m now trying to move into multiplayer. I’ve learned the basics... listen client, LAN, etc... but the project I’m working on is a 1 player vs 1 player matchmaking system. It’s meant to be fast matches, and since it’s 1v1 and requires matchmaking, my understanding is that I need a dedicated server to handle connections, matchmaking, and even possible cheaters.
However, just like Unity has Photon, which allows 100 concurrent players for $45 per year, I did some research on dedicated servers but only found hosting services. I’d just like to know if that’s really the only option for a poor indie dev who can’t spend much money.

[dapper lagoon]

does anybody know my server browser only works when lan is enabled? my default engine.ini is correct and i have advertising on

pls im about to publish my game

[exotic wasp]

photon isn't a dedicated server, no? I thought it was just the ability to host a server that supports that number of players

I believe steam and other services allow matchmaking. if you want both players on a third party server as opposed to one of them hosting , you will need to pay to host somewhere

[latent heart]

my understanding is that I need a dedicated server to handle connections, matchmaking, and even possible cheaters.
This you can do through steam or eos

[verbal ice]

Yeah you can use Steam's relays or EOS' P2P to connect players without using dedicated servers

one of them would just be the host

[lost inlet]

yeah but if cheaters are a concern, then I'm guessing it's fairly competitive

so you don't want to give one player a clear advantage by being the server

1v1 is pretty shit for server density too

[latent heart]

You can use the matchmaking stuff in steam to connect players to any kind of server. Dedicated or not.

[lost inlet]

if you want something more lightweight than an Unreal game server instance, then that's custom server territory

[verbal ice]

misread their message a little, but yeah ik

[scarlet mountain]

Its 1v1, but its Turned Based, so its no that high advantage

[latent heart]

You can do that with a webserver better then probably.

[lost inlet]

yeah that can be a custom thing

[urban bramble]

I am getting confused, has anyone had this issue before?
I'm working on networked/replicated stuff. I'm spawning in an actor with BPs server side. I then attach the actor to a second parent actor server side. The reason is I want the parent actor to move around and the child to follow it. (Object on a vehicle) So far so good. Child follows parent around.
I then try to destroy the child after detatching it server side. This works on the host session but not on the client side of things. Child actor stays there. :\

The strange thing is if I don't attach the child, everything works just fine. Attaching it seems to be the cause of the failure to destroy the child.

[dark edge]

show code

[urban bramble]

I... just found the issue. I think, if the BP is not a child to another actor, it works. Something about attaching it to another actor is causing this. I'm going to try making a USceneComponent that does what my spawner does and see if it helps.

[scarlet mountain]

When you make a X Actor be the Child Of Y Actor, the Y Actors now OWNS the X Actor, so, if a client, that dont OWN Y Actor, wants to Deele, it cant Delete because lacks Ownership.

You can make a RPC to the server side by the client i think maybe will work

[nocturne quail]

This fixed the jitter in forward/backward state
but rotation still jitters little bit

void AVehicleBase::MulticastHandleAttachment_Implementation(class ASurviveCharacter* Target, const FName Socket)
{
    Target->GetMesh()->SetSimulatePhysics(false);
    Target->GetCharacterMovement()->StopMovementImmediately();
    Target->SetCanMove(false);

    Target->GetCharacterMovement()->SetMovementMode(EMovementMode::MOVE_None);
    Target->SetActorEnableCollision(false);
}

void AVehicleBase::HandleAttachment(class ASurviveCharacter* Target, const FName Socket, const bool IsDriver)
{
    if (Target && GetMesh())
    {
        if (!IsDriver)
        {
            Target->GetCharacterMovement()->bIgnoreClientMovementErrorChecksAndCorrection = true;
        }

        /*Location, Rotation, Scale*/
        FAttachmentTransformRules NewAttachRules(EAttachmentRule::SnapToTarget, EAttachmentRule::KeepWorld, EAttachmentRule::KeepRelative, false);
        Target->AttachToActor(this, NewAttachRules, Socket);
            
        MulticastHandleAttachment(Target, Socket);
    }
}

[tardy fossil]

the actor class also has a virtual function OnRep_AttachmentReplication you can override

[nocturne quail]

yeah it is virtual and called when the replicated actor has something attached/detached

    UFUNCTION()
    ENGINE_API virtual void OnRep_AttachmentReplication();

    UPROPERTY(Transient, ReplicatedUsing=OnRep_AttachmentReplication)
    struct FRepAttachment AttachmentReplication;

[nocturne quail]

Exact issue as mine
https://www.youtube.com/watch?v=rDSHA7c6GIo

[tardy fossil]

actually its called when the actor itself is attached/detached to something

well only for clients though

[knotty rampart]

Hello,
Does anyone has a way to use **OwnerRelevancy with Rep Graph **? It feels its not take in account and i dont find usage in code ?

[frosty helm]

Hi, I need some advice.
I have a side scroller game, and I made an ability where you shoot a projectile towards the mouse. When I spawn the projectile I pass in a direction Vector. What is a good way to replicate this vector to the server and clients?
Should I use Target Data, an ability task, or a variable on the ability itself?

[meager spade]

target data

[halcyon ore]

I know UE has some functions for like global is this variable replicated, custom wise
I can't find any form of is this variables replicated person connection/ player, custom wise
Player 1 get data, but player 2 doesn't sorta deal.
All I see is
Everyone gets it, or no one gets it

Is it weird, or just not something you can do?

[verbal ice]

You can't make variables replicate per player really

Well, yes and no

You can make it only replicate to the owner, not the owner, stuff like that

And if your engine version is high enough you have access to net groups iirc

Lemme check the docs on that again

Mmmm no, net groups are only for subobjects

But you could replicate properties to X players through a subobject that way @halcyon ore

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

That or you have a proxy actor that contains the properties you wish to only replicate to certain players

And then you override IsNetRelevantFor

[halcyon ore]

Hmmm, so probably more work then its worth, at least right now.

[verbal ice]

In theory I feel like you could do it with structs and custom net serialization

Since you get access to the package map of the client

Never tried it though but it doesn't sound far fetched

[exotic wasp]

https://dev.epicgames.com/documentation/en-us/unreal-engine/replicate-actor-properties-in-unreal-engine#custompropertyreplication

nvm, can't change on a per connection basis

trash

[verbal ice]

Yeah it's odd considering how often it comes up

You'd think the engine would have a way to

I kinda wanna try out my idea with custom struct net serialization and the package map

Since technically you'd be able to know who's receiving it with that

I think

[exotic wasp]

I guess it would be hard to have an actor in a valid state if the property isn't always replicated

[verbal ice]

Maybe

[red lantern]

are there any good tutorials someone could suggest for multiplayer? my game is currently local (as we didnt need to go through the hell that is replication for a university module) but since we're motivated to get it on steam its just hard to find a place to start converting it to online. It works great locally, but i dont have any idea where to start with replication or networking. Ive been tinkering in a couple of multiplayer templates that has the lobby/joining friend thing set up to learn from, but ive also got to replicate damage, hp, melee attacks, picking up weapons, environment stuff too.

So id honestly appreciate any advice anyone can give, tips or even just a general direction of what helped them learn the online side of programming. Thanks guys

[halcyon ore]

Its hard to provide advice, given I usually suggest to design with multiplayer in mind, not do it later. Since it leads to stuff like this.

There honestly isn't much to do.
You kinda just gotta go chunk by chunk.
Theres no simple catch-all for it sadly.
Just gotta start from the bottom, and start to network it all.

I oddly find to better to just always design with networking in mind, even for a random singleplayer thing, or etc.
Just feels so much more correct.
Rather then going back over all my code, to make a server work.
Then, probably back over again to make singleplayer work again.

[red lantern]

Yeah thats fair enough, and honestly if it wasnt for a grade at university it definitely wouldve benefitted us to do that, but it was more so just writing designing and testing the game to have it functional in around 4 months.

I knew id have to essentially rewrite everything to have it function online properly with the ability to have it work locally via LAN as well, and I'm honestly okay with that, I just don't have much of a good place to start. I wasn't much of a coder before I started so most of my knowledge is purely local based games

[halcyon ore]

Yeah, from my past experience (BP graph modding for 4 years)
Replication can be hard to wrap your head around.
But, once it clicks, you kinda just handle it without realizing.

Some people act like you have to split your brain, cuz 2 things running the same piece of code, but differently.
So, its definitely extra hard to provide advice to a person new to networking.

Since, theres various slight different ways to do stuff.

[red lantern]

what I've seen so far is pretty much having the client call an event that runs through the server, that server event then runs to a multicast, and the multicast runs the actual code. But having a lack of knowledge I don't know if doing that is right or wrong, but considering my health and damage doesnt work and I can't even get print strings to display, I'd assume I'm doing it wrong 😅

I'll just search up some intros to replication on youtube, possibly find an online course or something if it's still hard to wrap my head around. Thanks for the replies

[halcyon ore]

Yeah, I know my advice ain't the best.

Theres just a ton of tiny things.
First thing, since your project was first made SP.
Did you setup the C++ correctly for replication (I guess i'm assuming C++, but i'd hope university wasn't BP)
Since, replication needs special Implementation functions, for the actual code.

Then, the stuff like how you can't just wildly use ROC, ROS, and multicast calls.
Cuz, they require some form of owner (ROC, and ROS), and you may not have owner setup, since SP doesn't need that.

[nova wasp]

read the pins

try to avoid rpcs for persistent state, use onreps

if possible

https://vorixo.github.io/devtricks/stateful-events-multiplayer/

[red lantern]

No everything blueprint, they didn't teach us coding it was more the art side of games, but they didnt expect us to code it. It was just making a vertical slice of a game, so almost everything art related had to be done by us, but we could use templates for anything else pretty much, we just had to make it clear that such and such was used. So i have very little knowledge of C++

[red lantern]

Ah thats my bad sorry, I didn't know there was stuff like that in there

[nova wasp]

yeah I feel like its a bit of a tall order given there are like 30 pins but there are a lot of really good "getting started" guides

you can skip the weird trivia ones you might not have the context for yet

BP multiplayer is possible but it's VERY restrictive compared to the freedom of C++ mp

but you can get pretty far with BP only stuff if you have to, its not unusable

also if you are making a small project for school or a co-op project you can avoid a lot of suffering by making stuff client authoratative because there is no need for anticheat/authoratative stuff

[red lantern]

Sorry I was just scrolling through and opening a few links to save for later.

Yeah I know C++ and BP go hand in hand, rather than one over the other, just most of my studies have been art based so I havent had the chance or it's been quite intimidating to try get started, plus when ive been developing something its hard to search for a specific thing, even now my main issue is just replicating melee attacks, but there's still more to work on than just that.

it started off as a small project for school but the hope is to push it to steam since we've recently won a competition with the game so far and the games studios local in our city that have seen and played the game love it, not much like negative or this needs fixing feedback just like casual tweaks and polishing, but having that sort of push is whats driving us to try publish it but its pretty daunting for me anyway to try and learn something this big

[nova wasp]

your goal is to replicate different parts of the melee attack

both the fact the person is meleeing and the thing that got hit getting hit

split the problem into small parts

[red lantern]

the like animation part and the meleeing player works, as well as the sphere trace by channel is detecting its hit a player, but it's getting that hit detection to detect it's been hit and deal damage. In the local version I was using a MeleeTrace plugin that did it for me and I'd just use a pre-made event that would deal the damage on hit (as all the characters have the same parent class) but using an anim notify state is also new to me so im not entirely sure if that works or not

[tender solar]

Hello did UE5.6.0 really made it so that you have to add UPROPERTY() to USTRUCT members to have them replicated? In patch notes i see "improvements to replication" but they didn't detail the changes.

[kindred widget]

You've always needed a UPROPERTY marker on a property in or out of a struct to replicate it.

[tender solar]

My code was working without that before

[kindred widget]

Hmm. I could see that if it's just grabbing the struct and passing it's full data minus anything explicitly marked NotReplicated. But I'm not sure that it is intentional. It's always been an Unreal kind of way to mark stuff UPROP for replication.

[tender solar]

I see maybe it was because they were in TArray and they made further checks

[quaint tendon]

Super weird bug. GameMode spawns character for player then gets possessed by player, in BeginPlay of character an event(sound+Niagara spawn visual effect). The event causes the character to become permanently desynced and laggy. This does not occur when the player is spawned by default pawn class.

If I disconnect the event and the particle+sound are not spawned the character is still desynced because of the event. This occurs even without any network emulation under perfect network conditions

[thin stratus]

If this is coming from BeginPlay, why do you RPC?

[quaint tendon]

So all players see and hear the particle/sound.

[nocturne quail]

Beginplay is an RPC out of the box and it calls on all clients and server, you don't need an extra rpc for the beginplay

[quasi tide]

What

That is not at all correct

(That BeginPlay is an RPC)

It is most certainly not an RPC

[nocturne quail]

EPIC GAMES :: we need an extra special attachment function specially for attaching characters to vehicles, maybe some like

AWhieldVehiclePawn::AttachCharacter(ACharacter* NewCharacter);

[quaint tendon]

I figured out the problem, the sound doesn't work even when not replicated.

There needs to be a delay

[nocturne quail]

this function will handle this issue... since the already existing attachment functino is buggy in terms of attaching characters to a VehiclePawn

#multiplayer message

[nocturne quail]

delay means, the character was not fully spawned and the event was executing, so 0.01sec delay can be good to go

[quaint tendon]

Correct

[nocturne quail]

if you want to use beginplay, don't use any rpc wit it, just call any event in beginplay, it will be alled on all clients and server

if you still want to use a multicast, put a check if server in beginplay and call your multicast

[nocturne quail]

or use event OnPossessed, this will be call quickly when character fully spawned so you don't need delay

[nocturne quail]

yeah, what i mean is it works like a multicast rpc, which calls on all client/server

[quasi tide]

No - it doesn't work like a multicast rpc because it isn't an rpc at all. It is simply a lifecycle method.

[nocturne quail]

Correct, but in easy terms it calls on all clients/server... the same way as a multicast called by a server

[quasi tide]

No - do not spread bad information

[nocturne quail]

Who calls beginplay when a character spawned?

[quasi tide]

It is not a multicast specifically due to it not being an RPC

The gamestate is what starts the beginplay process

[nocturne quail]

I agreed already that it is not a rpc, what i mean was by nature a beginplay calls on all clients and server which is what a multicast also does

[nocturne quail]

I mean server or client calls it?

[quasi tide]

People already have a hard enough time with multiplayer - don't say stuff that will only lead to confuse people even more

It is not an RPC. End of story.

It doesn't act like a mutlicast RPC either - because it is not an RPC

Use the correct terminology

Teach them what a lifecycle method is

[nocturne quail]

that's not my answer, what calls the beginplay in a gamestate?

[quasi tide]

World Settings

Your silly little game doesn't mean diddly squat Missty. Do not spread misinformation

[nocturne quail]

hmm, and which world? , there are two worlds in the game, one owned by client and the other owned by server.

[quasi tide]

I'm done with your game Missty.

[nocturne quail]

Don't be angry Sir, i want to learn from you

I am just sure that server is calling the beginplay... no matter from which direction but it will be still the server in teh end

[quasi tide]

I had the two mixed up anyway - here is the order of BeginPlay. #cpp message

[nocturne quail]

Great, but still there is no mention which UWorld, server or client

[quasi tide]

When you spawn something at runtime - it checks to see if begin play has already been ran. If it has, then it'll run begin play for that actor.

[quasi tide]

The server has to be the one that calls it because it relies on the GameMode - which is server only.

UWorld -> GameMode -> GameState -> WorldSettings

[nocturne quail]

This solved the issue and answered my question 🙂

[quasi tide]

The GameState is what is responsible for calling begin play on clients as well.

[blazing spruce]

Hi, I need a smart fella to explain something about overlaps to me.. why when playing as the server and overlapping something does it call both the begin and end overlap events at the same time.. or should that not be happening?

I'm using the pawns capsule component and calling these events on my interaction component when the player overlaps or stops overlapping with something, if the player is within range of an actor that is interactable it'll create a widget component and display an indicator widget at the location of the actor to indicate that the actor can be interacted with which only needs to happen on the client, if not then it checks on the server if the player is overlapping with the interaction overlap of an interactable actor and if so adds the actor into a Overlapping Interactable Actors array which is used elsewhere to actually select which actor to interact with, then when ending overlap for the indicator widget it'll find the right widget component, stop showing it and destroy the widget component.

The problem I'm having is with the indicator widget.. it should fade in when entering the indicator overlap and fade out when ending overlap, when I play as the server with other clients the indicator widget doesn't fade in it just appears immediately but it does correctly fade out when ending overlap.. weirdly this only happens when playing as the server player with other clients, when I play as the server with no other players everything works fine and when I play as the client alone everything works fine, but when I play as the server with other clients the issue happens.. if I unplug the end overlap event the widget correctly fades in instead of popping in so it must have something to do with the fact that both the begin and end overlap events are being called at the same time for some reason on the server player. Can anyone explain that to me? Only happens for the server, clients always see correct behaviour.

[nocturne quail]

I found the root cause of this issue when attaching a ACharacter to AWheeledVehiclePawn .... what should be done is just

    if (Target->IsLocallyControlled())
    {
        Target->bUseControllerRotationYaw = false;
    }

so my final attachment solution is: and it solved the issue permanently...

void AVehicleBase::MulticastHandleAttachment_Implementation(class ASurviveCharacter* Target, const FName Socket)
{
    Target->SetActorEnableCollision(false);
    Target->GetMovementComponent()->Deactivate();
    Target->GetMesh()->SetSimulatePhysics(false);

    if (Target->IsLocallyControlled())
    {
        Target->bUseControllerRotationYaw = false;
    }

}

// Called by server only
void AVehicleBase::HandleAttachment_srv(class ASurviveCharacter* Target, const FName Socket, const bool IsDriver) 
{
    if (Target && GetMesh())
    {
        /*Location, Rotation, Scale*/
        FAttachmentTransformRules NewAttachRules(EAttachmentRule::SnapToTarget, EAttachmentRule::KeepWorld, EAttachmentRule::KeepRelative, false);
        Target->AttachToActor(this, NewAttachRules, Socket);

        MulticastHandleAttachment(Target, Socket);
    }
}

the output is, an attached passenger can now look around using their camera, but their camera can't conflict with the rotation of the vehicle applied to the passenger client

also this not needs for the driver, since the driver is possessing the vehicle and already using the vehicle camera for looking around

[turbid escarp]

is anyone here have experience with switching levels on dedicated server for specific client?

instead of using main menu, i was thinking to move character creation to server side. so the flow would be: player joins → if they have no data on the server (first time join, no character), server sends them to a character creation level → after creation is done, they travel back to the game level. if they already have a character for that server, skip creation.

i have a few ideas how to do this but just wondering how other devs handle this kind of thing.

[exotic wasp]

I don't believe there's any way to have multiple persistent levels at a time. You could load a sublevel, make it only relevant for the one client, and spawn them into it, though

for something like character creation though, it doesn't need to be on the server at all I would think?

[turbid escarp]

Yeah that's what i did read.
Sublevel might be work, thanks for the suggestion.

[turbid escarp]

i want players to create their own character per server instead of using the same one for all servers. it’s not just about cosmetics, player will also have attributes based on their choice like “policeman”, “thief”, “nurse” etc. so keeping it per server works better for my project.

also thinking about saving the latest character locally when logging out from a server and showing it in the main menu, maybe at a campfire or something like that. could be cool for the player to join later and see their latest character sitting there waiting for them.

[glossy gate]

I have on the Character this function:

ESGItemType CurrentItemAnimationType;```
and then, I have a set function like this:
```c++ void ASGCharacter::SetCurrentItemAnimationType(ESGItemType NewItemType)
{
    if (!HasAuthority())
        return;

    UE_LOG(LogTemp, Warning, TEXT("Server: SetCurrentItemAnimationType: %d"), (int32)NewItemType);
    CurrentItemAnimationType = NewItemType;
}```
it executes the log and the variable is replicated on the GetLifetimeReplicatedProps. then, on the animation blueprint I have the character saved on the blueprint initialize animation event and on the update event I get the character current item animation type and save it on a local variable. then on the anim graph I have it set up as the image. but it doesn't work. 
if I play it with the server, it doesn't show on the clients, and if I play it on the clients it doesn't show on the other clients but yes on itself and on the server

anyone knows what I'm doing wrong?

[nocturne quail]

i would replicate CurrentItemAnimationType using onrep, and call from the animation class SetCurrentItemAnimationType(ESGItemType NewItemType) and pass CurrentItemAnimationType

this way you don't need to update the variable on tick each frame

[nocturne quail]

void ASGCharacter::SetCurrentItemAnimationType(ESGItemType NewItemType)
{
    if (!HasAuthority())
        return;

    UE_LOG(LogTemp, Warning, TEXT("Server: SetCurrentItemAnimationType: %d"), (int32)NewItemType);
    CurrentItemAnimationType = NewItemType;
    OnRep_SetCurrentItemAnimationType();//call this manually if using dedicated server, on listen it will be called automatically
}

void ASGCharacter::OnRep_SetCurrentItemAnimationType()
{
    AnimationRef->Event_OnUpdateCurrentItemAnimationType(CurrentItemAnimationType);
}

void UAnimationClass::Event_OnUpdateCurrentItemAnimationType(ESGItemType NewItemType)
{
    CurrentItemAnimationType = NewItemType;
}

[glossy gate]

it works!!! thanks :) <3

[exotic wasp]

it also might be possible to have the character creation done entirely inside of UI with a scene capture of something (pretty sure theres a better solution)

[grizzled garnet]

Is there an ideal way to set up a command interface for dedicated servers? Passing -log only enables printing, some online resources say to connect a client and use ExecServer, and I found https://dev.epicgames.com/community/learning/knowledge-base/3KEe/unreal-engine-receiving-exec-commands-on-a-dedicated-server-through-the-stats-port which uses a statsport to receive commands, I'm wondering if making a simple program on top to read from the log and send via curl is best

[tender solar]

Look for dedicated servers manager/launcher on github, most of them are made in Csharp. Basically they command the server via command line arguments, logs and settings, some also provide update functionality via steamcmd and there is also the possibility to use RCON for example to send messages to global chat. While a full featured manager is a lot of work, you can make a simple one pretty easily. As for the exec commands I haven't tried them. The ones made for Ark and Conan Exiles are pretty impressive so that can give you a good idea of what is possible.

[twin roost]

a bit new at making multiplayer stuff

How exactly does a player data go from like main menu to a lobby map?

How would the player data transfer work?

(making a coop game, so game save would hold all individual player data at first)

[nova wasp]

look up seamless travel

[twin roost]

I see, thank you, I'll loop it up more in depth

[turbid escarp]

Yeah, i already using in it my inventory widget for character previews.

[dark edge]

data can persist within a SINGLE INSTANCE OF THE ENGINE through GameInstance or Saving/Loading

if you mean "how does a client send data to the server" then that'd be through an RPC (run on server event)

[nova wasp]

oh yeah, they could just load the same data again

[dark edge]

This is multiplayer so I presume they're asking about how to talk to the server on connection

[twin roost]

yeah, was confused about the connection part

[dark edge]

In that case, it'd probably look a bit like the client loading some data, then sending it to server so the server can host it on their authoritative state of the world

It's all some combination of save/load and rpc

[twin roost]

sounds about right because all clients need to have some data of each individual players

[dark edge]

What are you talking about specifically, give an example.

Character name? Full save game? Something in between?

[twin roost]

name, item loadout, custom character appearance, etc

[dark edge]

Yes that'd be in a savegame, and you'd have an RPC to send the data to the server so they can apply it to whatever

[twin roost]

gotcha ty

[dark edge]

just make a struct representing all that data and it can be your payload for savegames and for the rpc

[twin roost]

handy!

[blazing spruce]

Hi, anyone got any ideas about this? #multiplayer message

[tardy fossil]

stick some debug print nodes at the beginning of the overlap events to be sure.. they shouldn't be firing at the same time

also not sure if this is part of your problem but the Play

Animation node returns instantly, not after the animation is done

[open wave]

has anyone ran in to the problem where you cant update relative location of a mesh on multiplayer I have tested my code with print strings and it replicates on server and client but when i plug it into the characters mesh it never replicates correctly.

the variable that is driving it is correct

[tardy fossil]

character movement component right? i believe it has something to do with the smoothing.. theres a function you can call on the character actor at begin play to fix it.. CacheInitialMeshOffset() i believe

[open wave]

so what im trying to do is adjust the height of the character as it ages. i have the mesh updating correctly but the capsule component is wrong after age= Y and then the capsule needs to be bigger im adjusting the half height and radius to suite the new size but then my mesh is not on the ground or in the ground depending on my character i have selected. i tried to do set relative offset and it works in single player. just not for the life of me i am getting it to replicate

I feel like the character moevement is playing with me i tried to set it up and do a z offset on the root bone in the anim graph but it does retarted poping back to 0 then to new size looks horrid

[blazing spruce]

Im watching it on the blueprint debug thing so I can see both of them firing at the exact same time when entering or exiting the overlap on the server

[blazing spruce]

This is also alright at the moment, for some reason when i call DestroyComponent it doesn't remove the widget thats already being displayed so it's not causing any issues at the moment cause the fade happens correctly lol

[tardy fossil]

hmm maybe the SetWorldLocation in your display indicator function is causing the overlaps to update and trigger the end overlap

i think if you tick "teleport" it would stop that

[blazing spruce]

I tried removing that node completely but it still happens lol

This is what I'm seeing when using the debug thing (the server one)

[open wave]

corey you have much luck?

[tender solar]

I dont think you need to check HasAuthority, what I do with my overlap is I get the PlayerController from the actor then check if that PC has a valid UI. If it does then I push the interaction widget.

[blazing spruce]

The authority check is to handle the ‘Overlapping Intractable Actors’ array that shouldn’t effect the indicator widget display as that should only be running on the client i think

[wet nymph]

Can I select which world to show in the viewport when running multiplayer? Because when I detach from the player it always shows the client world. Image on left = PIE running the server, image on right = when I detach the player it shows the client

[tender solar]

If Begin and End overlap fire at the same time you need to make sure it's about the same actor and component. About HasAuthority I find it strange because it won't switch if it is locally controlled.

[blazing spruce]

Not sure what you mean mate? Like print out ‘OtherActor’ to make sure its the same thing?

The HasAuthority isn’t firing in this scenario anyways because this is just to display the widget, the HasAuthority is for something else thats technically unrelated to this indicator widget being displayed

Also the issue only happens when playing as the server playing with other clients, if you play as the server alone, it works fine.. i dont get it 😂

[tender solar]

Yeah that's because you have this issue only when you play with other clients that I look into it. Basically your standalone has authoriy and is locally controlled (unless I got something wrong). As for your events they are custom and output an actor and a component, so it's possible that the begin event fires with a certain actor and a certain component while the end event fires with another actor and another component.

[tame kraken]

hey is there a tutorial on how to do proper portforwarding
i try to do it but it doesn't work
can i connect with remote windows dedicated server -server cmd command
and do join session/connect beacon to it

i can find its session but i can't join its session or connect to its beacon
what does it take?

[mystic estuary]

afaik portforwarding shouldn't have anything UE related. When I had to host a server on my machine locally for someone else to connect, I forwarded 7777 to the local IP of the machine I was running the server on, and setup two ACL rules to let the other player I was testing the server with in, and block everyone else

You might want to read UE and OS networking logs to see whether the server even gets any request from the client. If not, the problem should be related to the settings of the host router, unless there's something else

[glossy gate]

and if I want to do this I have to also do an onrep? because happens the same. but then wouldn't it be bad for network performance?

[blazing spruce]

Yeah so I unplugged all the logic on both of them and just did the print statements printing the actor and component and they're all the same and the correct actor & correct component (print is just from begin overlap, but end overlaps prints are exactly the same), I have no idea why the overlap gets called 9 times anyways which also somehow varies cause sometimes its called 4, 5, 6 times lol and even with just the print statements connected to both begin and end events they still both get called together at the same time.. no idea 😅

[echo pasture]

so, I found this very werid client ragdoll physics behavior I'm trying to wrap my head around

My steps are 1. Create default Third Person Template

2. added these nodes to player character

all this is does is ragdoll the character and make the capsule teleport forwards every very seconds (my tick rate is .5)

I would think the expected behavior is that only the capsule would teleport, not the ragdoll. in singleplayer, works as expected. in multiplayer, server works as expected, but in client I see the ragdoll teleporting when the capsule is teleported

anybody have any explanations? Is CMC making some assumptions here that I can't see?

oh I forgot to mention, it's the same behavior when only the authority wire is plugged in for tick

[echo pasture]

and for some reason this causes the mesh to completely disappear for client's character on the listen server... I'm so confused

[crisp shard]

I have no idea how to solve your problem but I do remember something about physics tick being async benefits ragdoll effects

[echo pasture]

thank you for the lead at least. Although even the screenshot above isn't even ragdoll, it's just a detach to component node (I turned off ragdoll and it still does the same thing)

[tender solar]

Why not use standard overlap event rather than custom and see if it works the same? If it does then it must be a geometry issue maybe?

[blazing spruce]

Mine are custom but they aren't really, all i'm doing is using the pawns capsule component's overlap events by binding too them so I can use them inside my interaction component and then using 'Create Event' to create both of those 'custom' overlap events

[nova wasp]

Outliner gear button

[wet nymph]

You mean the gear of the viewport, or the gear of the outliner? Because if it's the Outliner one, I know I can choose the world I want to see, it helps, but I would also like for it to reflect on the viewport

[echo pasture]

I'm not sure if this is the correct place to put this, or if I should move it to #freelance-jobs or something. But basically, I'm willing to give $20 to anyone who could help explain what's going on here, as I belive it's critical to my own project

It seems so simple but yet...I'm not sure

[grand axle]

Does anyone know why when I transition to another level my players aren't spawning? player 1 and 2 do. Players 1,2,3,4 player states are in the world and their camera is being set, but no player. Seamless travel is also on in the gamemode, I have a transition level put into the project settings too

[tame kraken]

ah i see thanks for sharing
were you able to get canyouseeme to see your ip?
because i failed that even when i did port forwarding

[tender solar]

OK I think you need to simplify until it works, so maybe just drop an overlap box with a printstring and see what happens

[mystic estuary]

Try running ipconfig in cmd (in case you're on windows). It should contain a bunch of local ips, including yours

[nocturne quail]

this is a tick stuff, no need for onrep

also just use movementcomp->velocity.size for the speed directly

[haughty ingot]

That wouldn’t be ground speed then

[quaint tendon]

Anyone implemented a triple jump for multiplayer? (i.e. jump higher each time like Mario) I'm finding it very difficult, especially with lag. The server lagging behind makes syncing the jump count almost impossible.

[exotic wasp]

how is it being implemented?

is the server actually lagging or is it getting corrected due to a desync between client and server?

[quaint tendon]

Character lands. Non-replicated jump count increases to 2, non-replicated jump speed increased, character jumps clientside.

Server still hasn't landed so when the character jumps it interprets as trying to jump while in the air so nothing happens, server resets jump timer, client has jumped, server says no client didn't jump and resets position to back on ground.

[exotic wasp]

might be worth changing the movement mode

[echo pasture]

Also gas could help

[versed tiger]

does ue5 exist a "Chunked Sparse Array"? stable item address + index reuse

[exotic wasp]

gas won't help with that

it already takes some effort to have abilities work with movement prediction

[urban bramble]

I'm trying to impliment a custom inventory toolbar for my game where there would be 5 slots that are not nessessarily weapons. I was using the LyraInventoryManager to store the items in and am working on the UI side of things. What I've done works so far in single player but when I drop into multiplayer, I'm finding that I'm having trouble getting my client to understand that the inventory has been altered. I figured there must be a way to hook into the inventory's array and use an event or something to listen for changes client side... but I can't quite find this. Am I missing something?

[dark edge]

There's TSparseArray, what makes it chunked?

[exotic wasp]

if the inventory is a replicated property, you can use the ReplicatedUsing specifier to call a function every time the property replicates to a client

you can then either directly call your UI refresh if it makes sense, or have it call a delegate

[frank birch]

Silly question I once knew the answer to...
If two replications on the same member trigger, but because of the gods of networking the packages arrive out of order...
Is unreal smart enough to understand that they are out of order and not update the client value with the older value?
(I feel it should be...)

[dark edge]

I don't know for sure if it's guaranteed to not be out of order but it is guaranteed to eventually be consistent

your code shouldn't rely on getting every state or not getting htem out of order, just should rely on being stateful

[dark parcel]

Someone told me as long its from within the same actor channel. It will be called in order.

[dark edge]

I know for sure you're not guaranteed to get all updates

don't rely on getting 1 2 3 4 5
your code should run just as well getting 1 4 5

[meager spade]

nope

well it will always be the latest

BUT it can skip stuff

so if you rely on that, your screwed

like if its for a state, and it changes twice before client gets it

then client could skip a state

ie server does > Chest Opening -> Chest Opened

client only recieves Chest Opened and misses the Chest Opening state

[frank birch]

as long as it ends up with the latest state, it works (assuming no lost packets here)
in your example, the client chest will never do ChestOpened->ChestOpening due to ooo packages

[meager spade]

nope

it will always be the latest

at the time

[frank birch]

yeeep, good enough for me 👍
thanks all of you ❤️

[frank birch]

Also, just for anyone that needs to hear it:

• If the "when" it happens matter, it's an RPC
• If you don't care "when" but only the end result, it's a replicated property
  👀

[dark parcel]

I dont agree. Rpc is a one time event.

Many case where people can miss it.

If you need to keep track of time then add a time stamp or some number to determine the order.

A state should never be RPC

[dark edge]

state + when is the tough one

[frank birch]

right, RPCs can also arrive out of order 🤔
I meant more like "if it only matters to you if you are present to see it happen", that's the "when"
If something that happened 5 minutes ago it is still relevant now, then it is probably a state and not an event 😛

[dark edge]

probably just include a timestamp with the state and check it vs synced time in the onrep

that way you can onrep your door state but not have to hear 30 doors squeak open when you walk into a town that wasn't relevent before

C++ has some way around that right?

something like old value or some timestamp or something

[frank birch]

if it does... I don't know about it 👀

[dark parcel]

The OnRep in cpp have access to old value

[dark edge]

I thought it at least had old value but idk, I haven't done much with c++ networking

[dark parcel]

OnRep does

[frank birch]

I don't see how the old value would stop the doors from squeaking tho 🤔

[dark parcel]

You check the OnRep time to determine how far ahead the door actually is.

If its already pass the zone where it just start to open then don't play the sound.

[thorny ore]

What do you convert unique net id into to make it useful?

Can't even run an equals into unique net id from playerstate

[frank birch]

GetPlayerFromNetUniqueId or something like that aint a thing? I feel I saw something like that

[dark parcel]

Some people only use bool to represent state of the door.

If open, play open anim if close play close anim.

So when you enter the town or just join the game. you end up hearing 30 squeak sounds.

Need to give more info to address that, such as time stamp.

[dire cradle]

Hi, I'm having some trouble replicating an actor that is set to Only Relevant to Owner that is spawned during runtime.

For context, Airship_Base class is a replicated pawn class that is Owner Only, I only want to replicate the player's own ship in most cases.
In cases where the player needs to see another player's ship, my plan was to spawn a proxy Airship_Base that mimics the other player's ship with the owner being the viewing client.
That way I don't have to replicate every ship's properties to every client, only replicate to the ones who actually need at the moment.

Above is a mock testing code for the Client A, when pressed 1, it should spawn a proxy Airship_Base owned by Client A that mimics the Airship of Client B, I thought that would spawn the actor for the Client A as well.
The problem is that the actor spawns on the server, but it is not spawned client-side for Client A even if it owns it.

Edit: Fixed it, turns out Pawns override ownership stuff when spawning. Changing the class to Actor fixed the issue

What could be the issue because honestly I have no idea why it wouldn't spawn on the client

[frank birch]

playerState->GetUniqueId() == NetId should work, shouldn't it?

[thorny ore]

At least in bluepeints it unconnects the node. But maybe thats because I'm trying to get it in game mode

[dark parcel]

Why does it matter where you get it from?

[frank birch]

this thingy, from a player state, should be comparable to other thingy like it? (dark blue wire)

[dark parcel]

Isn't it a struct? What do you see if you split it.

Probably have sometbing to compare i dunno

[frank birch]

it is a struct, it does have the == overloaded tho

(the FUniqueNetIdRepl extends the FNetUniqueIdWrapper)

[thorny ore]

You can't break it in blueprints.

[frank birch]

(how did you get a network id in the first place tho? )

[thorny ore]

You can just pull it from playerstate

I was doing that from a user wodget

So I'm trying to set which multiplayer character is which class so I was trying to store the unique net id ref and then in game mode spawn from that

[frank birch]

That thing be transient tho

[thorny ore]

The unique net id? That should be the same

[frank birch]

from when to when? (since you are storing it)

[thorny ore]

I'm having a player set it on a mossion console

So if its not set then I'd just default to host I guess.

Though, maybe not since I can't compare it. Hmm.

[frank birch]

the thing is, every time a player connects to a server, they might get a new network id.
And hard traveling is reconnecting so they might get a new network id
maybe a soft/seamless travel retains the net id, maybe not, I am not sure there 😛

the shape and lifetime of the network id depends on the network backend (epic, steam, lan, etc)

[thorny ore]

Cedric says unique net id is constant from the subsystem though?

[frank birch]

I started chasing it with "go to definition" and found it being created in LocalPlayer and in World as you spawn the Player in 😛

but in network, I trust cedric with my life 😛

so do as he says

[thorny ore]

I mean, honestly, if there is a better way to get a chosen character class and assign it based on the character I'd love to hear it.

I may just be tilting at windmills. If someone logs into a listen server I'd like the game to remember stuff about them.

Unique net Id seems to be the best way to do it?

Because it persists through logins.

[frank birch]

So... you need to persist data... across network thingies...
if only we had a wizard... that had cells...
wait, imma get the site

https://wizardcell.com/unreal/persistent-data/
thataone

[dire cradle]

Can you not replicate spawned actors with flag Only Relevant to Owner?
Edit: Fixed it, turns out Pawns override ownership stuff when spawning. Changing the class to Actor fixed the issue

[thorny ore]

I've looked into the persistent data stuff but I don't think its what I'm really trying to do...

I think I want to save stuff into structs on the server side and probably replicate from there based on unique net ID

[dark edge]

maybe a string for save game name?

or gettypehash on it

[glass plaza]

Anyone know how to truly decouple multiplayer sessions in the editor? We have a static AActor* singleton to easily access one of our classes that for some reason, since the Client's singleton spawns second as the map loads, updates the Server's Singleton, leading to call to that singleton to not refer to the right actor while playing in PIE

This stops when we are in Standalone Game (but not when loading both players as Net Mode = Standalone)

If I can't find a solution for that, might have to pull everything into the GameInstance for local singletons

[tardy fossil]

you can try unchecking "Run Under One Process" in the Editor Settings under Level Editor -> Play -> Multiplayer Options

[exotic wasp]

probably best to use a subsystem instead of a static anyway

[glass plaza]

You learn new things every day

I have gone all this time without knowing of subsystems

Can't use it in this case since it's an Actor, but still

[exotic wasp]

just think of it as a Singleton with a definite lifetime

you can store an actor reference in one just fine

[hybrid zodiac]

Hi everyone. I have a player pawn which is using the Mover 2.0 setup. It is working great, but when the pawn dies I want to tear it off so the pawn and its ragdoll continues to exist on the local client for local simulation, but on the server its destroyed (since a dedicated server doesn't have to simulate ragdolls and other client-side effects)

The issue is that the client-side pawn generates a huge amount of warning spam from the mover component post-death:

LogNetworkPrediction: Warning: Independent Interpolation starved: -2

I assume this is because the network prediction liason backend is freaking out because it's no longer receiving updates from the server. How do I inform the mover component that it is now operating independently? I tried changing the backend class in the TearOff() functions like so:

void ABSPawnBase::TearOff()
{
    Super::TearOff();

    if (MoverComponent_Private)
    {
        MoverComponent_Private->BackendClass = UMoverStandaloneLiaisonComponent::StaticClass();
        MoverComponent_Private->UnregisterComponent();
        MoverComponent_Private->Deactivate();
    }
}

void ABSPawnBase::TornOff()
{
    Super::TornOff();

    if (MoverComponent_Private)
    {
        MoverComponent_Private->BackendClass = UMoverStandaloneLiaisonComponent::StaticClass();
        MoverComponent_Private->UnregisterComponent();
        MoverComponent_Private->Deactivate();
    }
}

However this does not fix the problem at all. I assume because the backend class has been changed, but the existing backend is still operating. As you can see, even unregistering and deactivating the component does nothing.

[lost inlet]

if it has a transient specifier or not is pretty irrelevant. the unique net ID is always expected to remain the same for the same account, on steam, this is just your 64-bit steam ID

[latent heart]

Deactivate does nothing to Mover

It's component specific and mover doesn't implement it at all.

@hybrid zodiac have you tried UninitializeComponent() ?

[hybrid zodiac]

@latent heart UninitializeComponent doesn't help 🙁 Still spams

Very annoying, I'll dig into the examples and see if they have any death mechanic in place

[latent heart]

Maybe actually destroying the component? If that's even possible.

It may not even be the component.

It may be the backend having a registered component that is then like, "where'd you go, bro?"

[hybrid zodiac]

Yeah destroying the mover component does nothing either

Seems like Mover is determined not to die

[tardy fossil]

maybe you could manually call UnregisterInstance() from UNetworkPredictionWorldManager

it's a world subsystem so you can get it through the world.. not sure if it would have side effects though

[latent heart]

Sounds a good idea!

[hybrid zodiac]

I'll give it a try 🙂

@tardy fossil To unregister it, I need a FNetworkPredictionID. Do you know how to obtain this from the actor? (if it even can be obtained...)

Maybe the cleanest way to handle this is to destroy the original pawn entirely, and spawn in a new "dead body" actor instead

[latent heart]

You really shouldn't need to!

[hybrid zodiac]

Agreed

But the mover examples has nothing in there to show how to cleanly "tear off" the mover component. You'd think that would be an obvious use case given how ubiquitous death is in multiplayer games

Maybe there's a way to switch it to standalone simulation

[tardy fossil]

well i did a little bit of digging and saw it's actually stored in network prediction component class but under a proxy class which is protected..sooo this probably isn't the way

maybe you could just unregister/destroy the network prediction component too?

[tender solar]

Does it make sense to replicate a boxcomponent? It does not have any replicated property, but when I replicate it then nothing happens and when I create a local copy I get this warning: Warning: FNetGUIDCache::SupportsObject: BoxComponent <Component> NOT Supported. I can silence this by adding replication to it but it does nothing anyways.

It's not a defaultobject but created dynamically in runtime

[hybrid zodiac]

I'll see if I can manage that, thanks!

[latent heart]

That's what UnintializeComponent does and that doesn't work.

[tender solar]

It looks like BoxComponent->SetNetAddressable(); also silences the warning but it does not seem very useful in this case

[frank birch]

it is not a transient uproperty, it has a comment from epic saying "this is transient, it will probably change with the date of the login, you shoulnd't use it" 😅

but then again, epic comments have lied to me before 😛

[lost inlet]

Then it's probably a lie because I've never seen it be ephemeral on any platform

This property is often used for server persistence, backend lookups, forcing server bans, etc, for years

And I'm yet to learn of an OSS that deviates

[thorny ore]

I'm trying to use it to load save data on the server side of a listen server...

You can pull it from playerstate in blueprints but it won't let me find out if it equals anything so I'm not sure how to match it.

[lost inlet]

Does BP not have a string conversion?

[thorny ore]

Do you just have to match it in c++?

Also anybody know if you've gotta over ride copy properties if you're loadimg from there. Probably running GAS on playerstate.

BP doesn't have a string conversion.... built a c++ blueprint function for it yesterday though. I think I'm making progress but just struggling with data persistence.

[tardy fossil]

i think that unique player id does change when using the null OSS since theres no backend login service, but every other OSS its persistent

[lost inlet]

there's a cvar for enabling consistent netids for the null OSS

[ashen gyro]

Hey there! I've been tasked with adapting an existing system called "ATS" for multiplayer. I've been having some success with it, but there are some outstanding issues.
The first one I'm trying to figure out is that the animations don't always replicate, such as in the case in the first screenshot. This doesn't always happen, as shown in the second screenshot that is from the same run. (I'm using Dedicated Server)

I'm not very used to dealing with animations, so I'm not sure if this is a common issue with a simple fix, or at least if there's a path someone can point me towards

[blazing spruce]

Hi, can anyone explain this?

Both overlaps are triggering together regardless of whether the player begins or ends overlap, how is that possible? If I play as the listen server without any other clients they don't fire together and only fire once, same for playing as the client without any other clients, but playing with the listen server and other clients connected will then fire both of those overlap event together (on the server debug) for any player who begins or ends overlap.. I don't get it lol, I know that overlaps fire multiple times because its ran for every player or whatever whenever someone overlaps so that's not unusual but how the fuck do they both fire at the same time? 😂

[thorny ore]

Server/client miss match? Maybe try printing has authority to see when the server thinks they entered and exited?

[blazing spruce]

Not sure what you mean mate, it just does the same thing.. I just dont understand how it can fire both at the same time lmao

[dark parcel]

it could be anything, you need to dig more info when debugging.

print out the other actor and other components for a start.

[blazing spruce]

All the same component and actor, and if it was something to do with the actor, or meshes or components that's attached to the character, wouldn't it also print multiple times when not playing with another client (which is where it triggers only once and not at the same time as eachother)?

[dark parcel]

I would suggest to see what component or actor is actually begin and end overlap.

before making further deduction

[blazing spruce]

That's what I meant, they're all the same

and correct btw, those are the exact actor and component that is should be overlapping

[shut vigil]

can someone explain to me why when You call a repnotify event you have to do it this way?

Like

Why are we using a NOT boolean

why not just call the repnotify function straight up?

[halcyon ore]

You can’t

C++ can, not BP

[quasi tide]

Using a not so it just always does the inverse. You're setting the variable instead of calling it directly because when it does get called, the variable that the onrep is for is already updated. If you called it directly, it'd be just like calling a function locally. Does nuffin' for other connections.

[latent heart]

It seems silly to do it that way, though.

[surreal fox]

hey, I am working on a multiplayer game and I learned some basics on how Multiplayer works in Unreal Engine (blueprints). But I still feel like I'm not quite good at implimenting multiplayer and many times I faces replication issues or don't know "proper way of doing it".
Can someone share me any way of how can I learn multiplayer properly for Unreal Engine? maybe any course or yt video playlist?

[quasi tide]

Read the network compendium by Cedric and then just experiment.

That's pretty much all there is to it.

[tender solar]

I've used that one with UE5, despite a few changes it worked well https://www.youtube.com/watch?v=abmzWUWxy1U&list=PLZlv_N0_O1gYqSlbGQVKsRg6fpxWndZqZ

[quasi tide]

Is this the one where they do RPCs in the GameMode?

[tender solar]

IIRC he uses the PlayerController mainly

But yes there are some RPCs in GameMode

[surreal fox]

oh thanks man, didn't knew this exist on Unreal engine's official channel

[quasi tide]

lol

[surreal fox]

is it still valid? like.. for ue5

[quasi tide]

Should be. The basics of networking hasn't changed in forever

[tender solar]

If you go with null subsystem it should be ok, if you go with steam it wont work that well

[quasi tide]

But uhh - don't put RPCs or replicated variables in the GameMode

[surreal fox]

yup that's right I guess. This tutorial series based on listen server?

[quasi tide]

Very pointless, as it only exists on the server

[quasi tide]

Couldn't tell you.

It is a very very old tutorial.

I mainly just used the network compendium

[surreal fox]

haha okay

[quasi tide]

Then experiemented.

[tender solar]

actually nothing was working for me then I grabbed this tutorial and it worked one shot

[blazing spruce]

People say this all the time cause game mode is server only so 'it doesn't need rpcs' but what if i need to make it reliable?

[surreal fox]

Cedric? is that a yt channel?

[quasi tide]

Reliable how? It won't get sent anywhere because the GameMode only exists on the server.

Clients do not have it.

[quasi tide]

Check the pinned posts.

[surreal fox]

okay got it

[tender solar]

@Corey have you checked your collision mode btw?

[blazing spruce]

So you dont need to worry about that at all for game mode? Obviously you hear that you need to mark events reliable that absolutely have to get ran so it doesn't break anything under poor network conditions, but that doesn't apply to the game mode class?

[quasi tide]

Correct. It does not apply to the GameMode. Because there is nowhere for the RPC or replication to go.

[blazing spruce]

Interesting, never knew that lol always wondered why people mentioned not having to use RPC's in game mode but never really understood why considering reliability

[blazing spruce]

wdym mate? The ObjectType is Pawn with custom preset

[tender solar]

I've transposed that tutorial in C++ and I don't see RPCs though, it's mostly about Prelogin and Logout stuff

[tender solar]

Well your issue comes from somewhere, Collision Profile is a good candidate, other than that it can be that you have multiple actors spawned on top of the other but that seems less plausible.

[dark parcel]

Has absolutely nothing to do with reliability. The game mode object only exist on server. Clients dont have a copy so theres nothing to rpc from server to client or client to server.

[tender solar]

Just that one on Server, so not a big deal

[dark parcel]

Perhaps the worst epic tutorial ever made.

Just straight up wrong

[blazing spruce]

Yeah no idea lol, I dont think its because multiple actors are overlapping and it should be able to handle that anyways but right now i haven't got a clue why the both fire together lol

Its also very possible its a GMC related issue, ive asked in their discord as well to see if its linked in someway

[tender solar]

Maybe try OverlapOnlyPawn or something like that?

[dark parcel]

You bought that plugin?

Cost like half of a gpu

[tender solar]

When nothing worked that one worked for me though.

[dark parcel]

Read the pinned material in this channel. Wizard tips and trick and exi compendium.

Youtube multiplayer tutorial full of garbage.

[blazing spruce]

sure did! I got it when its was GMCv1 tho so was only $300 before the price increase split between me and my mate.. bargin!

[dark parcel]

Last i check Matt aspald he place HP in player controller.. avoid.

[tender solar]

That tutorial used the PC a lot so I've replaced it with a Subsystem, then I used parts of Lyra code to handle the sessions. Still it was good to get started.

[blazing spruce]

He is right, youtube tutorials are mostly shit because they dont take into account context, wheres those pinned docs help explain the whole framework rather than 'use this node and this node and this..'

They always do em wrong as well lol

Using MC's when they should be OnRep's ect..

[dark parcel]

Can't rpc with sub system, they are not replicated.

Client only know their own PC. So placing any variable that needs to be known to other such as attribute is straight up wrong.

Wizard tips and trick article illustrate whats replicated and not.

[tender solar]

No he uses PC to fire and suscribe to dispatchers, I replaced that with a Subsystem.

That tutorial isn't bad at all when it comes to networking:https://www.youtube.com/watch?v=gru6EmDmevw

[verbal ice]

<@&213101288538374145>

[glad escarp]

Hey smart people. I'm trying to figure out a simple same-screen local multiplayer issue where I have multiple gamepads plugged in and I'm using "Create Local Player" in the game mode to spawn in additional players, but none of them are responding to input from my other gamepads.

[shut vigil]

so, were doing the NOT because, lets say, I have the flashlight, and if I went to pick up another it would NOT pick it up because its doing the inverse that it already has

but what if

I pick up the flashlight

and then drop it

and then go to pick it up again

wouldnt it not pick u p?

or i guess it would save beause whenever I pick it up im destroying that actor, and then when I pick it up it creates a fresh one

But lets say, just theoretically, i I wanted it to be whewre the flashlight is still on the ground after i interact with it, and i go to interact with it again, wouldnt it let me NOT pick it up the first time but then let me pick it up the second time?

[dark parcel]

Its just toggling a boolean value. True become false, false become true.

[shut vigil]

I know. But what I am asking is, is if I had the rep notify give me something, like a component. then it would now be True, because the default is false. Soif i wen to give it to me again, it would NOT give it to me because It is now false, and then if I did it again, it would Give it to me because it would then be true

Is what i just said correct?

[blazing bear]

Hi everyone, I'm wondering, where do you initialize all the widgets that are necessary at the start of the game? I've noticed that APlayerController::AcknowledgePossession runs before the player character and its components' beginplay on the server, whilst on the client it runs after. In my case it's causing problems because one relies on the other to be already set-up but I can fix that.

[halcyon ore]

lol
I ran into this quite recently as well.
I took the advice of others, and seperated them.
So, the components/ logic doesn't rely on some visuals to operate.
The timer will still tick down every second, the points still go up with every kill.

But, then the widgets just either check on tick, or use delegates to detect changes, then read the variables.

Thus not needing a certain order of operations for my widgets to function correctly.

So, the game can technically operate without issue, if the widgets were to suddenly vanish, cuz the actual logic that runs the game just calls delegates, and hopes the widget exists

But, for me, I just constructed them all on the hud begin play.
And, since there not required in some special order of operation now, it just works.
Widgets bind to delegates, and widgets update fine.

[blazing bear]

Yeaah I'm already on that delegates type of setup, it's just that I ran into a weird scenario where, the inventory widget can't be initialized until the inventory component of the player character itself is initialized, which happens at beginplay since the component relies on a data asset. So what I did was have a delegate on the component saying "I'm ready!" but that crashes on the client because the delegate isn't bound yet as the binding happens on AcknowledgePossession which hasn't fired yet

I'll try having the logic on the hud's begin play like you said, that could work. Otherwise I'll just fix the case where the delegate isn't bound yet during beginplay.

[halcyon ore]

Since I also have an inventory system.
My setup, is to just instantly bind to the inventory.
But, just detect item changes

Don't wait for any on ready.
Either the widget begins, and the inventory is ready, so data is just loaded.
Or, widget begins, and inventory isn't ready, and delegate tells it that an item changed, so the widget updates.

Does sound like your doing similar, but seems odd your delegate crashes, shouldn't they be pseudo anonymous, so null or valid shouldn't care

[blazing bear]

It crashes because the delegate isn't bound to yet, as binding happens on AcknowledgePossession which itself hasn't run yet. But yeah we're doing very similarly, I'll just have to check if the inventory is ready or not and continue on that!

[halcyon ore]

Are you using some special delegate.
I don't have a ton of C++ experience, but have yet to run into a delegate that crashes if its not bound.
Isn't the whole point of them to not care about the bound thing, so null shouldn't matter?

[blazing bear]

I ran a quick test with the logic being on the hud's begin play and apparently the logic also runs on different order in server vs client, but anyways that doesn't matter anymore

[blazing bear]

Yes if a delegate isn't bound, it'll crash if you're calling .Execute or .Broadcast, if you don't want it to crash you could check .IsBound or just run .ExecuteIfBound

[dark parcel]

I have no idea what you are doing but checking if a player own something using boolean like that is wild to me.

[fallen fossil]

Question about subsystems. Can they check authority?
I would like that subsystem to spawn an actor on server and then that actor would replicate itsefl to others

[quasi tide]

This would most likely be a world subsystem, in which case, you can check the world's net mode. Can also have the subsystem not initialize on clients.

[tender solar]

They can always do Actor->HasAuthority(), if you don't have the reference to an actor then you can broadcast to an actor manager class that is an actor itself, as long as it listens to delegate only on server it should be able to do what you want.

[dark parcel]

subsystem ain't an actor

[shut vigil]

I was just asking if what I said was logically correct

[dark parcel]

I wouldn't use boolean to give a component. Why is giving a component a state? That should be something the server handle and if the client have a say in it, then server RPC it.

tldr, I think what you are doing is not gonna work anyway

[glossy gate]

then why if it's on tick it doesn't work? (the legs animations only work on server and the client that walks or only in server if it's the server)

[dark parcel]

Shouldn't OnRep, simply drive it with GroundSpeed on tick which is calculated based on player's velocity

look at Default Third Person template

[glossy gate]

https://blueprintue.com/blueprint/82aioen9/ I have it set like that

which I think it's the same setup as the third person template, but the legs doesn't animate correctly

[dark parcel]

Not the same setup..

Have you looked at the pinned material on what object is replicated and not?

Clients only know their own controller.

With your logic atm it wont go oast the cast for client as controller is null

Thus the idea of storing youe replicated variable such as the pitch and yaw in that code is also incorrect.

[glossy gate]

so I'm looking at it right now and I should do it instead of the player controller on the character shouldn't I?

[dark parcel]

Yeah the character exist on all machine.

So get rid of your player controller ref in the anim bp

Thats not gonna work for clients.

[glossy gate]

okeyyy, thanks a lot

[dark parcel]

Look into getBaseAimRotation

That should give you the player control rotation.

Not sure how you set your yaw and pitch but control rotation is already replicated.

[glossy gate]

I was setting it as this:

void ASGPlayerController::Look(const FInputActionValue& Value)
{
    const FVector2D LookVector = Value.Get<FVector2D>();

    AddYawInput(LookVector.X * Sensitivity);
    AddPitchInput(-LookVector.Y * Sensitivity);

    Pitch = FMath::Clamp(Pitch + -LookVector.Y, -18.f, 18.f);
    Yaw = FMath::Clamp(Yaw + (LookVector.X * .25f), -15.f, 15.f);
}

it's the same as using the getbaseaimrotation?

[dark parcel]

I dunnoe, dont have editor on me.

But theres already replicated variable to get the control rotation.

Its already compressed too

So you have to do some math to restore the value for clients.

[glossy gate]

I'll look into it then. thanks again :)

[dark parcel]

Well start with your ground speed first.

Character should start walking now if you remove the player controller from anim bp.

I can share the code tom if you still stuck.

[glossy gate]

yeah it works :)

[tardy fossil]

hmmm, i'm giving servers the ability to change their async physics tick rate via a config, but having the client match the tick rate when it connects seems to be a problem.. Theres no network data being passed before the client creates the world right? by the time any connection is made the physics solver is already created and the physics tick is set

i guess the only way to do something like that is to kick the player and have them set the right tick rate and reconnect

unless theres some way to modify what UE sends in the handshake packets

[thin stratus]

Can't you send it via the Session Info?

You can also try a beacon connection first, communicate the tickrate and then connect fully

[thorny ore]

Team, I don't want to sound too confident here, But I think maybe I've pushed the first successful rpc in Unreal history...

[dark parcel]

You can post the code here if you are not sure.

[honest bloom]

confidence and arrogance are different
you can be as confident as you wish

[thorny ore]

Trying to carry data over in a struct saved to a game instance subsystem...

And it works on hard travel. But doesn't seem to work on seamless travel.

[thorny ore]

Probably should add the subsystem to asset manager...

[dark parcel]

@thorny ore whats the GI got anything to do with traveling?

Each machine gets one when the game run and it get destroyed when they exit the game.

The lifetime doesn't relate to traveling maps.

[thorny ore]

Nothing. I was using a Game Instance Subsystem to store a struct I was updating from Game State. Everything was working fine in play in editor, but it broke in a packaged build.

I thought it was because of seamless travel, but ya boi didn't add the subsystem to assets.

Game instance always betraying me by being unreplicated and existing on every client.

I just assumed it was screwing me over again.

[dark parcel]

Game instance is never replicated.

Its created when you run your game. Its nothing to do with networking.

As mention their life time start when you open the game and destroyed when you close the game.

[thorny ore]

It does if you cheat. 😂 set a struct on it, update the struct from game state and then download it after seamless travel.

Probably better ways to do persistent data but its my first real success.

[dark parcel]

No, you can ofc pull out data from GI and send it over the network but it does not mean the GI is replicated.

It is not, only the machine running the code have access to their own GI.

For my game. Save games are saved locally.

So every client just get their save game subsystem, then send it to server via server rpc.

Replicated object / actor means that every machine have a copy of it.

In the case of GI it doesn't. Player 1 does not have a copy of player 2 GI and vice versa.

[thorny ore]

Yeah. Saves seemed like the way to do it. But this is just gameplay properties I wanted so its working.

[dark parcel]

You dont need saves to carry pressistent data you can just use the GI.

You need to question your self, who needs to hold the data , who to send, etc.

Might be easier to just have the server track and keep the state then apply it on the next map, but it really depends on your game.

E.g player scoreboard, have the server save the value.

When the travel is done, just set the game state player score to w.e stored in the server G.I

[thorny ore]

Yeah. Switched to a struct so I didn't have to repetitively set things to send to game instance. Just set member in the struct and set once.

[thin stratus]

Player Data between ServerTravels should just remain in the PlayerState tbh. Unless you actively need to persist the data between 2 servers, at which point you need a backend if you don't want players to cheat

There isn't really a need to store this on the GI or in a SaveGame.

+- the PlayerController fwiw.

UE has built in methods for both to move data from previous to new instance.

And for the PlayerState that includes players that reconnect (with the requirement to have some unique net id via an Online Subsystem to figure out which PayerState belonged to the reconnecting player).

For just moving between levels you use CopyProperties in the PlayerState or OnSwapPlayerControllers in the GameMode. For reconnecting you use OverrideWith in the PlayerState.

GI and SaveGames are only needed if you need to move data to the Server from before you connect. But since you are talking about cheating I don't see that being a thing you are doing.

[thorny ore]

Ah. I thought copy properties was firing too slow on seamless travel because I could never get player state information to persist through seamless travel.

But you're saying if you can match playerstates you can keep information?

[thin stratus]

Btw, if your save game gets too big you will need to send it via multiple RPCs. Ran into that in The Ascent.

[thin stratus]

Too slow? It's literally meant to move data from old to new PlayerState on seamless ServerTravel

[dark parcel]

Thanks for the heads up, I am at a point where I just save cosmetic and nothing else. Good to know going forward.

[thin stratus]

Lords of the Fallen 2 also had an annoying problem where saving the progress to the coop client caused the game to stutter more and more the further you got into the story.

Ultimately recorded them a video and told Bruno to forward it cause it was at some point almost unplayable

The reason was quite obviously that the data that was sent got too big eventually.

[dark parcel]

Yup, make total sense.

[thin stratus]

Or maybe it was the act of saving all together. But the saving was fine in Singleplayer, so probably the RPC

But yeah those two examples are ListenServer coop games where cheating doesn't matter

And where designers wanted players to take their characters with them to other servers/friends.

For anything that can't allow cheating, dedicated server and keeping the data on the server is a must anyway

Gotta drive to the store now. Good luck!

[thorny ore]

Yeah. I'm making a listen server game with co-op so if people are gonna cheat whatever. 😂

I'm also just an idiot. Never considered matching player states. But I did only now get unique net ids working.

Thanks Cedric.

[dark parcel]

Not sure what you mean by matching but when seamless traveling as stated by cedric, you can retain the data from the old player state from previous map.

[thin stratus]

You don't necessarily need to match them. CopyProperties calls already on the old or new one, passing the other one along.

[thorny ore]

Yeah but thats never worked for me ever. Before I was trying to keep an enum on the player and it would never remember from playerstate.

[thin stratus]

Only thing you want to have is a proper inheritance hierarchy, so your specific PlayerStates move the data they know about.

[thorny ore]

Not on the client. The server host always remembers.

[thin stratus]

There is nothing to it though. Seamless Travel is a requirement but that's about it

[thorny ore]

Oh you just have to call it?

[thin stratus]

It?

[thorny ore]

Hmm. Maybe I just wasn't getting seamless travel to work. I'll test it.

Sorry. This is just me being dumb again. I'll go print some strings. In the past the clients have never remembered anything.

[thin stratus]

Assuming you are on GamplayLevelA with a Server and a Client. The Server will need to ServerTravel to GameplayLevelB and the GameMode used on GameplayLevelA needs to be marked for Seamless Travel in its settings. Which all GameModes that are used in Multiplayer setups should be (e.g MainMenu GameMode doesn't)

[thorny ore]

Yeah. Done. But I'll double check

[thin stratus]

If you are able to ServerTravel in the Editor, without enabling the console variable for allowing it in PIE, then you aren't using Seamless Travel.

[thorny ore]

Should be set in my parent game mode.

[thin stratus]

The console variable is experimental and can lead to crashes. Best testing is done in standalone or ultimately in packaged builds of course.

But try the console variable first I guess.

Without it it will print a warning if you try to server travel seamlessly in the editor

[thorny ore]

Thanks Cedric

[thorny ore]

Anybody know the best place to destroy session? Is it just on logout? Can't rehost or join after being kicked to main.

[thin stratus]

Potentially just in your MainMenu GameMode tbh

That's more or less the clearest point at which you know you shouldn't be in a session anymore.

[ashen plume]

@grand kestrel know anything about whether we need to override FillAsyncInput() or its sibling functions? just finished reading through your github repos, and was glad to see that i had came to almost exactly the same code conclusions, but didnt see anything regarding the async input function or struct

[grand kestrel]

That's for async character movement and I have no idea if epic ever got it working or not, if you're not using it then no

[latent heart]

Anyone know how to "unregister" a mover component so when you tear off it doesn't spam the log about being starved of input? Or just unpossess the pawn.

Destroying the pawn (on server and client) doesn't actually stop the spam.

[wicked whale]

Hello everyone. I'm using the MVVM plugin and trying to replicate the uproperties of a given view model so when the server sets it, it updates the UI of all clients. Generally it works, but I'm having an issue with one of my properties. It seems that calling UE_MVVM_BROADCAST_FIELD_VALUE_CHANGED is somehow clearing some internal flag (although this is just a wild guess on my end) and the field is not replicating/triggering the repnotify on clients. If I remove the call to UE_MVVM_BROADCAST_FIELD_VALUE_CHANGED, the field replicates as expected. Has anyone experienced anything like that?

[wicked whale]

Nevermind, I think I found the issue and it's in my own code.

[halcyon ore]

I asked this a bit ago, but something just made me think.
So, I had asked, is it bad to just have a replicated variable that barely changes, but will still change.
IIRC, someone had said that oh, its no worry, cuz the server will check if the value changes, not just blindly send it every 5 seconds and waste bandwidth sorta deal.

But, wouldn't it still have to use bandwidth to check the values between server/ client?

[latent heart]

It doens't check the client.

It checks its own value.

If the client changes the value itself, but the server doesn't change, the server will never know that and won't replicate the variable to correct it.

[halcyon ore]

How would that work with lag then?
Lag usually corrects itself, but if server is 5, and hasn't changed...
Then the lagged out client is just stuck in a limbo of 4?

[latent heart]

Variables are reliable. The server will send 5 until the client acknowledges it. I think anyway.

[halcyon ore]

Ah, ok.
Didn't realize that.
I assumed the default is unreliable.

[radiant cedar]

Is there anyone who has issue about "OnlyOnwerSee" in skeletal mesh (in lyra 5.5.4)?
In B_Hero_ShooterMannequin, i add skeletal mesh component and set SKM_Manny (Used in B_Manny)
and set OnlyOwnerSee = true
but Every Client can see other client's skeletal mesh

And if i change Skeletal mesh asset (SKM_Manny_Simple), OnlyOwnerSee works correctly

[echo pasture]

anyone know how to notify a client about a gamepause event? I'm having trouble doing it because once the game is paused the rpcs aren't accepted anymore

[nova wasp]

how are you setting it?

[nova wasp]

onlyownersee/ownernosee uses the chain of owners of the viewtarget to figure out if they are "owned"

so what it really means is if they are the local view target or not

I'm wondering if it just needs to be marked render dirty after the fact or something

kinda strange setting the skeletal mesh matters

[radiant cedar]

But if i just changed SKM asset, it works well. Only SKM_Manny (and quin) has issue

[nova wasp]

are you changing this in the defaults or at runtime?

[radiant cedar]

First person mesh is Skel comp i just added and Set skeleal mesh in default( editor )

if i used skel mesh asset in lyra project, it has error and other skel mesh doesn't has error

fisrt skm_manny : No error / Second Manny : has error

[nova wasp]

does it support the anim instance set on the skeletal mesh component?

[radiant cedar]

for First Person Mesh?

[nova wasp]

yep, the one you are having issues with

anything in the output log warning about it?

[radiant cedar]

nothing. jsut new Mesh spawned at (0, 0, 0)

and if i set OwnerNoSee = true at Skeletal mesh component in B_Manny
Same issue happen (lyra SKM_Manny -> Show mesh also to owner, other mesh- > Owenr can't see mesh)

[nova wasp]

so I asked you earlier if you spawn this at runtime

[radiant cedar]

No. I already add skel comp in editor

[nova wasp]

what is the log from then?

[radiant cedar]

Not spawn at runtime

[nova wasp]

just in case, can you show clicking on the mesh and showing the value of only owner see on it? make sure you set the world in the outliner to the client

[radiant cedar]

second check is OnlySeeOwner

and each client can see other client mesh

If i change Lyra SKM_Manny to Otehr SKM_Manny,
Each client can't see otehr client mesh

[nova wasp]

I'm surprised because that should work fine... if they have the correct outer chain to a not locally veiwed actor

[radiant cedar]

I wonder why SKM_Manny from Lyra work like this..

[nova wasp]

the fact the skeleton matters makes me think something from the anim instance is intefering but for now I guess you can just band-aid and just set it to hidden when they are not locally viewed and show when locally viewed :/

[radiant cedar]

First of all, I want to check out the same and different versions of the new Lyra Project. Thank you for your help

[nova wasp]

yeah I would need to debug the actual render calls to see what it thinks it is doing here

[radiant cedar]

Spawn of something usually at 0, 0, 0 is also a problem caused by incorrect replication settings, but it's complicated because it's a multiplayer environment..

[dark parcel]

can you elaborate? You are having issue spawning an actor?

[radiant cedar]

1. Add new Skeletal mesh component to Lyra Hero Character
2. Set OnlySeeOwner = true, Set Skel mesh asset SKM_Manny (provided by lyra, used in B_Manny)
3. Play in editor (play as client)
4. then Client 1 can see Client 2's new skeleltal mesh (client 2 can see client 1's new skel mesh)
5. if i change Skel mesh asset to other mesh, It doesn't happen

[echo bough]

are the replicated variables in the same actor component guarantee to arrive "at the same time" on the client if they are both dirtied at the same frame on the server?

[nova wasp]

nope

if you want them to arrive at the same time I would suggest making them a single struct to use atomic replication

https://vorixo.github.io/devtricks/atomicity/

Iris kinda does this by default for structs too afaik but doing this will work for now

[echo bough]

hm, i have a FFastArraySerializer but i also need a way for the client to know that this variable has gotten the latest replication from the server, i was thinking to have a separate bool for the server to replicate to inform the client

or am i thinking too much? when the FFastArraySerialzier is replicated to client, it should be the most current version of the server at the time of initiating the replication isnt it?

[fossil spoke]

You are overthinking it.

[chrome bay]

Changes made in the same frame will all be sent at once. The problem is that you might receive those changes out-of-order relative to other changes, so relying on atomic properties is generally quite difficult.

And in Epic's own words, Any order is considered an implementation detail that should not be relied upon

If you want to check the status of multiple replicated properties after replication, use PostNetReceive()

In non-iris replication it's possible for the client to get into a state that never existed server-side if properties change over multiple frames.

@echo bough if you can give more background on what you're doing, there might be a way around it.

[echo bough]

i am doing a game state for a multiplayer scenario, the game should start in WaitForPlayerReadyToStart, during this state, the server spawns the players respectively, and also preparing the map for gameplay (e.g. spawn enemies, item, etc). Each client will RPC to the server when they have their Acknowledge Pawn being set to signal that they are ready to start. The GameMode wait for all player to be ready then proceeds to start the game.

I wanted to add an additional condition for the Client to be considered ready to start. All other player pawn should also be replicated on that client before they are considered ready. I was thinking to use a FFastArraySerializer to keep track of the other actor reference whether they are replicated or not.

My problem comes in, since players may join in different times during the WaitForPlayerReadyToStart state, how should i handle this properly?

[chrome bay]

The simplest thing to do here is RPC to the Server when you receive another player pawn too, and track Server-side when all players have received all pawns. I don't think you want to involve any property replication here.

naive psuedo-code:

TMap<PlayerController, TArray<APawn>> PawnsReceivedByClients; // game-mode

AMyPlayerController::Server_ReceivedPawn(APawn* ThePawn)
{
    GameMode->PawnsReceivedByClient(this, ThePawn);
}

AGameMode::PawnsReceivedByClient(Controller, Pawn)
{
    PawnsReceivedByClients.FindOrAdd(Controller).Add(Pawn);
    
    if (HaveAllPlayersReceivedAllPawns())
    {
        // Go
    }
}

AMyPawn::PostNetInit()
{
    if (AMyController* LocalController = GetWorld()->GetLocalPlayerCOntroller())
    {
        LocalController->Server_ReceivedPawn(this);
    }    
}

[echo bough]

but if i wanted to specify which actor the client should wait, it probably should be a replication of actor reference?

[chrome bay]

You can't replicate an actor reference if the actor hasn't been received yet. This is why only the Server can track whether players are "ready" or not in this scenario

The idea here is whenever you receive a pawn on the client, you tell the server about it, and the server tracks who has received what. The server decides when everybody is "ready".

This also assumes you don't have to worry about things like dormancy or relevancy.

And you'd have to re-test the condition server-side whenever players leave, or pawns are destroyed/spawned etc.

If a player joins after all the other players have been determined ready, you either set the game mode back to the waiting phase if you can, or you ignore them and carry on anyway

Keep in mind there is also a greifing/hacking opportunity here - if a client doesn't send the RPC for whatever reason, your server will stall, so I'd advise a timeout too before it progresses anyway. Otherwise hackers could abuse this by blocking those RPCs being sent.

[echo bough]

hmm thanks for the scenario, yeah i will need to plan it out

[chrome bay]

Probably how I'd do it anyway

[echo bough]

yeah the point where "letting client to determine things" can be a breaking point if somehow it is blocked at the client.

so the idea is to let client tell the server, "i recieved some pawn", server decides whether it is relevant to game start, and tells the player to start when condition or timeout is met

[chrome bay]

Well it's not that you'd explicitly tell the player to start or anything, the game would just naturally progress to the next stage

But regarding the timeout, what I mean is the Server only gives each client a brief window to acknowledge the pawns (a few second or so) - after that, it stops caring and progresses the game anyway.

[echo bough]

in my case, it would be changing the game state, then that replicates to client and they remove their loading screen and such

[chrome bay]

yeah sure. To be honest, when it comes to these "waiting for players" states before games start, its usually just the server waiting for players to connect, it doesn't typically extend to clients receiving data too.

[dark parcel]

Its soo annoying that in some game, such as rainbow siege. Sometime we just get stuck at the start game.

Happend when one of the player doesnt respond but i guess its a bug because theres no time out.

[chrome bay]

Yeah, ideally you don't want to allow a way for the server to get "stuck" because it's waiting for a client to do something - or if you have to do that, you want somekind of timeout so it can't be abused

And ofc you have to make sure you re-test those conditions when a client drops out or something

[echo bough]

if that is the case, wouldnt the start time of each player be quite different? i am thinking of games like Lost Ark where they (i think) waits for all player ready to move before starting so you get a more similar starting time(able to move, etc)

they have a timeout too

[chrome bay]

Not sure what you mean, the server is deciding everything here

[dark parcel]

Don't the server have countdown?

Perhaps their starting time (a state saying game is inPlay) is a little different by a mili second. But thats the price you pay for having big latency. Nothing the server should compensate imo.

[chrome bay]

It can't really compensate anyway, your latency is your latency, can't make it lower

[halcyon ore]

Unsure if Multiplayer, or online-subsystem.
But, how do you do server side checks, without fully connecting?
Such as a whitelist.
I know games like ARK (when I started), makes a full PC, and "connects" a player, then do whitelist, and kicks.
Surely that can't be the best/ only way.
(and, same deal for passwords, and etc)

[quasi tide]

Beacons

https://dev.epicgames.com/documentation/en-us/unreal-engine/using-online-beacons-in-unreal-engine

[halcyon ore]

Thanks.
Seems a bit more complex then I would've thought honestly. 😛
But, I'll look into it/ work on it.

[chrome bay]

tbh this is typically something you'd do directly in your backend rather than bother the game with it

[rotund urchin]

hey

im having some issues trying to test multiplayer within the editor

im running the following settings. players 2, net mode play as client, launch seperate server true, run under one process false. with these settings it loads a completely empty map despite the default maps and modes being set correctly so i have override the game mode in the world settings witch gets the map to load. but then, my players are not spawning at the player starts and my custom pawn isnt being used, so im just an immovable ovject spawned on the outside of the map (seems to be spawned at the same location every time, but not a meaningfull location, like not at 0, 0, 0 or anything)

[shut hazel]

Is there a collection of resources for optimizing multiplayer performance?

[rotund urchin]

it works fine when not using run under one process

but then i dont know what's going on. i need to debug some code, particularly for my inventory system which is all server authoritative. when i get issues with it i dont know where the problem is coming from so i want to completely isolate the server and clients to their own processes

for example when not running under one process, the server crashes related to my inventory plugin, but when using one process it never crashes

oh wait the player is spawning at 0, 0, 0, my bad

[halcyon ore]

Wouldn't only big games like MMO have a dedicated backend for stuff like this?

having a backend for each private dedicated server seems a bit much?
Or, do I miss-understand, and backend means something else?

[quasi tide]

You wouldn't have a backend per dedicated server. One server could handle millions upon millions of requests.

[exotic wasp]

I don't see anything wrong with rejecting a player after initial connect if they violate some condition

[humble idol]

You gave ArK as an example, so I think that was the context he was using to give you advice.

[halcyon ore]

Some people may not know what ARK is, so I wasn't sure.

[quasi tide]

So you'd have one server that would handle doing small pings to. That would have the information that you need as a joining client. Then you would just get that information when needed.

[exotic wasp]

isn't that overkill for just a self hosted dedicated server?

[lost inlet]

ARK is definitely not the example for technical excellence...

what you describe should be possible via beacons

[halcyon ore]

Its not info the client needs.
Just preventing the client from joining, based on server side info.
Rather then making a full PC, and connection to the server, just to close it like 1 second later constantly.

[exotic wasp]

is there anything wrong with that?

[halcyon ore]

Just seems a bit much?
Handle an entire client connection, taking up player slots, etc.

[lost inlet]

well yeah, it's why beacons were invented

[exotic wasp]

or just do something in prelogin

[lost inlet]

yeah PreLogin is good for something like a password or handling things like a ban list. It sounded more like server slot reservation-y which is more beacon territory

[exotic wasp]

if you truly don't want the game server to even know a player gets rejected it sounds like beacon is probably best

but I would think rejecting someone in prelogin is completely sufficient for most cases

[lost inlet]

PreLogin is pre-PC creation since that function affectively gates the creation of one

[exotic wasp]

yeah

I guess you could get login spammed? but you can probably just temp ban the IP or something

[halcyon ore]

No.
Purely just check whitelist/ password, without a full game connection.

I just know my only context is ARK, and in ARK you do a full connection, then get booted out of the server.
and, I hoped that wasn't the only method.

[rotund urchin]

erghhh

[lost inlet]

I think there's even PreLoginAsync now which allows you to do an async backend query, process the result, and allow the login based on that

PreLogin is pretty damn early in the connection process so it's fine

[rotund urchin]

why is the console for the server closing

it used to remain persistent so i could log stuff on the server side

is this new to ue5? a bug? is there an option to keep the console persistent?

[lost inlet]

well is it actually running and not just crashing? what launch args are used?

because it definitely works

-newconsole is even a thing

[rotund urchin]

it could be crashing, lemme double check

looks like it is

yeh its crashing while trying to access my inventory data, but that works fine on the client.

is there anything with the server where it doesnt include your data tables or something?

[exotic wasp]

did you build full debug and not debug game?
is it a dedicated server build?

[rotund urchin]

its debug game. but im running from PIE so that should be ok shouldnt it?

its not a seperate server build

[lost inlet]

well it's not even a cooked server build so there isn't even a question of including content

[rotund urchin]

so every time you need to test multiplayer you need to cook a server build after a change?

its set up as follows. my inventory system is its own module/plugin. the plugin has settings for data tables to populate your inventory data which then gets cached by the server and client to link everything with simple integer IDs so not to have to send names between client and server.

the client and server compares an md5 hash of the cache, if there is a mismatch then something is wrong with the data and the client is disconnected

those settings should hold the same data tables specified by the user in the plugin settings on the server right?

[loud fox]

Hey guys, I'm making a multiplayer game, and for some very strange reason, my player has skills that work normally — but after a server travel, the skills only appear for the server. Even if the clients are standing right in front of the server, they can't see them.

[lost inlet]

no? if you need to test with your actual cooked server then you need to cook

what content is included with the build has no bearing on standalone

since that's uncooked

[kindred widget]

There's nothing complex about beacons. It's just a connection that gets done to the server similar to normal joining but not quite. The difference is that you use beacon actors to communicate with RPCs instead of getting a full map load and full on replication and such.

I mean. If anything. It's probably the absolute simplest and most direct way you're going to be able to get some basic info from a server or make requests to it.

[quasi tide]

It is. Which is why I said to use beacons originally. I was just expanding on Jambax's answer

[graceful flame]

sounds like you're using replicated variables but should be using rep notify instead so that client can do something with the changed value

[loud fox]

Nop i just spawn an actor same a fireball and the server can see but the client cant but before the server travel everything is okay

[graceful flame]

if u server travel then spawn before client is ready then client doesnt have the actor

[loud fox]

the server is attacking in front of the client and nothing happens to the client, something curios is that the client can take damage so the skills are in server but not in client

[graceful flame]

please stick to one issue at a time

can you show how you are spawning in this actor that has the replication issue?

[torn zinc]

I'm struggling with syncing stuff and replication. Thought i had it, but i don't 😖
What is the right order? Run on owning client, and then run on server?
I'm just trying to figure out Physics Handle and Cable component, and getting it synced.

[torn zinc]

I saw some tutorials to refresh my memory, gonna see if i can resolve it. But i am also struggling with physics collisions between players. I am however using SmoothSync plugin, and am not quite sure if that handles physics aswell

[reef hearth]

Hi all! I've been banging my head against a wall with an issue and was curious if anyone had thoughts. I am using SteamSubsystem w/seamless travel to manage multiplayer. I have a lobby with a lobby controller, lobby hud, lobby character, and lobby overlay and game mode. I am able to get players into the lobby and then go to the main game. The main game similarly has its own controller, hud, character and overlay and gamemode. After the game is over, I server travel everyone back to the lobby. Now here is my issue, everyone comes over properly and the hud and overlay and character look good, but for some reason the Lobby Overlay no longer works. the buttons just stop working. I'm wondering if I'm missing something obvious, why would my Overlay react differently the 2nd time I am coming back to the lobby?
I am not using PostLogin to initialize stuff since I know that only happens once. Another weird thing, when just doing this with 1 player, (the server) this issue doesnt happen, but when there are 2 players it happens.

[torpid lantern]

My goal is network efficient projectile system. I'd like to build something that does not require a replicated "bullet actor".

I am using GAS to call a func which spawns a BP_Bullet on the server and a BP_Bullet on the client. Those bullets are fed the same trajectory and speed. BP_Bullet is not a replicated actor.

On the BP_Bullet's tick for both client and server, I move the bullet along the trajectory at the given speed, at the time it is scanning for collision hits.

On Server's hit, the bullet passes damage.
On Client's hit, the bullet leaves an impact mark, makes sound, and triggers anim reaction (if hit character).

Everything is working with my setup, but I notice that sometimes the bullets get desynced just enough to miss characters. Resulting in a false positive hit client side - bullet stops, blood is spawned, but it wasn't actually a hit on the server.

What are my options to get around this false hit without having to replicate the projectile actor? Should I reconsider this approach in general?

[dark parcel]

What's an overlay? Widget?

Are you using console controller? Wdym the widget stop working, like you cant click buttons?

[boreal flicker]

i'm trying to make backwards reconciliation for hitscan in my fps. i have a perfectly accurate network synchronized clock that re aligns itself every few seconds, and all my characters record info about themselves 60 times per second on the server. when the client shoots, it sends an rpc to the server requesting a shot and providing a timestamp, and its camera location and rotation, and the server sets all the players back to where they were at the specified time using its records. however, there's like 20-40cm of error if there's a decent amount of latency. i think this is because the server sees different things than the client at any given time, so does anyone know how i would work around that?

[thin stratus]

The client has to tell the server the timestamp of the enemy data too

Server needs to roll back the enemy to that timestamp and then perform the hit validation

Without that the server won't be testing the correct enemy state against the hit

[boreal flicker]

hmm

so theres a communal list of data

and the client just tells the server which one it wants?

[thin stratus]

If a player runs in a straight path, they themselves have the newest data and are the furthest along that path. The server will be next and the other clients will see that player the furthest delayed.

So when you tell the server to validate a shot, the server will already have progressed the other players further. The timestamp you send must be the one of the enemy you hit, so that one can be rolled back to the point that the local client saw.

[boreal flicker]

like what the running player sees?

how do i get that

[thin stratus]

No what the shooting player sees

Every pack of data that defines the position of a player has to also contain a timestamp.

So that the local player can tell the server what replicated data they saw

[boreal flicker]

so when the server sends movement data to the clients, it attaches a timestamp?

[thin stratus]

That would be ideal.

[boreal flicker]

so how do i do that

[thin stratus]

The timestamp under which you also saved what data to some history on the server so he can roll it back.

[thin stratus]

Might be enough to have a replicated property in the character. They should replicate together then.

[boreal flicker]

ok

[thin stratus]

But you would need to test that

[boreal flicker]

i guess i'll try that

thanks

[dark edge]

What's your movement math?

[torpid lantern]

On Tick I move the projectile CurrentLoc + (Trajectory*DeltaSeconds)

I run a trace OldLoc to CurrentLoc, and if I collide with a thing, then stop tick and trigger an OnHit event

GPT suggested a solution that works, but I am not sure if it's so clean.

I've changed Server projectile to instead multicast the OnHit event, then on client side's OnHit, I reposition the projectile according to the server's passed in hit loc, and then trigger projectile effects at that location. I get a little bit of weird warping in my bullet trail when I relocate the client projectile, but I'm frustrated enough with bullets to call this "good enough".

[ebon pollen]

How to correctly resync state / play montages from the right position in multiplayer?

For example, there's an event N where an actor must play a RootMotion animation (an AI character passing through a door). On the server the montage starts immediately, but on a client the OnRep() that triggers montage playback may arrive with network delay. The result is that the client starts the montage from the beginning, while on the server the montage is already further ahead.

How to properly synchronize montages so that the client starts playing from the correct point in time (not from frame 0) and stays in sync with the server’s RootMotion state?

[ebon pollen]

To complete the question:
Is it a good idea to play AnimMontage in multiplayer via OnRep() structure, which will contain

• The montage itself
• TimeStamp taken from the server to take the delta from the client?

[dark parcel]

I would suggest to use GAS play montage

depending on the effect that you want, some things are more involved.

[ebon pollen]

well, I've already made a component, which takes an array of this structures, and according to server's timestamp plays montages. If I need to play montages one after another, I just need to calculate timestamp when it will be played (server time + animation length) When OnRep() comes to client with network delay, component calculates delta between this events and outputs StartTime for montage. If delta is too big, montage gets skipped.
Works like a charm.
GAS is, in my opinion is a bad decision, because in order only to play correctly replicated montage on door I need to give it an ability.... It's too overcomplicated for such a task.

[lost inlet]

wouldn't a "delay" be acceptable anyway because everything else is?

though I wouldn't have thought something event based like playing an animation would use an OnRep

[dark parcel]

How far in do you want to be in sync? if the player is delayed enough the animation will skip too much from the offset.

[lost inlet]

It feels a bit of a solution looking for a problem. Like everything you get from the server is going to be delayed by at least half RTT

but an OnRep is still a bit of an interesting choice because that'll be bound to the net update frequency of the actor

[ebon pollen]

if client delta > animation length, it should not be played at all

[lost inlet]

which would introduce more delay

[ebon pollen]

nope

this is only visual

what delay lol

ok, I'll record a video to show

just wait a bit

[lost inlet]

well you're the one talking about delays,

and for something that's an "event" why is it not a multicast?

[ebon pollen]

this what you get if you simply play animation OnRep()

door has small NetCullDistance for demonstration

[dark parcel]

yeah that's obvious

i would say look at what GAS montage do

[ebon pollen]

AI had already walked through, animation will play from start

[lost inlet]

which is generally why you don't do event based things (playing a transitional anim, spawning particles, etc) in an OnRep

once you are in relevancy distance, then it runs

[ebon pollen]

this is montages via component

[kindred widget]

For simple doors like this, on Beginplay set it to the current state of the property open or closed. On open or close, multicast it and play the montage based on direction.

If it's not in relevancy range it won't multicast to said client. When it is in relevancy range it'll beginplay.

[ebon pollen]

There are 4 montages, 2 for AI to enter, and 2 for exit.

When the client gets the info, it should be properly replayed in sync with server

[lost inlet]

all this to avoid a multicast

[ebon pollen]

multicast doesnt' work at all, lol