multiplayer

[meager spade]

you could adjust RelevantTimeout in the config

this is what is keeping your relevancy hanging for a while

(defaults to 5.f iirc)

NetConnectionClassName=OnlineSubsystemSteam.SteamNetConnection
RelevantTimeout=2
bNeverApplyNetworkEmulationSettings=true``` for example

[warped berry]

in the sessions interface, what's the callback for when the host gets disconnected or destroys his session? because I want the clients to destroy their session as well at that time1

[desert mist]

their sessions automatically get destroyed along with the hosts

[lone pine]

I'm trying to test multiplayer, and it's playing as two separate games where what one "player" does isn't visible to the other.

[warped berry]

but when I try to create a new session on a client it says the session already exists

I mean after the host leaves

[desert mist]

Are you testing through the editor? I have similar issues when doing so

[lone pine]

yes

[warped berry]

no not in the editor, in your game does the session get destroyed when the host leaves?

[warped berry]

they can see each other but not when they move or? tell us more!

[desert mist]

Yeah, the session gets destroyed for each client as a result of a connection error

https://gyazo.com/8ac27cd300a8514b4145cd6d79a49e52 which can be caught with this

@lone pine it sounds like your clients are not connecting to the hosts session but try running outside of editor as testing networking from within is not reliable

[warped berry]

ah alright I'll check for the c++ version

[desert mist]

Oh you're doing it through C++, I decided to go the BP route but it's UEngine::HandleNetworkFailure() and the failure type is ENetworkFailure::ConnectionLost. If their connection is lost I don't quite understand how they would still have a valid session, you're sure your clients are all in the same session?

[warped berry]

oh okay,,, and yea they are in the same session but I didn't override HandleMatchHasStarted or ended so im starting the session manually cause im doing a lobby, maybe that's why?

the test scenario is:

• A player creates a session and goes to lobby map
• Other players join this lobby using ClientTravel
• Host player clicks leave session, then other players get to main menu with network failure
• Whenever one of those clients try to create or join another session it says "session already exist" OR "cant join twice" !

so I guess that means that those clients still haven't destroyed their session, Right?

[warped berry]

oh I did override it but left it empty without calling super because I only want to start when the host clicks the start button

[lone pine]

neither player is visible to the other, they don't see the world changes each other make, and they both use the player 0 start position.

im testing with two clients on the same computer

[ancient badge]

Hello, is their any other way of saving a lot of variables for each player instead of using a mysql/mariaDB?
Understanding Ue4 is hard enough, but learningn HTTP, php, mySQL too is just to much.

[bitter oriole]

Well yeah, multiplayer games are hardly the stuff of one person

[dull lance]

quick question: for a P2P, game instance subsystems exist in all machines, right?

[bitter oriole]

They're completely local so no matter the multiplayer mode there's one on each

[silent valley]

Sure, use the built in savegame system to save player data on the server. When they reconnect, load the data for that player.

[ancient badge]

@silent valley will look into that thanks

[south rampart]

IOnlineSession has RegisterPlayer functions. But it needs a SessionName (FNamedOnlineSession), I only have access to the FOnlineSession object.

I want to register players from the client on the server before they are connected to the server. Will I be able to called these RegisterPlayer methods on the client to register players on sessions? Or is this only callable on the server where the session was created? (seems like it)

[golden nest]

Hi, does someone know if a created session destroys itself when all players leaves including the server?

Or only when server calls destroy session

[thin stratus]

Shoooould require a DestroySession call

[digital current]

What sorts of games are viable for a ListenServer setup

[winged badger]

anything non-competative with <16 (<=4 if you're networkign in BP) or so players (depending on your skill)

[grizzled stirrup]

Does anyone know why when calling WidgetComponent->SetWidgetClass(WidgetClass); would cause WidgetComponent->GetUserWidgetObject()to return null on the same tick ONLY on clients?

On the listen server host it works as expected

[twin juniper]

Since PS is replicated, do i need to replicate my variables inside or it is automatically done ?

[grizzled stirrup]

Yes you do need to replicate each variable

Just because a class is replicated doesn't mean each variable automatically replicates

As mostly you only want a small number of properties to replicate

[twin juniper]

K, thx you !

[vague fractal]

Hey uhm, i'm having a UInventorySystemComponent which is a member inside of the player class.
I'm not really sure why the client isn't able to create a widget there.
I have this here in the BeginPlay of the InventoryComponent.

        M_InventoryWidget = CreateWidget<UPlayerInventory>(M_OwningPlayer->GetController<APlayerController>(), M_InventoryWidgetRef, "Inventory");
        M_InventoryWidget->AddToViewport();
        M_InventoryWidget->SetVisibility(ESlateVisibility::Collapsed);

Works just fine for the server, but the client will get a crash at the SetVisibility line cuz M_InventoryWidget is a nullptr

[grizzled stirrup]

@vague fractal lol having this exact issue

Client only

[vague fractal]

xD

[grizzled stirrup]

WidgetComponent->SetWidgetClass(WidgetClass); to set it, calling WidgetComponent->GetUserWidgetObject() right after returns null only on the client

[chrome bay]

First thing you should do is remove the "Inventory" text, just leave the name blank or you might get a clash with object names

[grizzled stirrup]

Server works fine

[chrome bay]

My second guess would be that GetController() returns null, so creating the widget fails

So possibly a race condition

[vague fractal]

Removed the name, still a crash.
I gonna check the controller

[grizzled stirrup]

In my case Jambax I'm calling it from the PlayerController Begin Play, is there any possible reason it would be null here?

// In begin play on the player controller
WidgetComponent->SetWidgetClass(WidgetClass);

WidgetComponent->GetUserWidgetObject(); // NULL only on client unless I delay calling this until later

[chrome bay]

AFAIK you can't guarantee that the "possession" will have replicated before BeginPlay

So the Pawns' Controller property and/or the Controllers' Pawn property may not be set yet

[vague fractal]

Yeah, you were right.
The controller was not valid, but i don't understand why 😅

[grizzled stirrup]

Any ideas on why the widget object would be null in the controller itself?

[chrome bay]

It's because the Possession hasn't yet replicated, there are inherent race conditions there between the controller and the pawn.

I override SetPawn() in my controller, and call an event on the AHUD object, since that's the only place where you can be sure everything is up-to-date.

[vague fractal]

Phew, seems kinda weird to me to extend the PlayerController class just for this :c

[chrome bay]

Pretty common for multiplayer tbh, you have to code around the expected race conditions

[grizzled stirrup]

A pawn isn't necessary in my case though right so I'm really confused as to why it only works on the server and not client on the same tick.

[chrome bay]

Not sure why a widget comp would behave differently on server vs client though

[grizzled stirrup]

It's strange

I though it was due to a race condition

AS the OnRep that inits the UI happend before BeginPlay

But then I also created the widget in the OnRep and the same thing happened

Seems null at least for a short time after it is created, maybe a tick or two? Only on the client

Haven't encountered this before

[vague fractal]

Actually, would it maybe work to create the widget through the player class's BeginPlay or is there still the same problem ?

[chrome bay]

Same issue

[grizzled stirrup]

Same problem

[chrome bay]

The only place you can garauntee that both the pawn and controller are updated is from AController::SetPawn, which is called on Server and Client despite the name

[grizzled stirrup]

It can be a good idea to init / create stuff like this using GS delegates like OnMatchStarted

So you can be sure that the player is loaded in and the PC ready

[chrome bay]

If Pawn replicates first, it will have the controller but controller won't have the pawn. If Controller replicates first, controller will have pawn but pawn won't have controller.

For some reason, Epic decided that both Controller and Pawn should have replicated pointers to each other - so at least one of them will be out-of-date at some point.

[vague fractal]

Alright, PlayerController extending it is then 😄

[grizzled stirrup]

You'll more than likely need to extend the PC for other stuff anyway

So don't see it as a bad thing

[chrome bay]

PC is almost always extended, since it's a pretty core thing

[vague fractal]

👍

[grizzled stirrup]

Ok I guess the only solution I can see for this widget issue is to make another function on a timer to get the reference slightly later

Yuck...

But it's all that seems to be working

[chrome bay]

Check out what SetWidgetClass does

It doesn't do anything unless the world has BegunPlay

[grizzled stirrup]

AHHH

thats it then

[chrome bay]

Whether the world has "Begun Play" is replicated via GameState - so there's another race condition 😄

[grizzled stirrup]

Since the OnRep fires BEFORE begin play

[chrome bay]

joys of multiplayer

[grizzled stirrup]

Mystery solved

Thanks a lot

Was really thinking I'm an idiot for missing something obvious for hours haha

[chrome bay]

Using BeginPlay for initialising stuff in MP games is probably the cause of 90% of "random" bugs tbh

[grizzled stirrup]

I'm going to steer away from it and move this code to a state based thing like I suggested earlier 😄

So when the match actually starts

So the PC has definitely called BeginPlay by then

[vague fractal]

I think i've used a custom player controller once (Or maybe it was for the AI controller). How do i tell my PlayerClass again that it should use my custom one ? 😅

[chrome bay]

It's a double-edged sword because you either have to have different objects talk to each other to notify them of state updates, but that ties objects and systems together, OR you can have a global event system that different thing subscribe to etc.

@vague fractal controller class is set in GameMode 🙂

[grizzled stirrup]

Yeah I'm doing the subscribe thing

GS has the events, broadcasts them

Anything can hook in

[chrome bay]

See for me even GameState is too damn late 😄

[vague fractal]

I see, thanks ^^

[chrome bay]

I'm using a WorldSubsystem now for those events since you can guarantee it'll be initialised before any actors or UI widgets etc.

So if in some 1/100 situation the HUD is received before GameState, it can still safely initialise etc.

[grizzled stirrup]

Ah that is a good idea

What do you do for cases where an actor spawns and has an OnRep calling before its BeginPlay?

I actually realized I have the exact same problem in another actor there

[chrome bay]

OnReps etc. are always called before BeginPlay IIRC

[grizzled stirrup]

This could happen at any time during gameplay

So if the OnRep Inits UI

Not sure how to get around it without introducing a delay

I guess a timer for next tick isn't that bad

For any stuff that needs beginplay to have 100% been called

[chrome bay]

Well the trouble is you can't even be sure BeginPlay() will call next tick

[grizzled stirrup]

Oh really it's possible to take more? Damn..

[chrome bay]

Since if the GameState takes a few extra frames to replicate etc.

[grizzled stirrup]

Then I guess a timer for like 0.1f

Yuck

😄

Is this even the case on an actor spawned mid match?

Where BeginPlay has been called already ages ago

But just on the actor itself it hasnt

[chrome bay]

Yeah unlikely in mid-match as presumably the world is already in the "BegunPlay" state

[grizzled stirrup]

Ok cool might be able to get away with the next tick timer

Would you do something similar to avoid the race condition here?

AS I can't see another way around it

[chrome bay]

I'd never use a timer to get around it 😄

Since it's a time bomb waiting to go off really

[grizzled stirrup]

Well if something gets inited right after spawning, how do you ensure that BeginPlay is called before it gets inited and therefore is safe to init UI?

Do you spawn it invisible and init slightly later?

[chrome bay]

Usually I have multiple call sites to the same "Init" function, and the Init function checks everything is available

But as for UI/HUD, all my UI/HUD manages itself and it's own lifetimes

Then subscribes to events when needed

[grizzled stirrup]

Say a pickup in this case, it spawn an interact widget component UI that populates itself from the data coming in on the ONRep

So if the onrep happens before beginplay

It won't be valid on the client

So my options are: delay the init until later or call the init function again on begin play and check if not already inited?

[chrome bay]

So I guess in that case it's a self-contained UI/object system - so I would call the Init from both BeginPlay and OnRep

[grizzled stirrup]

Ok will do that, thanks!

And will just check if null to see if it has already been created

Another annoying thing is then having to store that data coming in via the ONRep as a property in the class

To ensure it's available for the late begin play edgecase init

Multiplayer design 🙂

We love it

[chrome bay]

Yeah honestly it's pretty common to have that setup. It's better to do that than get 6+ months into DEV and have a bug that says "2/99 times the UI doesn't show up for this pickup"

Because f*ck debugging that 😄

Been there.. learnt the lesson 😄

[grizzled stirrup]

Good to know I'm not doing something stupid

And it's common 😄

Yeah will definitely save the headache

Like it works fine on 3/4 players

WHy not the 4th!

Down to this issue usually it seems

[chrome bay]

I mean when I say common I mean that as "well that's what we're doing" but it works out well 😄

[grizzled stirrup]

😄

[chrome bay]

HLL has endless bugs but thankfully few of them are network-specific things anymore..

It's pretty stable when it comes to that stuff

[grizzled stirrup]

Out of curiosity how do you manage your time when it comes to fixing stuff?

Critical first, then gameplay features then if you have time smaller bugs?

I've been trying to fix all bugs as they come to prevent them building up

But can be very time consuming

And would be more beneficial to get game work done instead

[kindred widget]

If you can fix it, fix it. If you cannot easily fix it, consider doing something you can do. Chances are the solution might even come to you when you're not considering it.

[grizzled stirrup]

But what about thinking "oh that's easy, will take 5 minutes"

And it takes up 3 hours

Because of some strange edge case that is hard to track down

I guess with time and experience I'll be better at judging how long it will take

[kindred widget]

My experience is limited to two months professionally so far. But I find that it can be worse to force yourself to keep trying to fix something. Also from experience, you don't even know about the edge cases you don't know. I have spent hours trying to reproduce a bug that a few people reported multiple times and I can never get it to happen. Patch it up best you can and move on. Chances are that you'll either come up with a better solution later, or you could even end up just throwing it all out and overhauling. And that's gonna feel shitty if you do that after spending countless hours fixing it.

[chrome bay]

I can't answer that tbh that's more of a production thing, somebody else prioritises what is more critical etc.

For personal stuff though.. write it down in trello, add a "FIXME" and forget about it until it goes away by itself 😄

[grizzled stirrup]

Ugh so the OnRep happens BEFORE begin play on the client but after on the server

So the double function call really is the way to go for many of these cases

[chrome bay]

Haha yep

[grizzled stirrup]

Also doesn't the "Average" network emulation profile seem like a very poor connection in reality?

It seems to be around 200 ping

The "Poor" profile is 660 ping...

I suppose they might only mean it on either outgoing or incoming, not both

But I would say average would be something like 50-100 right?

And poor 200+

Trying to test in "pretty bad but reasonable" conditions

As 660 ping isn't something that will ever provide a good experience

[brazen sluice]

Hello! all happy french mother's day
I have been using FSocket to bind a custom port in the network to send some packet in parallel to Unreal's
So when a client connects, after coinnection to the server it then connects to the second port too through TCP.
It works fine normally, but with Steam's network OSS it fails
I'm assuming that for obvious security reason, the server needs to tell Steam to accept connection on both port, but I have no clue how to actually do this?
Or is it automatic with FSocket and the answer is somewhere else?
PS : When I connect I correctly user steam.123123123 as the IP

[chrome bay]

@grizzled stirrup hell if I know we have players trying to play on servers with like 300+ ping, god knows why

I don't think i'll ever consider a server unless it's like <60 ping but living in the UK probably factors into that decision too 😄

[grizzled stirrup]

True 😄

I'll tone down the bad preset a bit to hit 300 max 😄

[lost dune]

Please i 'm stuck on How to replicate dynamic material instances changes (color) on all clients

I trigger a multicast on the event who changes the parameter values on the DMIs

The DMIS variables are replicated , (replication condition is replay or owner)

the color change on the owner client but not on the other clients

[grizzled stirrup]

Share code

When they replicate down you'll still need to set the params on the client

[unkempt tiger]

Is there anywhere I can read more about the work currently being done towards a general network prediction solution, and how I can use it?

[lost dune]

@grizzled stirrup wait i share it

the event multicasted calls a function

where it change the parameter values on materials

a function is not replicable so ...

the server calls the event on all clients if i understand

replication is so hard to understand ...

the color changes on owning client but not on other clients

[peak sentinel]

660 ping means 0.66 secs to receive a network update from server lol

At some point players also should respect you and have a good connection before pressing play 😄

Testing at net pktlag=500 means "it even works in extreme conditions" but it does not need to provide a good experience

[kindred widget]

@lost duneThat is an input event into a multicast. Clients cannot multicast. Clients can only ever talk to the server. You have to server RPC from clients, and then multicast. Although you really should just create a property to set and let it replicate from the server, and use an OnRep to change the rune thing.

[vague fractal]

Is it possible to have virtual OnRep methods ?
EDIT: Yeah, seems to work 😄

[spark leaf]

So you have to change the value on the server and than have the variable be replicated. So your client can make a rpc call to server to change the value. The sever will change it. Than it will be replicated to all clients

[distant talon]

Noticed an issue that happens maybe 1 in 100 times but it's still game breaking when it does. I override my pawn's onrep controller so that as soon as the controller ref gets replicated to the client it gets triggered, but sometimes it just doesnt get called.

void AMyExamplePawn::OnRep_Controller() {
    Super::OnRep_Controller();
    ClientOnPossessed(Controller);
}
```ClientOnPossessed contains some critical setup steps for the client which rely on a valid controller reference. Anyone know why it might not get called sometimes, or have a suggestion for an alternate design to make this unnecessary?

(to clarify, its not that the controller ref isn't valid, it's that the function doesnt get called at all)

[kindred widget]

I'm confused. Why do you need to replicate the controller pointer to the client? Client already has access to it's controller.

[distant talon]

So, the server replicates the controller ptr to the client. I am overriding the onrep for unreal engine's pre-existing replication there

because i need something to happen when the replication happens

and 1 in 100 times the onrep just doesnt fire, which causes stuff to break

[kindred widget]

I find the restart functions much easier for that stuff.

[distant talon]

never heard of that, can you explain what you mean?

was using rpcs before but it'd fail pretty frequently, probably because sometimes the rpc would call before the pawn was finished initializing on the client

i can guess that's also whats happening with the onrep but i would have thought that once the replication does make it through it should still call the onrep

[kindred widget]

It's part of the possession chain. OnPossess is ran on server. This calls ClientRestart with a pawn input. Client version of the controller at some point calls GetPawn()->PawnClientRestart()

They're terribly named, and even worsely commented functions probably dating back to UT days.

But they're part of the possession chain, and virtual in C++.

[distant talon]

Oh. Yeah i would have never have found those, i did look for them too and i kept thinking "why isn't there already a clientside equivilent of OnPossess??"

Ill give those a try and hopefully those are reliable

thanks!

Is there something similar for the playerstate by the way?

[kindred widget]

For which?

[distant talon]

For when the playerstate becomes valid on the client pawn

[kindred widget]

Yep. A little further up in the base Controller class.

It has an OnRep for playerstate.

I have a memory of there being something in Gamestate to do with that as well.

Ah. right.

AddPlayerState in the GameState. It's how PlayerStates are added to the PlayersArray in the GameState. PlayerState gets replicated, and when it does, it'll add itself to the client's GameState array. It does it by calling AddPlayerState, which is virtual. Could override there too.

[distant talon]

Thats handy as well, thanks

[lost dune]

@kindred widget thank you i dident know OnRep exists

[agile lotus]

Why does unreal 4.26 always spawn players at 0,0,0 when opening a listen server or connecting to one

[hoary lark]

https://tenor.com/view/arnie-arnold-terminator-told-you-gif-13330636

[sand iris]

Are functions that are bound to an input button... bound in the client only?
Or do I have to do something like !HasAuthority() so that it doesn't bind it in the server too?
(so that the server is not continuously checking for input from a keyboard that does not exist)

For example, in my custom Character.cpp I have:
PlayerInputComponent->BindAction("BasicAttack", IE_Pressed, this, &AHVS_Character::DoPrimaryAttack);

but maybe I should have:

if (!HasAuthority())
{
  PlayerInputComponent->BindAction("BasicAttack", IE_Pressed, this, &AHVS_Character::DoPrimaryAttack);
}

[meager spade]

local only.

[eternal canyon]

Yea input is already local only as kaos said

[twin juniper]

Hello everyone.I am getting pending kill error on third client but remianing two clients are working pretty good.I kept "max no of players as 3" and "netMode as Play as client".Third client is pretty blank and pawn is not even spawning.Thank you

[twin juniper]

Just found that there is something wrong in my pawn class.If i change my pawn class i can see 3 clients individually.There is something wrong but there are no compile errors as well.

The third window is client.It is pointed towards sky and completely non-responsive

[thin stratus]

What is marked as pending kill? You need to give us more info

[twin juniper]

This is other pawn which worked for 3 clients but not working for 10 clients.Same problem when ran as 10 clients

The third client is giving isLocallyControlled as false in it's own window.But remianing two clients are giving as true and creating their UI but third client is not creating it's UI.

[slate basin]

@twin juniper add a few of those player start things into your level

I had an issue where it couldn't spawn the player

[twin juniper]

okay i will try

ChaosDuck my saviour it worked

I am using spawn players at camera location for convenience.Somehow it got messed.

Thank you @slate basin @thin stratus for helping

[summer tide]

How do I use this GetLifetimeReplicatedProps?

So I have this in the protected section of my header. virtual void GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const override;

[thin stratus]

Implementing it would be the first step :P

You usally also don't need to declare it

If you have a replicated marked property, it should automatically declare it via the GENERATED_BODY() macro or so

[summer tide]

I have this in the cpp file. https://gyazo.com/32f93adc5afed092c5c671d8b1a0bc82

I kept getting errors: https://gyazo.com/3ff87bef5fefa749393f9939054490ab

@thin stratus Do you have any idea?

[thin stratus]

Try including

Net/UnrealNetwork.h

Something like that

You are lacking the header that declares the macro

[summer tide]

Yea got it working. Ahy it's needed by the way?

[thin stratus]

Sorry?

I'm stepping through the InactivePlayerState code and I'm largely confused. If I reconnect, it replaces the NEW PlayerState with the INACTIVE/OLD PlayerState.
And then calls OverrideWith on the OLD PlayerState passing in the NEW PlayerState. ?!

I would have thought that it grabs the OLD/Inactivate one and calls OverrideWith on the NEW one.

Specially since the Input is called OldPlayerState.

Like, what am I supposed to do in OverrideWith? I basically got my old PS back and that gives me the option to nuke some data on it?

But OnReactivated could already be used for that

This looks buggy :D

APlayerState* OldPlayerState = PC->PlayerState; <<<<<<<<<<<< This is not the "Old" PlayerState. It's the new one from me just reconnecting.
PC->PlayerState = CurrentPlayerState;
PC->PlayerState->SetOwner(PC);
PC->PlayerState->SetReplicates(true);
PC->PlayerState->SetLifeSpan(0.0f);
OverridePlayerState(PC, OldPlayerState); <<<<<<<<<<<<<<<<< Override the Inactive PlayerState with the one I just got new but is labeled old, why?
GameState->AddPlayerState(PC->PlayerState);
InactivePlayerArray.RemoveAt(i, 1);
OldPlayerState->SetIsInactive(true);
// Set the uniqueId to nullptr so it will not kill the player's registration 
// in UnregisterPlayerWithSession()
OldPlayerState->SetUniqueId(nullptr);
OldPlayerState->Destroy();
PC->PlayerState->OnReactivated();
return true;

Looking through UTs code they either have a bug there or I'm missing something.
In PlayerState::EndPlay, they remove the player from its team.
So the PlayerState pointer in the Team and the Team pointer in the PlayerState will be nullptr.
But before that happens, it duplicates the PlayerState to make an inactive one.
So that one now has a team but isn't part of that actually.
When coming back, I get that InactivePlayerState, which has a Team I don't belong in, and the PlayerState that just joined but got replaced with the Inactive One got a Team, which is instantly "nulled" again.
I don't see UT ever handling that case

Why the hell are they not calling SetInactive to true on the InactivePlayerState? They only seem to do that when finding the Inactive one and then only on the new one that gets destroyed the same frame.
I must be missing something, is anyone actively using OverrideWith and InactivePlayerState? Just logically it seems utterly wrong

I guess I can override the outdated Team with the new one in OverrideWith, that would make sense.
But the SetInactive call is strange to me.

But even if I do that (UT does it), the Team would have the other PlayerState in it. So that would still be a mismatch..

[manic agate]

Hey guys, quick question, is there a delegate that is fired when server travel finishes which can also be bound from Blueprints?

Specifically, I would like to be notified when a pawn "enters the new level" basically

[winged badger]

@thin stratus i have the PS save sufficient data to fully restore the PlayerPawn on reconnect

[thin stratus]

Yeah I now changed it so my Restored PlayerState tells the TeamState that it got restored, passing in itself and the "old" PlayerState, so I can update the arrays properly.
Seems to work so far

[winged badger]

that function you pasted is just a little weird 😄

[thin stratus]

I can live with a good chunk of it. I do however think the SetIsInactive is missing/wrong

[winged badger]

it is somewhat unnnecessary, agreed

but it doesn't break anything

[thin stratus]

Well no, unless you rely on "IsInactive" to return true for the inactive playerState

[winged badger]

they are already swapped by that time, the "OldPlayerState" has no data except the unique net ID in it at the time, and is promptly destroyed right after

well, has no data except what the OverrideWith can copy

i do find the local variable naming... unfortunate

by the looks of it IsInactive only prevents it from registering with the gamestate

[manic agate]

Anyone for my question? I'm getting kinda desperate...

Hey guys, quick question, is there a delegate that is fired when server travel finishes which can also be bound from Blueprints?
Specifically, I would like to be notified when a pawn "enters the new level" basically

[thin stratus]

Pawns don't survive a Seamless Travel by default

Unless I remember incorrectly

[ancient bramble]

i have made basic replication like player A shoots player b and player B's health is reduced. It works perfectly when playing in editor(with 2 clients set to play as client) but when i package the project as a server and run the server, the logs show a warning that the actor is not relevant :
LogNet: Warning: Actor BP_serverIndicator_C / BP_serverIndicator_2 has no root component in AActor::IsNetRelevantFor. (Make bAlwaysRelevant=true?)
and replication also stops working showing this error:

    ThirdPersonCharacter_C /Game/ThirdPersonBP/Maps/ServerMp.ServerMp:PersistentLevel.ThirdPersonCharacter_C_2147482549
    Function /Game/ThirdPersonBP/Blueprints/ThirdPersonCharacter.ThirdPersonCharacter_C:ExecuteUbergraph_ThirdPersonCharacter:064E
[2021.05.31-10.31.03:093][308]LogScript: Warning: Script call stack:
    Function /Game/ThirdPersonBP/Blueprints/ThirdPersonCharacter.ThirdPersonCharacter_C:ServerFire
    Function /Game/ThirdPersonBP/Blueprints/ThirdPersonCharacter.ThirdPersonCharacter_C:ExecuteUbergraph_ThirdPersonCharacter

how can i fix this issue?

[thin stratus]

@ancient bramble Are you using C++ for that Actor?

[manic agate]

That is correct (as far as I've seen), I kinda explained myself in the wrong way. Let's just say, I'd like to be informed when a server travel ends for a controller, is there anything like that?

[ancient bramble]

no im not

[thin stratus]

HandleSeamlessTravelPlayer in the GameMode I guess

[ancient bramble]

this is my replication settings for ThirdPersonCharacter

i mean it works normally when i click play but it doesnt work when i connect to the local headless server

[chrome bay]

Anybody tried replicating a component property in the actors' replication list?

Actually.. forget that 😄

[thin stratus]

Is the Server Map maybe wrong and there are no spawn points on that one or something like that?

Or is it only the firing of the weapon?

You probably have code problems. Hard to help with just he information we have

[ancient bramble]

i have a player start, its spawning fine

and the map is also the same

[thin stratus]

Then I would start placing print strings and see what the log offers

[ancient bramble]

i just type the command open 127.0.0.1 in the console to connect btw

[dark edge]

Remove pawn from the world and try it, does it spawn you one?

[ancient bramble]

you mean inside the game mode i should make the pawn to none?

[ancient bramble]

nope i removed the default pawn to none and it doesnt spawn in the player character

[dark edge]

Game Mode should have whatever class you want as Default Pawn. Remove the pawn from the map tho, and make sure there's a PlayerStart actor on the map.

Then when you start up it'll spawn you a pawn and place it at the PlayerStart

[ancient bramble]

yeah thats what it does by defualt right, i havent touched anything but it still shows up like this

i mean if it works when you click play but doesnt when you connect to the headless server then somewhere else is the problem right?

[ancient bramble]

also there is no pawn in the map, just the player start

so when the player joins a server i should spawn a pawn in the player start, then posssess the pawn to a specific controller?

i just want to test if the player spawns and the replication works on a local headless server

but it doesnt

[ancient bramble]

should i keep the auto possess player to player 0 or 1

[thin stratus]

Neither

Just set it to not auto possess

The GameMode already takes care of this if you have the default pawn selected

[ancient bramble]

yeah i set it disabled

[terse prawn]

I'm working on a shooter and if the client's ping reaches a certain point, when they shoot and their bullets hit an enemy the bullets freeze and sit there until their lifespan is up.
Is there some way to mitigate this?

[thin stratus]

Predict the hit and hide it locally

[twin juniper]

What is better ? Trust client on the hit and then verify it server side later or predict it on the server before sending it to the client ? 🤔

[thin stratus]

Just predict visuals and keep damage on Server

[twin juniper]

Fortnite does trust the client and then verify on the server 🤔

to be sure he dont lied ?

[thin stratus]

Poor take and not really needed here (:

And trusting the client would indeed mean that the Server accepts without verifying

[ruby ferry]

Hello!
I want to create a system in C++ to replicate animations montages, the gameplay of my game will heavily use it so I need to make sure it get replicated properly:

When the client do the action, it should instantly play it
The server will do the verification then replicate it to others clients
If a client is late to get it, it will play it and set the position of the animmontage where it is currently.

Is there any built-in system to do it?

I want to use that mainly for the characters to replicate animations on things that aren't players like the environment.

[twin juniper]

K k

[vague fractal]

Might sound a bit weird, but is there any way to wait until an RPC call is finished before you execute other code ?

[dark edge]

You'll need to somehow send back a confirmation or some other bit of data to let you know to proceed. You could have the 1st RPC call back into the caller to do the next bit

[vague fractal]

I could see how that works, i'm just not really sure how to keep my DragDropOperation alive for the time 😅

[dark edge]

@vague fractalWhat exactly are you trying to do? Drag and drop inventory?

[vague fractal]

Basically.
Currently i'm at the "Let the dropped inventory item spawn into the world" which works just fine.
The problem is just that i have to update the inventory once i drop it.
This works also just fine for the server, but for the client it doesn't work.
I assume it's cuz the RPC call isn't fully finished at the point where i call the UpdateInventory method

I guess i could do it with a other way, but that way is kinda more lazy cuz i'd check if the inventory item amount got changed since the last tick

[dark edge]

@vague fractal Have the drop be the first thing that the server knows about. You should have some sort of Inventory to World function, the drop would call that

That function is what would do the actual removal from inventory and spawning into world.

[vague fractal]

I think i have that already

[dark edge]

As far as the server is concerned, whether you drag and drop or just use a hotkey or any other method, dropping an item is done the same for all of them.

[dark edge]

Then what's the problem? Just at the end of the drag and drop, you call that event with whichever item you're trying to drop. There shouldn't have to be any sort of waiting or call back

[vague fractal]

I have it like here

void Foo::NativeOnDrop(...)
{
  OwningPlayer->GetInventorySystemComponent()->Server_DropItem(InventoryItem->GetItem());
  PlayerInventory_DragDropOperation->OwningPlayerInventory->UseActiveSortButton();
}

[dark edge]

So is the problem the timing of the sort?

just have sort happen after inventory is updated

nothing to do with the drop function

[vague fractal]

Ye, that was basically my second plan. As in the inventory checks if the item amount got changed since the last tick

[dark edge]

RepNotify

Dont check things on tick unless they're needed like maybe for physics or movement etc

[vague fractal]

I think i'm not able to use this method due to how i made the things 😔

[dark edge]

You should be able to, your inventory is a replicated struct or array righT?

[vague fractal]

Yeah, but it's stored in my UInventorySystemComponent.
Problem here is that my UPlayerInventory isn't stored anywhere cuz i wasn't able to store it.
The problem was that when i create the inventory on the client the Pawn or Controller were not synced or similar

[dark edge]

You could either have the inventory sort every time it changes, or just have a manual sort button if ppl might want to have their inventory laid out in a certain way like WoW has it.

[bronze arch]

what if you can disable destroy and spawn new playerstate when player leaves?
is this possible tho?
then player reclaim the owner of the current playerstate when they rejoin the game

[dark edge]

Wait, so the server doesn't know what's in a players inventory?

[vague fractal]

It should since it's using the original items from the UInventorySystemComponent

[dark edge]

So what exactly is a UPlayerInventory?

[vague fractal]

Basically just the visual inventory (UUserWidget)

[dark edge]

Then just have the RepNotify call Update on the widget after sorting

RepNotify -> Sort -> Update Widget

[vague fractal]

But for that i'd have to store my widget somewhere. Otherwise i'm not sure how to reach the widget for his methods

[dark edge]

Where are you creating the widget from, HUD or PlayerController or where?

[vague fractal]

That's also done in my UInventorySystemComponent once the player presses the button to open the inventory

[dark edge]

K so then the component can store a ref to the widget and tell it to update when the RepNotify fires

[vague fractal]

I've tried that. On client i'll only get a nullptr once i try to store it in a member variable.
But it does work just fine if i work with a local variable

[dark edge]

ya something sounds fucky here. is the UI in screen space or world space (3d)? I'd recommend haveing all the UI handled in the PlayerController or HUD and not in the inventory component. If you're reusing the same inventorycomponent on chests and mobs and AI characters etc, it's unnecessary.

[vague fractal]

The UI is in screen space

[thin stratus]

UE4 does that by default.

Which was the thing that broke stuff for me, cause I expected it to work slightly different

[vague fractal]

Tbh, i think the easiest way here would be really just to check if the item amount from the player got changed since the last tick.
Cuz currently i'm creating and destroying the PlayerInventory once the player wants to open/close it.
So the price of using Tick in there shouldn't be high at all

[bronze arch]

so you can't change it and remove the destroy/overriding PS?

[thin stratus]

I could, but I want to use it. It's also sort of working now

[bronze arch]

I see, i was thinking to disable that function so i dont need to mess with copyproperties (even if it works for now)
because it wasting bandwidth to copy new PS replications to all players again

[thin stratus]

It's not replicating the Inactive ones

[bronze arch]

mean the new one, when players leaved New PS goes spawning isnt is it?

[thin stratus]

Yeah, they duplicate the old one and set it to not replicate

[bronze arch]

old one is inactive ofc

oh

[thin stratus]

The new one that is created when they rejoin

Is probably not replicating much

as that all happens in the same frame

[bronze arch]

oh thats weird

at the my project it was happening on leaves

and after firing a rpc it goes replicated automatically to all players

[thin stratus]

It shouldn't

They mark it as non replicated

[bronze arch]

but how does it works on my project tho

even i can get Level integer from that spawned new PS

if i can match the player ID

[thin stratus]

You can't even access that by yourself

So whatever you are accessing is not the duplicated one

It's not part of the PlayerArray

[bronze arch]

but when i firing that RPC from copyproperties (before leaving and after) it shows different PS names like spawned new one

[thin stratus]

Idk, all I know is that it's marked as not replicated

[bronze arch]

interesting

[twin juniper]

Hey everyone, I'm looking for a person who's very well-versed in designing multiplayer in UE4/UE5, I've questions that I'd like to ask to a competent person who'd be nice enough to give me 10-15 minutes of their time. Preferably someone who's released and tested multiplayer. You'd be saving me a lot of effort and time and anxiety.

[meager spade]

#instructions @twin juniper

[twin juniper]

whoops, sorry.

didn't know that existed.

Not asking around for a job listing or anything, by the way. Just have a question about the general topic.

[meager spade]

i can write an entire game in 10-15mins.. lol

#define true ((rand()&15)!=15)

but mine is true most of them time 😄

ah true

[vague fractal]

#define return if (rand() % 100 < 2) throw std::exception(); else return

👀

[ancient bramble]

https://youtu.be/3UsnVUOs-H8

this is my issue exactly

[south rampart]

Does anyone know a good tutorial on beacons, especially LobbyBeacons? To be used on dedicated servers.

[cerulean escarp]

hey y'all I'm getting back into UE4 and I'm currently setting up my GameMode and GameState. I wanted to start with something simple like networked spawning/respawning of a simple player pawn that I made but I'm running into an issue I don't recall having last time I set a respawn system up.

the problem is that the player respawns but doesn't get transported to the transform of my invisible "spawn" actor. I've tried setting the transform to a static value at 0,0,500 but it behaves the exact same.

the way I have this set up is:
"run on server" RPC is called within the playercontroller
the player controller RPC calls the multicast function in the gamestate
the gamestate RPC calls another multicast function in the gamemode that calls the "Restart Player from Transform" node

it's been a while since I've done any work in UE4 so there's probably something simple I'm missing

[dark edge]

@cerulean escarp Don't reinvent the wheel. The GameMode has functions for this. Override them if you have to.

[cerulean escarp]

I know... I'm using that function to respawn the character

"Restart Player at Transform"

the difference here is that I'm making a bridge between the player and the gamemode in order to allow the player to call the respawn function

[heady python]

What happens if my servers arent optimized well? I know that the lobby will eventually crash if im overloading the server too much, but does replicating less events/variables do anything noticable? Will it affect ping, data loss, etc?

[dark edge]

@cerulean escarp Why are you multicasting those? It should just go
input -> run on server -> do stuff

GameMode only exists on the server anyway

[cerulean escarp]

I tried that and it still just resets my camera without moving the player to the spawn location

also just to clarify something, I was under the impression that custom events which are intended to be called outside of the GameMode should be set to multicast. do they have to be set as an RPC in any form or can they just be non-replicated custom events?

alright so I just made it work by using the input -> run on server -> do stuff logic along with destroying the player pawn before calling the Restart Player function in the GameMode and that worked

[dark edge]

What is the players Pawn in this scenario? You doing anything weird or just have a pawn with a camera on it?

[cerulean escarp]

it's just a character with movement code and a camera attached

[dark edge]

And that class is set as default pawn in GameMode? And you're initially starting it the normal way?

Does player pawn exist on the map at startup or do you let GameMode spawn it?

[cerulean escarp]

yep it's the default pawn in my GameMode and the GameMode spawns it on one of two PlayerStarts I have placed in the test world

I ditched the weird actor search method I had posted earlier since I realized PlayerStarts have spawn tags

[dark edge]

Just try this. Input on Controller or Pawn -> Run on Server -> Get GameMode -> Restart Player

That should snap you back to however you were when first loading.

[cerulean escarp]

that didn't work, it seems to restart my character but in place rather than moving it back to the player start

[dark edge]

How is it initially finding player start? Just the normal way or something custom event?

[cerulean escarp]

the default way

[dark edge]

Youre calling RestartPlayer and not RestartsAtLocation right?

[cerulean escarp]

the one that works I was using Restart Player at PlayerStart but when I did what you suggested I used just RestartPlayer

[dark edge]

Hmm that's strange. I'm not 100% sure on the call order between the different restarts.

[cerulean escarp]

alright, well it works and is replicating properly between clients on the server so I think it's ok to use

just doesn't seem right to me to have to destroy the player pawn before restarting them

[dark edge]

Is that what you're having to do? Manually destroy then restart?

[cerulean escarp]

yeah

last time I set up player spawns on a different project that I no longer have I didn't have to do that

[dark edge]

Yeah something seems fishy

You sure you're not overriding any of the start spot functions?

[cerulean escarp]

I don't believe so

only event that I have in the GameMode is the custom event I use to call the Destroy Actor and Restart Player at PlayerStart nodes

[dark edge]

Try removing those

You shouldn't need any custom events for this

[lost dune]

IS it a good thing to store Characters in the game mode? Or where else can I store them

[dark edge]

@lost dune what do you mean by storing them?

[winged badger]

why would you store them?

[cerulean escarp]

alright I disabled the custom event and now the only thing I'm doing is in the player controller calling a run on server event that runs the RestartPlayer node directly inside of the playercontroller

no code at all in the GameMode

and it does the same thing where it just restarts the player in place without taking it to a spawn

[lost dune]

In my game mode, on post login event, I spawn a new character and add him in an array of characters

[dark edge]

@cerulean escarp WTF that's weird. You'd think it'd at least do what it does the first time.

[cerulean escarp]

ikr that's why I've been so confused

[dark edge]

Unless it defaults to something other than RestartPlayer. Try the other options.

[lost dune]

Couldn't it be in the game state?

[winged badger]

PostLogin kinda works, HandleStartingNewPlayer is better

unlike PostLogin, it works with seamless travel

[lost dune]

Ok

[winged badger]

keeping an array of characters is optional

especially considering its the one fully safe use of GetPlayerCharacter[Index] function

[cerulean escarp]

none of the RestartPlayer options worked until I added a Destroy Actor node before it

[dark edge]

Dafuq

[winged badger]

GetGameMode - > GetNumPlayers -> For (0 to NumPlayers - 1) -> GetPlayerCharacter[Index]

[cerulean escarp]

this is wack

[winged badger]

will get you all the player characters, without the need for caching them anywhere, works only on server

[cerulean escarp]

I suppose it's alright to use though since it replicates properly

[dark edge]

@winged badger Isn't player pawn stored in PlayerState by default or nom

[lost dune]

Excellent thank you

[winged badger]

it is, but this is less nodes to iterate them all

as you don't have to pull pawns from PlayerStates in PlayerArray here

it is the version that works on clients as well, so... @lost dune

[dark edge]

@winged badger Any insight into this RestartPlayer BS?

[winged badger]

GetGameState -> GetPlayerArray -> Foreach -> GetPawn (might be something similar, function name) will also iterate over all Pawns

i didn't read from start it was a little long

[dark edge]

Should it default to restarting in place without using start spot like first startup?

It's respawning pawn but keeping location. Uses start spot if pawn is destroyed first

You'd think it'd do the same as first startup

[winged badger]

there is a ShouldSpawnAtStartSpot function in the GM

that caches it in AActor* StartSpot in the PC

and by default returns StartSpot != nullptr

[dark edge]

Ah

[winged badger]

if it returns true it will skip choose/find playerstart

i find it best to override it to return false;

[dark edge]

@cerulean escarp There you go

[cerulean escarp]

awesome, thank you both!

I'll override it and give it a try

[winged badger]

as ontop of everything else, it caches the StartSpot before you can get any team information in

its really terrible

@cerulean escarp why are you multicasting stuff from GameMode?

[cerulean escarp]

I'm not anymore

[winged badger]

good

[lost dune]

Can someone help me with set master pose for multiplayer client server? The same node call works fine in single player, but in multi its stuck on idle animation

[dark edge]

@winged badger I already reamed him for that one

[cerulean escarp]

lol

[dark edge]

Show what you're doing right now

[lost dune]

Ok

[winged badger]

animations don't replicate

nor can you replicate stuff inside anim BP without significant (and very much nor recommended) custom work

you replicate what you need via pawn/character

your BlueprintUpdateAnimation does TryGetPawn->Cast

[lost dune]

I was sure it was the try get pawn

but why does it works in single player

[winged badger]

then it reads and caches everything

and uses only what it cached during updateanimation in anim graph

no BP logic, just read the cached variables in anim graph

or you lose the multithreading for animations

[lost dune]

i'm lost

I just replicate the variables responsable for the animations

the Anim BP get them and choose the anim to play

why it works for the "character mesh" and not for the armors skeletal meshes

they use the same animBP and share the same skeleton

[dark edge]

@lost dune Show your TryGetPawn

[lost dune]

ok

[dark edge]

Ya don't do that

Oh wait I thought that was a call into the character BP

[lost dune]

No

The skeletal meshes(armor pieces) are animated but stuck on idle anim

its not like if they were not animated at all

[dark edge]

You using Master Pose Component?

[lost dune]

Yes

works perfectly in single player mode

[dark edge]

Then one of your driving variables isn't being replicated

Show the anim graph

Also snipping tool

Win alt S

[lost dune]

stuck on idle/run state

even if my character strafeLeft

[dark edge]

What's the transition rule to strafing?

[dark edge]

Dude use the snipping tool, half of these screenshots is discord lol

[lost dune]

sorry 🙂

[dark edge]

@lost dune k and show where you set bStrafeLeft in the character BP

[dark edge]

There it is

Input is only on local client

Any particular reason you're doing it that way and not a velocity driven blend space?

[lost dune]

No , i 'm just finishing learning the basics and re implementing it

[dark edge]

Ok so I would either switch over to a blend space (the good version) OR start calculating the movement booleans based on velocity (the bad version)

Either way, you don't need those bools on the character. Not the movement ones anyway.

[lost dune]

but my character is rolling pressing R key , i have to do a boolean for that

the question is why the character mesh is correctly animated and not the armor pieces , sharing the same ABP

[dark edge]

Is character mesh correct in multiplayer?

[lost dune]

Yes

[dark edge]

Even strafing?

[lost dune]

The armor pieces are ""spawned"" using set child actor class on the child actors of the armor pieces

just after that i call set master pose , it fails

ohh , it dosent fail , its stuck on idle

[dark edge]

What are all the errors you're getting?

[lost dune]

there are a lot for the moment i have not cleaned yet the output log , but i check right now

[dark edge]

Anyway, for multiplayer, your set up is pretty screwed up. I would recommend taking a look at the third person template and seeing how they do their animation blueprint. Don't even worry about armor right now.

[twin moat]

Anybody know an easy way to get a user's public IP address (for PC)? to then get their general geolocation

[eternal canyon]

I mean if ur the server u can

[twin moat]

is it possible to get client's IP?

[eternal canyon]

@twin moat ^^

[twin moat]

ok thanks

[lost dune]

Is it possible and faiseable to copy pose of the character mesh to his skeletal mesh armor ( instead of using anim BP)

[twin moat]

I think you only need Master Pose component. No need to assign an AnimBP - https://www.youtube.com/watch?v=yQQYyHzTrS4

[severe tendon]

How would I go about teleporting all clients to a position?

I have a "host" client who has an interactable Widget on their hand and when they press a button it casts to the GameState and runs a Server event with the positions of the teleport, which then runs a multicast that lets the client camera fade out, checks if the client is the host/client and teleports them to specific positions based on that data.
It works when you're playing solo, but the moment another user joins it (the widget) stops working entirely

[lost dune]

great

I have forwarded with it , but now the armor is not animated at all in multiplayer (works fine in single player) the set master pose fails in multiplayer i don't know why

[dark edge]

@lost duneYou need to spawn the armor on the server and everywhere, set master pose locally

[lost dune]

ok

so i tell the server to do a multicast?

[severe tendon]

Yes

[lost dune]

the armor keep not animated

only in multiplayer

[severe tendon]

Are you parsing the components that need to be animated/attached across to the server?

Also why not just do/attach them to targets

[lost dune]

attach component to component?

[severe tendon]

Yeah, or attach component to bone, that way you don't have to update it realtime

Unless thats what you're doing

[lost dune]

They are skeletal meshes deformed by multiple bones

if they are attached to a single bone it will go throug the vody

body

the spaulders and helm are static meshes

for them its simply attached

but gloves boots breast and legs are skeletal

NEW , well animated in the BP editor with set master pose in construction script

It's a multiplayer issue

[severe tendon]

I'd still love a hand with this 😐
Anyone know anything about 3d widget replication?

[dull lance]

yes ofc it stops working with multiple elements. Your GetPlayerPawn(0) should be ran locally, not from the server

since GetPlayerPawn(0) from the server is just the Host; no one else is considered

Eeh never mind; I misread on the GetPlayerPawn(0).

How are you getting to run the Teleport to Entrance?

GameState doesn't have a replication owner per say, and thus can only run Net Multicasts when you're already the server

Furthermore, this type of action doesn't make much sense to run from the GameState

[severe tendon]

Yeah I moved it from the GameState to the parent widget actor

Its running via a Widget button press

Widget is spawned on everyones end via joining a session and if you aren't the host then it disables yours/hides it

I assume Widgets aren't replicated so I've tried to basically push it over to the actor that has it as a Widget Component

It works fine when you're in SP or alone in a server but the moment another users joins it just stops working

oh yeah and this, ofc you actually need the TP

I was running Teleport in Server but moved it back to Client

Based on this forum post I'm reading you can only call RPCs from controlled pawns?
🤔
however it is 6 ears old

[turbid radish]

Hi, I have a problem which I am not sure how to handle correctly. I've got a multiplayer game where I want to open doors so that if someone opens a door it opens for everyone and everyone should be able to use doors. Problem is that server owns my door actors. and I cannot trigger Run On Server event on interaction from client. It took me a while to figure out that I have to first make the client owner of that actor before I can run the events. So now It all works but on every interaction I first make the client owner of that actor and then run on the server, multicast to make it happen for everyone. For me it sounds like there should be smarter way of doing this. can I ignore the ownership alltogether somehow ? to make it so that every client can run the "Run On Server" events

[hollow eagle]

You're correct, there is a better way to do that. Send a Server RPC through either your player character or player controller.

[severe tendon]

Yeah, there are a ton of better ways to do it but at this point its just a duct-tape fix for something that has to go out tomorrow. I'm hoping running it through the Pawn will fix it 😬

[hollow eagle]

that was a response to Proge, not you. But yes, you can only call an RPC on an owned actor.

[severe tendon]

ah ok

[hollow eagle]

It doesn't need to be a pawn, it can be the player controller or any other actor that's owned by that client.

[sand iris]

is APawn::AddMovementInput a server RPC? If so, how can I tell that it is?
If not, then then why does calling MoveForward() (which is bound to my forward axis input and is client sided) able to move my character in both client and server?

[hollow eagle]

It isn't.

It sends the input to the movement component (if there is one). If this is a character, what it does from there is complicated.

tldr: CharacterMovementComponent applies the input locally and also sends it to the server. But that can get rolled back if the server disagrees on the result.

There's an overview of how CMC networking and prediction works here - https://docs.unrealengine.com/4.26/en-US/InteractiveExperiences/Networking/CharacterMovementComponent/

It's not as simple as just sending a server RPC.

[sand iris]

oh I see, that makes sense. I see that AddMovementInput sends the input to the movement component's UPawnMovementComponent::AddInputVector but after that I get lost lol

oh thanks for the link, i'll take a look!

[lyric lagoon]

@turbid radish RPC's cost more bandwith, you could also share a variable "bool DoorOpenState" and use a rep_notify function which will play your door opening or closing animation on clients.

[turbid radish]

Thnx ill investigate.

[lyric lagoon]

Here is a good link from the UE4 Documentation that should help you, you can read it all or take a look to the Variable Replication section:
https://docs.unrealengine.com/4.26/en-US/InteractiveExperiences/Networking/Overview/

[ancient bramble]

https://www.youtube.com/watch?v=lPOSiM_-g74
any1 know how to fix this issue?

[dark edge]

@turbid radish Simplest robust method

Input -> Run on Server -> set replicated variable -> Repnotify

Bool bIsOpen or float OpenAlpha

Depending on if a door can be half open

[lyric lagoon]

@ancient bramble Have you set a rootcomponent in your blueprint/cpp constructor ?

[ancient bramble]

i didnt do anything i just have the default third person gamemode and set auto posses to disabled.

im using blueprints for the replication part

i just have a player start on the map, and that it

[lyric lagoon]

I am more comfortable with cpp but the logic is the same.
You have a blueprint called BP_serverIndicator_2 which is shared on network but does not have a rootComponent assigned.

And BP_serverIndicator

Which means there is one per player.

What are you doing with this serverIndicator?

[ancient bramble]

nothing, i dont even have that blueprint

i mean it plays fine when i click play, so it should play fine when i connect to a headless server right?

[lyric lagoon]

I see it in your folder ThirdPersonBP/Blueprints his name is BP_serverIndicator

In theory but not always, maybe this warning is not related to your issue but it's good practice to remove all your warnings so you can see what's going on clearer.

[ancient bramble]

that the text renderer

bp_ServerIndicator is the text rendering actor

it was set to replicate

i changed it

ok the warnings are gone

but still the replication is failing

[2021.06.01-05.59.20:299][545]LogScript: Warning: Accessed None trying to read property K2Node_CustomEvent_Gun
        ThirdPersonCharacter_C /Game/ThirdPersonBP/Maps/ServerMp.ServerMp:PersistentLevel.ThirdPersonCharacter_C_2147482549
        Function /Game/ThirdPersonBP/Blueprints/ThirdPersonCharacter.ThirdPersonCharacter_C:ExecuteUbergraph_ThirdPersonCharacter:064E
[2021.06.01-05.59.20:300][545]LogScript: Warning: Script call stack:
        Function /Game/ThirdPersonBP/Blueprints/ThirdPersonCharacter.ThirdPersonCharacter_C:ServerFire
        Function /Game/ThirdPersonBP/Blueprints/ThirdPersonCharacter.ThirdPersonCharacter_C:ExecuteUbergraph_ThirdPersonCharacter```

[lyric lagoon]

Are both of your windows clients ?

[ancient bramble]

yes

[lyric lagoon]

This is odd, can you try:

• Make sure your BP_Character is replicated
• Make sure all the subComponents of BP_Character are set to replicated
• Give it a try

[plucky sigil]

are there some cons with calling a server rpc without HasAuthority check ?

[twin juniper]

Since only the Server has authority, yes

That’s literally like « hey client, I authorize u to do what the server can do, do it !! »

So yeah HasAuthority is smth important (not just for RPC.)

[plucky sigil]

are you saying you should always do the HasAuthority check regardless

void DoSomething()
{
    if (!HasAuthority())
    {
        DoSomething_Server();
        return;
    }

    // Do the something
}

void DoSomething_Server()
{
    DoSomething();
}

So it should always be like this ?

And when you want to do something you should be calling the DoSomething() and not DoSomething_Server() ?

Even if you know you are server ? E.g. GameMode
And also as a good practice ?

[lyric lagoon]

What's you function is doing there is checking if this code is executed by the client, if yes then you call the RPC server method so it also execute on the server.

[plucky sigil]

but my questions is, should you always have this template for all rpc calls ?
regardless of whatever situation

[lyric lagoon]

Because of the return it will only be executed on the server and not the client.

[plucky sigil]

but because the actor or whatever is replicated, it will reflect on the client side, hence we should use this template for all rpc calls ?

[lyric lagoon]

It is a standard template use by UE programmors, you don't have to use it but I think it's good practice.

[plucky sigil]

you say

you don't have to use it
what is the alternative ?
and is it better ?
and better in what sense

[lyric lagoon]

I personnally wouldn't use something else.

Not meaning you can't.

[plucky sigil]

do you have some examples of the "something else" ?

also, lets say you know you're server, would you still use this template for rpcs ?

[lyric lagoon]

If you are 100% certain the code is running only on server side then you don't need to, as the server do not need to RPCs to replicate.

*server side

[plucky sigil]

are there some kind of overhead/cons with calling rpc on server side ?

[lyric lagoon]

Beside that you are making an extra call and that your logic is not properly handled (and might be confusing as the project grows) no I don't think so. The server will just execute the function.

[plucky sigil]

cool cool i think that clears up some of my doubts, thank you

[lyric lagoon]

You can refer to the documentation here (section: RPC invoked from the server)
https://docs.unrealengine.com/4.26/en-US/InteractiveExperiences/Networking/Actors/RPCs/

[plucky sigil]

i think its not informative enough

[lyric lagoon]

I undertand. However it shows that when you are the server instance executing a server UFunction, regardless of the Actor ownership it always runs on the server.

[plucky sigil]

Are you familiar with GetNetMode()
I feel that we should avoid using them ?
I mean if you actually just want to check for GetNetMode() then its fine

But i dont think its good or useful/adequate enough when used to check whether you are server or not
The better way is to use HasAuthority() to check whether you are server/client ?

And to check whether you're yourself then IsLocallyControlled()

What do you think ?

[lyric lagoon]

I am experiencing a weird behavior so It's a very intersting question to me.

I actually have my clients spawning a projectile showing as:

• Having Authority
• Local Role: ROLE_Authority
• Remote Role: ROLE_SimulatedProxy
• Locally controlled: yes
• Owned locally: yes

And the projectile appears only on client side, the server doesn't spawn it. (even after the hasAuthority check)

So I am trying to figure out what I did wrong in this project, but normally the hasAuthority is enough to know if you are on server or client side.

[dark edge]

I'm not 100% sure but wouldn't client-side only actors have authority?

Yeah they will

[hollow eagle]

They would. You want GetNetRole

[dark edge]

Where are you spawning the actor from?

[lyric lagoon]

I am spawning the actor (a projectile) from a weapon.
The weapon is owned by the character.

I also set the ownership of the projectile to the weapon but right after spawning the projectile.

[dark edge]

But are you doing all this server side or client side?

What machine is calling the spawn actor node

[lyric lagoon]

I'm using the same template as Jekas

void DoSomething()
{
if (!HasAuthority())
{
DoSomething_Server();
}

// Do the something

}

void DoSomething_Server()
{
DoSomething();
}

It's run on client and supposed to call the Server RPC but because of the Authority being always true the client never call the RPC.

[dark edge]

The client should not be authority over the gun or character

[lyric lagoon]

That's what I don't understand. I've used this "template" before and I never ran accross this issue.

[dark edge]

Double check that the gun is being spawned by server lol

You might have a local only gun

[lyric lagoon]

I think you might just have found out.

The weapon is spawn during the beginPlay of the Character.
I would guess it should exist on the server side too.

[dark edge]

Gated behind Authority right?

[lyric lagoon]

It wasn't 👀

[dark edge]

So you'd have 2 guns I'm pretty sure

[lyric lagoon]

It's a collaborative project, I have to adjust several things. I have random crashes as the weapon doesn't exist locally anymore, but I think we are on good track.

[thin stratus]

BeginPlay in the Character is too early

You can't properly specify an owner

OnPossessed is a better point to Spawn the Weapons as you then have a Controller you can use for the Owner Pin

OnPossessed runs only on the Server too, so easier to manage

[lyric lagoon]

It's alright, you can even do it before in the PostInitializeComponents. I did that in another project.

I just need to replicate the variable of the weapon I think now and we should be good.

[chrome bay]

Run the game with some simulated latency/packet loss. That's a good way to start finding the cracks in your logic.

Of which there will likely be many if that's never been done before

[lyric lagoon]

I wasn't aware of this possibility, would you have a link about how to simualte latency?

[chrome bay]

PostInit / BeginPlay etc. is essentially way too early to start using other replicated actors - you can't garauntee they'll be valid at that point. That's what OnRep callbacks are for.

Just go into the advanced play settings in the editor, and check the "enable network emulation" boxes

[lyric lagoon]

In the PostInit and BeginPlay I only spawn the weapon. Still too early?

[chrome bay]

Server can spawn it there if you'd like it too, but there's no guarantee the client will have it in BeginPlay/PostInit

(In another actor, that is)

[lyric lagoon]

Makes sense. Thanks.

[severe tendon]

Can someone help figure out why this is only teleporting the first player?
Its in the GameMode and sets the clients positions via the server

[lyric lagoon]

Can you debug/breakpoint your player array and display the elements in it?

I'm about to go to bed, I can stay 10/15min but then I will have to go.

[severe tendon]

Yeah, it prints player names when a player connects and gets both

Ahh cheers

We're using VR so we can't debug via UE4 itself 😐

Going to do a Get All Actors + Foreach on the server so it covers them all and hopefully it force moves the camera

[lyric lagoon]

From what I see your logic is good.

[severe tendon]

Yeah, it just won't move the 2nd VR clients camera

[lyric lagoon]

Maybe it's not running on the server side and runs locally.

[severe tendon]

Im assuming they're not in the array so I've just hard coded it like I said just before, hopefully this fixes it. If it doesn't I'd be surprised
Cheers for your help 🙂

[turbid radish]

you need to ask server to tell players to teleport

[severe tendon]

That is the server telling players to teleport

as well

Host tells server to tell all to teleport to specific location

for some reason Cli 2 doesn't

[lyric lagoon]

Telleport all clients is set as a RPC server ?

[severe tendon]

Not from Authority

It was from another Cli

I'll try that

The change I just made moves the 2nd player but only a tiny bit

It moves them forward and they force move back to their previous position

oh... I think I know what it is 😐

I force set the client camera position

Thank you everyone, I'm going to go lie face down on the concrete for an hour and question my life choices

[lyric lagoon]

haha

Glad it's working now.

Have a good night.

[severe tendon]

It didn't work 😐
I have no idea whats happening anymore lol

[pine bobcat]

I got a problem of handling animation for multiplayer. Right hand side of this video is showing server looking at client movement and the animation works well. However, left hand side of the video showing when the client looking at server movement, the transform of head and hands seems to be reset to a certain position when server is walking but back to normal when the server stay still.

I have applied some IK logic to the animation BP, and I replicated the camera and motion controller transform. Does anyone have any idea what's wrong?

IK in anim graph

[rocky night]

HI, i have a Problem wehre the CLIENT via Listenserver sees the AI moving but falling in to the Ground heres a video.. they are clipping up and down

[winged badger]

they might not be in the same movement mode

walking vs nav walking

on client/server

other, scarier version is that your Base (reference to the component deer is standing on) is not net addressable

in which case it would not be clipping through floor and back, but teleporting to 0,0,0 instead

for everyone else

[lost dune]

Can someone help me

[low helm]

those map deformations aren't replicated, and it won't look right until they are

[rocky night]

Hi @low helm replicating map deformation is a thing? Sorry i am still a beginner

[rocky night]

@low helm oh yes, but i use no Voxels its just the ue4 landscape

[chrome bay]

Oh well you can't deform UE4 landscape at runtime so you're fine

collision always uses the highest LOD, the morphing verts are visual only

[bronze summit]

I made a equipment component which swaps succesfully, I used a delegate to callback to the character itself but in MP it seems to do RepNotify before being bound (binds on OnRep_PlayerState and BeginPlay to be safe). Somehow it Reps the component variables before playerstate and thus not being able to call the correct function. Is there another function I can use to bind delegates before OnRep of components?

[scenic turtle]

hi all, I would like to have a VR client spawning in with a VR listen server, but what I get is that only the listen server will be visible while the client is not even spawning.. I know that probably the issue is with the get player controller, but I don't know how can I reference the player controller otherwise.

[dark edge]

@pine bobcat You need to replicate whatever your driving variables are

For VR that'd be the head and hands transforms at a minimum or something derived from them.

[thin stratus]

GameMode supplies you with the Players in PostLogin. Or even better in the overridable function called GetDefaultPawnForController.

[terse prawn]

Can someone help point me in the right direction for level streaming in multiplayer?

[scenic turtle]

Blueprint Runtime Error: "Accessed None trying to read property CallFunc_GetPlayerController_ReturnValue". Blueprint: GameMode_Darts Function: Execute Ubergraph Game Mode Darts Graph: EventGraph Node: Possess
I am also getting this error, which is I guess due to my incorrect use of get player controller. where would I use the GetDefaultPawnForController? Sorry I am a still new to blueprinting and Unreal in general.

[thin stratus]

May I ask why you do multiplayer if you are new to this?

Multiplayer is the second step of learing coding in UE4, not the first

Either way, it's an override in the functions tab of your GameMode blueprint

You can select override when you hover the function tab

GetPlayerController is 100% wrong

Because even if it wouldn't return nullptr, it would return the Server's Controller all the time

So you would never possess the other players with the correct controllers

[scenic turtle]

I am looking into multiplayer because of a project that we are working and I am aware that this is not the first step learning it, I just thought there might be an easy fix for it. Thank you for your help.

[shy hill]

Hey hey, I'm learning multiplayer so forgive me if I ask anything stupid ! Is there a difference between using a 'is local controller' bool check vs using a custom event that runs on client only ?

[silk abyss]

I think this question is asked without context. So better state the situation as to why you need to do such a check and what you want to achieve.

[lost dune]

Does someone know how to make work "set master pose" in multiplayer

Please.

[chrome bay]

It's not replicated like most things, you'd just have to do it on each client independently.

[south rampart]

Does anyone know if a LobbyBeacon(Host) implementation can work on a dedicated server. As in the dedi server is able to communicate with players before they join the map.

If not please stop me, because that's what I'm about to do

[dark edge]

@lost dune Best way would probably be something like a repnotify on the Character for when EquippedItems changes, takes each item and sets MasterPoseComponent for them.

[lost dune]

Thanks a lot for the idea , i test that as soon as possible

[dark edge]

It's usually a good idea for reference to flow in One Direction so that's why I'm suggesting having the character take the initiative to tell the armor piece to set its Master pose component rather than the armor piece having a reference to the character

[grizzled stirrup]

If you have several OnRep properties that call the same thing when repping down, it's completely safe to just make 1 OnRep function and have multiple OnRep properties call it right?

    UPROPERTY(Transient, ReplicatedUsing = OnRep_Health)
    float CurrentMaxHealth;

    UPROPERTY(Transient, ReplicatedUsing = OnRep_Health)
    float CurrentHealth;

    UFUNCTION()
    void OnRep_Health();

As opposed to having unique OnRep functions that each call duplicate code

[winged badger]

that depends on the overload

[grizzled stirrup]

As in if passing in the old value?

Say if not passing in the old value

[winged badger]

yes

[grizzled stirrup]

Is it fine?

[winged badger]

should be, yes

[grizzled stirrup]

Great thanks

And I assume if you do pass in the last value it'll just take whatever the last one repped

Which is bad of course

But for a case like this should make things a bit neater

Good to know it's not tied to a specific variable or even variable type

[winged badger]

i would still have all separate OnReps call the same function to handle them

[grizzled stirrup]

Yeah in case I need to do unique logic per property it would be wiser down the line

[winged badger]

makes it easier when you find yourself debugging things

[grizzled stirrup]

True also

I won't be going crazy with it but there are a few places where it's a nice cleanup

[jovial abyss]

Hey everyone, im trying to figure out how to make a matchmaking system.
Ive looked around and all it shows me is the basics of online multiplayer and nothing on how to set up teams and such.
How would I go about making this after making the initial multiplayer settings (lobbies and such)

[spice gorge]

I have a setup where players interact with mechanisms in world (buttons, levers), which communicates via messaging. The blueprint for the mechanism updates the instigator character rotation and location to line up to play an animation. I'm sending the updates through the server so they're replicated across all clients, which is lerped through a timeline.
After the timeline ends, the character snaps back to its original position. I presume what's happening is there's conflict between the player controller and the updated rotation/location. Is there a method I should be using to properly inform the player controller of the update, bearing in mind that his is happening in the mechanism blueprint placed in the world?

[spice gorge]

Teams would be extra data that your game logic refers to. You could have a widget or some logic that selects a team for a player, then have an array for each team that you populate and can use for reference via your game logic.
I did a quick youtube search and saw this video that covers team selection for multiplayer. Hope it helps. https://www.youtube.com/watch?v=aW6XSshcYwE

[severe tendon]

Is there any reason a VR Camera wouldn't teleport when a server forces set actor transform?

[spice gorge]

Resolved the issue. I have the server multicast to get each client to run the animations. Then I do a Get Instigator Controller and Set Control Rotation on just the controlling player so that their input rotation updates to match the animation output. This could be the wrong way to go for many reasons I guess, but it works at least for this prototype.

[pine bobcat]

I have replicated the values and I checked that the values in server and client is the same

[edgy valve]

How can i trigger an event from a client to the server ? ex : I want a client to push a button in the UI and then the server would run the node " get all actors of class > player controller " then for each player controller i would like to change a variable

I thought the " run on server " event would work but i believe i dont quite understand the concept

[dark edge]

Run on Server works on OWNED actors

in your case, probably just Pawn and PlayerController

so route through your pawn or PC

In your case prolly the PlayerController. UI is local only

So you should go like
UI -> PlayerController -> Run on Server -> ??? -> Profit

[edgy valve]

So all i have to do is to change the logic to the player controller class ?

[dark edge]

ya

[edgy valve]

and i call that event from the ui ?

Awesome, i will try it now

On button clicked > get player controller > Event X

[dark edge]

Although, what are you trying to do? Modifying everyone's PlayerController smells weird

Yes, Event X being a Run on Server event

[edgy valve]

i have a lobby where players can choose between team 1 and team 2

i just want the UI to be the same for all players

[dark edge]

That should live on PlayerState

[edgy valve]

so if i switch between team 1 and team 2 , all players will be updated

[dark edge]

The State of the Player (what team they're on) should live in PlayerState

or at least GameState (Team Red has Players A,B,C, and Team Blue has players X, Y, Z)

Everyone would locally use that info to populate their UI

[edgy valve]

I think i understood, i will try it to see if it works

thanks a million man

[dark edge]

@edgy valveCheat sheet

[edgy valve]

Thank you man, now it is very clear ! 😄

[dark edge]

You can probably just do a run on server in PlayerState, not 100% sure but I think so

[edgy valve]

GameState would be a better option innit ?

I will try some experiments and i come back to you haha

[dark edge]

I'd prefer PlayerState then you can aggregate them to get team rosters etc

But I'd do either/or, not both. Have 1 source of truth for which players are on which team

[thin stratus]

RunOnServer doesn't work in GameState

Please read up on Ownership (:

We usually make a new AInfo Actor (similar to APlayerState, which also inherits from that) called ATeamState. (A for Actor in C++).
And then have that hold all the info about Teams. GameMode spawns those and saves them in an array.
GameState also gets the set (from GameMode) in a Replicated Array (can be done "more improved", but this works for the start best).
TeamState Actor should also replicate and marked as Always Relevant.
Then you can have PlayerState arrays in that which replicate.

That way your Players can access the Replicated Team array and then the Replicated PlayerState array.

With a bit of OnRep and EventDispatcher/Delegate magic, you can make sure that the Players get informed when the Team changes.

(and you can use the TeamStates for even more logic, like TeamName, Color, checking who's the top player in the team etc, neatly packed into one actor)

@edgy valve @dark edge

[digital current]

I have no experience with networking so I might sound a bit ignorant. If I package a dedicated server executable while having my OnlineSubsystem be set to steam (also have AdvancedSessions installed) and I run it on a pc, will the server show up in 'Find Sessions' (also would like to know if I would need to forward ports for it)?

[wary compass]

hello, anyone here have a problem with the join session node fire on success but the client does not load into the lobby level?

[twin juniper]

Hello everyone.I have an drone which has replication enabled and i spawned it on server.But movement is not being replicated across server.I am controlling the drone by possessing it on server.But when i possess the player the drone is at starting position only.Thank you.

I also enabled component replication as well.

[bitter oriole]

Non-ACharacter pawns have no movement replication support at all and need it built from the ground up

This course has an entire section dedicated to a multiplayer vehicle : https://www.gamedev.tv/p/unrealmultiplayer/?product_id=1500305&coupon_code=JOINUS

[bronze summit]

I'm having an issue where my OnRep functions are not being called. Also on the client-side the component has no Owner. Anyone knows if im making a stupid mistake? (Component is replicated)

[chrome bay]

Components can't be arbitrarily replicated, their outer has to be a replicated actor.

And the component itself needs to be replicated - you're replicating the pointer only

[bronze summit]

The outer as in the character actor onto which it is attached correct?

[chrome bay]

Yep, when you create the component you need to use NewObject<UMyComponent>(SomeActor)

[twin juniper]

@bitter oriole Is it simple server call and then rpc call for replication or is it more complicated

[bronze summit]

The NewObject doesn't really change anything for me under the hood. It currently seems to work the same as CreateDefaultSubobject (according to logs). I think its more of a timing issue on the client side. Idk if the OnReps will be called once initialized but I guess I need to do some more logging. Weird thing is everything was working fine yesterday untill I added two variables

[winged badger]

@bronze summit breakpoint AActor::OnSubobjectCreatedFromReplication

and see what's going on

[bronze summit]

Will try that. Its also apparently common for that specific component that sometimes the detail panel in UE goes blank and I have to rename the variable. But thats more of a hotreload issue I believe

[winged badger]

yeah, never do that

it also doesn't take kindly to renaming the component in c++

or changing its class via FObjectInitializer

note that the above function won't happen for components on the CDO

just created and replicated at runtime

[bitter oriole]

It is quite a lot more complicated

[bronze summit]

Aha the function is not being called or atleast not hitting a breakpoint

[prisma ore]

Hey guys, how does one connect multiplayer using LAN ?

[winged badger]

that would indicate no component created at runtime replicated

[bitter oriole]

open <ip> in console, or sessions with the default NULL subsystem

[bronze summit]

This is how I added it to the class Is there some kind of crucial flag/step Im missing? As the InventoryComponent I handle exactly the same which does call OnRep's succesfully

[bitter oriole]

If you are creating a component like that, more work is required

[winged badger]

in constructor, you use createdefaultsubobject

that component is not net addressable

[bronze summit]

Yeah but both NewObject or createdefaultsubobj have equal result in this case they both wont hit the breakpoint

[winged badger]

because its not a default subobject

default subobject components are not created from replication

so they don't need to hit that breakpoint

they are instead spawned with the actor, and have NetGUID assigned to them

[bronze summit]

These NetGUID should be the same between client and server?

On the instance

[winged badger]

yes, memory address would be of little use sent over network, NetGUIDs are sent instead

[bronze summit]

So do replicated components push an initial OnRep when they are created? So lets say I change a variable that is replicated on server, after that the component is created on client and thus onrep called because it already has changed on the server?

Because that might actually be the issue on my end

[prisma ore]

"sessions with the default NULL subsystem" .. can you elaborate ?

[chrome bay]

The OnRep will be called anytime a new value for it is received by the client, and/or when the object pointer resolves to something else.

If it wasn't created at runtime, then the OnRep will not fire - but a default subobject pointer shouldn't be replicated anyway

[bitter oriole]

Using the engine's sessions system.

[prisma ore]

Guess i did not ask the right question, what i try to know is how to connect a multiplayer game using LAN !

because i want to test my game with my wife !

[bitter oriole]

Well yeah, that's what you asked

I answered that the easiest method is the session system, using the default ("NULL") built-in online subsystem, that only does LAN

Look up Advanced sessions plugin, put up four Blueprint nodes, enjoy instant LAN matchmaking

The second method I suggested was the "open <ip>" console command which works just as well, except manually, using the IP address

[prisma ore]

Thanks, will try that

[lost dune]

My set master pose still does not work in multiplayer , i can't continue to work

help please

[chrome bay]

It doesn't have any multiplayer functionality

You have to handle different clients setting it up yourself

[lost dune]

i make a multicast from the server which calls the set master pose

so the clients execute it locally$

i don't know why it fails

the skeletal meshes are replicated components

is it about it?

[bitter oriole]

Skeletal meshes don't have any network feature, so you have to carefully replicate everything you do on them on every device

[lost dune]

i was wrong , they are not replicated , ther's just a variable repnotify

[bitter oriole]

That's replicated

[grizzled stirrup]

@chrome bay regarding that BeginPlay triggering after OnRep events thing from a few days ago, if you have 2 RepNotify variables being set in sequence, will they reliably replicate down in order?

[bitter oriole]

Nope

[grizzled stirrup]

It appears they do when testing with 10% packet loss and 200 ping

Hmm ok

Thanks

I'm setting on as part of a deferred spawn and the other after the spawn completes

So not sure if that affects it

[bitter oriole]

They'll very likely do it most of the time, but there's no gurantee, if the first one is lost in the network it won't be resent

[grizzled stirrup]

Ok got it thanks

This is all for an edge case where a projectile explodes too quickly after being fired so the tint isn't set yet as the original repnotify variable that inits the projectile hasn't reached the client yet

So the client gets the exploded variable before the init variable and explodes with default colors and FX

[chrome bay]

yeah variable replication is not ordered

[grizzled stirrup]

So I guess the solution is to check if the tint is uninited on the client and call the same logic twice

Thanks

[chrome bay]

If you need properties to replicate atomically, put them in a struct together

[bitter oriole]

And make the struct atomic

[grizzled stirrup]

In this case it's an edge case where a projectile explodes too quickly after being fired (if firing into a wall close to you)

Causing the explode repnotify to rep down before the init repnotify var potentially

It happened all the time when I was initing the projectile with BeginPlay as the on reps always happen before

[chrome bay]

yeah that can be a tricky case to handle

[grizzled stirrup]

But now since changing I never notice it

But as said

It could very well happen

[grizzled stirrup]

Just curious what this means? Serialized as a single unit, does this mean it ensures the entire thing gets repped each time rather than only the changed properties within the struct?

Is this the correct way to mark it?

USTRUCT(Atomic)
struct FProjectile
{
    GENERATED_BODY()

    UPROPERTY()
    AActor* A;

    UPROPERTY()
    AActor* B;

    FProjectile()
    {
        A = nullptr;
        B = nullptr;
    }
};

[chrome bay]

I'm fairly sure structs replicate atomically anyway, so if you change two properties in a single network frame, you should receive both changes together and never individually

But ofc if you change a property, then network sends out updates, then change another property, then you would get multiple on-reps in different states

But failing that ofc you could also guarantee it by creating a custom NetSerialize(), but you lose the per-property replication ofc.

[grizzled stirrup]

Ok good to know, in my case in other examples I'm setting both at the same time, so should be fine without marking Atomic?

As they are both set in the same frame

[chrome bay]

I think so, I think I saw some mention of it on UDN a while ago

And I'm also fairly sure I have some things riding on that too 😄

[grizzled stirrup]

Might be no harm to mark it then I guess? 😄

Or is there a downside to marking with Atomic?

[chrome bay]

Not sure actually

[grizzled stirrup]

It all seems to work fine without it but of course I haven't seen what it's like with 12 players in real world conditions!

Emulation can only do so much

[chrome bay]

Some interesting stuff from UDN:
When an actor is replicated all of its changed values will be sent as an atomic update. This means that we guarantee if you receive the update, you will receive all the properties that have actually changed in that update. This includes subobject properties as well.

What you can do in order to treat a struct as atomic is to force it to use a custom serializer, see FVector or FMovement for an example of how we do this.

But I guess, the first comment sort of overrules the second - if the entire actor is replicated atomically, then it wouldn't matter for structs individually :/

Shame there's no easy way to test this

[bitter oriole]

Yeah I've never gotten a 100% answer on Atomic

Not even on UDN myself though

[chrome bay]

Yeah.. I don't 100% trust this even from them 😄

[twin juniper]

Good morning guys. Look, I watched the third video of a tutorial about multiplayer games using listen servers in UE4. At this point, we have created the first class with attributes that will be replicated over the network. But what I don't understand is: In the first video, he didn't code anything, just set the project to 2 players and to run as a listen server and set their viewport sizes and BAM, they're sync and can see each other. I did the same but, i have 3 players, 1 server 2 clients, but they're not sync at all. What is the reason behind this? Apparently, they are automatically sync after his first task, no code involved at all. (https://www.youtube.com/watch?v=JCjSyzXv9CQ&list=PLD1wDiU3QkLKvSFrE6P72FFkgsJAv9-el&index=2), but they aren't in my project, sometimes one of them see another one, but the other don't see him, etc. Also, in the first class he have create , he used bReplicatedMovement to sync actors between peers, but it seems that is deprecated, so will bStaticMeshReplicatedMovement do the job, because isn't working neither?

[twin juniper]

Btw he used the third person template, I used the twin stick template. Apparently, the Third Person template goes fine, but something in the Twin Stick is messing around with the synchronization.

[thin stratus]

@grizzled stirrup I had the same problem a few weeks ago in The Ascent.

I can't 100% recall how I fixed it

But I think it had to do with simply giving the Actor some time before destroying it

It's a "common" mistake to instantly destroy the actor

Sometimes it makes sense to just deactivate it (hide, etc.) and destroy it 3 seconds later

Iirc I used a struct with information about it being exploded, which I use to explode it locally if it's not too long ago

There are some solutions

[twin juniper]

Guys, how can I replicated a Pawn position over the network? I couldn't find an example

[meager spade]

set bReplicatesMovement

then set its location on the server

if you need to do it smoothly, you need some interpolation system, for example the CMC, interpolates the character mesh but teleports the capsule

[twin juniper]

Thanks for your reply! I'm using the twin stick template, and I tried to change the code to do movement using another way. It happens that the code has problems on other parts so i decided to stick with the template code for the pawn, and the code moves the ship using RootComponent.MoveComponent(). Based on that, do you think that I have to do is first to store the FVector used by this method, mark it with ReplicatedUsing= in the UPROPERTY, create a RepOn_, and implement the GetLifetimeReplicationProps(), and using and authority guard inside the Tick() where the RootComponent.MoveComponent() is called, using hasauthority?

{
    // Find movement direction
    const float ForwardValue = GetInputAxisValue(MoveForwardBinding);
    const float RightValue = GetInputAxisValue(MoveRightBinding);

    // Clamp max size so that (X=1, Y=1) doesn't cause faster movement in diagonal directions
    const FVector MoveDirection = FVector(ForwardValue, RightValue, 0.f).GetClampedToMaxSize(1.0f);

    // Calculate  movement
    const FVector Movement = MoveDirection * MoveSpeed * DeltaSeconds;

    // If non-zero size, move this actor
    if (Movement.SizeSquared() > 0.0f)
    {
        const FRotator NewRotation = Movement.Rotation();
        FHitResult Hit(1.f);
        RootComponent->MoveComponent(Movement, NewRotation, true, &Hit);
        
        if (Hit.IsValidBlockingHit())
        {
            const FVector Normal2D = Hit.Normal.GetSafeNormal2D();
            const FVector Deflection = FVector::VectorPlaneProject(Movement, Normal2D) * (1.f - Hit.Time);
            RootComponent->MoveComponent(Deflection, NewRotation, true);
        }
    }    
    
}```

I'm asking because I never did it =S

Or must I only replicated the FVector property that i must create and replicated together with a FRotator property , replciate them, and only change the names inside tick, based on the information that the server runs the tick method ehre ?

[thin stratus]

Pretty complex topic, it's really not the worst idea to read a bit through the CharacterMovementComponent

[twin juniper]

Thanks for your reply! 'm inexperienced, but a task was asked to me

Also, isn't not a Character, since I'm using the Twin Stick template, its a Pawn

[thin stratus]

Well, does your actual Mesh looks like a human character?

Because there is no need to use a pawn then

[twin juniper]

Could you give and example about how to set the location on the server?

[twin juniper]

Its a ship, is not even rigged, its just a mesh without skeleton

[thin stratus]

You could still use a Character for it

Would save you weeks of trouble :P

[twin juniper]

I need to solve this today XD and there is no example in the internet

The deadline is today

[thin stratus]

That aside, your Tick function is missing the Super::Tick call