multiplayer

[torn bane]

I know im frustrated now im sorry

[fading birch]

I didn't take offense

it's all part of the troubleshooting process

what could be happening, and happens to me is your ISP could be blocking the ports

or theirs is

[torn bane]

I had to ask that i need to open some ports

[twin juniper]

The best action right now is to take a break. Sometimes, fresh air can relax your mind, to a point you start to see whats wrong with your code

[fading birch]

i don't think their code is the issue

if it works locally 100%

on 2 pcs

with 2 steam accounts

the code is fine

[twin juniper]

I would say NAT, but he's seeing the session

hummm

[torn bane]

Yea that"s wierd

[twin juniper]

Are you specifying any ports? Are the ports open?

[fading birch]

NAT has nothing to do with being able to see the session

that's run entirely through the Steam OSS

Can you do a mobile hot spot?

and test from your phone wifi

to yourself

[twin juniper]

It was a quickly idea that I had, I know its used to redirect the connection request to the correct device inside a network XD. Also, I was thinking about connectivity issues he could have based on the NAT type, if is open or strict... If the NAT of the network where the hosting machine is located is strict, his friend could have connectivity issues, more lag, etc... I don't know how the Steam OSS deals with it

[torn bane]

I havent changed anything, i mean idk API of adbbanced steam sessions, maybe i can search for ports informations in thier site

Thanks a lot guys I will write when I find the solution

[sharp hornet]

If it's a NAT problem make sure to try the SteamSockets plugin, it's not on by default

Although I don't know how SteamSockets works in LAN mode, I've never had to use it as I would just use the normal public networking unless you're seriously bandwidth limited. If you're doing LAN for real you probably need to turn off steam networking entirely and fall back to the manual ip/port joining which bypasses sessions entirely

[wise bridge]

Like that? But it don't get the same effect at all, it's shown on the player screen not above the player

I don't know the right way to create / destroy an widget on an object

[karmic sparrow]

Wait. I made a mistake. Use an actor with a widget, not a widget component. That way the client has to spawn the actor, then attach the actor to the target.

It depends on what you're going for really. Having the client spawn the actor with the widget, then attaching it to the target will allow the widget to be shown in either screen space or world space on that object. Since the client is the one who spawned the actor, that actor and its widget will be visible to the client.

With that method, the widget does not need to be added to the viewport since it's part of the actor you attached to the target. If that makes sense.

[wise bridge]

The actor can't spawn the object

[karmic sparrow]

Have it spawn from the player controller.

[wise bridge]

When you tell me to use widget instead of widget component, it's the same thing no? When I type widget I got that, and when I pass my cursor on it after it say widget component

[wise bridge]

Can't either, it's on the map by default and if someone drop an item it's spawned by the game mode

[karmic sparrow]

Yeah do that. Just make an actor with a widget as a component, vs using widgetcomponent bp. That's the distinction I was trying to make between the two.

So the widget elements need to be visible at spawn, or just when the player looks/interacts?

[wise bridge]

Only when the player looks interacts

And it's a multiplayer game, and the server see what the client is looking

[karmic sparrow]

The client can still spawn actors and attach them to objects that were spawned by the game mode. The actors that the client spawned and attached would be owned by the client.

[wise bridge]

But that mean that each time a player look for something, I should hide the object only from his eyes, spawn a new one at the exact same location with an UI?

[karmic sparrow]

Hmm

If the player is looking straight at something or interacts with it, that would be a good time to spawn + attach the actor that displays the widget, then when the interaction is done, the actor with the widget destroys itself.

At least that's how I would approach it.

[wise bridge]

Oh I guess I got it

[wise bridge]

Ok so it almost work, I got this warning and for one frame a new item state can be shown to the server sometimes, or it cancel the shown one of the server if the client is looking it @karmic sparrow

[karmic sparrow]

Client interacts with target actor --> Client spawns new actor with widget --> Client attaches actor with widget to target actor.

This should work from the player controller

[wise bridge]

I didn't spawned a new actor, might be why, gonna try this tommorow

[summer spade]

I spawn a replicated projectile from a client then it spawns on all the clients and the server but it is spawned twice in the client which spawned it first so what should I do so that the original client not have two projectile

[hollow eagle]

@summer spade to answer your question in the correct channel...
You can spawn a "fake" projectile on the client, then when the client receives the real one from the server interpolate it to the position of the server's and then delete it.

so you'd really have two projectiles - the fake one the client spawns, and the real one replicated from the server. The client's only exists until a bit after the server's does.

this is the basics of how network prediction works... which isn't a simple task to get right, but this is the gist of what you need to do.

[hoary lark]

is that a "real" solution? that doesn't seem like it would work at all

[hollow eagle]

sure it is

why wouldn't it work?

[hoary lark]

i mean i guess it would work for like a bowling ball

it wouldn't work at all for a "real world" shooter

[hollow eagle]

for a projectile based one it would

which is the point

if the time the projectile takes is longer than the roundtrip latency then you just immediately delete the server's projectile when it gets received on the client.

ostensibly the client's fake projectile would have already played out the same effect

[hoary lark]

the projectile would warp way back and play out something completely different

[hollow eagle]

right, which is why you wouldn't immediately delete the fake projectile on the client, nor would you immediately make the real one visible. To do everything correctly you'd interpolate the fake projectile's movement (but also have to account for server -> client latency, so there will be some extrapolation too).

[hoary lark]

why bother then though?

[hollow eagle]

because if you don't spawn a fake projectile you end up with laggy shooting. And if the projectile isn't fast enough to beat the round-trip time then you still need to correct for errors.

[hoary lark]

just let the predicted projectile play out.

[hollow eagle]

Sure, if it matches what the server sees. That's why CMC's prediction system has a range in which it won't correct.

If the projectile is too fast to notice anyway then yeah this is somewhat pointless - just spawn a fake projectile and ignore the server's replicated one.

But if it's not super fast (a grenade would be an important use-case for this since it has a long lifetime) then you'd need to go through all of this for things to look correct.

[hoary lark]

yeah, I can buy that. I doubt there is any decent game in existence that would do this for e.g. a sniper bullet

[hollow eagle]

Battlefield or arma with very large maps maybe

an RPG in something like that would also probably need this, since if the client is sufficiently off on a large map the explosion of the hit would be in a completely different spot

[hoary lark]

yeah, it's the old "pick your poison"

[dull lance]

Battlefield doesn't really do that [resyncing] [at least not before Bf1]

[hoary lark]

explosives are such high value events in those games (and usually slower) so it's worth correcting, but bullets, it'd be worse

[hollow eagle]

Yeah I agree that bullets are unlikely

[hoary lark]

so the TLDR is I should have said "what kind of projectile are you actually dealing with @summer spade "

[summer spade]

It is like a spell

[dull lance]

so a slow speed projectile?

[summer spade]

Yeah

[hollow eagle]

If it's slow, then you probably need to go through all the stuff I said. Though I'd start with just spawning a fake projectile on the client and not resyncing it with the server yet - get that to work first.

[summer spade]

Ok

[hollow eagle]

So spawn a projectile on the client, also spawn one on the server, and come up with a way to ignore the server's projectile (/delete it) on the client that fired the projectile.

see if that's good enough for now. If it isn't, then you get into the complex interpolation stuff.

[hoary lark]

I think the simplest (and least robust) solution is something like 1) spawn it locally on the client "shooting", 2) spawn a non-replicated one on the server, 3) broadcast an RPC from the server to spawn local ones on all other clients, but ignore it on or don't broadcast to the shooting client. let each client just play their own FX, usually they will match what the server does by luck. damage can either be applied by the server instance or RPC'd up by the shooting client if cheating isn't a concern. if this simple solution doesn't play out well enough due to your game's dynamics then I'd probably immediately switch into doing everything else siliex described

[sand crown]

Hey I'm using Advanced sessions etc, And trying to make a simple Players list, to show the current players in the online session. I'm trying to call them through an Array PlayerStates / GameState etc, I have done this in the widget for the current online players, But It seems to be just calling the same client name etc for both. It seems to be getting that there is 2 clients connected, but in the list it is listing the same client name twice for both clients. And only shows the Clients name who is looking at the player list, shows 2 of the clients name.. can anyone think of what might be causing this ? ? Any hints be great. Thanks.

[twin juniper]

Can we make RPC inside dataasset ?

[thin stratus]

No

@sand crown need your code to be able to see what's wrong

[sand crown]

here's my open player list widget

the Online Player Widget

what else you need ?

[thin stratus]

The second image is pretty cursed

Replicated variable inside of widgets are redudant

And you are getting PlayerController 0

Which is the local player

So no wonder you see the same player twice

You arr already calling set player name

Why the code in thr online player widget?

@sand crown

Also your code will break once the delay in your first image is not long enough

[sand crown]

idk followed some stupid tutorial once, was the only thing i could find at the time on making a simple player list, it worked for him, but not for me and now can't even find the tutorial or any other

[fading birch]

you already have the player state

[thin stratus]

I only know about epics tutorial which is garbage

[fading birch]

you can get the name from either the session info

and set it in the player state

[thin stratus]

SessionInfo in bps?!

It's enough to just set it when creating the widget

[sand crown]

can you by any chance put an example together with a few images ?

[thin stratus]

I'm not on my pc, so sadly not

Remove the code that is in your second image

That should already improved things

In your first image you are setting the player name

That should be enough

[sand crown]

then the create widget won't be calling anything in the first image yeah ?

[thin stratus]

First image can stay

[fading birch]

nono in the BP of their player state

[thin stratus]

Second image breaks it

[sand crown]

@fading birch are you saying to call it in the playerState Event graph ?

[thin stratus]

Don't get confused

[sand crown]

im always confused lol

[thin stratus]

Just remove the code from the second image

And try again

[sand crown]

what do i do with the create widget in the first image tho ?

just leasve it

?

[thin stratus]

Yeah leave it. You are creating the widget, settung the PlayerName and then adding it to the list, so that's fine

[sand crown]

ok will try

[thin stratus]

Only thing that i don't know is is how that set playername function is looking like

Cause you didn't post that

[fading birch]

that's what I meant by setting it in the player state

not sure if you can do that via BP tho

[thin stratus]

Not sure what you mean

The Playerstate already has a PlayerName

They already use it in their first image

That's all fine

[sand crown]

removing first image code not work,, now just says player name twice.. not getting the separate desktop client info or steam names now.

[fading birch]

idk if that is actually set in steam oss

[thin stratus]

It is

It's set in every OS usually

[thin stratus]

I said the second image

Not first

Also what does SetPlayerName look like?

[sand crown]

sorry yeah was the second image

[fading birch]

@sand crown I just realized I have the exact BP setup you're looking for

so. This is my lobby list widget

it's responsible for creating the actually lobby list, and creates a widget for each player by looping through the player state array from the game state

When the widget is constructed, I bind a delegate, which is called after a player joins my lobby

that then calls this function, which creates a lobby player widget, which contains info about the player:

open the original for it to be readable ^

here's what it looks like in action:

In code I am setting the player name: c if(IOnlineSubsystem* Subsystem = Online::GetSubsystem(this->GetWorld())) { if(IOnlineUserPtr UserPtr = Subsystem->GetUserInterface()) { NewPlayer->PlayerState->SetPlayerName(UserPtr->GetUserInfo(0, *UniqueNetId)->GetDisplayName()); } }

@thin stratus i looked through the engine, and I don't think that the OSS sets that at all. You have to get it from the online subsystem

which I don't think you can do in BP at all

[sand crown]

ah well will see what i can do. if not I'll have to scrap it

[thin stratus]

It's not true

The PlayerName is set by the engine

You don't need the oss

You don't need cpp either

My lobby kit on the Marketplace is BP only

@sand crown are you even using that name variable?

I only see you setting it

Is it used in a binding?

If not either bind it or additionally call SetText on the PlayerName text

FString ULocalPlayer::GetNickname() const
{
    UWorld* World = GetWorld();
    if (World != NULL)
    {
        // Try to get platform identity first
        FString PlatformNickname;
        if (UOnlineEngineInterface::Get()->GetPlayerPlatformNickname(World, ControllerId, PlatformNickname))
        {
            return PlatformNickname;
        }

        auto UniqueId = GetPreferredUniqueNetId();
        if (UniqueId.IsValid())
        {
            return UOnlineEngineInterface::Get()->GetPlayerNickname(World, *UniqueId);
        }
    }

    return TEXT("");
}

@fading birch

[fading birch]

ah ty

I was looking for that

learned how the engine handles from ack handshake -> spawning player though

xD

went down a rabbit hole

[thin stratus]

// Send the player nickname if available
FString OverrideName = LocalPlayer->GetNickname();
if (OverrideName.Len() > 0)
{
    PartialURL.AddOption(*FString::Printf(TEXT("Name=%s"), *OverrideName));
}

[fading birch]

yeah, the options get parsed by the game mode

among other classes/functions

[thin stratus]

FString UOnlineEngineInterfaceImpl::GetPlayerNickname(UWorld* World, const FUniqueNetId& UniqueId)
{
    IOnlineIdentityPtr IdentityInt = Online::GetIdentityInterface(World, UniqueId.GetType());
    if (IdentityInt.IsValid())
    {    
        return IdentityInt->GetPlayerNickname(UniqueId);
    }

    static FString InvalidName(TEXT("InvalidOSSUser"));
    return InvalidName;
}

[fading birch]

I don't generally use listen servers, so i'm a bit lost on how to accomplish this. I want to change the value of an uint8 in my player state. The value is stored as an on rep. I have 2 sets of functions. 1 is a normal function, the other is a server function updates the variable and calls the onrep for it. Nothing appears to happen though.

[thin stratus]

ListenServer and DedicatedServer are no different in terms of Replication

I would breakpoint and check if your code even calls

[fading birch]

relevant code:
.h

    UFUNCTION(BlueprintCallable)
    void SetTeamColor(ESquishyColour NewTeamColor);

    UFUNCTION(Server, WithValidation, Reliable)
    void ServerSetTeamColor(const ESquishyColour& NewTeamColor);

    UFUNCTION()
    virtual void OnRep_TeamColor();

    UPROPERTY(BlueprintReadOnly, ReplicatedUsing=OnRep_TeamColor)
    ESquishyColour TeamColor;```

.cpp
```c

void ASquishyPlayerState::SetTeamColor(ESquishyColour NewTeamColor)
{
    ServerSetTeamColor_Implementation(NewTeamColor);
}

void ASquishyPlayerState::ServerSetTeamColor_Implementation(const ESquishyColour& NewTeamColor)
{
    TeamColor = NewTeamColor;
    OnRep_TeamColor();
    ForceNetUpdate();
}

bool ASquishyPlayerState::ServerSetTeamColor_Validate(const ESquishyColour& NewTeamColor)
{
    return true;
}

void ASquishyPlayerState::OnRep_TeamColor()
{
    if(ASquishyCharacter* SquishyCharacter = Cast<ASquishyCharacter>(GetPawn()))
    {
        SquishyCharacter->SetEnumSquishyColor(TeamColor);
    }
}```

that was my plan, then I got side tracked digging through the engine lol

[thin stratus]

Please Review the RPC

Or rather

The normal call

And what you do in it

@fading birch

[fading birch]

oh

duh

[thin stratus]

Also

You might run into a classic race condition with this

Unless your Character also queries the Color

If you have no character on the client at that point, it would never get the color

[fading birch]

oh don't worry about that

that's for later handling

we have a bunch of NPCs that follow the player around and change their color to match the player that controls them

[thin stratus]

Just saying

I had to implement my fair share of customization systems

And it's easy to forget

[fading birch]

Ah I see

I'll likely just grab it from the begin play or post init components

[thin stratus]

In the Character?

[fading birch]

yes

[thin stratus]

In the Player Character or follower?

[fading birch]

both inherit from the same base

[thin stratus]

Well

Player Character has no PlayerState until possessed

[fading birch]

ah

[thin stratus]

So beginPlay and Post Init both won't work

You need to use OnRep_PlayerState

[fading birch]

that's a very good point

yes

[thin stratus]

And your Follower won't have that

[fading birch]

no it won't

[thin stratus]

So that needs a custom OwnerPlayerState

[fading birch]

but it has the owner

yeah, i've already set that up actually

[thin stratus]

Yeah but Owner is Controller or Character

Doesn't mean the PlayerState replicated yet

Best and cleanest would be an OnRep PlayerState variable of the "owner"

[fading birch]

the player can't control the minions until they walk up to them

so at that point the PS will be valid

or at least should be

[thin stratus]

Fair enough

[fading birch]

also they're absolutely adorable

[thin stratus]

What about other clients that join

And the Followers already exist

But the new Client has the PlayerState not yet replicated of the other player

(i hate multiplayer as much as I love it)

[fading birch]

so the NPCs are actually spawned by each player

by spending goo (blue stuff on the UI there)

and can only be done on at their base

or a base they take over

[thin stratus]

Alright, well just making sure you think about all of this. It's annoying to figure out when suddenly a player sees the wrong color

[fading birch]

oh believe me

that's what started this whole damn mess

xD

[thin stratus]

[fading birch]

mmhmm

[woeful ferry]

Hi,

We're making a survival co-op experience. When saving multiplayer sessions, would it be easier for the local player to save its characters content (inventory et.c.) and tell that to the server what the player had when joining the session with matching ID, or let the server save all the characters content?

[manic terrace]

I think saving it on the server is better I guess. Cause maybe the player could change the files saved and could easily cheat.

I am using the GameState and trying to use the PlayerArray at the start of the game. But it is null. I guess it hasn't yet been set by unreal. I tried at BeginPlay() and at PostInitializeComponents() but it's an empty array. What function can I override so that the PlayerArray is set? I want to some set some stuff at the start of the game in the GameState.

[woeful ferry]

@manic terrace Cheating is not a huge issue in this case, since it would just ruin for your friends experience. It's a co-op experience, but I get what you mean 😄

Thank you for the input

[stoic ore]

There are a lot of implications with both decisions and I don't think there is an answer w/o knowing your game much better. For example, is it only co-op? Do you always need a server to play or could it get played via couch co-op? How would you handle that a player changes sessions? etc.

[woeful ferry]

@stoic ore No, it's co-op or singleplayer and no couch co-op.

Anyways, I'll elaborate more this afternoon. It's lunchtime for us at the studio.

[meager fable]

Hi, I want to stream levels independently for server and clients this works unless a listen server walks into the trigger, then it loads the level for everyone

[cobalt apex]

hi, I haven't been able to connect the plugin to the server side for a week, please tell me how to do this? the "Water"plugin. when I start the server, it requires me to install it, but I do not know what I need to write ((((I really ask you!

[foggy wave]

hi guys , after many builds and testing of my game suddenly the client that joins the host lags very much when he moves like a tremble and when he pick up an item the item doesnt get destroyed, he keeps adding the item

[cobalt apex]

this is lagswich, in this case, I advise you to put a ping check on a high ping to kick the player

[foggy wave]

sure but how do i fix that lag ?

maybe a loop causing that lag

[cobalt apex]

does this occur in all players ? or just one?

[foggy wave]

just the player that joins the host , the host is just fine , and btw that happens only in the built version not in the editor

[cobalt apex]

a very strange event

[foggy wave]

and it didnt always happen

[cobalt apex]

maybe there are problems with the Internet?

[foggy wave]

nah i dont think so

i tried to connect localy on the built version , it doesnt lag that much but the bug with the items still happening

[sand crown]

@fading birch @thin stratus I had no luck with players list, just keeps calling 2 of the same name.. thanks anyways.

[manic terrace]

bIsDead = true; if(bIsDead) { UKismetSystemLibrary::PrintString(GetWorld(), "1", true); } else { UKismetSystemLibrary::PrintString(GetWorld(), "2", true); }

I execute this on the server and the 1 gets printed

then I am getting that replicated variable in the animation blueprint

and it should be going to the dead state and play animation.

yea just wanted to test if it was happening because I am getting something weird. The animation doesn't play on the server but it does on the client

and when it plays on the client it does play one the server

I have no idea what's happening I have a listen server and a client. When the server it to be killed the animation plays on the client and not on the server. And when is supposed to die it dies normally both on the server and the client.

[boreal geyser]

Hey guys so recently I've ran into a strange occurrence. So I changed the scale of my player, but after this, some clients would stop spawning. Their user interface widgets wouldn't even show on screen. However, after I moved my 'player start' objects farther from the ground, all clients finally spawned and had a user interface widget. What do you think happened here?

[fading birch]

it's likely that they weren't able to find a good spawn area since you're player starts weren't in good locations with the new size.

[boreal geyser]

ah that makes sense. Thanks!

[fading birch]

double checked

pawns by default have SpawnCollisionHandlingMethod = ESpawnActorCollisionHandlingMethod::AdjustIfPossibleButDontSpawnIfColliding; set

which the engine falls back to if you don't override the game mode functions for spawning players

or if you don't specify it in your pawn

actors however will always spawn regardless by default

character's use the same default behavior as pawns

[dull lance]

forgetting that this is a thing by default for pawns has caused me so much pain in the past xD

[heavy marlin]

Does anyone know if you can conditionally
a) Exclude a component from an actor based on Target (ie. Server), and
b) Choose a different implementation of a component based on Target?

[grim rain]

Hey guys im trying to make a function work in multiplayer but it doesnt work when playing on client, works standalone though. the equip function is a c++ function and i tried to make it run on servcer and multicast but that didnt work, or i probably did it wrong idk. could anyone give me some pointers? any help appreciated 😄

[fossil spoke]

@hot sage Do not post the same message across multiple channels, read the #rules.

[nimble parcel]

:triangular_flag_on_post: KuShaan_BroSL#0012 received strike 1. As a result, they were muted for 10 minutes.

[grizzled flicker]

functions only run on the server

you need to pass through your client-only event to the server by creating a reliable server event

then lastly a multi-cast event

but you have so much going on there im not rly sure exactly how to help, and thats waat makes multiplayer real fun to code! lol

[twin juniper]

Guys, doesn't own an APawn the PlayerController that have already possessed it? RPCs from the client to a server requires that the client owns the actor where the RPC is being called, and I'm calling my RPC inside the APawn, but the client isn't sending the RPC. EDIT: yes, it does, when the APawn::PossessedBy(AController*) is called, server-side. Since the PlayerController already owns the Pawn, after possessing it, I still don't get it why the RPC sent by the client isn't working, should I do a Multicast, inside the Server RPC scope? ```// Called every frame
void APongGameplayPawn::Tick(float DeltaTime)
{
Super::Tick(DeltaTime);

if(!MovementDirection.IsZero())
{
    const FVector NewLocation = GetActorLocation() + MovementDirection * Speed * DeltaTime;

    if(GetNetMode() >= NM_Client)
    {
        GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Orange, TEXT("ServerRPC called."));
                    
        ServerRPCMoveActor(NewLocation);        
    }
    else
    {
        SetActorLocation(NewLocation);
    }
}

}

bool APongGameplayPawn::ServerRPCMoveActor_Validate(const FVector& Location)
{
return true;

}

void APongGameplayPawn::ServerRPCMoveActor_Implementation(const FVector& Location)
{
GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Orange, TEXT("ServerRPC executed."));

SetActorLocation(Location);

//MULTICAST CALLED HERE?

}```

[foggy idol]

I just have my own on rep variable and use that to know when the game states variables have been initialized on a client

[marsh pine]

Hello.. I am working with pixelstreaming and I realized that the pixelstreamerinput component is destroyed as soon as the client loads the server's map. Pixelstreaming keeps working, but I cannot connect to it through the (now destroyed) component. Does anyone knows how can I avoid it, so I can use pixelstreaming in a client-server setup ?.. Thanks !!!..

[stiff ledge]

hello guys i am a new unreal dev and i want to practice in multiplayer vr apps. is there any good tutorials that you could recommend to me?

i prefer blueprints because i am not good c++ programmer

[red lark]

hi everyone

how could I make matchmaking in my game

[smoky plinth]

Very broad question, you can make your own, use Gamesparks or AWS services for example.

[stiff ledge]

???

yeah i can see some videos. do you recommend any of those specific? its all the same for vr app?

[twin juniper]

Hello everyone.I gave my player five choices for a character to choose from.Based on his choice i will change skeletal mesh in that way.When i am changing the skeletal mesh i am doing a multicast then it will change across all clients.But if my player joins late then that player character is not updating it's mesh at all.I also tried setting replication for mesh component but it is not working.Plz help me.Thank you.

I mean if my player joins late then already existing players are not changing their mesh.

[winged badger]

put a USkeletalMesh* with OnRep

and set it from OnRep on clients

multicasts are no good if you need to keep state

[woeful ferry]

Hi,

I'm kinda lost on how to solve this problem. We're making a co-op survival experience and when a player joins, they should have had their character variables saved, which is solved.

However, how do I detect which player is who? I've looked into UniqueID in player state, but it seems to change for every session.

[steep terrace]

Hello, everyone~ I have a problem of multiplayer. How can I send Render image to server from client ? Even I use the "Run on server" and "Run on multicast" , the texture of server is empty but client is exist。

[bitter oriole]

You'd need to send the image as a compressed archive

Compress to png, send it, decompress and upload to the GPU

[split siren]

Agree with @bitter oriole , but try to minimise that as uploading pngs can be very bandwidth draining.

[bitter oriole]

Yeah obviously this would be for like a player avatar at login

[split siren]

But @steep terrace wants to send it from client via RPC to server and I assume server would then re-distribute it to other clients. Just be aware of the costs associated with those actions.

[steep terrace]

sorry, I am not understand how to upload to the GPU? Is something like Postman or URL ?

My game is a player(using ipad) drawing in the panel, and the his drawing will upload to the computer.

The variable type of Render image is texture. The log said that it is not support when client send to server.

it sound like a good idea ! I will try it! Thx a lot ~ 😆

[naive elm]

about RPC with validation, is the (call)_validate executed on both server and client or just the client?

what do you mean just the client not the server? unreal works with server-client model which means the server always knows what happen on each client

if you are starting to learn about multiplayer there are some useful links pinned on top right corner in this channel, about your question, you have to check replication boxes on blueprints

the one who have to destroy the object have to be the server

[thin stratus]

I think it's rather the opposite, it's the Server that calls it.

never ever used it haha. I always returned true

There was never a need for it

I did however hear that you would actively kick the client if you return false

Which I'm not sure if that's true, but if it is, then I don't see a lot of things you can place into that

A simple disagree on some ammo value, if the ammo is already replicated, shouldn't kick someone

[twin juniper]

Guys, my second player/client movement is laggy as hell.To make him see the changes made in the server, through a server RPC, I just called a multicast. But the client movement is laggy. Isn't this snippet the way you normally do? I read in another thread that one solution would be call a ForceNetUpdate inside the Tick, but it didn't solve it ```void APongGameplayPawn::MulticastRPCMoveActor_Implementation(const FVector& Location)
{
GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Orange, TEXT("MulticastRPC executed."));

SetActorLocation(Location);

}

// Called every frame
void APongGameplayPawn::Tick(float DeltaTime)
{
Super::Tick(DeltaTime);

if(!MovementDirection.IsZero())
{
    const FVector NewLocation = GetActorLocation() + MovementDirection * Speed * DeltaTime;

    if(GetNetMode() >= NM_Client)
    {
        GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Orange, TEXT("ServerRPC called."));
                    
        ServerRPCMoveActor(NewLocation);        
    }
    else
    {
        SetActorLocation(NewLocation);
    }
}

}

bool APongGameplayPawn::ServerRPCMoveActor_Validate(const FVector& Location)
{
return true;

}

void APongGameplayPawn::ServerRPCMoveActor_Implementation(const FVector& Location)
{
GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Orange, TEXT("ServerRPC executed."));

SetActorLocation(Location);

MulticastRPCMoveActor(Location);

}```

[thin stratus]

Well

It's kinda the way

But you are lacking all of the movement replication principals

[twin juniper]

Hello Cedric! Could you clarify this point, please?

[thin stratus]

I'm searching for a website to showcase it

gimme a few min

[twin juniper]

kk thanks

[thin stratus]

https://www.gabrielgambetta.com/client-side-prediction-live-demo.html

You will see two dots

This is a 2D example

but doesn't matter

It's a Server and 2 Clients

You can see the update time on the server (middle)

and 3 settings, as well as lag on each client

If you have none of the checkboxes turned on, you'll notice how laggy it is

That's basically what you have

Now there are 3 things

Prediction: Means that the Client performs the Action while also telling the Server.
You do that so the Client doesn't have to wait on the Position to be replicated to them again.

If you enable that, you'll see that the circle moves faster, but now gets weird corrections

That's where Reconciliation comes in.
This makes sure that the client and server communicate which move they are currently handling.
That means when the Client tells the Server to move, it sends a timestamp along

As well as the result of the move, so the Server can move and compare, and either accept or correct the movement

The correction is what you see if you only enable Prediction

Specially when changing directions

That's because the replicated location from the movement comes back to the client when they are already miles away

Overriding whatever they were doing

Reconciliation makes sure that the client knows what update comes in, and then replays all the moves that are older than that update.
So the correction is if at all minimal and the player keeps moving smoothly

The Interpolation part is only for the other side, so if you see another client you only get the location update, so you want to interpolate between the last and the location

The CharacterMovemnetComponent does all of this for you

If you use a Pawn, you'll have to recode this all

If the text above is hard to understand, start at the beginning of the website I posted you and read through it

https://www.gabrielgambetta.com/client-server-game-architecture.html

This helps a lot to understand what is going on

[twin juniper]

Thanks! 🙂 i need to use the website and read the notes. People in #multiplayer told me, some days ago, to use an ACharacter instead an APawn, but I discovered that I can't change the capsule collision shape without breaking CMC (that would require me to write a custom CMC using a Box component instead, and a capsule collider doesn't fit on a pong paddle), and yesterday they told me to use APawn again. So, I'm cornered: or I rewrite the entire CMC, using a Box component collider, or I code the movement behavior for a Pawn. I'm fucked

[fading birch]

@thin stratus there's a good GDC talk on how overwatch handles their networking that covers what you typed as well. Let me see if I can find it

https://www.youtube.com/watch?v=W3aieHjyNvw

they use a bit of ECS for their networking, which is why the game runs so damn smooth

[thin stratus]

Yeah that'S up to you

I always try to use the Character

[fading birch]

you can sort of cheat it

and have your pong ball react to a certain collision channel

change the collision channels on your capsule comp to ignore that

and then have a box collision on your paddle that blocks it

may be worth a shot @twin juniper

[twin juniper]

Thanks, I could that for the ball, but I haven't its class yet, is my paddle movement that is laggy XD

[fading birch]

no i'm saying on your paddle

just use a custom collision channel

which you can set via your project's properties

[manic terrace]

Is the free steam app id normally that laggy. Or is my code just bad?

[fading birch]

steam has no bearing on latency really

outside of creating/finding a session

[twin juniper]

it worth it a try, but in the case of using an ACharacter, right?

[fading birch]

once you're in game, it's on you

[fading birch]

correct

[twin juniper]

thanks

[fading birch]

so you don't need to rewrite the CMC

[twin juniper]

let me think how I would do that, and I will post here later

[fading birch]

give the pins a solid read/watch.

Replication is a very basic term for working with multiplayer

[manic terrace]

Could bad replication code make the game laggy? Because I may have some of that or it depends on WIFI?

[fading birch]

If you're playing locally and you're having lag it's your code. If you're playing online and have lag it could be code and/or your internet.

[twin juniper]

I guess I will, for learning purpose, to try to code it, since I have found this thread https://forums.unrealengine.com/t/client-prediction-and-server-reconciliation-for-pawn/46658/4, where a guy explained how movement prediction and correction works (in the CMC, I think) in network games using UE:```/*
Here’s how player movement prediction, replication and correction works in network games:

Every tick, the TickComponent() function is called. It figures out the acceleration and rotation change for the frame,
and then calls PerformMovement() (for locally controlled Characters), or ReplicateMoveToServer() (if it’s a network client).

ReplicateMoveToServer() saves the move (in the PendingMove list), calls PerformMovement(), and then replicates the move
to the server by calling the replicated function ServerMove() - passing the movement parameters, the client’s
resultant position, and a timestamp.

ServerMove() is executed on the server. It decodes the movement parameters and causes the appropriate movement
to occur. It then looks at the resulting position and if enough time has passed since the last response, or the
position error is significant enough, the server calls ClientAdjustPosition(), a replicated function.

ClientAdjustPosition() is executed on the client. The client sets its position to the servers version of position,
and sets the bUpdatePosition flag to true.

When TickComponent() is called on the client again, if bUpdatePosition is true, the client will call
ClientUpdatePosition() before calling PerformMovement(). ClientUpdatePosition() replays all the moves in the pending
move list which occurred after the timestamp of the move the server was adjusting.
*/```

I will try the @fading birch approach, if something goes wrong. But I guess I can "use/copy/override" the functions above, and try to use them on my custom Pawn?

[twin juniper]

And I was thinking, if I want to follow a movement prediction approach like the one presented in Cedric's link, I should assume that the first step to correct the code I posted above is to ```// Called every frame
void APongGameplayPawn::Tick(float DeltaTime)
{
Super::Tick(DeltaTime);

if(!MovementDirection.IsZero())
{
    const FVector NewLocation = GetActorLocation() + MovementDirection * Speed * DeltaTime;

    if(GetNetMode() >= NM_Client)
    {
        GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Orange, TEXT("ServerRPC called."));
                    
        ServerRPCMoveActor(NewLocation);        
    }
    
    //Predicts the movemwent that will be validated in the server
    SetActorLocation(NewLocation);      
}

}```and then I should use GetWorld()->GetDeltaSeconds() value as a Timestamp, to verify and correct the position... To resume it, I must repeat what is in Cedri'cs link and what that guy said (the same thing). How prone to error I would be? XD

[thin stratus]

The Server RPC should have the NewLocation but also the data to actually perform the move

And then perform the move and compare what the client said should be correct

[twin juniper]

Thanks for the tip, I will make it work, slowly, but I will: I was reading the Valve article, which was referenced in the link you have posted

Also, in the same article, Now, at t = 250, the server says “based on what I’ve seen up to your request #1, your position is x = 11”. Because the server is authoritative, it sets the character position at x = 11. Now let’s assume the client keeps a copy of the requests it sends to the server. Based on the new game state, it knows the server has already processed request #1, so it can discard that copy. But it also knows the server still has to send back the result of processing request #2. So applying client-side prediction again, the client can calculate the “present” state of the game based on the last authoritative state sent by the server, plus the inputs the server hasn’t processed yet.is the reason behind the CMC PendingMove list usage, I got it. I guess you guys, Unreal Slackers moderators, are saints, tolerating a bunch of guys/gals coming out of nowhere asking things XD

[twin juniper]

Besides the Location and Timestamp (as a float), are you talking about the acceleration and rotation?

[thin stratus]

For example

[agile lotus]

[2021.07.01-18.37.19:300][646]LogNet: Warning: Network Failure: PendingNetDriver[PendingConnectionFailure]: Your connection to the host has been lost.
[2021.07.01-18.37.19:300][646]LogNet: NetworkFailure: PendingConnectionFailure, Error: 'Your connection to the host has been lost.'
[2021.07.01-18.37.19:300][646]LogNet: DestroyNamedNetDriver SteamSocketsNetDriver_0 [PendingNetDriver]```

Using steam sockets I can't get a client to travel to a listen server map

if I use steam subsystem it works fine

[agile lotus]

It appears my client is trying to connect to the wrong map

Browse: steam.109775240936920135/Game/Maps/MAP_Startup
but it should say

Browse: steam.109775240936920135/Game/Maps/MAP_MainMenu

[twin juniper]

thanks!

[kind ember]

Is there a way to make HTTPS request from PlayFab cloud script?
Seems like it can only do HTTP.

[frozen nexus]

I have a anim montage replication problem. The montage is playing in the wrong direction for clients (its always facing down towards the ground). The base animation sequence used in the montage is using Additive settings (local space) to get the correct direction (in the direciton of character forward vector, works for the server). I am calling PlayAnimMontage() in a OnRep_Method() to tell the clients to play the anim montage. Any ideas to what I am missing here? Thanks!

[split siren]

Just checking, RPCs should not go through if actor is set to Dormant All, am I right?

[split siren]

That sounds more like a legal issue rather than technical one

I have no idea, I was just wondering if you are asking a technical or legal question. From technical standpoint, it should be doable. But I guess the safest way would be peer-to-server-to-peer

I don't think this is the right channel to ask for legal advice. I believe it is more programming oriented.

AWS has very limited free options, none suitable for game server if you are asking that. "Is it good"? Yes? It's a cloud server of spec you pay for..

Dunno

[woven sinew]

anyone got problems with session current player count not being updated too ?

[warped hearth]

What is the equivalent of this node in Unreal Engine 5?

[shy hill]

When using the steam online sub system to connect to a listen server, is it normal that by default, the basic character movement replication is not smooth ?

[split siren]

Not smooth in what scenario? Is the owning client not smooth? Server when client is observing it? Client viewing moving client?

[shy hill]

client viewing moving client

[split siren]

I believe there is a default client side mesh prediction which should be smooth enough.. I tried it just now and looked fine on my end. Can you send a video of it happening?

[shy hill]

sure, let me record one quickly, thanks !

[split siren]

Ha, there is your issue

Paper2D Does not support client-side movement prediction. That feature is only for meshes.

[shy hill]

my character has 'replicate movements' on and this is my movement node

argh really ? good to know

[split siren]

I tried to write my own couple months ago with some success..

But definitely buggy

[dark edge]

Wait wtf, the prediction is dependent on the mesh and doesn't just predict the capsule? That's damn weird.

[split siren]

Yeah, because it needs to handle animations and other stuff

[dark edge]

Wouldn't those just be driven by the capsule movement and end up the same either way? Seems like an ass backwards way to do things.

[shy hill]

so theoretically, if I replace my sprite with a cube... would that work ?

[dark edge]

@shy hill are you based on ACharacter

[shy hill]

yes

[dark edge]

Does it go Capsule -> Skelmesh -> Sprite?

[dark edge]

Try attach sprite to mesh

[shy hill]

but right, I don't use the mesh

[dark edge]

Its still there tho just empty

If that's the component being predictably moved then attached components should follow. Try it.

Although common sense goes out the window when dealing with the CMC

[shy hill]

still a bit laggy, but definitely better 🙂

thanks a lot, that already help a lot, I spent many hours trying to figure it out :d. My concept relies on pretending to be an NPC, so ideally there shouldnt be any lag at all, if you have any tips to improve it further, I'd be happy to here them (I tried 'smooth sync' but it came with other issues I couldnt solve )

[plucky prairie]

what is the Proper setup for Dedicated server testing? When I use the editor and run 'clients' they behave differently to when I package a dedicated server build and the run it. It's a pain to have to have to package client/server every time I make a small change, what is the best way to go about this?

[thin stratus]

You can run servers standalone too

Might still be slightly different to how packaged behaves though

But removes the need to package

Most studios set up buildmachines with jenkins and p4 though to automize stuff like that

[plucky prairie]

so if I make a small change to a blueprint how do i run the server standalone?

you mean i jsut dont package?

[fading birch]

you can make a shortcut like this:

"EngineLocation/UE4Editor.exe" "ProjectFolder/ProjectName.Uproject" -server -log```

[plucky prairie]

ah ok cool

then is there a way to run a client like that too

instead on in editor?

[fading birch]

yes. replace -server with -game

[plucky prairie]

excellent, thanks so much

[timid moss]

Hey. I also found this post from searching for "turn in place jitter". Did you ever figure this out? I'm having the same problem

[lucid vault]

Yes, iirc it had to do with the order in my animBP for tip and spine rotation

[summer tide]

If I randomize materials and pass it to SetMaterial to my Mesh in BeginPlay, do I have to replicate this?

[oblique bay]

Does anyone know or have any pointers on how to implement spectating teammates like in CSGO or Valorant where you basically see your teammate's POV

[calm bison]

Having issues with a flying vehicles location being incorrect if it collides with something

anyone have any suggestions?

they're just completely off lol

[peak star]

@oblique bay I dont know those two games but I think the easiest way would be to setviestargetwithblend on the teammate's pawn.

If you want it as part of the HUD instead of changing the entire viewport over, you can do that with a scenecapture2d on the the team mates pawn and a render target as your texture on the hud widget.

But if you want the exact view the other player has as a picture in picture in your HUD including THEIR hud, then I am not sure how to do that.

I think for most use cases you wouldnt need any network code to do it though

[thin stratus]

Unreal Tournament or Shooter Game might have code for you

[merry harness]

Hiho, what exactly is better to have a fixed game mode and to regulate everything via a game mode or a parent game mode and some child game modes?

Master Game Mode (Main Game)
MenuGamemode (Login Menu)
ThirdPerson Gamemode (everything about the player / character)

or

MasterGamemode (for everything)

[merry harness]

Someone have any ideas? ^^

[split siren]

Maybe a bit too specific question, but does anyone know why actors gathered by UReplicationGraphNode_DormancyNode are not network culled based on distance later on?

[merry harness]

That's probably true, I also think that it serves as an overview, there are also aspects such as widgets that should run on the client in the third-person game mode (widget = client) and other things such as the status values, strength of the opponents, etc. server-based so that nobody can cheat ^^

[thin stratus]

I would always tend to having proper Hierarchy

I would never want my GameMode for the MainMenu to have Gameplay Code

Neither would I want MainMenu and Gameplay Modes to have code for Lobby etc.

[winged badger]

someone can always cheat

and until you have a functional game you shouldn't even try to account for that

[merry harness]

I agree with you, but client-based data is always easy to change, while data on the server is always freshly accessed and cannot be influenced by changes to the client.

I have a little problem and hope someone can explain how to fix my problem.
I know that widgets work at the client level and not work at the server level.

What exactly is the difference between a widget and a UI?

How can I fix this error that when I press "i" to open the inventory, the inventory also opens?

Before the switch to "Play as Client" everything worked ^^

[meager spade]

Widget is a UI layer

UI is local only and has no business being inside GameMode.

[merry harness]

Do you mean this should not be in the ThirdPerson gamemode??

[meager spade]

correct.

GameMode should not create or do anything with widgets

[merry harness]

ah ok

[meager spade]

Check the pinned compendium

GameMode is server only. Clients would never get a widget

[merry harness]

but my errors are not in gamemodes

Do you mean the PDF? i have read 2 times

[meager spade]

If you are trying to access GameMode from your GI on clients, that would not be allowed either

tho i cant tell what those errors are doing

[merry harness]

i can tell you

pls give me a second ^^

wow

Ok i have deleted the Create Main Widget from the ThirdPerson Gamemode (no Error) and copied the code into the ThirdPersonCharacter (now i have Errors) xD

@meager spade Ok can you explain why i get this error Code?

this is in the ThirdPerson Character

I didn't get any errors when the same code was still in gamemode.

The same Error Code in the game Instance...

[dull lance]

just dropped by: @merry harness dedicated server?

[merry harness]

Yes Play as Client

[dull lance]

iirc, dedicated servers cannot create widgets. So if your code is ALSO running on the dedicated server itself, that could be why

[merry harness]

The main Menu isnt replicated

[dull lance]

that's not what I meant

Widgets cannot be replicated anyways

[merry harness]

And the Main widgted Event /to create) ist only run as client

So that's exactly why I have all the stuff in the MasterPlayerController. I told every event there that it could only be carried out on Cliets ...

should i have the shortcuts also into the MasterPC?

These are in the ThirdPersonCharacter

[merry harness]

someone have any idea?

[vague fractal]

What would be the best way to set the rotation of an non-gameplay relevant thing for each player ?

As in, Object 1(Which exists for every player) should always look at the "local" player

Might make more sense if i explain the situation.
My enemies are having a UWidgetComponent which will show a widget with his health and similar above his head.
And i want this widget to always look to the player on his client

[dull lance]

On Beginplay, find the local player... then on tick, Interp to Local player find look at rotation? ^

[vague fractal]

Finding the local player is kinda my problem here ^^"

GetWorld()->GetFirstLocalPlayerFromController() is the best i found, but even there i have no idea how to get the character from ULocalPlayer

Oh, seems like it has a PlayerController variable

[thin stratus]

Just putting it on ScreenSpace isn't enough?

[vague fractal]

I feel like there is a way to avoid the NetMulticast here, but i'm not sure how.

This here is my TakeDamage method

void AEnemyBase::TakeDamage(const FWeaponDamage& DamageAmount, APlayerCharacter *Causer)
{
  if(M_AttributeComponent->GetIsDeath()) return;

//Damage calculation...
  if(M_AttributeComponent->GetIsDeath())
  {
    Server_HandleDeath();
  }
}

Server_HandleDeath Is basically just this here

void AEnemyBase::Server_HandleDeath_Implementation()
{
  HandleDeath();
}
void AEnemyBase::HandleDeath()
{
  GetMesh()->SetCollisionEnabled(ECollisionEnabled::QueryAndPhysics);
  GetMesh()->SetSimulatePhysics(true);
}

But this whole logic doesn't seem to work on the client

[thin stratus]

Client should never call that

Neither should there be a serverrpc in that

Server rpc should happen waaaaayyy earlier when your client performs their input

Unless this is a Multicast

[vague fractal]

I'm sadly still a bloody beginner when it comes to networking 😓

[thin stratus]

Then you mislabel it quite hard haha

You should always remember that state changes should be done via onrep variables

Not multicasts

Being dead is a state change

Make it an OnRep Boolean

[vague fractal]

I've tried to make a OnRep method with M_AttributeComponent, but it didn't even fire

[thin stratus]

It will fire automatically clientside

If you also need it on the server then you need to call the Onrep by hand when you change the variable

[vague fractal]

I've tried it with a debug message, but it was never called.
Can it be that it's cuz M_AttributeComponent is a more complex type than a simple struct ? (It's UCharacterAttributeComponent : public UActorComponent)

[thin stratus]

I don't follow. If you have such states in a component then thr component itself in additon to the actor has to be marked as replicated

And then you would have the Onrep boolean in that component

The pointer to the component doesn't need to be marked as replicated. Component is spawned in construction on clientside anyway

Phone is dying soon. So might stop answering

[vague fractal]

Oh, so i should basically get the OnRep notify within the UCharacterAttributeComponent class and in case IsDeath will be changed to true i'll call the HandleDeath method from the AttributeComponent ?

Argh, wish my brain would be quicker when it comes to networking

[fading birch]

@vague fractal is there a reason you're not using virtual float TakeDamage(float DamageAmount, struct FDamageEvent const& DamageEvent, class AController* EventInstigator, AActor* DamageCauser); ?

[vague fractal]

Yes, i've heard it's getting deprecated in UE5

[merry harness]

Ok noone knows..

[fading birch]

where'd you hear that from? It's not marked as deprecated in the early access.

[vague fractal]

Several ppl told me that

[vague fractal]

Yeah, sry for my question flowing down your question 😅

[fading birch]

you don't need "Run on owning client" as a an RPC for widgets. A simple check of role on the controller will suffice.

Without seeing how your inventory component toggle works, we can't help you

you should probably ask in #umg as this isn't a multiplayer related question

[fading birch]

i'm staring right at UE5 source and not seeing it marked as deprecated, so

[vague fractal]

It seems trust worthy to me if even Siliex* claims that it was said in the patch notes
#cpp message

[merry harness]

Ok i thought its multiplayer because the widgets are working ijn singleplayer (with out server) Thanks ^^

[hollow eagle]

The damage stuff is de facto deprecated even if it isn't marked as such. It's a bit odd that they're not deprecating before removing, but UE5 is as good a chance as they're going to have to make breaking changes so meh. It's likely something coming with the full release at this point (or maybe a future EA). I haven't checked if the main branch has removed it yet.

Damage stuff still exists in ue5-main for now. So they haven't removed it yet. Or the migration guide is entirely wrong and they changed their minds on removing it.

[gleaming viper]

hey guys, how would I go about replicating flashlight's pitch? I got something like this, but the spot light pivot is kinda screwed up and it doesn't rotate properly, could you help me out?

[fading birch]

you would think they would at least mark it as deprecated

[hollow eagle]

You also think they would have proofread the migration guide.

Obviously something is wrong there, for now I'd assume it's going away.

[waxen breach]

I posted this in #virtual-reality but I really need some help doing Oculus VR multiplayer

anyone able to do this?

Well here's the main issue

I have only ever made singleplayer games

but, that being said

there is zero documentation about VR replication

Well, there's tutorials showcasing them turning the first person and third person tutorials into Networked apps

I'm just looking for something that has to do with VR replication because the motion controllers are apparently different

Well again that's the issue

I'm going off what I've read here

I'm just not even sure where to start, because there's nothing to follow rn regarding this

I think i found some lead

but i'll have to see how it goes

[fading birch]

speaking of VR, is there a good way to test two VR players by yourself?

[severe tendon]

Not really, we have 2 Quest's just to test on Oculus 😐

[hollow eagle]

I'd almost recommend making a non-VR mode just for testing game features.

it's a bunch of extra work but... it doesn't need to be polished and you might make that time back with improved iteration speed on anything that isn't directly tied to motion controls.

[fading birch]

ugh, damn

[severe tendon]

Anyone know what would cause this error in a packet?
We're using BP over C++ for simplicity

[mossy lantern]

Hey all, when trying to build a dedicated server to test out my project that I have been working on in Unreal with multiple people, the build time for all of the files has taken significantly longer (about 10 hrs) than what the github page estimated for it to complete. So, I was just curious as to if this could be because of my hardware specs and not being connected to ethernet or if it could be because of an ulterior reason.

[severe tendon]

Build times are based entirely on your hardware, primarily your CPU
but iirc you can just launch the server from the client exe with -server

https://docs.unrealengine.com/4.26/en-US/ProductionPipelines/CommandLineArguments/

[fading birch]

@mossy lantern were you building the engine from scratch for the first time?

A normal first build time for a dedicated server can take anywhere from 10m for an empty project to 2+ hours for a larger project

our Build machine takes ~30m to build an updated version of our dedicated server and that build machine is bonkers fast

in addition to what @severe tendon linked, you can also do this:
make a shortcut like this:

"EngineLocation/UE4Editor.exe" "ProjectFolder/ProjectName.Uproject" -server -log```
I usually create a shortcut off the `.uproject` file and then construct that in notepad and paste it in. `-log` is especially useful beyond seeing a log because if you close it, the server also closes. If you don't have `-log` you'll need to close it via task manager

[tidal venture]

Does someone have a solution for the choppiness when two character colide while moving with latency?

[severe tendon]

Lerping/smoothing?

There is a smooth move plugin iirc

[tidal venture]

So I should expect my character to teleport when someone move into them? I know the plugin, I use it when I need to use physic.

It work very nicely when I disable the network simulation

[severe tendon]

Movement and colliding is physics
The reason its so choppy is because of the server and client positions not being exact, Client thinks the server object is at Pos 1 when its at Pos 2, so smoothing should fix that as far as Im aware

[tidal venture]

I'm going to give it a try, I was more hoping about something simple to setup in the CMC networking panel

Sadly it's true, smooth sync just resolve it. I didn't wanted to use it, but that just seem impossible without it

Thank you for your output

[mossy lantern]

Yeah I was building it from scratch for the first time and ah okay interesting, I'll make sure to try that. Many thanks to you and @severe tendon .

[fading birch]

building the engine from scratch is expected to take a 30m - 4+ hours.

depends on your CPU

[dull lance]

quick question: at which point does an actor class has their network role established? Ctor? OnConstruction? PostInitialize? BeginPlay?

[fading birch]

constructor

AActor::AActor(const FObjectInitializer& ObjectInitializer)
{
    // Forward to default constructor (we don't use ObjectInitializer for anything, this is for compatibility with inherited classes that call Super( ObjectInitializer )
    InitializeDefaults();
}

void AActor::InitializeDefaults()
{
    PrimaryActorTick.TickGroup = TG_PrePhysics;
    // Default to no tick function, but if we set 'never ticks' to false (so there is a tick function) it is enabled by default
    PrimaryActorTick.bCanEverTick = false;
    PrimaryActorTick.bStartWithTickEnabled = true;
    PrimaryActorTick.SetTickFunctionEnable(false); 

    CustomTimeDilation = 1.0f;

    SetRole(ROLE_Authority);
    RemoteRole = ROLE_None;```

[dull lance]

I did check that but that doesn't seem to account for networking specifics.

[fading birch]

what do you mean?

[dull lance]

Well, this seems to be before say things like simulated copies get their roles assigned

[meager spade]

Anyone know why a client leaving a game would not tell the host they have left?

    {
        if (UOnlineSession* const LocalOnlineSession = GetOnlineSession())
        {
            LocalOnlineSession->HandleDisconnect(World, World->GetNetDriver());
        }
        else
        {
            GetEngine()->HandleDisconnect(World, World->GetNetDriver());
        }
    }```

this is what i call when a client clicks the quit button, but they end up not actually leaving, but the server will time them out

[severe tendon]

I've had that issue with Connect/Leave, I ended up just writing a jank 5 second timer that checks if there are more actors of the player type in the level than there are in the array of active players and then if there are more/less then it removes them and updates the server.
I still can't figure out how to actually have it update 😐

[odd sundial]

I have this weird issue.

I have some UI set up where players can choose their loadout. When they save what loadout they want, that information is stored in the player's Player State (it's just an array of "gadgets").

The first player spawns. No worries- the gadgets he chose are there, and he can use them.

However subsequent players that choose their loadouts will spawn with their gadget choices in addition to the choices made by the previous player.

For example, if the first player chose a smoke grenade and a flashbang...

And then the second player chose camoflauge and extra ammo, the second player will end up with all four gadgets.

What... what could be going on here? It's like they share a common PlayerState

[thin stratus]

No idea without seeing your code.

[odd sundial]

void ASpy::InitializeEquipmentBasedOnLoadout()
{
    if (SpyPlayerState)
    {
        if (SpyPlayerState->GadgetArray.Num() > 0)
        {
            for (int i = 0; i < SpyPlayerState->GadgetArray.Num(); i++)
            {
                TSubclassOf<AGadget> Gadgetclass = SpyPlayerState->GadgetArray[i];
                FString GadgetName = Gadgetclass->GetDefaultObject<AGadget>()->GetGadgetName().ToString();

                UE_LOG(LogTemp, Error, TEXT("You have selected: %s"), *GadgetName);

                if (InventoryComp)
                {
                    InventoryComp->AddGadgetToInventory(Gadgetclass, 1);
                    if (bShowDebugs) { UKismetSystemLibrary::PrintString(GetWorld(), TEXT("Spy.cpp - InitializeEquipmentBasedOnLoadout() called.")); }
                }
            }
        }
    }
}```

From the PlayerState BP

The UI that adds the gadget array to the playerstate

Might any of that help explain what the heck is going on here?

As i said, the loadout works great, but it's like they're.... sharing a player state

This is called from the character to take the gadgets from the player state and equip the player with them

[thin stratus]

First image

Is your issue

GetPlayerController0

[odd sundial]

Yeah???

[thin stratus]

You can't use that node in Multiplayer like this

If you call this on the Server, which you are

Then it's the Server's PlayerController

And thus the Server's PlayerState

[odd sundial]

..... and that would make perfect sense

[thin stratus]

Locally you can use GetPlayerController0 if you have no local coop stuff

So e.g. in the Widget

But not if you start communicating between players

Where is that Server RPC in?

In the PlayerState

[odd sundial]

That server RPC is in the PlayerState BP

[thin stratus]

Why do you get the PlayerState again from the PC?

You are already in it

It might even be the correct one

[odd sundial]

... good point

[thin stratus]

The SecondImage is fine-ish

But even here you should probably use "GetOwningPlayer"

And make sure you pass the PlayerController into the CreateWidget Node

[odd sundial]

Okay amazing I'm going to try and implement this right now

[thin stratus]

The third image looks bad too

In the Character you can do "GetController"

Or even "GetPlayerState"

Not sure why you use GetPlayerController0 here

That's again the Server's

The PlayerController creates the PlayerState, so in your Character you can just use the OnPossessed event or whatever it's called, and do "GetPlayerState" and get the Data

Taht event calls Server side only

I assume you want to spawn gadgets server-side only anyway

Something like that

[odd sundial]

Thank you! I'm going to try and get all this in and see how she works

[odd sundial]

Re this image.... this BP code is from the Character's BP, not the player controller. I can't seem to access the Event OnPossessed from the character, even if I try to from the controller node

[thin stratus]

That event is part of teh Character

@odd sundial Might just be called Possessed

[odd sundial]

AH, okay found it here

Hmmm yeah the loadout system doesn't work for servers or clients at all anymore

[thin stratus]

Yeah not sure how the rest of your code works

But given what you posted this should be enough

I assume the Loadout selection and the Spawning of the Character happens after each other and on the same map

[odd sundial]

Yes, spectator pawn is possessed, player chooses their gadgets (held in the player state) then clicks spawn - player spawns with their gadgets loaded in from the player state

PlayerState (new)

from the Widget blueprint when they save which gadgets they've chosen

Called by the character's BP

[odd sundial]

Where is this done? This doesn't look familiar

[thin stratus]

Where you Create the widget

[odd sundial]

So this is from the controller BP..

Everything else I think seems to be working, but when I try to add my UI, it causes a hard crash. I'm guessing there's a conflict between the 'Possess' event on the player character and this 'On Possess' event? Perhaps? If I disconnect the UI from being created/added to the viewport, it doesn't crash

[odd sundial]

Yes... so above is causing a hard crash but I think the rest of the functionality is working..

When the UI loads in, it crashes

[thin stratus]

You can't use pins like this

Only because the EventGraph allows it doesn't mean you can pull wires as you please

If you need a Callback to add UI that depends on the Pawn

Then you should use C++

There you have the OnRep_Pawn function you can override

The ClientRPC obviously would work in terms of calling, but you can't bes ure that the Pawn is available on the client yet

And if you want the pawn, just use GetControlledPawn

Don't use the PossessedPawn pin like this

You are moving between Networks, the Client has no idea what the value of that pin is

@odd sundial

[odd sundial]

@thin stratus Appreciate all your hard work here!

Yeah I can't get.... around these hard crashes because of the UI. Ughhh I'm so tired. I give up for now... thanks for your help

[thorny jay]

we have a real time multiplayer online racing game ...
our dedicated server has 16 core cpu and 16gb of ram ...
how many players can this server support simultaneously?

[thin stratus]

Yeah nothing we can answer. You'll have to profile it yourself and then judge.

[manic terrace]

I was wondering why the default Net Update Frequency which is a 100 is that high. Isn't that just too much? I have mine to a value of 5 and from what I have seen so far it is working fine. I changed it on my character and haven't seen any dramatic changes. Should I have it higher?

[sweet pier]

For multiplayer is it better to make a single player game, then convert it to multiplayer or to make it with a multiplayer framework to begin with

Thanks

[azure hollow]

At the end of my race I need to send a ghost structure to the server. The weight of the struct is 244kb, in your experience is this a high number or is it ok? my first time with server stuff 🙂

[azure hollow]

after serialization

[chrome bay]

Quite large for a one-off packet, but might go through ok

If not you'll have to spool up a socket

[azure hollow]

is there any 'standard' size to take as reference? I know it may be a silly question, I'm trying to understand 🙂

[chrome bay]

IIRC the default "saturation" limit in 4.26 and above is 100kb, but that's for a full seconds worth of data

UE's networking is designed for very small packets at high rates

[azure hollow]

ok thanks a lot

[chrome bay]

Epics recommendation BTW is to use sockets if you have to do this

[azure hollow]

got anything that I can read about this?

[dry cipher]

Hi @ all
I trying to replicate a physics actor. Can someone explain to me why this is not possible with my settings? I spawn the balls on the server but on the clients it have different positions

[thin stratus]

The Actor also needs to replicate movement

But be aware that this is not smoothed at all

And that Replicated Physics shouldn't be used for Gameplay, as physics aren't deterministic etc.

[dry cipher]

@thin stratus
How would you do such gameplay in principle? Are the physics in games like rocket league or fallguys fake?

[thin stratus]

Rocket League has done a lot of additional work to get this working

There is a youtube video about it, obviously not detailed enough to easily copy it

Fall Guys is not UE4, or?

relatively sure that's unity and also kinda sure that they had to do a lot of groundwork to get this working

[fading birch]

it's Unity

[dry cipher]

@thin stratus
I am a programmer, but no C++ so far 😅. If this means a lot of work, I'll have to rethink my gameplay. My plan was to have small races with mini-games in between, but it looks like I will have to cancel the mini-games. It's just a hobby project 😄
@fallguys: oops i always thought that was the Ue4 but Djriff is right it is unity

[thin stratus]

Yeah it might be a lot of extra work

At least if you want the players to have a good experience

[fading birch]

I was pretty surprised it was made with Unity

Unity is a fine engine, but the marketplace makes me run away as far as possible

it's a sad state

[green spoke]

We use your network guide all the time Cedric. Thank you!

[thin stratus]

Glad it helps (:

[dry cipher]

@green spoke
@thin stratus
Yes, the best guide for repication! thanks alot

[fading birch]

i'm not familiar with that

[fading birch]

ah

[vague fractal]

Is it a bad sign that the physic body's aren't 100% sync ?
I'm kinda afraid that it could break my interaction system since you have to look at the dead enemy to loot him

[meager spade]

replicating physics is a nightmare

hence why you don't care where a dead body is (if might be slightly different place/position on eveyr client)

but why does that matter?

[vague fractal]

I was just afraid that the server might think Hey, you try to loot an enemy here, but there is no enemy at the place you are looking at

[meager spade]

client can just tell the server hey i wantr to loot this

[vague fractal]

Alright, i'll try to ignore it then ^^
Currently it's anyways already like 95% sync (Likely wont last for long xD)

[twilit radish]

Until it all falls apart with high latency D:

Also, are there any VR devs in here? I was wondering how people deal with room scale and multiplayer, it seems like an insecure and weird mess to me 🤔

Especially when for example already dealing with the Character Movement Component. I have for example been trying to support room scale for a test, but my clients keep desyncing because I try to move the actor to the camera, which obviously the CMC doesn't like. But even that is still a very insecure way and not something you can correct if it goes wrong on the client (a desync). I really wonder how games like Pavlov deal with this.

[twilit radish]

Room scale refers in this case to the person in VR physically walking inside their own real life room, so if I walk 1 metre in the real world my camera will also move 1 metre relative to the actor. Why I move the actor towards the camera is to make sure the collision of the character (the root capsule component) stays relevant for.. Well collision. This makes sure people can't literally walk through for example walls in the game. But at the same time like I said this solution is really not cheat proof and to my knowledge also not a good way that can be corrected by the server if the client does desync from the server.

The cheating aspect would obviously be, who says a client doesn't make speed / teleport hacks out of this? They could say the camera is suddenly 20 metres in front of them, you could only really do checks with this such as "Isn't the camera maybe 20 metres away from the original centre of the room?" or "Isn't it moving literally metres per frame?" etc.

I'm not too worried about hacks though, but I would prefer a client not having really weird issues if they for example maybe lost track of the headset and the headset suddenly teleports all over the place or goes to a 0,0,0 relative location 🙂

It's weird a feeling correct, but there are many games that don't allow this by pulling back the player camera (which is what I described). Which isn't an ideal solution, but better than walking through a wall and possibly getting in the most weird places if you would ask me. But fading to a black screen is also a solution yeah.

[vague fractal]

Is there maybe any good guideline for when to use what(As in when should i use OnRep, when should i use a Server RPC, how do i call it ect..) ?
I feel like i'm doing everything wrong while it still somehow works.

[vague fractal]

Welp, i guess i should just buy a course like that one.
If anyone ever tried that one, would be really cool if you let me know if it's good 😅
https://www.gamedev.tv/p/unrealmultiplayer/?product_id=1500305&coupon_code=JOINUS

[meager spade]

https://learn.unrealengine.com has free courses @vague fractal

i think it may also have that one for free.

[kind ember]

Since when did they added this?
And does it work well? Are there any additional steps?

[rocky stag]

Hello everybody
I have a multiplayer game that I load sub-class of my game’s character from a data asset when a player connects.
I want a recommended way to spawn this character and possess that on the controller. Currently, I’m using On posses but I think there is a better place to do this.

[kind ember]

Wow Epic! Lol why did they put that in there.
I heard UE5 gonna support 64 bit world coordinate, what do you think?

[modest rune]

hopefully simple question (my google-fu seems to be failing me on this one, im probably searching for the wrong term) but in the context of something like a multiplayer shooter (and in the context that i'm a hobbyist noob and still dont know the nuances between some of these items), should input be handled on the character or should I make a playercontroller? Should I make my character from the unreal character class or the pawn? Any recommended resources for learning more about why I should do one or the other or how to properly implement a player controller?

[kind ember]

Oh great!

[muted perch]

How would I avoid using multicast in places? what are some conditions where I wouldn't need to use multicast? (I don't need like a 100% rundown, just like general rules would be the most helpful)

[modest rune]

Ok I guess my confusion is, I created a character and bound input axis and actions. But I did not create a controller, is it creating a default controller that I should edit? Is that where those input bindings should actually live?

[kindred widget]

@modest rune Your GameMode has the default classes for those things. The Engine will use the UE4 default controller class for possession if you have not specified your own in GameMode. As far as input bindings, you should put them where they're meant to go. This heavily depends on your game and personal design, but a good example might be something as simple as a tab button to open up a typical shooter's game stats page with KDA stuff, game time, etc. This should probably live on the controller, since you'll likely want players to see this when their pawn is dead, or even before it's spawned. Movement should most likely go on the Pawn itself because you can't guarantee you won't create different pawn types. Classic example is human versus car/horse. Car/Horse will have majorly different controls than a human pawn, and having to route that through ifs and branches in logic is a headache that can easily be avoided by keeping the input in the pawn that uses it and possessing them correctly.

[kind ember]

Does anyone know if GTA V use deterministic physic or semi like default Unreal?

[twin juniper]

Guys, I'm passing a USTRUCT as a reference in a server RPC, but, for some reason (probably is something I'm missing), the reference isn't working. If I discard the struct and use its member as the RPC parameters, directly, everything works fine. Here are the snippets:

USTRUCT()
struct PONGONLINE_API FMovementPredictionData
{
    GENERATED_USTRUCT_BODY()    
        
private:
    friend class APongGameplayPawn;
    
    float Timestamp;

    FVector Location;

};

(...)

UFUNCTION(NetMulticast, Reliable)    
void MulticastRPCMoveActor(const FMovementPredictionData& PredictionData);

UFUNCTION(Server, WithValidation, Reliable)    
void ServerRPCMoveActor(const FMovementPredictionData& PredictionData);```

What is wrong? Should I use the UPROPERTY(Replicated) in every USTRUCT member, even if the struct itself isn't a replicated property and is passed in a RPC?

[hollow eagle]

anything you want replicated in a struct needs to be UPROPERTY() (not Replicated)

[twin juniper]

Thanks, @hollow eagle ! The compiler just told me right now: ``LogCompile: Error: Struct members cannot be replicated```

[hollow eagle]

read what I said again

[twin juniper]

? Should I only mark struct members as UPROPERTY, and not as UPROPERTY(Replicated). Did i misunderstand it?

[hollow eagle]

correct

struct properties are replicated together, they aren't opt-in like a UCLASS property.

[twin juniper]

Thanks, let me test this, because I don't now if the lack of UPROPERTY in the struct members was the cause of my issue

Yeah, it was 🙂 Thanks @hollow eagle

[fading birch]

you can opt out certain variables from replicating if you want in a struct

[thin stratus]

Has anyone ever extended the CMC ServerMove RPC Functions?
I tried that a quite some time ago (probably 2 years ago or so), because I needed more info from Server to Client than there was available. But I think it wasn't really working.
If someone did that, are there any "here is how it should be done" posts?

Because the Wiki entry that explains how to use SavedMoves does it wrong. They just RPC the extra data in a second RPC, which is of course not synced to the ServerMove one.

Base ideas would be adding custom ServerMove functions, adding either the specific parameter or a struct that properly net serializes to them and using those instead of the default ones. +- copy pasting a shit ton of code because the CMC has too big functions with no options to easily place code in between

I'm aware though that 99.99% of the time, the Server most likely has all the data it needs to perform a move, so the flags for "I want to do XYZ" are enough.

[fading birch]

I've always just modified the CMC code

it irks me that stuff isn't marked as virtual

forcing you to use source

[thin stratus]

you mean in a custom engine

[fading birch]

yup

[thin stratus]

Yeah not having that option in this project

But it comes down to the same

[fading birch]

you can technically get around it

with a few redirectors

and just copy the entirety of the CMC

I briefly toyed with that today

as i'm doing an engine upgrade, and had to copy over our CMC changes

[thin stratus]

Yeah that's also all fine. The "How to make it work" is not what I'm interested in

I know I can make it work. I would love to know what the best way is in terms of implementation of the additional parameters

E.g. by default this is the server move signature:

ServerMove(float TimeStamp, FVector_NetQuantize10 InAccel, FVector_NetQuantize100 ClientLoc, uint8 CompressedMoveFlags, uint8 ClientRoll, uint32 View, UPrimitiveComponent* ClientMovementBase, FName ClientBaseBoneName, uint8 ClientMovementMode);

The CompressedMoveFlags is the only info we can additionally send along

e.g. "User pressed key"

Like Jump or Crouch

but what if I want to say "User pressed Key, and wants to perform this action with these values."

"these values" have no place

And if the value is only known in the frame that the user performs the action, then the Server could not be in sync

An easy example would be if you want to jump with a different strength

I can edit JumpZ runtime, but not without an additional rpc

I mean, it goes against the design to let the client specify those values, but if cheating is not a concern then who cares :D

I also don#t have enough custom flags to even specify multiple different actions -_-

[fading birch]

this was the exact issue we had

and why we had to modify CMC

I'm sorry I don't have any answers for you, i'm still neck deep in this engine upgrade otherwise i'd look into it. If you do find out, please share as i'm interested in that.

[thin stratus]

It's not urgent. It's just a thing that comes up every now and then and I was curious if others solved it

[fading birch]

If I get some time, i'll look into it this week

but my plate is pretty full both on and off the clock unfortuantely

I have next week off though

😄

[thin stratus]

Buddy, that's your free time. Enjoy life. Don't look into this sh't for me :P

[fading birch]

hey, i want to know too xD

i'm like a sponge accumulating semi useless knowledge that serves me no purpose, except to pass onto others

[thin stratus]

You'd be surprised how much it's worth to know a lot of stuff, even if not very in-depth

[fading birch]

it's saved my ass a few times actually

surface knowledge is like gold

especially in this industry

[thin stratus]

enum CompressedFlags
{
    FLAG_JumpPressed    = 0x01,    // Jump pressed
    FLAG_WantsToCrouch    = 0x02,    // Wants to crouch
    FLAG_Reserved_1        = 0x04,    // Reserved for future use
    FLAG_Reserved_2        = 0x08,    // Reserved for future use

Those have been reserved for ages. At this point they could just make them custom too

Whatever they are going to add is doesn't even need to be of any value to me

E.g. like what if my character doesn't freaking crouch

[fading birch]

:/ c // Bit masks used by GetCompressedFlags() to encode movement information. enum CompressedFlags { FLAG_JumpPressed = 0x01, // Jump pressed FLAG_WantsToCrouch = 0x02, // Wants to crouch FLAG_Reserved_1 = 0x04, // Reserved for future use FLAG_Reserved_2 = 0x08, // Reserved for future use // Remaining bit masks are available for custom flags. FLAG_WantsToSprint = 0x10, // Wants to sprint FLAG_WantsToSlowWalk = 0x20, // Wants to walk slowly FLAG_SlidePressed = 0x40, // Slide press FLAG_Custom_3 = 0x80, };

we didn't touch them

[thin stratus]

https://giphy.com/gifs/starwars-star-wars-episode-3-3o84sw9CmwYpAnRRni

[fading birch]

¯_(ツ)_/¯

we were worried about the future

cause you know

these have changed in the past 10+ engine versions

[azure hollow]

Since it's my first time with server/multiplayer stuff, what is the best way to compress ghost data (struct of rotation and location)? I'm doing the serialization to json but I don't know if it's the best

[abstract pond]

hey was wondering if anyone could help with this im using the advanced vehicle system demo project and im trying to set the visibilty of the 3rd person character to hidden when they enter the car

and its meant to be for multiplayer - but whats happening instead is that on the client both players are invisible as is meant to be, but on the server the server player is hidden and the client player is visible

[pallid mesa]

so... from the server u see the simulated proxy visible?

[abstract pond]

i have no idea what that is not going to lie

[pallid mesa]

hahaha

let me check if I can find any resource explaning what that is

its essential to understand multiplayer

hold on a second

https://michaeljcole.github.io/wiki.unrealengine.com/Replication/#Terminology

take a look on the roles section

[abstract pond]

the quick review of roles?

[pallid mesa]

mhm, but I think its explained a bit too complicated

boouf yeah it's explained a bit complicated everywhere

[abstract pond]

yeah im not getting it from reading that tbh

but i do know that i tried to do the hidden in game through a custom event on the server and through a multicast

[pallid mesa]

so ill make it simple

[abstract pond]

and it had the opposite results

[pallid mesa]

a simulated proxy is the players u see on your screen except for you

got it?

[abstract pond]

yeah

[pallid mesa]

that's a simulated proxy

now authority is wether you are on the server or not

and autonomous is your own client version of self

there is a bit more into it and its a bit unaccurate but I think it can get you to start grasping concepts

so if you are playing with your friend

and you want to make him invisible just for you

you need to grab this simulated proxy and make it invisible

got it?

[abstract pond]

yeah

[pallid mesa]

nice so what is happening then?

explain me your problem using this terminology

so lets see if we can figure out together

ur simulated proxies are visible?

[abstract pond]

so in this screenshot im setting the simulated proxies to invisible once they enter the vehicle -

[pallid mesa]

okay but you would like to set also the autonomous and authority versions to invisible

[abstract pond]

it works on both the client version for itself and the server version for itself - in the client version the server player is also invisible however in the server players perspective the client player stays visible

[pallid mesa]

so from authority

your simulated proxy is visible

where did you set this hidden value?

server or client?

[abstract pond]

server

[pallid mesa]

okay so if you want everyone to acknowledge that visibility

you'd need to multicast it

assuming that visibility isn't replicated (I guess it isnt)

[abstract pond]

im not entirely sure on what you mean by that everything from the other player their nametag and vehicle they drive and stuff is replicated and both players can see

[pallid mesa]

no haha what I mean is that some variables on the character are replicated underneat (that you cant see)

so rn I dont know if visibility is or not, because if it is replicated it might work just setting it on the server

but since I guess it isn't

you should multicast it

[abstract pond]

so this is multicast

[vague fractal]

Probably super blind here, but i can't seem to find anything with the keywords Multiplayer or Networking 😅

[pallid mesa]

thats a multicast yeah. It will execute everywhere, including where is launched

[abstract pond]

and this is the result - the smaller window is the server player and the bigger window is the client player

the client player is behaving correctly the way i want it - both players invisible in the car

but you can see the client player there in the car on the server side

[pallid mesa]

so this is launched from the server?

just call hidden on the server aswell

[vague fractal]

From what i've learned so far it should be a case for the OnRep method

[abstract pond]

so do another custom event on server?

[pallid mesa]

he doesn't need a variable for this

no

just add the sethidden

right after the multicast

so you do the multicast and the call on the server

[abstract pond]

thats done here

[pallid mesa]

no

[pallid mesa]

right after the mc node

put the set hidden

haha

[vague fractal]

I mean, if that means that he have to use a multicast it sounds like a variable is better

[pallid mesa]

irs essentially the same however a variable onrep adds the overhead of having a variable

:)

[vague fractal]

And the multicast might not even fire for clients where it isn't relevant

[pallid mesa]

well in terms of late joiners and netculling

yes an onrep would do better

[abstract pond]

so doing this

[pallid mesa]

yeah

[abstract pond]

same result

the client player is visible for the server side player

but both are invisible for the client player

[pallid mesa]

are you sure this is all execd from the server?

[abstract pond]

this blueprint is a function for the interact button

for the player

[pallid mesa]

yeah thats not the server

haha

[abstract pond]

is that literally why... klsjadjksadls

[pallid mesa]

yeah hahehhaha

XD

[abstract pond]

...

[pallid mesa]

its okay you are learning

so you need to carry this action to the server using an rpc

and then once you are on the server you can multicast

although from authority that will essentially be the server

although. Listening yo @vague fractal lets follow good practices and I'll explain you next relevancy

because that's another networking concept you need to understand

relevancy means wether an actor should care about another actor over the network

the less actors an actor has to care about

the less traffic

got it?

[abstract pond]

yeah

makes sense

[pallid mesa]

sooo

one of the techniques we can employ

is turn on relevancy based on distance

if an actor is so far from you

why would you care about it?

thats what network distance culling is

once they are in range you start to care about them

so what happens is...

if some property of your actor has changed while it wasn't relevant for another actor

once it becomes relevant your other actor has to see this property changed

if we use multicasts that wont do the trick

:(

we need to use onreps!!

so as Yinsei pointed out in a smarty pants move

is that "what about relevancy?" well, he was right

if we want this visibility to change when we have relevancy changes we better create a flag variable that will be in charge on performing an action every time it changes

this type of variables are called onrep

so once you have carried your action to the server

you can have a visibility onrep variable on which you execute the sethidden code

aand

it will work like a multicast (just in blueprints, in C++ is different)

[abstract pond]

gotcha thats just a way of doing it thats less taxing i suppose

[pallid mesa]

not taxing

just more appropriate

because with multicasts you aren't defining a state

with a variable you are

therefore

multicasts in general are just for visuals

non important stuff (please artists dont kill me)

an onrep is to define a state

that will react accordingly with an action once the state is replicated

[abstract pond]

gotcha

its working now that i've changed it to be on server now tho cant believe i didnt realise that lmao thank you for the help and teachings i shall try to put them to good use

[pallid mesa]

:)

[slim matrix]

if i want to do sprinting and not have jitter from server correction will i need to do it in c++

because every blueprint implementation of sprinting in multiplayer i see fails miserably when lateancy is involved

[vague fractal]

I think the problem here is that you can only override some CMC related stuff via C++, but i think a simple sprinting should be possible with BP only

[slim matrix]

like ive tried diffrent tutorials for multiplayer sprinting and even tried a project from the market place but they all fail as soon as i introduce a little lag

only thing ive got to work was someones c++ project

[twilit crag]

How would you make it work via blueprints? At a guess, I imagine the problem with jittering comes down to the fact that you need client-side prediction and server corrections

more specifically the server needs to be willing to accept the client's predicted actions and apply them retroactively

[slim matrix]

yeah only solution ive found is to do it in c++

[twilit crag]

default CMC does that, but any naive blueprint implementation won't have that, so you have the client either lagging and then being corrected forward, or being corrected backwards, because the sprint only begins when the server says it begins, and the server makes no attempt to smooth out the client experience

[slim matrix]

this video explains the problem with sprinting in BP pretty well https://www.youtube.com/watch?v=RtQRMcupJs0

[glossy veldt]

Hey guys, I have the following problem: when i do a line trace on the client then the impact point does not match with that of the server. Any Idea why that is?

[twilit crag]

so, your options are to either roll up a system to predict sprinting client-side and apply those predictions server-side

which could technically be done in blueprints

or you use C++ and integrate those changes with the CMC, which already does those things. Although I've never actually implemented this kind of behaviour in the CMC myself, so I don't know how hard it is, but I'd imagine it's easier than building an extra system on top using blueprints

[slim matrix]

so could i have the server lerp the clients speed changes to prevent jitter

[twilit crag]

I think so.

It's possible that the CMC needs messing with regardless to prevent it from sending bad corrections

but you basically just need code on the server to recognize that, after receiving the client's updated sprint status, it has to look back and figure out where the client should be, according to when they hit the button

[slim matrix]

my idea is the clients speed lerps between the changes while the server just applies the speed change so maybe the time it takes to lerp to the sprint speed will compensate for some lag

[twilit crag]

Do you have any more details about the trace? If you're tracing from/to moving objects, then the impact point would be unlikely to be exactly the same between the client and the server

[glossy veldt]

At the moment the server is standing and the client shoots him. It works most of the time but seems inconsistent.

[twilit crag]

It might smooth out the experience for some or most players, but it's effectively applying a fixed client-side offset to account for lag, which basically means that the experience will go from being "ideal" at 0ms, to being ideal at some other latency; anyone above or below that will still see some correction jitters, and the behaviour will vary depending on whether they're faster or slower than that

[twilit crag]

How different are the results between the client and server? And, are you using the control rotation to determine the trace?

[glossy veldt]

I dont know how i did it but the impact points are now almost synced. it is maybe 0.1 or so off.

[slim matrix]

i did find a plugin to solve some of this but to also have it work in ue 5.0.0 ill probably need to recompile it

https://www.unrealengine.com/marketplace/en-US/product/smooth-networked-movement

[glossy veldt]

I was using the C++ function PlayerController->GetPlayerViewPoint with out_Location and out_Rotation. I made a custom BPL to expose it.
And i am using 2 traces. First from the player view point forward and then use that impact point as the end location of the second trace.
Works fine for me now

But thanks anyways

[twilit crag]

If you're using the control rotation, I think that control rotation is "low resolution" over the network; to save on bandwidth, only an approximation of the player's control rotation is sent over the network

so you'd get slightly different results by default

I don't have total confidence in that though, it's just something I bumped into while writing some simple networked FPS code

and it was a while ago

[azure hollow]

In order to send a structure over to the server, Serialization to json is the best way to compress the file? I'm trying to reduce the volume of the data

[smoky plinth]

what about binary?

[azure hollow]

honestly I don't know 🙂 works better?

[smoky plinth]

If you want to save it to a file a binary is usually lighter

but no human being can read it xd just machines

Unreal has FMemoryWriter FMemoryReader and IFileHelper to help you

[azure hollow]

I have to send struct of position and retrieve when next game starts

[smoky plinth]

i think there is no other reason than legibility to use json instead of binary imo

[azure hollow]

great, I didn't knew it!

thanks a lot dude, do you know where can I find more about this?

[smoky plinth]

Digging the engine:
FMemoryWriter
FMemoryReader
IFileHelper
Google them also as binary unreal compression or somthing like that

[azure hollow]

thanks dude🙌 really appreciate

[fading birch]

Unreal has access to a few different compression libraries. They seem partial to zlib

[true stream]

what service would you recommend for a MP indie game just starting to go online?, so far I've heard amazon works ok.

I'm at the prototype phase, so it would be shared with a couple of friend for now.

[azure hollow]

take a look at playfab too

[true stream]

interesting, seems to be free to start

[smoky plinth]

i've worked with aws on amazon and its ok if you are building a medium size indie project, for smaller project maybe its a little bit expensive

[true stream]

I was under the impression that it was free

or you mean after reaching a certain threshold of users/data?

[smoky plinth]

i think i remember that any long-term server running in aws cost money

[true stream]

for now I only care about being able to test and prototype it with a limited number of users

[azure hollow]

until 100k users playfab should be free

[true stream]

without much hazle

[azure hollow]

I mean, if you leave the game in development mode and don't go live it's actually free

[true stream]

yeah, that's what it seems

[azure hollow]

I am using it and not paying so...give it a try

[true stream]

I wonder if there is like, a way to learn what steps should I take when transitioning from closed prototype to full online

in terms of, marketing, visibility, etc.

maybe there are companies that specialize in this, no idea.

[azure hollow]

can't tell, maybe make sure the game works and then you see 🙂