multiplayer

[twin juniper]

Not really an Unreal question but are there any good articles relating to intentional input lag to deal with multiplayer synchronisation?

[winged badger]

find Halo: I shot you first GDC talk in pinned messages

[twin juniper]

okay thank you @winged badger !

[winged badger]

its more about hiding lag then intentionally creating it though 😛

[twin juniper]

Yes so by intentionally creating "lag" you'd be removing inconsistent packet delays, which is more noticable than a constant say 50ms input delay right?

So it would be better in that case to have the delay rather than let everyone rely on their network speed? If I'm interpreting it correctly.

[winged badger]

no

there is no great way to deal with variance except timestamping packages and syncing network clocks

intentionally crating delays to make it seem like there is no variance is suicidal

[twin juniper]

ooh..

Because I was reading a few games did that I think like Smash Bros and Tekken

But I could be wrong

[fathom aspen]

No, on client. It's generally called when input is fired, and that happens on the client

[formal solar]

Yes I have been doing that I just looked at a answershub that said doing it on sever as well solved lag for somebody

I think I have a lead and that my scene is too large and is causing precision error with movement

[winged badger]

whats the size?

[formal solar]

I posted in general

ue4

Oops no in blueprint sorry

[winged badger]

ok, then no, 200k is not enough to suffer from float precision

and first thing that would go os physics, not movement

[quasi tide]

Nothing from the screenshot shows that it shouldn't. Only thing I can think of at the moment is if something in that method that adds it is acting funky.

[formal solar]

even with movement speed? Im wanting to cross my whole landscape in about 10 seconds max

[winged badger]

with 20k speed

you will want to give CMC client auth

lets them cheat, but its only way it won't break

[formal solar]

So it may break, so sounds like one solution, awkward but not technically complex, is just to downscale everything

[ocean geyser]

its begin play. no clue whats going on with it

[winged badger]

speed is really problematic relative to the correction thresholds

here

with move speed of say 400 (jogging speed) you need only few UU tolerance and it will work fine

you have 50 times that

so your maximum error to correct is at least 50 times that, and probably way worse

[formal solar]

So correction thresholds are based on UUs ok

[winged badger]

but also every time you lose a packet at that speed, odds are you'll end up corrected

[formal solar]

I guess the reason I made my scene large was because I have insect characters which i want to be size 1 lol

[quasi tide]

I meant this one. I know there is a node for this, but looks like it is a custom one you have.

[ocean geyser]

ah, nope thats the default

[winged badger]

and travelling with mach 1?

[formal solar]

hahaha, well relative to the scene it's not so crazy a speed

but in UUs its enormous speeds

[quasi tide]

I take it your placement reference is just a scene component?

[ocean geyser]

yes

testing on the character now as well infront of the camera, still nothing. its like it doesnt appear at all but replicates

[ocean geyser]

ok so it does spawn, but it doesnt set the mesh on the client

[quasi tide]

omg - I'm a dolt; for some reason the text underneath the node title was throwing me off. I can't recall actually seeing that before for this node.

[ocean geyser]

ah fair lol

[quasi tide]

You can set the mesh if you click on the node. Not sure if that actually gets replicated though. If not, maybe manually setting it afterwards?

[ocean geyser]

did that its set to a mesh that doesnt appear on clients. i tried setting it afterwards on the server and same deal. i then set it to rep notify and threw it in a variable and set it there and had the client do it and it worked but thats not ideal

[quasi tide]

I wonder if there is some funkiness with dynamic components and initial replication 🤔

[ocean geyser]

no clue, i added a delay beforehand to make sure but no luck. very odd

[quasi tide]

I mean, I still think a repnotify makes sense though. Changing the state of the mesh component and all.

[fathom aspen]

No, GameMode does that already for you. As long as you spawn the actor on server and the actor is set to replicate, that shouldn't be an issue.(BeginPlay in GameState fires for both server and clients)

[ocean geyser]

yea, but i cant do that unfortunately. this is for my plugin on the marketplace i forgot about a feature that i needed to add when i was stripping it from my main plugin

[twin juniper]

Thank you

[quasi tide]

Can you set the node to replicate?

[ocean geyser]

did

[quasi tide]

So either one of these options.

[ocean geyser]

both are true

[quasi tide]

I got nothin'

I blame Tim

[ocean geyser]

figured. wonder if its just bugged, never used the node before

[quasi tide]

This will be weird but, what if you expand the transform node and just don't do anything with it 😅 (I know, grasping at straws here)

[ocean geyser]

that straw was to short lol, nope

[twin juniper]

@winged badger This was the delay I was referring to

https://arstechnica.com/gaming/2019/10/explaining-how-fighting-games-use-delay-based-and-rollback-netcode/3/

[quasi tide]

Well - everything should've been working to my knowledge. If you ever find the cause, please ping me; as I'm quite interested in it.

[ocean geyser]

will do lol

[formal solar]

I have a little trouble understanding what character components I need to replicate. I am making a game with flying pawns with serious issues at the moment with client movement lag. Up to now I had 'component replicates' active on my character mesh. I am using character movement component. I read online though that if I turned the option on my mesh off, it would solve some lag issues and indeed it has - now I don't lag when moving in a straight line, only when rotating (so some improvement lol). I was under the impression I would need this box ticked for pretty much every component but I guess the CMC handles things automatically? Or its only parent components that matter

[half drum]

trying to lower a players friction, do i would have to run the event as the server or do i run it on the server and owning player?

[shadow aurora]

hey guys, so I'm working on a spectate system, and a bug that I'm seeing is that on a larger map when spectating another player, other players seem like they're outside of net relevancy. From what I can tell it's still basing the net relevancy on the location of the spectator pawn instead of the view target. What exactly can I do to remedy this? Do I just need to attach the spectator pawn to the person they're spectating or something along those lines?

[fathom aspen]

I'm wondering how you implemented your system. Did you use the engine functionality, i.e ChangeState(NAME_Spectating)?

[shadow aurora]

Yep using that function call, and then setting the viewtarget to the player's killer on both the client and the server... From what I've seen that should be enough for the replication system to pick up relevant actors, but it definitely is not working that way haha.

[fathom aspen]

Yeah iirc the spectator pawn spawned stays at its initial location, thus it could be really the issue. I haven't tested the system on large maps, but now you made me wanna check that for sure heh

[shadow aurora]

Yeah that's my thought is that since it's just chilling there maybe it's trying to use that for relevance. I'm hesitant to do it, but I kind of just want to try attaching the spectator pawn to the new viewtarget as well and see what happens

[fathom aspen]

I've seen other ways of implementing the system where they attach the spectator pawn spawned to the spectated pawn, but I ended up going the for the engine's relevant calls as it worked more seamlessly

[unreal epoch]

I'm having a hard time replicating a jetpack.

the code is relatively simple: pressing the space bar will toggle the replicated "using jet" bool

then, it will add force every tick on the server

for some reason the client's jetpack accelerated about twice as fast

[shadow aurora]

Yeah also looking into overriding IsNetRelevantFor and modifying SrcLocation to the location of the local view target. Think that might work for what I'm going for here!

[unreal epoch]

I've tried multiplying the force by deltatime, but that doesn't change much

[fathom aspen]

Yeah that's what I was going to suggest you to look into, but wanted to test it myself beforehand lol. Give that a go, let me know if it works out for u

[grim valve]

Given a situation of a lobby-level with player slots, should I put and replicate this information on its level, or on its gamestate? Is there a benefit to choosing either here really?

note that both gamestate and level is unique for the lobby level.

[fathom aspen]

What do player slots represent? This sounds like more a PlayerState class info

[red musk]

I'm trying to call Move To Simple Location on my player character (so not specifically an AI), on the server.

Unlike Add Movement Input which is done on the client and then syncs with the server, this approach doesn't have any client input. Is there a way I can change the client to not expect input for the duration of the pathfinding, so that it updates position, direction, triggers walk animations, etc, based on what the server is doing?

[red musk]

It looks correct for other remote clients, I basically want the local client to behave that way too

Like a simulated proxy I think? Not sure how to change its role at runtime though

[grim valve]

Perhaps it could be, but I am struggling to conceptualize it as such. Player slots are set by the host, where they will select CPU, or OPEN (which switches to PC once a person loads in and there is a slot for them). I assumed that AIControllers would not have a PlayerState, so I figured that was off the table.

Further, player slots have to be fixed relative to each other. My idea was player state holds the slot its in, and the player controller allows them to select the avatar bound to their slot. But to actually be the slot itself seems like the wrong abstraction.

I don't want, say, "Player 3" switching to "Player 2" because the old player 2 went offline.

[plucky prawn]

remember when i didnt tick replicates on my actor?

[fathom aspen]

I'm not sure I do

[plucky prawn]

i do because i ticked it and its working working properly now with multicast RPC and replicated variables

[fathom aspen]

Why the multicast rpc though. Just change the values on server

[plucky prawn]

ye i did im was just checking if that was the source of all my problems in life and it was

but now i have more problems

[fathom aspen]

Fix them

😎

[plucky prawn]

ye im not really sure how. ill have to think about it more

[fathom aspen]

I'm not sure what CPU means here or OPEN, and how AIControllers are connected

My brain kinda went brrr there

[grim valve]

This is a board game. I dunno if you ever played like say, civilization, in multiplayer. In these sort of games you create slots for people to log into, allowing the host to select how many players are in the game (adding and removing), mixing CPU (Ai controllers), and players (a real world players). OPEN is a Player slot that does not yet have a player assigned to it. When all open slots are filled, the game is startable.

[fathom aspen]

So slots are kinda like sessions that players can opt to join and stuff. AFAIK GameInstance is the one usually in charge of session stuff.

[mystic saddle]

Hello I'm using a server to save my player data but to save the player's inventory what to do I can't save the actor directly should I save its name and get it by its name somehow or there is another better way?

[fathom aspen]

Just tested it and it really looks like an issue. Though we didn't have it, as pawns are bAlwaysRelevant as maps aren't that big. What you suggested, should make it work ^^

[mystic saddle]

Another thing when I run the project server build it gives me an error I did searched for it some people said I should build the project using the GitHub engine version but building the engine from source takes a lot of time and I want to be up-to-date with the epic games store version

[ember dagger]

Are you replicating to server then to multicast? Make sure you also use an is locally controlled -> false in the multicast right after the custom event node, and before you add any force. Or it will play twice on the owning client

[pulsar lotus]

How to switch level from main menu to server?

I try seamless, but when i'm call function level just blink

void USC_MainMenuWidget::PlayButtonOnClick()
{
    GetOwningPlayer()->ClientTravel("127.0.0.1:17777", ETravelType::TRAVEL_Relative, true);
}

[shadow aurora]

Sweet I’ve written up the changes but haven’t had time to sit and test it yet. I’ll let you know what I find!

[vague spruce]

anyone have any idea why two spheres would overlap on a server but wouldnt call OnComponentBeginOverlap? the client is calling it, but not the server

[unreal epoch]

@ember dagger The 'add force' node is hooked up to an event tick, with a 'switch has authority' right in front of the add force so that the movement only executes on the server, then is replicated by the pawn itself (as 'replicate movement' is set to true). If I replace the switch on authority with this if statement, nothing seems to execute at all after it.

right now it looks like this. before the 'add force', I have a node to update a progress bar showing fuel

[ember dagger]

Ah you're using this in a pawn? I assumed it was in your character class as I had a similar issue and the fix was what i said

[unreal epoch]

I've tested the amount of force, it is the exact same magnitude on the server and client if I print it. So im in a 'JetpackPlayer' class, which inherits from 'Player', which inherits from 'PlayerParent' (this was added for vehicles and such with common attributes, like health and UI), which is inherited from 'Character', not 'Pawn'

so no, its not in a pawn

[ember dagger]

Hmmm. So for my use I had a slide that I needed to replicate. I calculated the force locally and added the force locally. Then called a custom run on server event with the force as an input, into a multicast event with force as an input into is locally controlled to false to an add force with the force being the input from the mutlucast which worked fine for my use case.

[unreal epoch]

ok, so are you saying that I should keep the stuff used to find the force vector local, then pass it to a 'run on server', then to 'multicast' with locally controlled==false, then add that passed force vector?

Heres another interesting thing I noticed @urban flicker : when I run the game with just one player, the jetpack has a certain amount of force. Then, if I play two players, the server jetpack actually has doubled force, and the obviously the client has double that force.

so, I wonder if this has anything to do with framerate

[ember dagger]

Idk if that's the best way, but from what I know and from what has worked for me then yes. Just make sure you add force locally before you call the run on server event

[unreal epoch]

ah, I removed the delta time from the calculation, it must already take that into account

[ember dagger]

You can try setting quality to lowest settings and see if anything changes

[unreal epoch]

but obviously that only fixes that one issue

ah, I just fixed everything

so apparantly the issue was that some of my variables were replicated that were needed for calculating the force

i dont know how that caused an issue, but seems fixed now

thanks for the help 👍

[deep shore]

How can I change the variables on a character based on the level/game mode? for example, suppose a character has a boolean “can respawn”. by default this would be set to True…but I am having trouble figuring out how to change it to False once they join the game. It doesn’t seem like Event Begin Play would work because players may join at different times.

[fathom aspen]

So what, from what you're saying you want to change that variable per character. So each character does that at his own BeginPlay. Though you would need a SwitchHasAuthority to make sure you're on the server(if you're getting some info from the GameMode as it exists only on server)

#online-subsystems

[stone knot]

couldnt tell if i shouldve put it in there or not since its a plugin for a subsystem and not directly for it, but ill repost it in there

[fathom aspen]

You are not alone, a lot of people do the same ^^

[deep shore]

thank you for your help @fathom aspen … unfortunately i’m not sure I follow you. there will be two levels with different rules. one will allow respawns, one won’t. You’re saying I need to change the variable on the character class on Begin Play? I was thinking that the changes would need to be called from the Game Mode BP.

[fathom aspen]

Well now you fed me with more info, so my answer will vary. What you are describing is really the prefect example to why each level can be assigned a certain GameMode. So Level A can be assinged GameMode A that supports respawns, while GameMode B that is assigned to level B won't.
To eliminate the need for reinventing the wheel, you would need to make a BaseGameMode class were GameMode A and B will inherit from. GameModeBase can have that boolean variable bAllowRespawn which each GameMode child class can set its value as they like

Technically you shouldn't be setting rule variables on any class other than the GameMode, as that what is was designed for. It also exists only on server, that way you know server is the one who decides game rules

[deep shore]

thank you for clearing that up. So, when a character dies, an event should run on server and cast to the game mode, then get this boolean. Using a branch, either show them a “Game Over” screen or create the widget that allows them to respawn?

[fathom aspen]

Correct

[deep shore]

Thank you so much for your help.

[fathom aspen]

Though widgets are client only. So you can't create widgets in the same server event, without calling a client RPC, or binding to a delegate.

[frank pecan]

I have a plugin for 5.0.0 that can't install on 5.0.1 is that right or is something funky going on. i figured 5.0.x wouldn't matter for plugins

it's just not in my list of plugins

[fathom aspen]

#plugin-dev

[frank pecan]

ty

[grim valve]

how do I get the current list of observers?

[nova wasp]

spectators or blackboard keys?

    for (FConstPlayerControllerIterator Iterator = GetWorld()->GetPlayerControllerIterator(); Iterator; ++Iterator)
    {
        APlayerController* PlayerActor = Iterator->Get();
        if (PlayerActor && PlayerActor->PlayerState && MustSpectate(PlayerActor))
        {
            //This is a spectator so add it to a TArray or something, you're the boss!!!!!!!!!!!
        }
    }
``` @grim valve

I found some code for getting the number of them

[grim valve]

spectators

maybe that was why google wasn't turning squat up, i kept thinking the term was observers

[nova wasp]

haha, yeah

no clue if anyone actually uses the built in spectator setup

I assume it works but I have never used it

of course I have never made a game with working spectators so don't take my word for it

[grim valve]

yeah, I am kinda intending to abuse it anyways for the lobby. that said that code is interesting. MustSpectate is implemented to determine what is "to be" a spectator, meaning its actually not some stored data but rather a deterministic monad

[nova wasp]

it's just a few boolean values

you can read it

it's really stored as bOnlySpectator in the player state

[grim valve]

ok, so it is actually stored somewhere

I assume thats set on the first MustSpectate

[nova wasp]

which makes me wonder, is it that they can ONLY spectate or that they currently ARE spectating?

perhaps there's another way to set it

[grim valve]

i think i saw something related to spectators on the session code.

so its possibly used to enforce some sort of restriction at that level

it might be that for my use case there is actually no need for pawns or spectators in the lobby at all. that my slots system is more of a replacement for that level.

[nova wasp]

lol, all I can find is people on a forum for older UE forums talking

https://www.oldunreal.com/cgi-bin/yabb2/YaBB.pl?num=1571698776/3

these guys using UE2 in 2019

respect...

[grim valve]

well the modding community i assume

Id be surprised if anyone is actually using it for dev these days, isn't it still under a more restrictive license?

[nova wasp]

btw, don't get too intimidated by the MARK_PROPERTY_DIRTY_FROM_NAME

it's just pushmodel saying "we need to replicate this!"

as opposed to the old way where afaik it just iterates over every replicated value

[grim valve]

nothing intimidates me, this is only being used to guide lightweight strategic nuclear warheads, so it breaking would not be the end of the world, just a small geographical area.

[ancient bramble]

how do i dockerize a dedicated server build?

i have packaged the server files already what should i do next?

[fathom aspen]

The old way is the one we have when replicating a property normally. Right?

[nova wasp]

Yep

[fathom aspen]

Traverse through PlayerArray and check if IsSpectator() then count++

You would need to SetIsSpectator(not sure of function name) when setting player to spectate using the engine spectator setup to make it work

[fathom aspen]

Do you think the push model should be used over the old replication system at all costs?

[nova wasp]

Not sure how much better it makes things

[alpine owl]

Hello, Im coming from a C# background with unity, Im familiar with basic multiplayer concepts with steam and Im trying to learn UE with blueprints first but I have an hard time figuring out how to setup the multiplayer.

My understanding atm is, epic online services is like steamworks but for epic ecosystem, online subsystems are apis to communicate with different services like EOS or Steam etc.

I want my game to use steam lobbies and I saw there is a plugin called "advanced sessions" that a lot of people seems to use so I installed it and created a prototype with a main menu, create session, join session.

It works well BUT I don't understand why, because I didn't setup steam app id etc so I assume it's not using steam lobbies.
Why there is a "Use Lobbies if available" option when creating a session?
Why everyone in UE is talking about "Sessions" since in Steam it's named "Lobby"? Are they the same or not?

tldr: There is a lot of stuff for multiplayer in UE (epic online services, online subsystems, advanced session plugin), what do I need to do to use steamworks api? (steam lobby, friends, voice, steam networking sockets etc)

[latent heart]

I think the answer is don't? Simulate the physics client side, tlel the server what you're doing and it have it apply the forces as well and then correct the client.

[vague fractal]

Wasn't there an option like "Replicate physics" so that you'd only tell the server via an RPC to apply the force ?

[fallow shadow]

Does SpawnActor replicate by default? When i spawn a projectile it doesnt seem to spawn on the server

[mint drift]

Guys. I need your help. I am for a quite while trying something stupid and have looked on forums, tried what exist etc etc etc. But THIS is not working at all.

What I am trying to do: When the player overlaps the overlap thing it should spawn a AI. And this AI should follow and shoot the player.

Whats happening: The AI is being spawned, but player cant see the AI and shoots are working fine. Just the AI itself is not being shown tot he player.

The location and rotation of AI and the shooting is fine. But he is a invisible object to player.

help

[mint drift]

I did this to spawn projectile.

works 100%

[fallow shadow]

uhh im doing this in c++

but i think i know how ill do this

nope i have no idea what im doing

[dark edge]

You want to spawn a replicated actor. Not replicate the spawning of an actor

[fallow shadow]

How do i do that again?

[sinful tree]

You spawn the actor while running on the server, and make sure it's a replicated actor.

[mint drift]

in my case it is replicated but dont show on client.

[blazing spruce]

Hi, can anyone tell me why this isn't working properly, the widget is displaying on the server player but not the clients, ive got the ShowMatchStartingTimer event being called from the Game State when a timer is started, the ShowMatchStartingTimer event is on the Game Mode, calling the ShowTimer event on the Player Controller, any ideas?

[magic helm]

The game mode only exists on the server is why, you should move that to the game state if you want all clients to have it happen.

[eternal canyon]

Very much depends

[blazing spruce]

So i moved it into the Game State but it still wont show for clients

[magic helm]

Is the timer being started on the server?

[blazing spruce]

Yeah, its called from the Game Mode when the player count gets to 2

[magic helm]

1. Do you care about state? Because if that does not matter(like players joining doesn't matter) then I would say switch it to a multicast function

2. If you care about the state syncing up then I would then not have it be an RPC and instead use a rep notify variable tracking(simple boolean will do) that the timer is shown, then when it is set. Show the timer on the player controllers in the level (since they only replicate to the owning players anyway)

Oh also don't grab the player controls from the game mode, unless you ONLY want it to run on the server

Game mode only exists on the server, so that might be another spot of where its breaking

[obsidian cargo]

What is the intended way for a client side player controller to get a reference to the pawn it possesses? The On Possess events do not appear to fire on the client.

[fathom aspen]

GetPawn

[unkempt tiger]

Is AGameStateBase::GetServerWorldTimeSeconds still kind of inaccurate as described in this article? https://medium.com/@invicticide/accurately-syncing-unreals-network-clock-87a3f9262594

It speaks of slight inaccuracies on 4.18

[fathom aspen]

Yes, nothing has changed

[obsidian cargo]

Is there an event I can use for when GetPawn will be valid?

I tried an RPC from the server to the client after possess, but it is too early. The returned pawn is null.

Currently modeling this in Blueprint just to get something quick, but intending to change to C++ for a final solution

[gleaming vector]

there is a bunch of stuff in Lyra for catching when pawns, player states, and stuff are valid on the client

[pallid mesa]

I'm working in a subsystem following Jambax advices that in theory it will be very easy to plug and play in any project

I plan to release that for free ofc crediting James, but first I need to know that I am not missing anything

[latent heart]

I mean you could just add onreps for everything you want to look at. They all trigger a function which checks everything is valid and only does osmething when they've all been replicated.

[pallid mesa]

So far the instructions for setup will be minimal

[pallid mesa]

yes this is what it does more or less :)

[fathom aspen]

For C++ you can wait for the OnRep_Pawn callback and check if the Pawn is valid

[pallid mesa]

but it uses delegate black magic 😄

so far, gamestate, pawn and playerstate are handled

do you guys think something else is missing?

[fathom aspen]

PC crying in the corner

[pallid mesa]

oh dear

the PC!!

😂 😂 😂

[fathom aspen]

heh

[latent heart]

Add game mode. Just to fuck with people.

[pallid mesa]

you are evil

👁️ 👁️

[latent heart]

If they want to wait for that to replicate, they don't deserve a fancy subsystem.

[fathom aspen]

They will die waiting

[pallid mesa]

actually...

isn't the local PC... always before GS?

or am I completely wrong?

[fathom aspen]

Hmm you tackled me with this

[pallid mesa]

Because I am using the PC to receive pawn and ps

the gs handles itself

aaaand

PC is just assumed to be there

[latent heart]

Is there no generic callback when an actor is replicated?

[pallid mesa]

PostNetReceive i blv

[latent heart]

A global one?

[pallid mesa]

thats at an actor granularity

[latent heart]

Yeah.

That's no good!

[pallid mesa]

but im using the onreps on the PC, those are great enough

so far I think this should be part of the engine

😵‍💫

a nice world subsystem

[solar stirrup]

Yeah that article discusses some potential solutions

Personally, I've had good enough results by just adding RTT / 2 to the time

I generally use the default one or ^ if I need to sync stuff as close as possible using a server timestamp

[obsidian cargo]

After some basic (PIE) experimentation, it looks like overriding APlayerController::AcknowledgePossession(APawn* P) and calling a BP event is the simplest way to expose a local posess event

This seemed to trigger exactly once for both server and client (when using a listen server) during possession.

I didn't test all server / client configurations, nor did I test in a packaged build.

OnRep_Pawn would fire twice on the client for me, with a valid pawn in both cases.

[pulsar lotus]

Why the variable is not replicated to the server from the player controller?

[solar stirrup]

Replicated properties only replicate from server to client

Not the other way around

[pulsar lotus]

Ok, thanks, how can I transfer changes in the Player Controller to the server

[solar stirrup]

Use a Server RPC

[pulsar lotus]

Thanks

[pulsar lotus]

This is how I was able to transfer the information, is this the right solution? This is the only way to change the value from client to server ?

[solar stirrup]

Send it through the PlayerController

The GameMode only exists on the server

@pulsar lotus

[pulsar lotus]

Thanks

[grim valve]

If you kick someone from a session, what sort of facilities do you have to prevent them from simply rejoining, do you need to maintain like a custom kick list once they are kicked?

[solar stirrup]

You can reject someone connecting in AGameModeBase::PreLogin()

I'd just keep a list of banned/kicked players

[tough river]

Does anyone know a solution to this problem?

[regal solar]

How can I get game session name from unreal?

[fathom aspen]

This has nothing to do with multiplayer, maybe see #graphics

[fathom aspen]

This is a #online-subsystems question, but anyways see SessionInfo.h and OnlineSessionSettings.h they have a SessionName property.

[fallow shadow]

for some reason the client just seems to lag when moving

The movement is definitely replicated and i can move

the server sees the movement as smooth

but the client keeps getting snapped back

also i gotta ask

how do i test a dedicated server?

do i just use listen servers assuming the behavior will stay the same?

[fathom aspen]

Interpolate movement between server updates

But that should be done if you're using the CMC

[fathom aspen]

Wdym? It's Play as Client configuration

Dedicated servers have no visual representations, if that's what you're asking

[dark edge]

I would test by launching the project as server on another computer all the time. It's fast and simple and gets you pretty close to the real thing.

[frail sentinel]

How do I create a Widget only for the local player on BeginPlay?

In my PlayerCharacter blueprint, I create a HUD Widget, but it seems to actually create one for each player. That is, Player 1 seems to create a widget for both Player 1 and Player 2

[blazing spruce]

Hi, im trying to set up a timer that displays when there are 2 or more people in the pre lobby, the timer then ticks down and if no one else joins within the specified time, the game will just start, ive managed to get the countdown widget to display and update on both client and server, but if i have 2 players in the pre lobby and the timer starts, if a third player then joins once the timer has already started they dont get the widget created for them, what is the best way that i can make sure anyone joining after the timer has already started gets the widget created for them and the correct timer is showing for them and doesn't just start from the beginning value? The way ive got it set up is that on the Game Mode OnPostLogin event im casting to the Player Controller and adding the controller to an array of Player Controllers, then calling an event to check if the timer can start, this event just gets the length of the ConnectedPlayers array and checks if its greater than or equal to 2, if so it casts to the Game State and starts the timer, when the timers started the Game State casts to the Game Mode and calls a Show Match Starting Timer event which gets the ConnectedPlayers array, loops over all of them and set a RepNotify bool which displays the countdown widget, am i doing this in the correct way?

[vague fractal]

In case that it's about ACharacter.
this problem can happen when you also replicate the capsule component.
happened to me already xD

[fallow shadow]

oh wait it is likely that

[vague fractal]

creating it only for IsLocallyControlled may work

[fallow shadow]

oh also

applying force in c++ seems to just snap the character back into place

aka it does nothing

[pallid mesa]

Someone has an implementation of NTP synced clock that could share? I'll giv cookies 😄

[stone knot]

Is it possible for in a listen server situation. Say the camera blends somewhere, it works fine on clients, but when it occurs to the server. All clients have it occur to them. Anyway to have it so it’s isolated to the player?

[fathom aspen]

Are you using SetViewTargetWithBlend?

[stone knot]

Yes

[fathom aspen]

Ok show code

[stone knot]

here, made a new node for the target

it is supposed to take the player that intersected the box collision and blend their view

[fathom aspen]

Who calls JumpScare? Also which class this code is in?

[stone knot]

It's called in the same graph, but at much more messy code

AI BP is where its located

I keep putting off setting up the actual boards and stuff so I have been throwing code in the BP

[fathom aspen]

I mean calling GetPlayerController(0) on the listen server should return the listen server's player controller. You're saying this is happening for all clients too. This shouldn't be an issue from the code I see

[stone knot]

I meant in the case of the server firing the code

it applies the view blend to all clients

[fathom aspen]

Yeah I get what you mean, this shouldn't be an issue. Are you sure JumpScare is being fired only once? It doesn't look like it

[stone knot]

it appears it now also makes the server view blend as well now

https://gyazo.com/584d6b3174cefd985ccd6961dc92ef22

[fathom aspen]

Did you debug your code and saw how many times that JumpScare gets executed?

[stone knot]

my prints are not showing up anymore

that is weird

ok yeah it worked now

it only fires once

it runs on server and client

[fathom aspen]

Honestly it makes sense that's working that way. I'm not sure how you differentiate between your players. Generally GetPlayerController(0) shouldn't really be used outside of some of the game framework classes, but you're using it in AI BP class which is weird

[stone knot]

it casted from the player at one point and grabbed a reference of its controller for some other nodes

should i just do that same method in theory?

[fathom aspen]

Oh maybe it's failing there. Maybe that's not the right player?

[stone knot]

i just hooked it up to the same controller ref and it still isnt happy

the jumpscare event runs on both server and client according to the print string

so smth is happening somewhere lmao

[fathom aspen]

Ok so it clearly running twice

[stone knot]

it prints once

[fathom aspen]

Ah wait, SetViewTarget calls a client RPC

[stone knot]

but its source states from client and server

[fathom aspen]

I would suggest you debug your code to get a better idea of what's happening.

And by debugging I don't mean print strings, I mean setting breakpoints and seeing how things flowing

[stone knot]

thats weird

wait nvm it isnt weird, i had a multicast running for player death

[fathom aspen]

Oh great

[stone knot]

it still casts to both lmao

so that wasnt it at all

switching authority works like a charm for the view blend

could it be because the code is in a actor placed in the world?

[fathom aspen]

If it's an actor placed in world and replicated, then it's placed for all and it's code runs for all connected players

[stone knot]

yeah its set up to replicate

[fathom aspen]

And technically SetViewTarget should happen on server(or at least I prefer it that way)

[stone knot]

so should the code be not replicated for the blend? First project I am messing with multiplayer so this whole replication stuff still throws me confused

[iron crest]

Hey, I have a question that ive been on for about a couple hours now that has to do with a homing projectile, I have a kunai i nwhich when you throw it, it searches for any actors that have the tag (Homing) and then goes to them and does damage etc. My problem is, since im only using one char bp for multiplayer, its also counting me as a tag with (Homing) so now it hits me instead, anyone know how to go about this?

[fathom aspen]

SetViewTargetWithBlend already does that for the client if bClientSimulatingVewTarget is set to false. If it's set to true then you have to handle that on the client yourself, and I haven't done that before.

I guess it's a matter of optimization to set that bool to true. But yeah it needs work.

[fossil spoke]

Has anyone dealt with setting up Instant Replays (AKA: Killcams) that has any resources on how to set those up?

Just checked the Pinned Messages.. Ill start there 😛

[fathom aspen]

Oh right, second message. I missed that too lol. Good that you asked, cause I need that in the near future 😛

[fathom aspen]

Well you can check if the returned actor != self

[blissful totem]

I keep getting hit with race conditions on my match startup logic. I use OnPostLogin, but I need to ensure that the player state is replicated too. Is there a clean way to do this aside from waiting a bit and checking again in a loop?

[fathom aspen]

@pallid mesa Aren't you done working on that subsystem yet. People waiting...

[fathom aspen]

Use OnRep_PlayerState

[iron crest]

what does the !- mean, not equal?

[fathom aspen]

Yes

[blissful totem]

meh, making me dip into cpp again

thanks though

[iron crest]

hmm I cant find where to implement that, do you mean in here

[fathom aspen]

Yes. ArrayElement make sure that it's != Self (Considering this code is in the Character BP) AND the condition you have right now

[iron crest]

oh, this code is in the kunai bp, I made the sm an actor to put code in it, do you think itd be better to put in in my char bp

[fathom aspen]

Yeah probably

It's still even doable here. You might just need to GetOwner, if the SM actor is spawned by your pawn and owned by it

[iron crest]

Ok, ill try to do get owner since I alr have my damage code in herer

[iron crest]

Dang, sorry if I sound slow in the head this is my first time working with homing, for the get owner, how should I plug it in, should it be through the array element i was think if GetOwner isValid then do nothing but ifits jnot then proceed?

[fathom aspen]

Yes. Proceed as if Self is GetOwner

[iron crest]

Hmm still seems to hit me instead of enemy (Ps im using the same graph for both players as its multiplayer) '

[fathom aspen]

Why are you using Is Not Valid execution pin though?

[iron crest]

I was thinking that only if self is not valid, then it could continue to find other tsrgets

[fathom aspen]

Also where are you checking that GetOwner != ArrayElement?

[fathom aspen]

You want to use it for this check, so you need to make sure it's valid, i.e not null

[iron crest]

oh mb it looked weird, it wasnt connected to array element

[fathom aspen]

So your editor doesn't complain

[iron crest]

ok ill fix that

[fathom aspen]

Also you are doing GetActorLocation - GetActorLocation?

This will result in 0,0,0

[iron crest]

ohhh shoot mb let me delete that other get actor, what shall it be replaced with?

[fathom aspen]

Ask yourself, I didn't design the system heh

I'm acting as a "debugger"

[iron crest]

ohhh ok

well I got the system from this youtuber

do you want me to send the one I got it from

[fathom aspen]

No please, I rarely watch YT tutorials, as generally they are bad

I already see that

[iron crest]

hmmm ok, well do you think I should start new and make my own system, I think this one is not very good either

[fathom aspen]

Yes please

Maybe you can take notes when you do your research, but don't copy others

[iron crest]

ok, well ill try to and if it doesnt work, should I come back for help

[fathom aspen]

This channel will always be open for help

[iron crest]

Ok, thank you!

[blissful totem]

Ok I have a system where the game mode watches for player states to replicate. Once all are replicated it sets the player state team variable. Then it spawns the units, which, in begin play assign themselves a color based on whether or not their team var (exposed on spawn) matches their local player controller's state team var.

I'm noticing that the unit's initialization replication seems to occur before the player state team variable gets replicated. So the units are being assigned to the wrong team.

Isn't the order of RPCs supposed to be consistent with the order they're sent?

[fathom aspen]

Well you seem to mix things up. Property Replication is one thing, and RPCs is something else. What you're doing is property replication(that how it sounds at least). Properties replicate in order only in the translation unit they are in, but still you shouldn't make assumptions of their order of replication anyways. RPCs are sent in order only if they are marked as Reliable.

[blissful totem]

@fathom aspen well, fuck.

that just ruined my night lol

[fathom aspen]

Well, no. You're lucky because you have OnReps

They are callbacks to when replication happens

RelicatedUsing=OnRep_YourPropertyName instead of Replicated

[blissful totem]

The timing/order of the replication relative to other things replicating is still out of my control though, no? Unless I explicitly set it with a reliable rpc?

[fathom aspen]

Correct. And you don't need rpcs for that kind of stuff, cause what you're doing is the perfect example for using property replication. Also replication is more performant than Reliable RPCs

You should avoid Reliable RPCs as much as you can

[blissful totem]

Hmm I'm with you 95%. I don't see this being an issue for actual game logic. But it seems to me that as this is a series of short one off intialization steps its actually a good time for reliable rpcs, no?

I mean I could wait for confirmation of each critical step being confirmed by the clients to the server before kicking off the next step, but I feel like that's just a bit overkill.. maybe not. As I type that out it actually sounds pretty reasonable.

[fathom aspen]

Again read my answer. You should use OnReps instead. Replication takes time, and you should wait along for things to replicate. Technically property replication is even faster than Repliable RPCs

[blissful totem]

So to be clear you're effectively suggesting

• Server sets var
• Property replicate to client
• Client triggers on rep to tell the server
• the on rep function... sends an rpc to the server to tell it its done
• When the server hears back from all players, move onto the next step?

[fathom aspen]

Client triggers on rep to tell the server know that the property's value has changed, i.e replicated.
And you definitely don't want to RPC back. Call a delegate that is bound to the server to notify it that all players are done

[blissful totem]

I’m not clear what calling a delegate that is bound to the server means. How does the client send any information to the server that isn’t an rpc of some sort?

[fathom aspen]

Yeah maybe you're right. Then wait for the OnRep on the server

[blissful totem]

That… also confuses me. In my understanding it’s always server setting a var, it replicates to clients, and clients call on rep. When would the server call on rep

[fathom aspen]

For this kind of stuff

For BP it's done automatically

[blissful totem]

Am I misunderstanding something more basic and the server has a callback for when it knows all clients have replicated something?

[fathom aspen]

OnRep would trigger on server for each time you change a certain value. Changing it X times(where X is the number of all players) will get X callbacks

[blissful totem]

Right and I get that. But my issue is the server changes two variables, and I need to make sure the clients process those changes in the same order. So if I cannot guarantee that order calling them in succession, I need to push change one, wait for all clients to send a message back saying it’s been updated, and then push change 2, no?

And the only way for clients to send back the confirmation that they have done step 1 is an rpc as far as I can tell. The client cannot cause an on rep to trigger on the server.

[fathom aspen]

Yeah sounds that way

[blissful totem]

Ok, thank you

[fathom aspen]

Honestly I'm not sure if OnRep on server gets called at the same time it gets called on the client(but I see no reason for it not to be). If that's the case then you increment a counter each time a property gets replicated from a new player and you're done when the counter hits the number of all players or w/e.

Also you need to call OnRep manually in C++ on server

For client it's called automatically

[twin juniper]

Folks, is there a way I can resolve this unusually new network issue my devs discovered in yesterday's playtest?

https://i.gyazo.com/106e79a8d50ce91228c5a377dab96b63.mp4

On the bottom left is the client in my test. I see now the problem one of the playtesters mentioned. I know not how to fix it... I tried the engine net ramp trick in the INI file(s) and so far that did not see to resolve this.

[iron crest]

Hey, im back from earlier with the homing projectile problem, I fixed most of my blueprint and thought that maybe when I hit Q(key to throw kunai) it would do a sphere trace for 300 units ahead, and anything it hits will be returned as a hit actor and make an array for it, therefor, then all I had to do was make that a variable, get the variables location, then turn on (Is Homing Projectile=true), now the homing doesnt even work, it just goes straight, any idea why?

[pallid mesa]

News on Tuesday/Wednesday, need to speak with James first, because it was his idea

[fathom aspen]

DrawDebugType is set to None. You might want to change that to something else so you visualize what's really happening

[iron crest]

oh, my bad

[fathom aspen]

Also you might prolly want to GetOwner location instead of kunai as if there happens to be a delay until that function executes then you're screwed

But draw debug first

[iron crest]

Ok ill try this rn

[twin juniper]

Apparently this bug is know as "rubber-banding". I have been trying to follow this tutorial to no avail.
https://www.youtube.com/watch?v=nHfSGuMKIkc&t=480s

[iron crest]

Hmm now the line trace seems to not be visible

[fathom aspen]

I said GetOwner and not GetPlayerCharacter

Literally GetOwner instead of kunai

What's hard about that heh?

[iron crest]

if I use get owner it converts it to a root component, thought that wouldnt work my bad

[fathom aspen]

You mean the root component of this actor?

[iron crest]

thuis

[fathom aspen]

No. It's because you're doing a GetWorldLocation. It expects a component. That's why It auto generates that RootComonent node for you

Do GetActorLocation instead

And provide it with GetOwner

[iron crest]

ok ill try this

[fathom aspen]

Same for below, GetForwardVector. Use the actor version of it

Also do a PrintString on GetOwner for a double check that it's the character

[iron crest]

ok that might be the problem, it fails to print my chars name, it doesnt print anything

[fathom aspen]

So it's probably not owned

Where do you spawn it?

The kunai object

[iron crest]

I spawn it through an anim notify

[fathom aspen]

Click on that arrow to extend the BP node

In SpawnActor

You see Owner. There is where you provide the owner for the spawned actor

Also where is this code in? Which class?

[iron crest]

its in my main char bp that is used for all my characters for multiplayer

[fathom aspen]

Ok, then why you're using GetPlayerCharacter? Use Mesh directly

And whenever you want a reference to the character instead, then use Self

[iron crest]

I guess I wasnt thinking when I put that part I fixed

[fathom aspen]

You should start avoiding GetPlayerX(0) functions. There are always other ways for getting your info without using them

[iron crest]

ok I will

[fathom aspen]

Who calls KunaiRelease?

[iron crest]

I didnt multi cast or run server for it so its just whichever player clicks the key

[fathom aspen]

Ok so it's called on key press?

[iron crest]

Yep once I press a key it plays an anim montage and in the anim montage it calls a notify that calls that event

[fathom aspen]

Ok then you're executing it on client(input is fired only on client), and that's not good. Not good, means not good for a multiplayer game.

I supposed your game is multiplayer because you're asking in this channel

So in multiplayer you spawn actors on the server and make sure they are replicated. As simple as that. And they replicate to clients.

[iron crest]

ya it is

[fathom aspen]

Ok make sure Kunai actor is replicated

[iron crest]

ok one sec

[fathom aspen]

And that event is running On Server

[iron crest]

ok there we go, its on client, and the actor is replicated

[fathom aspen]

Same goes for anim montage. If you want other players to be able to see it, then do it on a multicast RPC, and call that multicast RPC from the server RPC you have above

[iron crest]

Oh yea I alr have that done

[fathom aspen]

Also if you haven't done so, read #3 and #4 pinned messages in this channel from the top

[iron crest]

ok

Alr I just read through them, what should I do now with the problem that it still wont recognixe who the owner

is

[fathom aspen]

They take more than 4 minutes to read. #3 is a video that will teach you how to do replication the right way. #4 will change your life once and for all

[fathom aspen]

Have you specified the Owner in SpawnActor?

[iron crest]

I alr basically understand it, based off odf some youtube tuts from recent touches on this project, and yea I specified the owner as self in the actual char bp

[fathom aspen]

Seeing what you've done, you don't seem to be. Practice makes perfect, but still it's good to read and look into such good stuff beforehand

[iron crest]

alr Ill try to watch the vid and stuff rn thn

[fathom aspen]

Also before I forget, SphereTraceForObjects sweeps a sphere along the given line and returns the first hit encountered.

So it's either one actor or none hit

If you want to be able to hit more than one you would want to use MultiSphereTraceForObjects

And if you still don't see the Owner for whatever reason(though you should be), then try to move your logic to the character instead

[vague fractal]

Just wondering, was it that ?

[weak copper]

Did you find any solution?

[fallow shadow]

I replicated the capsule component as well

[vague fractal]

Unlucky xD

[little pendant]

Hey guys. I have a weird problem with Jumping\Falling in dedicated server mode.
When i launch my game in singleplayer mode, jump works fine - https://i.gyazo.com/656224dac71c7f8d190f287a886baefc.mp4
But when i start game in client mode (with dedicated server) - characters flying up - https://i.gyazo.com/f2c1e3bd40df510b546afa55a7e013b4.mp4

I have no idea why 🙂

[marble gazelle]

Well we neither, you gave us 0 information ^^'

[fathom aspen]

Fake it till you make it! Why change it, seems like your player has super powers 🦸🏻

[fallow shadow]

How would i do that?

[bitter oriole]

Measure the average server replication rate, and move on tick with quad interpolation to fill in the holes between updates

Say the server replicates every 100ms, you'd move from latest server location to newest server location over 8 60fps frames

While keeping velocity continuous

[fallow shadow]

Uhhh ok i think i can do that

i just need to know how to get the server replication rate in c++

[bitter oriole]

Array of 5-10 last measured times between replication events

Moving average, essentially

[fallow shadow]

How do i measure the time

[bitter oriole]

Set a float to zero on replication event, increment it on Tick

[fallow shadow]

oh well that's simple enough

[bitter oriole]

Next event, you have the time, put it in a moving average to get averaged replication rate

[fallow shadow]

Ok one more question, what's the replication event?

docs dont seem to know anything about it

[bitter oriole]

"ReplicatedUsing" in C++

[fallow shadow]

👍

[fallow shadow]

aight i got the average

now what

[bitter oriole]

Now every time you get a replicated location+velocity, you can start interpolating from whatever the current location+velocity is, toward that new one, on tick, over that average time

[fallow shadow]

ight

[brittle yew]

i think i did, but sadly i do not remember the solution, as its a really old project
the best way to get it to work is by manually including modules on package via the build.cs. especially the online subsystems need to be completely disabled for devices that do not support it.

        if (Target.Platform == UnrealTargetPlatform.IOS)
        {
            PrivateDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine" });
            DynamicallyLoadedModuleNames.Add("OnlineSubsystemIOS");
            //DynamicallyLoadedModuleNames.Add("IOSAdvertising"); commented out:Handled by plugin
        }
        else if (Target.Platform == UnrealTargetPlatform.Android)
        {
            PrivateDependencyModuleNames.AddRange(new string[] {"Core", "CoreUObject", "Engine"});
            DynamicallyLoadedModuleNames.Add("OnlineSubsystemGooglePlay");
        }```

[fallow shadow]

yeah no i have no idea how to do this nvm

ill do other things until i figure something out

[static flare]

Does Character Movement have a very special logic around replication? I'm trying to use an external custom CharacterMovementComponent, which works fine for the host, but connecting clients seem to "fight the server", in that any client experience being forced in-place instantly (back to where they attempt to move from). On client's screen the host moves just fine, but on the host's screen, nothing happens at all when clients attempt to move..
Could this be a case where I should replicate the entire component, rather than just the "effect" it has (should have) on the actor that owns it?

[static flare]

How can I make the client authorative regarding position? I don't want the server to enforce anything, only replicate.

[vast forum]

Hello, I asked earlier in #blueprint, but now I'm moving here, since it's really more a #multiplayer question.

I'm trying to debug a situation where calling SetActorHiddenInGame (on server only) is NOT replicating to clients.

[vast forum]

This sounds dangerous 😮

One option is to turn off position replication completely, and then make your own replicated property (or RPC) that you send from the client.

[static flare]

I'm not making a game where you'd cheat. I mean, if you really want to, go ahead 🙃 Just a co-op thing.

Simply replicating a position vector (+rotation etc) sounds laggy (like, teleport player per server tick?). I assume the default MovementComponent has a lot of sexy smoothing involved to make it seem fluid. I still want that logic, I just want the client to have authority over the server regarding the actual value.

[marble gazelle]

assuming that the value you set is replicated, is the actor you want to change this on being set to be replicated?

[vast forum]

Hey!

So yeah, it's a replicated actor.

I got myself into this trouble because I was trying to optimize my net-load.

Essentially I had a logic block that would hide the actor, and it ran on both client and server.

However I realized that actor hide state is a replicated property, so I can just set it on the server, and let UE4 sort it out

This works fine, unless I call SetActorHiddenInGame too close to the start of the BeginPlay -in these cases, the actor stays visible on the client (no replication)

[latent heart]

I knew it'd be something like this.

[vast forum]

Hmm?

I was pretty clear that it was an optimization for replicated actors.

Unreplicated actors must have that code run on both client and server of course.

But a replicated actor with a replicated property (bIsVisible) should only need to be manipulated on the Server.

I've made a parent actor in C++, with an overriden post/pre net recieve.

This should allow me to get a better handle on what's getting replicated, visibility wise.

[vast forum]

It's not a "gotcha" that I was running code on the client. It's strictly necessary for unreplicated actors.

OK my friends, I've got the answer

The replicated actor does not receive any post/pre net receive if called too early.

This is debugging in a scenario where I call setActorHiddenInGame after a 5 second delay: (emphasis mine)

// First batch of replication, right at begin play
PRE_NET_RECIEVE on replicated actor: Current Visibility is: VISIBLE
POST_NET_RECIEVE on replicated actor: Current Visibility is: VISIBLE

// Here is the server, setting the actor visible (current visibility is not a reflection of changed value)
SET_HIDDEN_IN_GAME on replicated actor: Current Visibility is: VISIBLE

// Here is the replication packet, as you can see, we set it hidden :)
PRE_NET_RECIEVE on replicated actor: Current Visibility is: VISIBLE
POST_NET_RECIEVE on replicated actor: Current Visibility is: HIDDEN

And the same scenario, when I call SetActorHiddenInGame with some tiny delay like 0.1 seconds:

SET_HIDDEN_IN_GAME on replicated actor: Current Visibility is: VISIBLE

In other words, pre/post net isn't received at all, neither before, nor after I set hidden in game.

[fleet crown]

is it normal that LogNetTraffic keeps printing Received ack without doing anything?

[vast forum]

Wow this is fascinating

What the heck. Literally this is so busted....if I call SetActorHiddenInGame (too early), the replication becomes permanently busted.

No more Post/Pre net recieve

[elder quartz]

Hi everyone! I'm working on my first multiplayer game. Does anyone have tips/guides for dealing with packet loss/slow networks? Our game uses about 25 KB/s of bandwidth. Is that a lot for a co-op (listenserver) game?

[willow prism]

Hi guys. I have a platform that moves in a spline from one point to another, but for some reason the platform that runs on the clients goes out of sync and with some lag. any advice to improve this?
this is my configuration. In this one I do not replicate movement, because I understand that this is for the entire actor and my actor does not move everything, only the mesh of the platform moves

[latent heart]

So if you call it too early, the value is never replicated even if it's changed on the server? Multiple times?

[vast forum]

This turned out to be false, more or less.

Future calls would cause a rep event, but only if the final state was different from the servers current state

So I was too hasty there

[iron crest]

Hey I have a homing projectile problem, I fixed most of my blueprint and thought that maybe when I hit Q(key to throw kunai) it would do a sphere trace for 300 units ahead, and anything it hits will be returned as a hit actor and make an array for it, therefor, then all I had to do was make that a variable, get the variables location, then turn on (Is Homing Projectile=true), now the homing doesnt even work, it just goes straight, and now my line trace fails to even fire, Last night, I was prompted to refresh myself with multiplayer and how that works (which I did) and im yet still stuck, anyone know why?

[mild urchin]

Hey everyone, i'm starting to use the steam inventory. I've managed to retrieve the player's inventory on the menu but now I want these items to show up in game. For that I suppose the server need to check every individual steam inventory in order to show them, however the steam inventory functions can only be called client side... Am I missing something here, or does someone else have another idea ? Thanks !

[static flare]

I actually did try those, but only in the BP I have extended from my custom C++-class, and for some reason they didn't do anything (maybe I did something else at the same time that fucked this up).. When I wrote it directly in code it actually did "unlock" the client to be able to move correctly. Thanks! There's still something fishy going on here though, it doesn't behave completely correct, but I'm definitely on the right path.

[static flare]

How is movement generally replicated? Is it sending input-commands, direction+velocity, or actual FVector positions?

[short void]

What does this do?

If I am doing a multiplayer racing game, wouldn't I need Position Lerp to be a relatively high number? It's really important for the cars to be in the correct positions

[dark edge]

How much it lerps towards the correct state when in error

You'll want to mess around and tune it, the default settings are super strict

There's a debug mode to see all the error stuff.

[short void]

It says higher number increases precision, but also can create some jerkiness

[dark edge]

Well yes

[short void]

But zero seems like it wouldn't ever be in the correct location?

[dark edge]

There's other correction, that's just the lerping

[short void]

I see

[dark edge]

look at the rest of the settings

[short void]

Appreciate it, it's weird because the cars are becoming completely unsynced for the clients. I must have missed something

[dark edge]

Show your current settings

[short void]

OK one sec

car Blueprint:

[dark edge]

Do you have physics replication turned on?

replicate physics to proxy or whatever

[short void]

Replicate Physics to Autonomous Proxy for the Mesh creates a really weird studdering effect and limits the speed of the car to like 40 mph

So I have that unchecked

[dark edge]

That's the default replication settings i was telling you about

so now the physics isn't replicated at all

so of course it doesn't sync up

[short void]

So this has to be checked, and I need to call events for control on both client & server via blueprint in order to have them synced?

[dark edge]

Replicated physics is HARD. I hope you don't need clientside prediction and are ok with a ping delay between input and things happening.

Start with making a super simple replicated physics pawn that just flies around. Start there before tackling a vehicle.

[short void]

Gotcha

[dark edge]

I got it working on my project but it took a lot of dialing in the settings to not be too strict, but not too loose

But I don't use the vehicle actor, made my own.

[short void]

I really don't need to replicate physics TBH

[dark edge]

I thought you were making a multiplayer racer

[short void]

But I assume that is required to keep the cars in sync?

[dark edge]

Do the cars drive around using physics?

[short void]

Yes

[dark edge]

K then. Why would you not use replicated physics, what DO you intend to use to make sure everyone agrees on what's happening?

[short void]

I wasn't sure if there was a method to bypass replicating physics and just worry about position data

I might be completely off base here

[dark edge]

That's what the replicate physics stuff does. It doesn't pass forces around, it just smoothly influences the client side versions of the physics bodies to move in accordance with the server-side one

[foggy wraith]

Anyone ever do a multiplayer skin selector? For example Fortnite and tons of other games let you pic your skin and cosmetic's. I have never done this but looking for someone who might have.

[dark edge]

Imagine you got a invisible server version of the actor moving around, pulling your local version with it like it was on a spring, and then if it gets too far, it Yanks it real hard. That's what it does

[short void]

I must have something missing then, because whenever I check Replicate Physics to Autonomous Proxy, it creates a really jerky situation for the clients. It's like the server and client are arguing over where the real position should be

[dark edge]

They probably are.

I would first check if there's any sort of replication magic in the vehicle that you're using, I'm not sure if there is or not.

You really ought to ask if the physics channels about this. I haven't messed with the stock vehicle much, I don't like it

[short void]

Yeah, I'm not using the stock vehicle, but I noticed it has the same issue

[dark edge]

What are you using then? You need to somehow get your throttle and steering and other inputs to the server

[short void]

That's what I thought, I'm 100% missing something here

This is for car control

[dark edge]

Yeah you'll have to look and see if the chaos vehicle handles replication for you like the character movement component does or not. I don't know anything about that, probably want to ask in the physics channels

[fallow shadow]

Any good guides on how 2 multiplayer in c++? i built my game on singleplayer thinking that implementing multiplayer with only a dozen classes cant be that hard but nope

now im at the point of making my own character movement (ignoring CMC) because it didn't fit into this weird ass thing i got going

[short void]

Been able to replicate movement with this node setup, but as soon as any actor has a collision (wall, other car, etc) they become desynced. There has to be something simple I'm missing

[strong pumice]

I'm interested in this also. Usually, we would have players array on the server with pos.x and pos.y, and clients will send messages to the server like "MoveForward", server would move player and return new position to all clients. I wonder how would you do this in UE.

[low helm]

If you want client authoritative movement just download smooth sync

[peak sentinel]

Dont use smooth sync for player movement, its not made for it

[low helm]

Works fine for me

You can’t just give a server your input data and hope it matches up

Multiplayer environments are not deterministic at all

[short void]

i see

[low helm]

Unreals Character movement does this, but it has a bunch of additional checks in case the clients version becomes too separated from the servers version, which introduces all sorts of correction glitches

[short void]

That makes sense, I figured something else was happening there

[low helm]

And ultimately you need to decide if the client or the server will have authority in case of a discrepancy

[short void]

Yeah, client should actually

Smooth Sync looks like what I need tbh

[low helm]

Smooth sync will automatically send location updates from the client to the server

It makes your game more vulnerable to hacking

But nobody cares

[short void]

Yeah, that makes sense, but I just want friends to be able to host their own server and race. If someone is hacking it kind of defeats the purpose of racing your buddies

[low helm]

Exactly

[short void]

Like you said, I don't think people care that much vs getting a smooth experience

[fallow shadow]

so i have this

https://developer.valvesoftware.com/wiki/Source_Multiplayer_Networking

i read it

it all makes perfect sense

and i was like "amazing time to do this"

then i remembered that im not using source engine

idk why i just find it really hard to comprehend this entire replication thing in ue4

back to the docs i go

maybe one more really good read will make it clearer

[solar stirrup]

The CMC is similar in concept

So it's a good read

[ember sinew]

I know that if AMyActor has a UMyObject property I want to replicate, I need to add a line to ReplicateSubobjects() (and GetLifetimeReplicatedProps, UPROPERTY(Replicated), etc.)
But of AMyActor has an UMyComponent with a replicated UMyObject property, would I still include that object in the actor's ReplicateSubobjects, like wroteSomething |= Channel->ReplicateSubobject(MyComponent->MyObject, ...)? Or would my component handle that in it's own ReplicateSubobjects implementation (is that something components even have?)

[solar stirrup]

Pretty sure components have ReplicateSubobjects

[granite wind]

Hello , I need some clarification on the RPC usage. I have a Client RPC and it is being called from server. For me the problem is that it is executing on the server itself. I am guessing this is happening because the owner of that actor is the server itself even thought it is a player character. The player character on the client will have the role of autonomous proxy . So how should I execute an RPC on the AutonomousProxy actor from server. I am new to unreal networking so please correct me if i understood wrong.

[toxic lion]

Yeah Just he components need to include that logic. Those are first-class classes that unreal considers when replicating

[shy hill]

Hi, is there a blueprint solution to control when players can / cannot find or join a session after it has been created ? I found this thread from 2016 when someone had exactly the same issue, seems like there wasnt any solutions back then:

'I want my lobby to be searchable like it is now. A session is created and you can join. But then once everyone is ready we servertravel to a map that has the actual multiplayer game mode. As of now anyone can still join the session while the game is in progress. That breaks the game mode as everyone starts with three lives so anyone dropping in late has an unfair advantage. So how, once the server travels to the new map and mode, can i disallow anyone to join in progress? Destroying the session obviously doesn’t work.'

https://forums.unrealengine.com/t/how-can-i-hide-my-session-from-search-once-in-game-so-no-one-else-can-join-it/74902/3

[latent heart]

A client RPC shouldn't execute on the server unless it's a listen server.

[molten agate]

where can i download MySQL for 4.25

[compact talon]

Can I store information on a session in blueprint? I am trying to have server names and passwords without using advanced sessions and I store the name/password for the host in the game instance as variables.

In my server browser I use the find sessions node and when setting the text for the server name etc I want to use those variables set by the host.

Or maybe there is a better way to do this.

or if the best way to do this is using advanced sessions, does anybody know if it works for ue5? All I could find were posts saying it doesnt work

[molten agate]

Advanced Sessions has inbuild database ?

[tulip ferry]

Hello there,

This is regarding the UE4 dedicated server in UE4.27. We have a dedicated server that has been correctly deployed on a remote machine. The correct firewall ports have been opened and also forwarded. We're using the SteamSockets Plugin. We've double checked the ini file for connection related properties.

The Dedicated server is visible to clients, however, whenever a client initiates an attempt to connect to the dedicated server, we get an error in the dedicated server console saying the following: LogSteamSocketsAPI: Warning: SteamSockets API: Warning Ignoring P2P signal from 'steamid: someSteamNumericalID', unknown remote connection #1276292343.

The someSteamNumericalID is the ID of the client that tried to initiate a connection.

The client who is in the process of connecting then gets kicked and sent back to the main menu.

This leads us to believe that the Dedicated server is able to see the client attempting to connect but is, for some reason, dropping the connection attempt midway. We do not have this issue when connecting using the listen server.

What could be the cause of this message? And what steps could we take to resolve this issue?

I would be thankful if anyone could help out with this and shed some light on what is happening.

[ancient bramble]

how do i create a dockerfile using a linux server build ?

[twin juniper]

Can someone please help me with my problem?

[ember dagger]

It's practically impossible to tell what's going on and why it's happening from your video. You need to show more. Is that happening just from walking around? Is it happening after you initiate some other movement ability. What is going on and why? What gets that to happen and what have you found from debugging. I'm not a wizard. Or a telepath. Idk your project

[twin juniper]

It happens when I move.

As I said 2 days ago (nearly 2AM ET on my end), camera/player stuttering or "rubberbanding".

[ember dagger]

Can you provide screenshots of your movement code?

[twin juniper]

I use scripts for my game. Code is reserved for external tech. Regardless. Give me a moment while I get the Blueprint screenshots.

There is a lot of scripts. Here is the movement code and Components.

https://i.gyazo.com/7a2077aa8be027a55970b38b2a523494.png
https://i.gyazo.com/24b77942775a4f5511b659b8f96682b8.png

[ember dagger]

Not sure about the vehicle component as I've never really used it. But the character movement component has two variables. bIgnoreClientMovemenrErrorChecks and bServerAcceptCliwntAuthoritativePosition. Setting both to true allows for client controlled movement. They do not save when restarting the engine so you'll have to set them in the begin play. Again idk I'd it's in the vehicle movement component. But it's worth a check though.

[twin juniper]

I can screenshare this on the feedback and support voice channel if you want to see more.

[ember dagger]

I'm on my phone at the moment. Could you show your replication section in the movement component?

[twin juniper]

Well that's the thing. I didn't make a custom movement component. The character just uses the regular CharacterMovementComponent from the PaperCharacter class.
https://i.gyazo.com/71cc0f31f1c58e0643903b09cef40d78.png

Movement functionality is bare-bones simplistic.

Besides animation

https://i.gyazo.com/9f029ab9d13916ce9c51b72146bdedae.png

https://i.gyazo.com/204b2b3246c24cbd30a77eb0c4123962.png

[ember dagger]

Does the paper character have a different movement component to the base one? It should come with a replication section on the right hand side when you click on it

[twin juniper]

Apparently not. Looks the same as the usual 3D Character class.

https://i.gyazo.com/8d2590bd55e9198032681e4554d455c7.mp4

[ember dagger]

If it's the same one you should be able to scroll down on the right side of the screen in this picture

I might be wrong

Click on your ne_character(self) and in the replication section there on the right side. You'll also have to scroll to it

Can you show that as well?

Trying to check variables states and see if they're correct

[twin juniper]

https://i.gyazo.com/55ef01c3785c1c872c262598edc42db7.mp4

Is this the one?

[ember dagger]

Yes, it looks like the movement component doesn't have one. Sorry, I just wanted to see if it did. Try clicking on Ne_character(self) now and scroll down for the replication section as well

That will have a bunch of variables for how the actor handles replication

[twin juniper]

https://i.gyazo.com/ab2ed00979dccc6fb239703c85612262.mp4

[ember dagger]

Hmm replication variables seem to be correct and you add movement correctly. I'm not sure if paper 2d replication is different than normal. One last thing I can have you try is clicking on the movement component again and in the top right searching for IgnoreClientMovementErrorChecks and ServerAcceptClientAuthoritativePosition and set both to true. This will remove server corrections in regards to movement. This will allow hacking and cheating of movement positions to be possible, but thats up to you and how you want to handle your server corrections. You will still need to replicate movement to other clients, but it just won't be corrected by the server. These variables don't save when restarting the engine. So you'll have to set them in the begin play.

Or possibly. In your add movement input your manually setting the direction and that number isn't replicated

Try making a variables for each direction

And use that instead

You can try both. I can't think of any other solutions from what I see

[twin juniper]

This right?

https://i.gyazo.com/a5ac51728e44db6882e545425de98e42.png

[ember dagger]

Yes. You can try that or the other solution

Whatever you'd like

[ember dagger]

Second solution. One variables for each direction and try plugging those in instead

[twin juniper]

Will try the second solution. I just did the first and it did not seem to resolve anything. Player is still rubber-banding.

[ember dagger]

Hmm. There might be some other issues. Maybe collision issues then

Because there shouldn't be any corrections in the first option

[twin juniper]

I found it! Turns out this was the main culprit.

https://i.gyazo.com/d4380b8ad3b30075dc81b5e81c7c773e.png

I disabled replication for the capsule collision.

[ember dagger]

Ahhhh yeah. For the most part I tend to avoid turning replicate component on until a last resort if I can't get anything else to work

[twin juniper]

And it works almost completely. The camera rubberbanding is gone, but the player sprite still barely stutters. I think that has to do with the sprite components replicating. I need them to however because of sprite changes in animation.

[ember dagger]

Normally doesn't do much and can cause some issues If not handled

[twin juniper]

I managed to disable all of the components and so far they're working again... Interesting... The sprites use to not update properly when component was unreplicated.

Stuttering still happens on the sprite (albeit barely), but that's fine for now.

At least its working 99%.

[trim kindle]

How is async loading usually solved in multiplayer? Let's say that client decides to use something and async loads it with soft ptr. What about server, is it ok to replicate call to server to tell it to also load the thing? Having everything always in memory could be difficult for listen servers.

[marble gazelle]

well load the resource and while it's referenced it's not destroyed, if you don't need it, just release the ptr or the handle from the resource manager.
At best your code already would have the server also go the same code path to load the resource, of even have the server notify the client to run the code which then will load the resource.

[fallow shadow]

Ok i think i finally figured it out

i can replicate most things normally but i want to do it a bit differently with characters

because if i dont there would be a delay between input and action which makes the game weird to play

so i do some interpolation and prediction and whatnot and it should work

[trim kindle]

Yes, however I wonder about situations when the request is client initiated.

[marble gazelle]

well depends on the needs, if the server needs the resource as well, you need to notify it, there is no other way I think

you could write some sort of network resource manager that wraps this logic for you and also releases the resource on the server if not needed anymore

[trim kindle]

makes sense

thanks

[marble gazelle]

also keep in mind that other clients then may also need to load the resource^^

[tulip ferry]

Hey, can someone help me out with this please?

[solar stirrup]

Replication Graph question

Is it not possible to have two replication graph nodes:

• One's the standard grid spatialization node
• One's an always relevant node for a specific list of players

And have one actor be in both nodes? That way it's always relevant for some players and spatialized for the others?

That's my current setup but they still seem to be affected by net cull distance even for the always relevant players

[chrome bay]

IIRC, no it's not mainly because of the way the "cull distance" is more deeply integrated with the graph

I'm on an older version (4.25) currently, but you can look at ReplicateActorListsForConnections_Default to see why

If the actor has any cull distance settings at all, it will be culled - the grid node is more about building the actor list efficiently rather than actually performing the culling

[solar stirrup]

Well that sucks :c

Yeah I see it

Guess it's engine edit time

[chrome bay]

yeah would be nicer if that was done at the node level tbh

for that exact case

[near bison]

GameState not present in BeginPlay of PlayerController?

[bitter oriole]

That's possible, yes

[near bison]

How is that possible? PlayerState is available in PlayerController, which means gameState should be too.

[latent heart]

If you want to make sure everything is available, add onrep stuff for every object you want to interact with and have them all run a function which checks if they are all availalbe and then execute your code when they are.

[bitter oriole]

In multiplayer, you can never make any assumption on timing

PlayerState is a vital part of PC, GameState is not

Many other actors also won't be there

Build your game logic to never assume anything about availability of objects

[near bison]

Ok I was wrong...GameState* is always available

my playerstate is not

lol

[bitter oriole]

Either is likely to happen regularly

[near bison]

that's just not possible

[latent heart]

Everything is possible.

[near bison]

I dug into the source code...every replicated actor has access to GameState, because that's the first thing that's created after GameMode

I'm 100% sure about this

The other actors idk

[bitter oriole]

As far as a client joining the server goes, BeginPlay just means "the actor has been spawned" - there is zero guarantee that any other has

[near bison]

An actor that has been spawned's beginplay only runs if game state is present iirc

[bitter oriole]

On clients? Pretty sure no

[latent heart]

Well, as you said, it's your player state that's missing, not game state.

[bitter oriole]

It doesn't matter anyway - make no assumptions and you'll be fine

Poll on tick in that player controller to check for every dependency's existence, and then fire a custom ActualBeginPlay function

[latent heart]

Why would you use tick?!

[bitter oriole]

Because it's perfectly appropriate

[latent heart]

It'd be more appropriate to use the events that actaully trigger when an actor is replicated...

[bitter oriole]

If every single object that you depend on has a rep event, and you have no other dependency or gameplay condition, and every actor that you depend on has its full initial state immediately, yes

Much safer to do this on tick and wait for an explicit set of conditions

[near bison]

why should I be using Unreal anyway, if I have to do this? lol

that's so stupid

where are the callbacks I can use to just check if an actor has replicated and I have access to gaemstate and playerstate

[bitter oriole]

Because, believe it or not, it's worse in other engines

[near bison]

it's not. I've been using unity for 2 years

It's a simple OnClientConnect callback I have to write

[near bison]

there is no WAY I use an onrep to handle this particular case. the gameplay framework fails in its use case if I have to

Btw, I can confirm GameState is always available for every actor's BeginPlay

[latent heart]

Then the gameplay framework fails.

It's been that way since its inception like 8 years ago.

[bitter oriole]

Yeah, using OnRep events for this is way too complex, just poll on tick to wait for set conditions.

Personally I keep the loading screen up during that time, and wait for an additional time to give time for texture streaming

[near bison]

mmmm, I will if I have to...but in the meanwhile, do let me know if there are any other elegant solutions. I really don't like this too much

I'm happy listening for an in-built event, instead of tick/delays

[bitter oriole]

I'm not sure what's inelegant about this, tbh

Events in multiplayer are stupid

[near bison]

not at all

[bitter oriole]

You never control the timing

[near bison]

events are the easiest way for me to keep my code clean, given what I'm doing

[bitter oriole]

Counterpoint: write your game on tick and never worry about timing ever again

[near bison]

but granted..the way I am using events is like single player. in OnRep if something meets a condition, I fire an event that all clients listen to. That works just fine

or in my multicast i call an event that clients have bound listeners to

etc etc

[latent heart]

Hope you're not doing that on the client.

[near bison]

events have nothing to do with multiplayer here in this context

[near bison]

doing what?

[latent heart]

Firing events that all clients listen to.

Multicast events only work from the server.

[near bison]

no, here's an example:

OnRep_TurnNumber
Call OnTurnChanged (event)

where client's controller listens to this event

[bitter oriole]

My software development career has been a 15-years ongoing realization that I have not been putting enough code in observer-type

Multiplayer inherently works with state - state is the only thing you can safely send to clients and be sure they'll eventually get it

Replicate state, avoid events, never trust timing

[latent heart]

And the engine has plenty of things which fire off when state changes.

[latent heart]

Ah ha, okay. Fair enough!

[near bison]

i think you're confused with what I'm doing. I will never have concurrency issues.

I am using OnReps, Server events etc..to change state, and in the callbacks when state changes (i.e OnRep) that's where I'm firing an event

That's just an effort to keep my code clean. So that I don't have 2 way dependencies. Nothing to do with multiplayer

[bitter oriole]

I will never have concurrency issues
I am using OnReps

[near bison]

read this, you will understand

[bitter oriole]

As a reminder, there is no guarantee that OnRep events will be called for a given value change

[near bison]

why's that?

[bitter oriole]

And there's obviously no guarantee on the ordering of OnRep events

[near bison]

ordering isn't a problem for me

[bitter oriole]

Because OnRep is a purely client-side process that tells you "I just got a new value" - getting a new value at all when it changes on the server is not guaranteed. A replicated frame counter that increments on tick would routinely replicate half the values or less

[winged badger]

OnRep events come in order of GetLifetimeReplicatedProps DOREPLIFETIME

[latent heart]

Nobody has suggested that object A will always trigger OnRep before object B.

[winged badger]

if you're talking blueprint, then sure, but that is not a replication callback to begin with

[bitter oriole]

Provided both change in the same frame and are considered for replication and no packet loss occurs

[winged badger]

they come in same packet

[bitter oriole]

If they changed in the same frame, yes

[near bison]

that's not desirable...how will I guarantee consistency in my data then? I mean I'm hoping in the next frame the OnRep on client will update the value correctly if it missed the previous server update? That's all I need

[winged badger]

actors don't update every frame 🙂

[latent heart]

• latency

[bitter oriole]

The only guarantee is that data eventually updates to some recent value

[near bison]

that eventual consistency is all I need

[bitter oriole]

If you have 50 changes in a second, you will get the end state eventually, but intermediate values may never come

[near bison]

nbd

[latent heart]

I'm finding it hard to see what that has to do with anything, weirder.

[bitter oriole]

Hence my point that observing the current state, rather that using events alone, is usually a great way to write more reliable multiplayer code

[near bison]

isn't observing current state == events?

I dispatch an event on client, lsiten for the same event on client in some othera ctor

[bitter oriole]

Use Tick, read the state, act accordingly

Or don't, i don't work in your QA dept

[near bison]

again I reiterate, the events I'm talking about has nothing to do with multiplayer. One actor subscribed to an event from another actor on the same local machine is never going to be missed, and has nothing to do with reliability, because it's all local

Anyway, if I have more problems, we shall discuss again! this was valuable though

[latent heart]

I do wonder if when onrep is called on, for instance, a player state, that it guarantees that the player state has been fully replicated or just the base object has been "net initialised."

[bitter oriole]

Yeah, local stuff is fine - I'm talking about multiplayer events specifically (onrep, multicast, client methods), rather than events in general. Though I also feel the same way with event-based code, to a much lesser degree. Happy to help if you have more MP questions

[near bison]

One more question -- is it better to do this where I call an event and listen on PlayerController, or call the function directly on the PC? I guess this is not a direct MP related question though

Only reason I wanted to avoid calling the function on PlayerController directly here is because I'd have to do a cast to my player controller

[latent heart]

Entirely up to you.

There's plenty of methods for doing that, none of them are particularly better or worse for something so simple.

[near bison]

Ok..I just did it this way because I hate the idea of continuously casting to something and not being able to store a ref to it..and keeping track of it especially in MP for a class like gamestate is a pain

so thought events will be cleaner

[latent heart]

Why can't you store a ref to it?

[near bison]

I mean I can...it's just..eh

[latent heart]

Yeah.

I like events anyway, it helps encapsulate your code.

[elder quartz]

Is 60KB/s bandwidth a lot for a 4 player co-op listenserver game?

[livid sluice]

Hey Guys a weird issue is happening. I have quite a large terrain (Hosted on a dedicated server) which takes roughly 5 or so seconds to load once the player connects to the server. Even though both players connect to the server correctly, they cannot see each other. They are there as if you approach a location where one player is the collision works in a glitchy way. However this issue is not there when connecting to a Test level which has no load time.
Any solution to this?

[winged badger]

sounds like they are not relevant to each other

[winged badger]

not really, but they better not still be using dial-up 😄

[livid sluice]

Haha even I thought it might be a relevancy issue.

[winged badger]

if they can meet at any spot and have glitchy collisions - they are replicated, as their movement does work

glitchy is just server, that has both of them correcting after a collision here

[livid sluice]

Yea I tried this, it does work as you say. Might be relevancy in which case. Is there anyway to refresh all relevant actors in an area?

[winged badger]

if it was just the visibility - then slide along collision would work, there wouldn't be any glitching, just an invisible capsule

i don't know what your approach to relevancy is

first, check the bAlwaysRelevant to confirm that is the issue

[halcyon totem]

I have set up a dedicated server and wanted to see if android and PC players can connect online, is epic online services the best way? I need to run the servers from my PC and NOT rent them somewhere, can I use EOS?

[winged badger]

i don't think EOS cares where the server is physically

there is no difference between rented server and one in your house either - without a public IP address you'll need to do some port forwarding on your router, thats it

[quasi tide]

As well as having to handle the attack vectors to your home network yourself.

[compact talon]

I am having some issues with basic sessions. The session name is generated automatically (I think because I am using the Steam subsystem it makes it your steam name), I cannot set a password for the session and the max players isn't actually max because you can still connect to it. All it does is if you have max players it hides your session from being found (which I also don't want).

I was wondering if anybody could offer some guidance on this, and would I need to delve into C++ to achieve what I want or can it all be handled in BP?

I figured I could workaround this by leaving the session info as default, and just changing the text that is displayed in the server browser. I got all the functionality necessary for this to work then I tried pulling it from my game instance but im a dummy and forgot that all the server information in the game instance is only available to the host.

If I could store this information in the actual session as an additional parameter that would probably work.

As for player count I assume I could have a work around by setting max players to the chosen max + 2, and displaying max - 2. That way it would still display the server if it was full. Then if you try to join a server that says it is full it just cancels.

[torn geode]

Ello, got an issue where although my component is replicated (tank turret) and i belive i have everything setup it wont rotate on the client end, only the server side, Anyone got any ideas of stuff i can try. i also cannot find anything about this online,
TLDR Cant replicate rotation of tank turret

[floral crow]

If I call a reliable Multicast RPC right before calling Destroy on a replicated actor, is the RPC guaranteed to run on all clients before the actors gets killed?

I'm not sure the "order of events guaranteed" applies here

[chrome bay]

It will be called on clients the actor is currently relevant for before being destroyed yes

[hot cairn]

What determines whether a replicated variable is passed across the network? Is it on tick? Is it when the variable is changed? If its changed, is it smart enough to see whether a change actually has a delta, or do I need to check manually before writing to the variable? (if anyone knows some good documentation on this that would be much appreciated too!)

[quiet wyvern]

Anyone know what this FUdpMessagingModule_AutoRepair is and why it is causeing my game to stutter ever two seconds

[bitter oriole]

Essentially after tick if the variable is different than the last frame, it may be replicated, depending on net update frequency etc

[pseudo bison]

Hey. I would like to make a multiplayer mobile game based on widgets (like on screen). Do you have any tutorial how to make connection to server etc?

[grizzled stirrup]

Can you start new sessions without having to load a new map, say for example you are playing through a game solo but your friend wants to join, can you create a session and invite him and he can just join?

Obviously ignoring stuff like him seeing the right state, just the session creation stuff

[pallid mesa]

pretty much, you would just open a listen server session and can have peeps joining to it through session discovery (assuming a proper OSS is used)

[grizzled stirrup]

Nice so it's completely separate to whatever map you have loaded and the OpenLevel step seen in most session tutorials is actually optional?

[fallow shadow]

hey how can i have a RepNotify for a character's location and rotation?

[pallid mesa]

as long as the server instance has the map loaded, it's fine

[fallow shadow]

I usually get it with GetCharacterLocation or GetCharacterRotation

[pallid mesa]

it was something like...

PostNetReceiveLocationAndRotation????

ugh I don't remember

well, surprisingly that was it

@fallow shadow take a look at that method, it's part of AActor

[fallow shadow]

aight

[pseudo bison]

Ok, but which server i need?

[pallid mesa]

uh?

[pseudo bison]

How can i host a mobile game?

How can i connect client to server

[pallid mesa]

I was answering kyle Kedholt 😄

[pseudo bison]

ok

[fathom aspen]

He replied to kyle

[pallid mesa]

Unfortunately I got no experience in mobile development! But I'm sure you can take a look at EpicGames' tutorials to learn how to do that

[fathom aspen]

And I would try my luck in #mobile

[dark edge]

The same way you host a non-mobile game.

[obsidian cargo]

Is there a way to give higher priority on OnRep order for specific params?

I have 2 params that get received on the same frame, and would prefer a specific param always have OnRep happen before the other. My logic supports either order but I can save some CPU cycles with the prioritization.

[fathom aspen]

I would be amazed if there is

[wheat magnet]

    {}```

this will called on server

    {
        Client_SpawnParticle();
    }```

does this called on client?

where Client_SpawnParticle is defined as : UFUNCTION(Client, Reliable) void Client_SpawnParticle();

[tacit bough]

I've implemented movement via the built-in floating pawn movement component. The server pawn is replicated correctly on the client, but the client movement is ignored on the server. I've got all components and the pawn itself set to replicate. What else can I do? (Blueprint-only project at the moment btw).

I thought built-in movement components are automatically replicated correctly by Unreal Engine.

[fallow shadow]

i cannot for the life of me figure out this prediction thin

[tacit bough]

@fallow shadow what thing?

[fallow shadow]

client side prediction

my client lags while moving and i just cant get rid of it

[wheat magnet]

        void AllSpawnParticle();```

this function is called inside character by click left mouse

but when client try to spawn, server and other client doesn't see it( only owning client see it)

but when server spawn, all client and including server see it.

what things are missing?

the function is already marked as NetMulticast

Note: I am spawning emitter inside function. Not replicated actor

[fallow shadow]

is there any method that executes with every packet that the client recieves?

[wheat magnet]

Can anyone tell me where is the issue mentioned above?

[obsidian cargo]

Multicasts called by the client only work for the client. They must be called by the server to be broadcast to everyone.

[wheat magnet]

this means should I call UFUNCTION(Server, Reliable) first?

and then inside this function I will call ``` UFUNCTION(NetMulticast, Reliable)

[fallow shadow]

ok so my current problem seems to not exist if the character is moving at the maximum velocity

otherwise it lags and snaps back

i still have no idea how to resolve this any help is appreciated

[wheat magnet]

@obsidian cargo ```void AmutliplayerCharacter::LocalSpawnParticle()
{

SpawnParticlex_Implementation();

}```

and ```void AmutliplayerCharacter::SpawnParticlex_Implementation()

{

AllSpawnParticle();

}```

where AllSpawnParticle() is marked as NetMulticast

and SpawnParticlex() is marked as Server

but it still same, when server spawns, the client see. when client spawn, only owning client see. not other clients and server see

what issue might be

[obsidian cargo]

I think so, I'm just learning multicast right now myself

I can't quite follow your code because your UFUNCTIONS aren't showing the function names

[wheat magnet]

        void AllSpawnParticle();```

[obsidian cargo]

Traditionally, you start the server function name with Server_ and the multicast with Multicast_ to make it more clear

Multicast_

[wheat magnet]

    void LocalSpawnParticle();```

    void SpawnParticlex();```

These are the UFUNCTION()

Which thing you will need?

and this is function implementation:```void AmutliplayerCharacter::AllSpawnParticle_Implementation()
{

UParticleSystemComponent* pdasdsad = UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), Partic, GetActorTransform(), true);

pdasdsad->SetIsReplicated(true);

}```

is this correct now?

[obsidian cargo]

Sorry I'm not certain. I don't want to say the wrong thing

[wheat magnet]

{

    SpawnParticlex_Implementation();
}

[obsidian cargo]

Did you look at cedric's network compendium in the pinned messages?

[wheat magnet]

Yes.

[obsidian cargo]

I'm having the exact opposite problem with multicast. My server is calling it, but the clients are not getting it.

But the component that has the multicast is set to replicate. It is triggering data OnRep, just not the multicast.

[wheat magnet]

I did exact it should be. created server and multicast function. called server rpc and inside server rpc I called multicast rpc

when server press left mouse, server and all clients see particle

when client press left mouse. only owning client see. but not other clients and server.

Ok. I fixed it.

I was calling function like this : SpawnParticlex_Implementation(); instead of SpawnParticlex();

[obsidian cargo]

Oh yeah, now that you point it out that makes sense

OFFS I'm doing the same thing

This is in my server func: Multicast_Event_Implementation(eventId, FEvent(parameters, indices.Num()));

Glad you figured it out!

It was probably auto typed by VS early this morning when I was half asleep

[wheat magnet]

Yes. Just to make sure you are calling actual function.

[fallow shadow]

2 days on the same issue oh my god

ok ok you know what

does anyone have any good guide or tutorial for fps networking in ue4 c++

actually this isnt even a problem

i just cant replicate the characters well

again they just keep getting snapped back into place

well they move its just snappy af

until i reach max speed at which point it stops

[obsidian cargo]

Sounds like you are a champion and figured out everyone's problem!

[obsidian cargo]

I think what you are describing is commonly called "rubberbanding" it happens when the server and the client disagree about the allowed movement speed

Or at least that is one reason it can happen and sounds applicable to what you've described

[fallow shadow]

Is there any way to prevent it?

i guess that there could be multiple causes to the problem and you need to eliminate them and it should go away no?

[obsidian cargo]

Yeah there are a lot of ways you could have that problem

Personally I'm using GAS attributes to control max movement speed and it seems to work well

I'm not experienced enough to really recommend anything specific though

I've just heard a lot of people having a similar problem as yours

[dark edge]

Have you tried with a lot of lag? Does it play nice changing speed outside of the CMC?

[obsidian cargo]

Let me test it again. I implemented this over 4 months ago. I was about to do lag and packet drop testing with my latest networking stuff.

I just finished the first half of replication for my Chaos destruction alternative. (destruction). Will be working on the opposite side (replicated repairing) in a little while.

[obsidian cargo]

Do you remember the console command to show net corrections?

Now that I'm looking at it more closely, I might have a micro stutter with my system

Found it!

p.NetShowCorrections 1

@fallow shadow Try ^ to get a better visual of your problem

Looks like my solution isn't as good as I remembered

[fallow shadow]

Alright! I will keep that in mind for tomorrow

[grim rain]

helllo anyone know how you would go about making a system like among us / garrys mod where u can select how many traitors is selected as an enemy and then setting that number of players as an enmy ?

[plush otter]

in a level's gamemode, how long will playerstate be kept after a player controller logs out? or is it kept till the server's game instance shuts down?

seems the controlled pawn is immediately destroyed

[latent heart]

It'll be gc'd at some point shortly after all references to it are gone.

I guess it should be destroyed as well? Is it not?

[plush otter]

Not sure I can still retrieve variables/components stored in it shortly after, and no pending destroy warning. Guess I'll do a test to see.

[static flare]

I'm adding custom rotation for the characters using quaternions to avoid gimbal lock, but am uncertain about how to apply the rotation in regards to replication.

Normal rotation input is handled in the Character/Pawn-class by calling AddController{Pitch/Yaw/Roll}Input(float), which replicates by default. It's adding Pitch/Yaw/Roll to the existing rotation instead of setting target rotation. I assume it is replicated like this to let all connected clients apply the rotation "offline" with some DeltaTime-interpolation to get a smooth rotation from origin to target, instead of just hard-setting the target-rotation per server tick, which would be experienced as jittery/laggy? (Though I guess the same could be achieved by sending the actual target-value, but I assume it has some unnecessary overhead and network-packet-size?)

However, if a single network packet is dropped, the "addition" to the rotation would be completely butterfly-effect out of sync over time, so I assume there's something "under the hood" that ensures that replication behaves correctly and syncs up at times?

Anyway, as I can't use the AddController{Pitch/Yaw/Roll}Input (because they're prone to gimbal lock), how should I apply quaternion rotation while also retaining replication of smooth rotation and ensure synced values?
(Per now I'm applying it with AddActorLocalRotation(..), but the question is if I should replicate the target-rotation, or the "aggregated" value I add to rotation, or a mix, or something completely different)

[grizzled stirrup]

Have an enum or bool stored on the PlayerState that specifies if a player is a traitor or not

[winged badger]

Not sure id use something as easily readable and replicated as PS for that

Whatever information clients have, they can pull out with a cheat

[grizzled stirrup]

Yeah I guess store serverside and only let the owning client know what THEY are until the end

[fathom aspen]

Put a breakpoint in AController::CleanupPlayerState and see if it's being hit

[solar stirrup]

@chrome bay Hey! Sorry for pinging you, just following up about yesterday's question on rep graph net cull distance checks. I'm currently implementing a way for nodes to mark specific actors as skipping net cull distance checks, and it's done for the _Default() replication path.

Do you think it'd be a good idea to also implement it in the _FastShared() replication path? I'm unsure since I haven't really meddled with it so far.

Thinking about making a PR for UE5 once I confirm it works fine

[latent heart]

Did you find out?!

[alpine owl]

Following my issue from #umg message
Why is my 3d widget button click event work in a solo environment and not in a client/host environment ?

By default I expect the 3d widget to spawn on every client and I can do a print string when the player click the button

Sorry for the ping but I have the same issue, did you find a solution for it ?

[chrome bay]

Yeah I think you'd need to do it for both for sure

[solar stirrup]

Pog

[chrome bay]

Any actor going down the shared path would skip it otherwise

[solar stirrup]

Dunno why Epic doesn't pass in the FConnectionGatherActorListParameters to the rep path