multiplayer

[grizzled stirrup]

It's easier for me to just do it for both in BeginPlay rather than needing a deferred spawn on server / separate call on the client

[winged badger]

that way if you get tempted to delay BeginPlay, the weapons will still have stats readable from the UI

[grizzled stirrup]

For this edge case it would make sense but I'm not doing it ever in my case as most of this happens at runtime when beginplay has already fired off

[winged badger]

you can't do it in BeginPlay on both

without the deferred spawn though

because server will call BeginPlay before you set the seed

[grizzled stirrup]

Oh right yeah sorry I mean the server would set the seed + manually call the OnRep and the client would auto call it when the seed replicates down

[winged badger]

provided world already started play

[grizzled stirrup]

I know bad practice and I should make a different func that OnRep calls

But yeah you are right

Client wouldn't have the replicated seed at begin play

[winged badger]

its just fairly annoying to debug

when server starts hitting OnRep_ breakpoints

[grizzled stirrup]

As you aren't sure if it's the client or the server calling it?

[winged badger]

yes

[grizzled stirrup]

Yeah I can see how that could be a big headache

[winged badger]

i mean, you can see it from callstack, but its still annoying

[grizzled stirrup]

Another thing I'm a bit curious about is that say you have this weapon with a seed and you move to another level via seamless travel, should you copy the seed over via CopyProperties or can I just copy the weapon pointer over and it'll remember the seed etc.?

Since it doesn't exist in the new level anymore at least spawned

Hard to think about when only the data should be transferred and a fresh weapon spawned, then inited with that seed or when the pointer itself should move, containing the data

[winged badger]

unless you plan on weapon having its own PlayerState

there is no CopyProperties

[grizzled stirrup]

I mean each player would copy it's specific equipped weapon in the PS

When traveling

[winged badger]

you can persist it entirely

[grizzled stirrup]

Yeah I might try that even though the pawns get destroyed

I suppose the weapon would then just be floating in space and could be re-equipped

[winged badger]

or you can have a seed, or a composite seed just written in your PS as inventory

[grizzled stirrup]

Yeah that's what I'm doing now

And it seems to work fine

Spawn a fresh weapon

[winged badger]

bonus points there, as you can regenerate the inventory on reconnect

[grizzled stirrup]

Get the seed from the PS

Same as the last level

[grizzled stirrup]

That's a great bonus

I'll keep doing that then thanks!

For games with inventory in general that needs to persist between levels but is not tied to a savegame, would this be the approach too? Store in the PS and move over via copyProprties?

[winged badger]

we keep our inventory and skill on PS for reconnects

with listen servers, connection is not as reliable

[grizzled stirrup]

Nice so when the player disconnects, their old PS stays around for X seconds

So if they reconnect their data is still there

[winged badger]

5 minutes

[grizzled stirrup]

That's great

I have to set that up

[winged badger]

thats already setup

engine does it for you

[grizzled stirrup]

Yeah I mean setup the rejoining and reiniting

[winged badger]

you might want to add some cleanup in APlayerState::OnDeactivated

[grizzled stirrup]

As my sessions are no longer joinable once they start

So I'm not sure how to get them back in

[winged badger]

and also restore it when Pawn is spawned with previously inactive PS

you can allow for rejoin

[grizzled stirrup]

Do you use the previously inactive PS or do you spawn a new one and copy the old properties over?

[grizzled stirrup]

Will this only apply to previously joined players and not any player searching for sessions?

[winged badger]

have the game save the session ID somewhere find that session even if its ongoing

[grizzled stirrup]

Good point will look into that

I'm thinking a simple form of host migration may be trivial with something along these lines

As in my case the entire level could restart

So I'd just need to cache state for each player each level

[winged badger]

there is no simple form of host migration 😄

[grizzled stirrup]

Yeah the issue being moving the connections over

[winged badger]

but you also can't persist any actors

as you are doing hard travel

[grizzled stirrup]

that's fine in my case it's all deterministic and the level would be restarted

[winged badger]

including PSs

[grizzled stirrup]

Yeah I'd have to manually save temp data in the GI per player

To reinit them

But the hardest part still being probably nominating another player to host and getting the previous players in their lobby

[winged badger]

use a GI subsystem, or LocalPlayer if you have any form of local MP

[grizzled stirrup]

I'd just have a simple struct most likely, there's really not a lot saved per player in my case

Equipped stuff and a very small inventory

[golden nest]

Hi, can someone help me solving a rep notify problem?

[winged badger]

maybe if you tell us what it is

[golden nest]

I have this event

and the rep notify

[winged badger]

always screenshot so its visible which BP is it

[golden nest]

ok

Thats the base character

[winged badger]

k

widgets do not replicate

[golden nest]

No, but i have a widget component on the head of my player

[winged badger]

that one would replicate, but its a part of the CDO

so it would happen very early

[golden nest]

But when i call the "SetName" from the PS it does not update on the server

[winged badger]

there is no guarantee a playerstate actor will have replicated by then

[golden nest]

CDO?

[winged badger]

infact, because of the low net priority PS has by default it very likely wouldn't have

class default object

that OnRep will fire once, before BeginPlay

and the widget component itself doesn't need to be replicated at all

you want to move that to OnRep_PlayerState

[grizzled stirrup]

In BP the server does not call the OnRep func automatically afaik, right @winged badger ?

[winged badger]

but that will just replicate a pointer to CDO component

on a priority 3 actor

and is relying on PS, a priority 1 actor, having replicated as an actor by then

which fails 99%+ of the time

[grizzled stirrup]

Sorry misread his issue

[golden nest]

Wow wow wow

To much info hahaha

[winged badger]

TL;DR; do not replicate widget component, you get nothing by that

it will exist, as its part of the CDO

hook that banner logic into OnRep_PlayerState

[golden nest]

I'm not replicating the widget component

[winged badger]

as you need a working playerstate for it to work

[golden nest]

Ok, so when i update the player state, i call the "SetName"

[winged badger]

pretty much

i imagine you get some accessed none errors there

[golden nest]

And it will call the event on the server too?

[winged badger]

with blueprints, yes, unfortunately, it will

[golden nest]

Cause what i have now is only the clients updating the name nor the server

[winged badger]

the blueprint OnRep is not a replication callback, its a hack presenting a property changed callback as a replication callback

so it will fire on server as well

[golden nest]

Ok, thanks ❤️

[winged badger]

c++ OnRep won't fire on server

consistency ❤️

[tidal fiber]

For now, we have a simple throttling mechanism for multicast events: a multicast function will not replicate more than twice in a given Actor's network update period.
(https://docs.unrealengine.com/4.27/en-US/InteractiveExperiences/Networking/Actors/RPCs/)
does this mean that for a single multicast function in a given network update period, the server will send the rpc to at most 2 clients?

[winged badger]

no

there is no mechanic to track that in the engine

it will always send the MC to all relevant clients simultaneously

[tidal fiber]

how should I interpret the quote?

[golden nest]

So i did what u said, and call the "SetName" from the player state, but the server keeps avoiding the replication

@winged badger

[golden nest]

Can i override a OnRepNotify Function?

[peak sentinel]

If it is virtual yes

[golden nest]

in bp?

[peak sentinel]

Override the one with _Implementation suffix

[peak sentinel]

Maybe, never tried

But dont think so

[golden nest]

i can't make the server call the rep notify

Is like it never call the "Set" on the variable replicated

[pallid token]

I have a bow class, that has a ReleaseBow_Server() RPC. When this RPC is called from client-owned bow, it does not work, but when it's called from the server-owned bow on a listen server it does work. If I put the Server RPC inside the character class, it does work but that won't work for my purposes. The Bow is bSetReplicates = true

[clever plinth]

I'm not an expert in this area, but I think your bow class needs to be owned by something that has a network connection (like the player controller, or its pawn) in order for RPCs to work.

[rancid flame]

GetLifetimeReplicatedProps should just be defined in the .cpp right? and not the .h? why is this complaining about an unresolved external symbol?
https://gist.github.com/benui-dev/3551a72399d10c3a59dbeb9565519624

[clever plinth]

Your error corresponds to a different class from the one in the h/c++ files (AMyPlayerState vs AMyGameStateBase)

[rancid flame]

I'm so sorry

[clever plinth]

Happens to everybody

@rancid flame Also, now that I look again, you want a declaration for your method in the header as well as a definition in the C++ file. Typically in header:
virtual void GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const override;

Then in cpp file:

void MyClassName::GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const {
}

[rancid flame]

Yeah I thought so too but this tutorial says you don't need it, and weirdly it does compile without it in the header? I've used UE4 for years but this is my first time touching network-related code.
Also this tutorial is from like 5+ years ago sooo

[silent valley]

It's added implicitly to the header by Unreal build tool as soon as you make a property in the class Replicated.

[clever plinth]

Is it a known issue that Unreal's "Network Emulation" settings produce higher pings than the latency settings would suggest?

[peak sentinel]

You mean the ones we set on editor preferences?

[clever plinth]

Yes. The numbers there seem about 3-4x lower than the measured ping I see

[peak sentinel]

10 packetlag is almost equal to 25 ping

I'm not sure though, but it should be very similar to that value

Other than that, normal 'ping' variable on playerstate is not totally accurate

There might be multiple reasons why you measured the unexpected value

[peak sentinel]

Ping * 4.f is actual ping but still not %100 equal

[clever plinth]

I'm using the value reported by stat net.

@peak sentinel Are the values in the editor preferences packetlag and what does that term mean in this context?

[peak sentinel]

Packet lag generates latency between network updates, network emulation sets a pktlag value to simulate the latency

[clever plinth]

Ok, the 10 -> 25 multiplier effect you mentioned above describes some of what I'm seeing. For example if I pick the "Average" profile in the editor preferences (30-60 latency) I see ~200ms ping.

[peak sentinel]

Average can be considered as bad though, for example if you are developing a fast paced FPS shooter you are right to expect maximum 125-150 ping from your players

Average settings also set high amount of packet loss

But a good quality of netcode should run perfectly on those settings

[clever plinth]

Pardon my naivete here (new to network games), but the average profile sets 1% packet loss. Is that considered high?

[peak sentinel]

Sorry my bad, thats not that high

I confused with my own settings

Its a good value to test

[clever plinth]

@lapis flint If I can ask another dumb question: At 200ms ping I'm seeing pretty noticeable jitter/jumping on my client side if I change directions quick enough (for example mashing the arrow keys quasi randomly, or turning around rapidly with the mouse). Anecdotally it seemed higher than what I had seen in other games I've played, so I've been reading through the character movement code and dumping values to chart/plot them. For example I see corrections on the client on the order of 50cm-100cm while traveling 600cm/s. That said I lack the experience to really say if this is typical. Is 200ms in the domain of "unmanageable" for a first-person style game?

[peak sentinel]

I never saw that intense jitterings on my own project with higher value of ping

'Turning around rapidly with mouse' can cause jitterings

Because if you dont factor lag compensation methods into your code it will take some time to arrive to other clients and server and if the latency is high it will be noticeable

But just using "add movement input" and such things should not cause any intense visible jitter

Because CharacterMovementComponent handles those things for you

If have a insane amount of velocity, you can try to tweak correction variables

For example, each server update server checks the distance of your old location and newly arrived location data

If it is higher than 256 units, server will teleport you instantly

Because it will think you're cheating or something really went wrong so it should correct your position

I tried to answer the question generally, mostly its about context

So the answer should be case-specific normally

Maybe client sets its position to A then sends it to server, but last position in the server is B and after 250ms server sent the B position and client reverted back to B

If you havent yet, I recommend studying "prediction" and "lag-compensation" topics for a while

Then take a look at to ShooterGame project (you can find it on Epic Games Launcher) and UnrealTournament repo

[clever plinth]

Thanks, I'll read about this a bit. I have been using the ShooterGame example as a reference for my project. I can see the jumps/jitter in ShooterGame as well if I push the ping up to around 200. My movement component is very similar (different speeds, but same class).

[peak sentinel]

ShooterGame doesnt include prediction methods at all, its only for demonstrating some concepts. Its actually outdated 😅

Try Unreal Tournament instead

But in any case, Character Movement should not cause any jitters if you tweak the correction settings

It it is, then you're doing something wrong

There are just some very specific-cases CMC fails with humanoid movement

[clever plinth]

Good tip, I'll check out UT

[peak sentinel]

This article does not explain Unreal Engine way of doing this but general idea of things work in any multiplayer games, you can also analyze this: https://www.gabrielgambetta.com/client-server-game-architecture.html (it has 4 parts)

[rancid flame]

I'm hoping someone can help me understand some Unreal multiplayer logic.
I've got a blank project and I have created a custom APlayerController subclass, with a tick function that calls GEngine->AddOnScreenDebugMessage to print its name.
In the editor, when I click Play in Viewport, Number of Players 2, Play as Listen Server, 3 messages get printed every tick:

MyPlayerController_0
MyPlayerController_0
MyPlayerController_1

In the World Outliner there are only 2 player controller instances, why does it seem like MyPlayerController_0 being ticked twice?
Similarly if I set a breakpoint in the tick, I can see 3 different AMyPlayerControllers instances 3 different memory addresses.
When I choose Play as Client, there are 4 messages printed.

[grizzled stirrup]

Does an array with no elements as part of a replicated struct use any bandwidth when replicating?

[rancid flame]

Oh, I should have used PlayerTick not Tick, the comment explains why

/* PlayerTick is only called if the PlayerController has a PlayerInput object.  Therefore, it will not be called on servers for non-locally controlled playercontrollers. */

[peak sentinel]

Structs only sends the changed element's data so it should not matter afaik

Arrays also send the only changed element

[grizzled stirrup]

Perfect thank you

[pallid token]

I asked earlier, but the answer I got didn't help, but I do appreciate it. So, I have a Character where I have,

void MyCharacter::BeginAttack()
{
  Bow->FireBow();
}

In Bow, I have

void MyBow::FireBow()
{
  FireBow_Server();
}
void MyBow::FireBow_Server_Implementation()
{
  //Spawns the arrow
}

Firebow_Server() is never called on the server when the client is firing the bow, but it is called on a Listen Server.

However, this works,

void MyCharacter::BeginAttack()
{
  BeginAttack_Server();
}
void MyCharacter::BeginAttack_Server_Implementation()
{
  Bow->FireBow();
}

Bow Class

void MyBow::FireBow()
{
  //Spawns the Arrow
}

I do have the owner of Bow set as the Character.

The reason I need it to work as the former and not the latter is because I have a socket on the bow where the arrow spawns, and when I am aiming the bow, the animation doesn't play on the server, so the socket is in the wrong place. I need to pass the socket position from the client to the server (Which isn't shown in the code above because I was trying to be concise).

[peak sentinel]

So simply sockets are different between client and server right?

Its probably not about your logic, animations sometimes doesnt run on server

[clever plinth]

@peak sentinel Regarding previous convo, this is what I meant by "jitter". I realized I probably worded it poorly. What I am seeing is discrete corrections in client position: https://i.imgur.com/WXh6OJb.png In this example I plotted server/client velocity and position (x-axis, in this case) after time-aligning them. Around 37 seconds in this example server velocity starts to drift away from client, and then a correction is sent to the client. These happen in the absence of collisions or any physics interactions (just walking on a flat plane). In any case, I'm still digging into it, but I wanted to provide clarification on what I was seeing since "jitter" probably doesn't capture it correctly. It's more like periodic jumps that can be spaced fairly far apart, but are pretty reproducible under 100-200ms of latency.

[pallid token]

Yeah, that's why I am trying to combat. I need to pass the socket location from the client to the server. It's easier to do that from within the bow actor, than to get the socket from the bow Mesh then pass it to the bow actor within the Character class.

[cyan bane]

I'd like to replicate position variables in/relevant to the Actor class without overriding the Actor class and making my own. Is the best way to do this just to make some sort of ActorNetworkComponent and do it all in there?

[peak sentinel]

Wow how did you even get the data to draw that graph lol 😄 Anyway, I'm really alien to the possible solution or anything about what could possibly going wrong, it can be even pretty expected considering the packet losses happen sometimes. What makes me think about this option is packet loss rate, to have an idea about that, you can set packet loss to 0 and increase packet lag a little so we can see if its happening because of it or not. Also ensure you're just using AddMovementInput and not using any external logic like sprinting etc.

[peak sentinel]

One sec

Sorry wrong tag

[peak sentinel]

set VisibilityBasedAnimTickOption to AlwaysTickPoseAndRefreshBones

this way server will run all animations

Anyway if thats not a solution for you, what I would do is have a replicated on rep variable named ArrowSocketLocation (FVector_NetQuantize100) and just update it from server, so client will only call an RPC and pass the ArrowSocketLocation value to server and server will update it, then call OnRep

And every connection will get forward vector of ArrowSocketLocation and fire it, simulate theirselves

But thats a very deterministic way

[plucky prairie]

any point me in the right direction for showing any enemy health bar but only on the client that did damage to it? I've got everything set up for checking who did the damage but cant work out how to show a widget spawned on another actor on just 1 client

[dark edge]

Where would be the place to store something like all the bank accounts for characters and factions in an RP game?

[rancid flame]

Isn't there an Originator property for damage dealt? Couldn't you use that?

[sinful tree]

I would do bank accounts as a component on the player controller simply to reduce excess network traffic replicating it through player state as other players don't really need to know about other's bank accounts in most cases.

[dark edge]

They need to be persistent and also groups can have a bank account. It has to all be aggregated somewhere as it's not really a PLAYER's bank account, but rather a characters, and is associated by UUID to a bank card. That is, a card can be stolen and used etc.

It'll just be an association of a UUID to a value, and possibly to the UUIDs of the bank cards themselves.

We've got a bit of a weird item system but the crux of the whole thing is that every item has a UUID, and can be individually distinguished. Enables all sorts of mechanics like, a police officer can investigate a scene and register the unique weapon that caused the crime, not just the type.

[harsh lintel]

The game uses a dedicated server, I have an actor that is replicated, I'm doing this in the blueprint, when I PIE as client, the actor is destroyed, but when playing the packaged game/server the actor is not destroyed

[sinful tree]

Maybe a single bank system component on game state in that case, and within it contains a map that stores your account UUID to structure containing an array of items within the account.

[ebon plume]

I created a system that uses a line trace from the player to the ground.

In short: my player floats around based off the specs I give it and dynamically changes height based on the terrain elevation.

The way it's hovering is by (adding force) I also add force to move it horizontally and vertically. All this is done in event tick.

This works amazing !!! .... Locally... it's super cool. But unusable when I try to replicate it.

I don't want to run all the physics or line tracing on the server , don't think that would be a good idea.

So we did all the physics and calculations locally and then on the server, we updated the location and rotation of the player.

This does not work.
The rotation works fine.
The hovering effect and movement is unbelievably laggy and unusable.

[kindred widget]

<@&213101288538374145>

[rich locust]

How do you create a very low size dedicated server build ?

Is there a guide on about it online

Lets say I have over 50+ gb build

but dedicated server only takes about 2 GBs

how do you do this ?

[tidal fiber]

if you replicate a pointer to an object that doesn't yet exist on the client, will the pointer be nullptr on the client? is this situation even possible?

[winged badger]

ofc it is

common occurence @tidal fiber is replicating a pointer to PlayerState, the PS Actor, having lower NetPriority, will generally replicate several frames to few seconds after the Controller and Pawn

until it does, the NetGUID cannot be resolved, and any replicated variables holding a pointer to it are nullptr

note that replication callbacks will fire after NetGUID is resolved though

[tidal fiber]

I see, thank you

[silent valley]

Dedicated server usually strips things like textures out automatically, so a Server build should be significantly smaller than a Game package.

[rich locust]

when I added "Texture" here and get a build

I got crash immediately

I am trying other stuff as well tho

[silent valley]

if your server build is 50GB, how big is your game package?

[rich locust]

same

lol 😄

I am trying to make an ACTUAL server build

I know im dumb

[silent valley]

how are you making the build?

fwiw, my game build is 8.5Gb and server build is 4Gb

[rich locust]

client build, then add the server target files to binaries

[silent valley]

oh

[rich locust]

now im trying to go for stripped build

[silent valley]

You need to make a new target for Server build

[rich locust]

We do

but we dont actually package for it

😄

But Im on it at the moment

[silent valley]

ohhh ok

well when you do that it should be a lot smaller 😄

[regal storm]

For reference, cannonballs are at about 440 meters per second, give or take for wind, etc.

So about half the speed of an average bullet

[hexed pewter]

I recently stumble across this excellent blog post by Exi
https://cedric-neukirchen.net/2021/06/27/ue4-multiplayer-sessions-in-c/

It proved very helpful as I'm just trying to incorporate session management in my own project. I ended up stealing literally the whole subsystem.

Now I have an issue, where I have all my main menu stuff in 1 module, and the upper mentioned subsystem ended up in other module (main module). I think I could easily connect these two by exposing delegates from my main menu module, however I'm not completely sure what class to use as a bridge, all that comes to my mind is gameinstance. Are there any other candidates for that job?

[violet sentinel]

how do usually multiplayer lobbies setup with dedicated servers?
currently the player creates steam session and opens lobby level
rest of players join the session
host configures session and launches, players seamless travel to chosen game map.

how would it be with dedicated server? searching an empty instance for first player to join on or creating them on demand with some cloud service?
(never dealt with DS before, only read basic details so far)

[silent valley]

If your game is session based then usually a load balancing type system manages a pool of servers and has the ability to spin up more on demand. See Gamelift, PlayFab etc.

[violet sentinel]

yeah, was reading about it

but what about "ownership", if nobody will be host how to decide who will be "master" allowed for setting up lobby settings. or it can be done via gamelist/playfab to know who requested instance to be master.
can't have everyone be allowed to modify lobby settings but some owner

[silent valley]

So any DS registers itself with some kind of service, whether public matchmaking service, or registers privately with load balancer which dishes out the connections to clients.

Other than that, DS works just like listen server but with no clients.

[ebon plume]

Why can't you simply update the location and rotation of an actor on the server?

The actor moves locally via physics and using applied force.

Trying to call on the server to update just the location and rotation does not work at all. The lag is tremendous

[sinful tree]

If actors are replicated from the server, then their movement should be getting made on the server. The client should never be pre-emptively moving a server controlled actor and then telling the server where to move it to.

[ebon plume]

Yeah and the problem with me doing this is the issue / difficulty of replicating physics :/

[twin juniper]

Pretty new to multiplayer, but the character on client can't sprint, only the host can. anyone know the fix?

[graceful mango]

What could be the issue? I cant connect to dedicated server and to listen server, having just permanent black screen

[wheat magnet]

can you try to press tilde ~ keyboard button ( to make sure it is working, not freezed )

[graceful mango]

console works, when i am trying to connect manually it opens main menu (via open ip)

i should say that blank project works, i cant connect to local listen server in blank project

[wheat magnet]

so you are opening using from console keyboard? for example open <level/ip>

[graceful mango]

first i am trying to use "play as client and launch dedicated server "

it isnt working

open level/ip drops me to main menu

on 4.23 ver all worked good

this is 4.27

[wheat magnet]

1: You may need to set up the maps in project->map&modes
2: or you need to lookup into server travelling ( make sure it is working )

make sure everything is correct setup in project maps and mode settings

i see, there is error " invalid steam id ", maybe this causing the issue?

[graceful mango]

i found

23:53:07 [LogNet] Error! UEngine::BroadcastNetworkFailure: FailureType = PendingConnectionFailure, ErrorString = Your connection to the host has been lost., Driver = PendingNetDriver IpNetDriver_5

23:53:07 [LogNetSerialization] Error! FBitReader::SetOverflowed() called! (ReadLen: 32, Remaining: 1, Max: 1)

and this is on the server side LogNet: Warning: PacketHander isn't fully initialized and also didn't fully consume a packet! This will cause the connection to try to send a packet before the initial packet sequence has been established. Ignoring. Connection: [UNetConnection] RemoteAddr: 127.0.0.1:63311, Name: SteamNetConnection_0, Driver: GameNetDriver SteamNetDriver_0, IsServer: YES, PC: NULL, Owner: NULL, UniqueId: INVALID

[graceful mango]

hm but it wasnt presented in 4.23

[wheat magnet]

you can also change steam id to 480

https://medium.com/swlh/ue4-tutorial-how-to-connect-a-multiplayer-game-with-steam-ccc89bd8d8a9

follow this article, there might be something you've missed, or need to modify/update

also try to google your error logs, you will find solution

[graceful mango]

@wheat magnet Alright i have found the issue

Epic Games has broken SteamOnlineSubmodule while making EOS

[wheat magnet]

ok great

[fading birch]

fwiw, that blog is the top pin in #online-subsystems

to answer your question, I personally use a game instance subsystem for that exact reason.

It's accessible anywhere

[tidal fiber]

can you put an FFastArraySerializer inside a struct and replicate the entire struct?

[winged badger]

seems like you should rethink what goes into what module there

if any of your modules at all has a or needs a dependency to main module, you did it wrong

[fluid summit]

Hi, I am having some troubles to trigger event with event dispatchers from server to remote, do they work on Mp?

[grand stratus]

guys if iam using seamless travel

does a new player controller spawn for each player

or the same controller stat

[fluid summit]

Not sure on c++, but on bp you can réplicate them with no problem

I would asume its doable on c++ if not available as default

[glass vector]

are player input events (ie, defined axis and key binding events) executed on the server automatically?

do they get executed on both client and server simultaneously?

does this BP node run on the server when the player presses right

[sinful tree]

No. Any input is only executed on the client. In most of the examples the engine gives you, they're using the character movement component which replicates the input for you automatically.

[ebon plume]

I've been here asking the same stuff quite a lot. Sorry.

But I have smoothed the physics finally and it looks pretty nice. Even with network emulation with some pretty nasty values.

I am curious though...

Is it okay to be adding force with event tick on the server (the entire time) its the only way to achieve the dynamic hover physics I want.

My thought is to run all the "add force" and physics calculations on the server, and then update the clients position rather than trying to add force on both client and server.

[hoary lark]

You kinda have two options... you can give up client-side prediction and pass player input to the server, let the server run the game, and update clients... Or you can build a customized prediction system like how CMC does it. I created a physically accurate jetpack character with a modified CMC that worked well in MP. I did allow partial client authority for minor deviations.

Lot of work for a full custom system with prediction

[thin stratus]

Last time I did networked hovering I coded a custom movement component same way the CMC works

[glass vector]

what is cmc

[hexed pewter]

characterMovementComponent

[glass vector]

thx

[pallid mesa]

How do I skip simulated proxies on ReplicateSubobjects?

can I simply do a Role check?

[thin stratus]

Does it not allow you to do that via the DOREPLIFETIME Condition of the Subobject?

[pallid mesa]

not exaaactly per se... look what I'm trying to do 😄

Might be unnecesary given rep graph exists. But I'm learning and I would like to make it work

[glass vector]

for apply damage Blueprint node, am I able to call it on the client, or do I have to use an RPC to call on the server?

[thin stratus]

Generally damage is processed only on the Server

Using those nodes or not, you want to make sure damage is not process by clients or directly requested.

Usually you only RPC for the Inputs of the client (e.g. pressed left mouse button to fire a weapon) and the whole weapon fire, line trace, project, whatever logic that ultimately deals damage would run on the server. +- some local only version of the same code that is used to predict hit effects

[fleet viper]

the spawn gun function doesnt get called on the server, tho it has authority, anybody knows why?

it works on client tho

[fleet viper]

also this just happends with one of my gamemode it works with every other gamemode

[fluid summit]

I'm getting a Rep Notify that is only triggering on the server side, is that okey?

[fleet viper]

nvm controllers werent init yet -.-

[fleet viper]

dont count me on that but i think that is how its supposed to work yeah

[fluid summit]

oh i tought it was exactly the opposite, that they are triggered when something changes on server side that is repnotify, so that you can update it on the clients (so only triggers on client)

[thin stratus]

RepNotify in cpp only call on clients. In BPs they call on both

[fluid summit]

I'm trying to use it in order to update the UI of the inventory, but i can't get to update the UI correctly, it seems like the data from the inventory is always one update behind and the rep notify triggers only on server.
Any advice on how to approach this?

[wheat magnet]

does session works over internet?

for example this node, does this works over internet?

[woeful pebble]

why does attachcomponenttocomponent not work on a server event?

[dark edge]

@wheat magnet assuming you have a subsystem to handle it, yes.

Steam, EOS, etc

[wheat magnet]

so session is just a way to join players together?

[mossy venture]

Essentially yes. Without needing to use a direct network address.

[wheat magnet]

i have question regarding this session node. i tested this node with lan, it works fine. But when i build dedicated server, after hosting the server, i can press the ~ keyboard button and type "open <ip>" then i can join server. But how these session node works with dedicated server?

[wheat magnet]

so you mean like open <ip> right?

[mossy venture]

Yes. Instead of that you find the session instead, and then join with the session id.

[wheat magnet]

when i build the dedicated server, which method should i use to join player in lobby?

[mossy venture]

JoinSession.

[wheat magnet]

i mostly tested multiplayer with LAN

[wheat magnet]

Thanks, does i also need the steam or EOS?

[mossy venture]

There isn't much difference from what I recall. Although you need to switch join by LAN off of course. I'm not an expert though and don't remember everything.

[wheat magnet]

i want to test game over internet

[mossy venture]

I believe you do need to use a different online subsystem from NULL for online, but I cannot remember fully.

[wheat magnet]

Yes in the book there is mentioned online subsystem from NULL only works over LAN, not internet

[mossy venture]

Then I believe you have your answer. Steam is probably easier to do, it has better documentation.

[wheat magnet]

So these session nodes also works over internet, right?

[mossy venture]

Yes.

[wheat magnet]

what is the best way/practices to test and build the game with dedicated server

[mossy venture]

I don't know, sorry.

[wheat magnet]

ok thank you

i remember when i was building and testing the game with dedicated server, the engine was recompiling each time and it was taking hours to building the dedicated server

[fading birch]

It shouldn't be doing that @wheat magnet .

As far as online subsystems go, there's some info in #online-subsystems about it.

[unborn trellis]

In my Player Controller, I have this custom event where a widget will display indicating the location of when someone is damaged. However, if the Player shoots someone and it hits, the indicator (sphere) spawns on the owning player, What i want it to do is spawn the sphere at the location of whoever is dealing the damage. I can send a video showing what i mean better

[fading birch]

you don't need to package a dedicated server to test it either. You can just launch your project with -log -server and you'll be right as rain.

[fading birch]

Player controllers only exist between the owning player and the server. You should move that to a player state, which is replicated to all clients.

[tidal fiber]

if you've built a networked game and want to add a singleplayer mode, is there an easy way to emulate singleplayer by running a listen server and connecting an AI controller? can anyone point me to search terms / resources about this?

[unborn trellis]

Okay, can i send my video anyway showing my problem?

[fading birch]

just drop it in here

[unborn trellis]

So essentially, it works, as in, the rotation when looking around the sphere, but the location at where it spawns is on the person receiving the damage, not who dealt it.

[fading birch]

single player just lets the client act as authority. Should be alright.

[tidal fiber]

thanks

[unborn trellis]

is that how i can get the damage causer's location? in the player state?

[fading birch]

you would need to get it off of the pawn

[unborn trellis]

like this? (this is in the player controller)

[fading birch]

I would check that hit location

that would give you your pawn

[unborn trellis]

i want the enemy pawn

[tight glen]

quick question. Where in the heck is the option to turn on seamless travel for maps. Trying to finish my lobby -> game start and I can't for the life of me find this setting. I thought you had to enable something from the project settings and then there were settings in the map itself but I can't seem to find them. Everything I find talks about the Umap settings but I know I've done this in straight up BP before

[fading birch]

then i would move this to the player state

gamemode @tight glen

[unborn trellis]

would it still be the same blueprint? or do i need to alter it?

[fading birch]

alter it most likely

[unborn trellis]

how could i alter it for it??

[fading birch]

how are you getting this hit location in the first place?

if it's running on the server, you can do it from the controller just fine

[tight glen]

THANKS! You're a saint and a scholar : b

[unborn trellis]

it is i believe

[unborn trellis]

This is how im dealing the damage. So when the player is hit, the health goes down and then the "show hitcircle" blueprint runs (in the player controller)

[fading birch]

just pass in the location of the damage causer to that function

and should be fine

[unborn trellis]

nothing shows up for damage causer

[twilit radish]

Why would you need to replicate something that often?

Also changing the priority / update frequency doesn’t guarantee that it will be replicated that fast anyway because of bandwidth limitations, if there’s no space left for it or other things have a higher priority it may not get replicated immediately.

[unborn trellis]

still having troubles with this damage indicator :/

[fading birch]

You need to pass in the damage causer when you apply the damage.

[tight glen]

one other question. Don't you have to somehow copy the playerstate properties when you seamless travel? Even if absolute travel is false?

[unborn trellis]

idk who to cast to tho. When i type cast, everything shows up

[fading birch]

Where are you doing the trace to apply damage?

[unborn trellis]

in the weapon blueprint

[fading birch]

Then just pass the weapon itself

Onreps do that

[unborn trellis]

but can't i have it spawn on the player tho?

[fading birch]

You can. You just need to grab the pawn that the weapon belongs to

What are you trying to replicate that needs to be done all the time?

Thats just not feasible

[unborn trellis]

when i cast from the instigated by, it spawns on whoever is dealing the damage. That's what i want, but now i somehow need it so the indicator displays on the one recieving the damage.

[fading birch]

So damage only runs on the server.

You'll need to call a client RPC on the controller to display that info to the person who took damage.

[unborn trellis]

what does RPC stand for?

[fading birch]

Remote Procedure Call

I would give the multi-player compendium a read

[unborn trellis]

ill have to look at this another time. :/

because i gtg

[fading birch]

Ah. Physics are a mess to replicate. I would just have each client do their own physics and have the server occasionally correct it as needed.

[tight glen]

Check out the multiplayer starter/replication tutorial from the epic live learning. They go into RPC's, authorative vs non, replciation, owner, and more. It's like an hour long and I think it would really help out.

does the physics matter for gameplay? If it doesn't and it's just for apperance then just run on each client.

mind giving an example of what you are tyring to do?

[unborn trellis]

I'm gonna take a crack at it either tomorrow or Tuesday

[twilit radish]

You can replicate things as many times as you want to clients but at the end of the day if latency pops up it will fall apart regardless of how often you send something, there's nothing you can do about people their bad internet. I would say try to rather build something that still updates often but can also be corrected if needed, this is in general the pain with physics and multiplayer because it just never fully works out. That's why correction is a thing 🙂

[tight glen]

Where's the setting/list of actors that get copied when you travel? Can't seem to find it in the docs or anywehere but they do reference it.

[twilit radish]

https://docs.unrealengine.com/4.26/en-US/API/Runtime/Engine/GameFramework/AGameModeBase/GetSeamlessTravelActorList/

[tight glen]

I thought you can edit or add things to it without c++ though

[twilit radish]

I'm not sure if BP has the option, someone else will have to answer that if they happen to know.

[tight glen]

ill double check if not then c++ it is :b. thanks for the help Thom

[mossy venture]

Does anyone have a guide on UI for multiplayer? I'm trying to destroy a widget on all clients, when going from lobby to the game map. However having issues with getting anything to work. I got a multicast running from the gamemode when it's ready to remove the widget, with the widget removal code inside. It doesn't seem to be doing anything though.

[tight glen]

widgets only run on clients

just do like this

[mossy venture]

Yes I know.

[tight glen]

remove from parent

[twilit radish]

The GameMode also isn't available on clients, it only exists on the server. So running a multicast in there won't do anything.

[mossy venture]

OK looks like I'm confused what a multicast is then.

So should I be putting the multicast on the controller instead, and then having the gamemode call it, when the widgets are ready to be removed?

[twilit radish]

About what a multicast is, it's a form of an RPC that can be called on the server to invoke the called function on all clients and the server it self. Since the GameMode isn't replicated down to clients it can never be called on clients since they don't have a GameMode instance. You'll need to place it somewhere where it makes sense for your game and which is shared across all clients. This is btw a helpful little overview of RPCs: https://docs.unrealengine.com/4.27/en-US/InteractiveExperiences/Networking/Actors/RPCs/

[wheat magnet]

link to unreal networking book :https://cedric-neukirchen.net/

[twilit radish]

I personally think an RPC may not even be the best way because I guess it should be connected to some state, if the game is in the lobby something probably already tells players they are in the lobby.

[mossy venture]

OK that is what I thought. I wasn't taking into account that it only replicates from the object it is called from.

Yeah I was thinking it might be easier to just have a variable that gets set when out of lobby.

[twilit radish]

You could consider setting up a general state for your game, so when people are in the lobby, when the game is about to start, when the game has started, when it has ended etc. (or whatever makes sense for your game). Then you only would ever need to refer to those changes / the state for these kinds of things and that probably will save you a lot of effort down the line as well 🙂

So simply said something that indicates what the current status of the game is, which also gets replicated down to clients.

[mossy venture]

@twilit radish @wheat magnet Thanks for the help! Will look into using the game state instead with a variable. Should be a lot easier.

[twilit radish]

Good luck! 👍

[wheat magnet]

it doesn't support with dedicated server, what exact mean by this

so how session nodes works over internet?

[mossy venture]

I don't know about dedicated server. But Session nodes will work over the internet with dedicated or listen server.

[wheat magnet]

ok thanks

[lofty abyss]

While discussing a replication related issue on a locomotion system plugin, someone told he solved the issue by using dedicated server, and that was the reply he got

[fading birch]

what is that in reference to? Also this discussion should be happening in #online-subsystems

[unborn trellis]

So i decided to try this out. The good news is that When the client shoots the server, on the server screen, the damage indicator works as it should (the sphere spawns at the location of the client's weapon). However, when the Server shoots the client, the widget displays but the location isn't updated.

[fading birch]

you'll have to handle that differently as you're using a listen server setup

[unborn trellis]

i am getting this error tho

[mossy venture]

Probably the listen server where it's not getting set, due to no replication.

[unborn trellis]

the widget is created on the client side

2 seconds, its better with a video lol

[fading birch]

that doesn't matter

you're using a listen server

meaning the host is the server

you'll need to handle it differently

[mossy venture]

It's still trying to access a variable on the server though, right?

[fading birch]

with that in mind

[unborn trellis]

any suggestions on how i could make it work??

[mossy venture]

By setting the DamageCauserRef variable on the server too basically.

Although your listen server is a client too, it's predominantly a server.

[unborn trellis]

im not too sure how to tackle it :/

although im getting closer with getting it half working

[mossy venture]

Get the local player on the server and set the variable.

[unborn trellis]

oh bruh, i think i got it working. I had to make my damage causer variable replicated 🤦‍♂️

yeah it's working now :P

thank you @fading birch and @mossy venture 👍

although i am still getting an error :/

so like, it displays and works on the client, but this error comes up

[mossy venture]

Somewhere it's accessing DamageCauserRef when it's not been set.

Maybe you're missing an instigator somewhere. Assuming you're using UE4's damage system. Although it could be several things.

[tight glen]

throw in a breakpoint and follow it back to see what is causing the none

[unborn trellis]

which node am i setting the breakpoint?

[mossy venture]

Just after where you're meant to be setting DamageCauserRef.

[unborn trellis]

so what im seeing is, on the first hit, the widget doesnt display, but then when the second shot hits, the widget gets displayed

for the client

[mossy venture]

Sounds like somewhere you're not setting DamageCauserRef before you try to access it.

you can put if (DamageCauserRef) before you use it to avoid the error. Although it won't tell you where you're missing setting it.

[unborn trellis]

seems like the error only happens when im using the Player Controller custom event

[mossy venture]

Sorry an isvalid on DamagerCauserRef. Forget you're using BP.

[tight glen]

set it on the one that throws the error then you can follow back to see why the value is none. Make sure it is getting set/populated

[unborn trellis]

never mind, it throws an error either way

[tight glen]

printscreen your blueprint

[unborn trellis]

this is in the Character Blueprint

[tight glen]

well looks like there is no way to access the seamlesstravelactor list unless you use c++ and for some reason player controller mesh isn't being saved even with seamless travel enabled. Anyone have an idea why?

put breakpoints on them all and see if they have valid inputs

im guessing the first cast breaks though

[unborn trellis]

when you say valid, as soon as it hits, the whole game goes grey right?

[tight glen]

yeah that means it hit the break poiint

point

brb in a game XD

[unborn trellis]

oh this is interesting

better if i record

[mossy venture]

Sorry no. Sounds complicated.

[unborn trellis]

So when i have 3 players, i shot the 3rd player, it didnt display the widget, but after the second shot, then the breakpoint initialised

[tidal fiber]

what is the "rpc overhead for components"?

[tight glen]

hm I nthink you probably want to check with server to see if it was hit

and then if it was the server tells the client to create the widget

otherwise you may get into a situation where there are hit detections but the server doesn't register them

also what calls the client hit circle?

[tidal fiber]

I see, thanks

[peak sentinel]

Its not worth to avoid it if you need to use RPCs in components but CharacterMovementComponent is a very critical system for projects thats why Epic tries too hard to optimize it in any means

Unless you have too many things or gameplay-critical things its fine imo

[tight glen]

@thin stratus Hate to ping you but just wanted your input on how to get seamless travel working with playerstates/controllers. Not sure if there is an easy way to troubleshoot as well since it only works in standalone mode so when trying to travel I can put in breakpoints or anything.

[fading birch]

you can breakpoint standalone just fine. Just attach your debugger to your standalone process.

[tight glen]

in visual studio or ue4?

[tight glen]

I'll try both. Haven't been able to find any decent documentation besides just the .cpp and .h stuff from epic.

[quiet fjord]

Guys should I do rpc to the player's movements or only with the component replicate movement is fine for me

[thin stratus]

Not sure what to help you with. Blueprints can't be breakpointed in Standalone, so you'll have to work with Log Prints

[thin stratus]

Depends on your movement. Usually all movement that relies on Player Input should go through the CharacterMovementComponent.
Custom movement code that the CMC doesn't offer to you might need C++ or you need to live with doing it in Blueprints and get corrections every now and then.

[tight glen]

Thanks Cedric. So from what I saw/read there isn't a way to expose the seamlessactor in BP. Do you know of any good examples of getting seamlesstravel working correctly or do you think it would be better for me to just use level streaming. My game will just have a main menu, lobby, and then the level that will be played.

[thin stratus]

Why do you need to expose the SeamlessTravel actor?

If you travel with server+clients, SeamlessTravel is preferred

You can use OnCopyProperties in the PlayerState and OnSwapPlayerControllers in the GameMode to move Data back and forth

[tight glen]

I have a character mesh that I am trying to have where the players can select their character before the game e.g in the lobby but when I travel from the lobby to the level the mesh gets set to none which means that on the travel my playerstate, whatever I am storing it in gets reset

[thin stratus]

And instead of PostLogin in the GameMode, you can use that Generic Initialize Player function or whatever it is called

[tight glen]

that's only avaliable in c++ right though the oncopyproperties?

[thin stratus]

No

I PRd that into the Engine ages ago

It's available in BPs too

Both of the functions I mentioned are

My Lobby on the Marketplace is BP only and uses those

[tight glen]

I actually just saw that XD

[thin stratus]

So yeah you use that to move the data over

[tight glen]

Where is this these function located OnCopyProperties?

[thin stratus]

PlayerState?

[tight glen]

only C++ are exposed to BP's?

[thin stratus]

I already answered that

[tight glen]

I made a child of player state but it doesn't show up with or without context

oh wait its Event Copy Properties

I will test this thanks for the help

[charred crane]

If I have an actor bp placed in a level, what's the difference between it if it's replicated vs not replicated?

Maybe it's better if I just state my problem. I have a static mesh (a wall) placed in my level. I have a non-replicated actor also placed in the level. It contains a trigger volume and on its begin play hides the wall and disables it's collision. Once a player walks over the trigger volume, I want the wall to become visible and enable collision. When anyone walks over the trigger volume, the wall becomes visible for the server, but not for clients, however the collision turns on for all.

[tight glen]

have you seen the ue4 videos on replication from epic?

[charred crane]

yes. is there something obvious I'm missing?

[tight glen]

I think so if you haven't seen the replciation video they talk about what replciation is as well as how to handle this

[charred crane]

I don't think that their video would've covered how I just solved it. the problem was that I needed to set the static mesh actor as replicated once I got the ref. I had a problem where when I tried to set its visibility immediately after setting it as replicated, the visibility wouldn't update. I need a 1.5+ second delay after setting it as replicated before it will propagate its visibility to clients.

[tight glen]

hm well theres many ways to solve the issue I was just saying that how to handle events only on clients or only on server are handled in the video

[charred crane]

I had the logic correct, it's just that I had to force replication on the object(since a base static mesh doesn't have a replicates property to enable) and use a delay.

[tight glen]

congrats on getting it

[glass vector]

Regarding Blueprint RPCs, i don't understand what can or can't be passed as variables into them as variables. it says that things that can be seralised can be passed into them as variables, does it mean that actor references can't be passed into them?

(ie actors and objects that have been spawned in the map)

[grand stratus]

guys i used server travel when all player joins the lobby

i used seamless travel btw

i really need to know why player state resets

i set some variables in it

and it just got reset when i travel

i wish one answers , thanks in advance

[fossil spoke]

@grand stratus Because the PlayerState is not retained during a SeamlessTravel. It however does provide you with a function CopyProperties that allows you to transfer the state of variables over into the new PlayerState.

[grand stratus]

so how i can copy it when i travel

iam using seamless travel

i thought that players state are kept

@fossil spoke

[fossil spoke]

I just said it has a function in it called CopyProperties that you can override.

[grand stratus]

Yeah i searched for it

[fossil spoke]

This allows you to literally copy the properties you want

[grand stratus]

But where does this function copy to

[fossil spoke]

Over to the new PlayerState

[grand stratus]

But i think the new player state appears only when i server travel

Ao the past one is removed

How can i connect both

[fossil spoke]

The function passes you a reference to the old PlayerState

This function is called before the old one is removed during travel

[grand stratus]

So is it a trigger event

Or a normal function

Can it be used in blue prints?

[fossil spoke]

It is a normal function. Yes

Its in the PlayerState

You can easily override it

[grand stratus]

So what i only need to use this function after server travel

[fossil spoke]

It happens during travel….

[grand stratus]

And the function carries the old player states anyways

During travel?

Then how can i call it in between

[fossil spoke]

You dont call it

Its called for you

[grand stratus]

Sorry iam still amateur

[fossil spoke]

Thats ok

It is automatically called

[grand stratus]

Called for me

Then why it do not copy anything

[fossil spoke]

You need to add in the properties you want to copy

That part is manual

[grand stratus]

So i call super

And then i add what i want

[fossil spoke]

Yes

[grand stratus]

Can i have an example

Sorry for that

I just need to understand better

[fossil spoke]

I am on my phone at the moment.

But

[grand stratus]

void AShooterPlayerState::CopyProperties(class APlayerState* PlayerState)
{
Super::CopyProperties(PlayerState);

  if (IsValid(PlayerState))
  {
     this->Test = "New Value";
     
      AShooterPlayerState* ShooterPlayerState = Cast<AShooterPlayerState>(PlayerState);        
      if (ShooterPlayerState)
      {            
          ShooterPlayerState->Test = this->Test;            
      }
  }

I saw this

But idk what is the ashooter player state

Why new one

He casted it

[fossil spoke]

Because in order to access that variable you need to cast the PlayerState to the right type

APlayerState does not have a Test variable

But AShooterPlayerState does

So you cast to it to access that variable

[grand stratus]

So what it the newly created player state

The ashooter

Right?

[fossil spoke]

Sorry can you rephrase that?

[grand stratus]

Sorry

There is a player state parameter

In the function

Is this the new player state

Or the old one

[fossil spoke]

I think its the new one. I cant remember lol

You should try and search where this function is called and verify

This would be a good practice for you

[grand stratus]

Okay last thing

If i have many players traviling

Traveling

How can i know which new player state crosspond to the old player state

[fossil spoke]

“this” will be the old PlayerState.

[grand stratus]

Okay

Btw the name of the player get copied automatically

Is this cause player name from the default variables

In player state not in my custom one

[fossil spoke]

If you look at the Super implementation you see it is copied for you.

[grand stratus]

Okay

So bro when i server travel

It will call now the custom copy properties

Not the default one

Automatically , i just create the blue print out of its c++

[fossil spoke]

Yes

[grand stratus]

Okay thanks man

[quiet fjord]

What do you think of my targeting system with loss of target?

[empty axle]

wrong channel

#work-in-progress

[quiet fjord]

ok thanks 🙂

[golden nest]

Hi, can someone help me understand concepts of replication and priority in my project?

Cause i'm implementing the same logic getting two different results :c

Here is my PS, where i load the user info from game instance

Here i set the head banner whit the name of the user

and here is the rep notify event

I'm only getting the clients to do the expected (update their banners on user data loaded), but the server does not seems to do the replication for itself

I added a print to screen when the rep notify fires, but only the client pawn is calling it

And here is the call of "SetHeaderBanner"

I tried calling the set header banner on input, but it only calls server functionality, client does not seems to work

and this is what i got, only server update

[sinful tree]

This event will only ever run on server.

Because you have the Head Banner set as an OnRep, then the clients run the OnRep function when the values change.

In blueprints, OnReps are also executed on server.

[golden nest]

Yes

But is not working like that

I think so

Hahaha

[sinful tree]

From your screenshot, it looks like it's working perfectly. Your server is calling the set head banner, then the client and server are both responding with their OnRep.

[golden nest]

but look here

The server does not update its banner

It keeps showing "Nombre" (that's the default value)

On clients works fine

[sinful tree]

Where are you actually changing the value though that the server can then read?

[golden nest]

I'm reading the value on PS from game instance, then calling the "SetHeadBanner" on the player's pawn

[sinful tree]

Your HeadBanner variable exists in the playerstate, but how does the server get the value you want to change it to.

[golden nest]

let me show u

That's the PS

[thin stratus]

Yeah that's not gonna work

Well

Actually maybe

But damn

[golden nest]

It's a mess?

Hahahaha

[thin stratus]

Kinda

You only want to call the ServerRPC on the LocallyControlled Client

And you don't need to have all the other execution paths theoretically

[golden nest]

Ignore the default values in case the player is not logged in

[thin stratus]

Unless use is expected to be invalid

Ah okay

Hm yeah then it should be fine

The boolean is a bit redundant

You can mark that as non-replicated

And just set it inside the OnRep of the struct

They won't replicate in order etc, so only making one of them OnRep is better

[sinful tree]

Are you sure you're even getting passed this cast?

[golden nest]

So u suggest that i call the rep notify on PS and update the pawn from there?

[thin stratus]

All I suggest is to make that boolean nonreplicated

and moving it into the OnRep

[golden nest]

yes, that's the parent class of my Gameplay_PC

[golden nest]

Oh, ok

But what happens whit the head banner

Still not working

The thing is that i can open as many clients i want and it works fine, but when it comes to the server it does not seems to call the rep notify after the "SetHeadBanner"

Could it be that there is no client to replicate the info when the server spawns?

Should it call the rep notify anyway?

[thin stratus]

It would call it anyway in Blueprints

Only reason it wouldn't is if the values are the same

[golden nest]

Let me try changing the default values

That's why i change the default to be "nombre" and "Rol"

Any other ideas?

Set it to be blank?

[thin stratus]

What makes you think that the code isn't calling for the Server?

Did you place print strings or put breakpoints in?

What is the OnRep even doing

[golden nest]

I'm printing a string on rep notify, and when the server start it does not print anything

This

Updating a widget component on the pawn

This widget

And both text components are binded to the values setted on rep notify

And it works fine for clients, but server is crazy :C

If i run only a server, i'm never getting the rep notify print

and now i noticed that is calling it twice

Now that's solved xD

I tried calling only on R input, and it works fine, but when i call it from PS it does not work

any ideas? :c

[split siren]

If you were to release a competitive shooter, what hosting service would you go for? I am thinking about AWS Gamelift, but the setup feel daunting

[thin stratus]

But that is not the OnRep of the UserData or?

[golden nest]

No, on rep user data updates the chat widget

[thin stratus]

But your screenshot never showed where you set the header

Ah you do that on button press

Where is the data from that is set?

[golden nest]

On button pressed i execute the same "SetHeadBanner" and it reads the data from PS, and that works

[golden nest]

But when i do it automatic from the "ServerSaveUserInfo" the server does not executes the rep notify

[thin stratus]

So the button press works

Hm

Not sure atm

Might be a timing issue?

[golden nest]

I like AWS and it's full of documentation on their website

It gives u the exact code that u need to get it working

[golden nest]

i think so

But i do not know where else call the update

Because i try on pawn start but it throws not valid error on reading the PS

I mean, on pawn begin play

[thin stratus]

Yeah BeginPlay of pawn is too early

Pawn calls BeginPlay when being spawned

It's not possessed at that point

Which means Controller and PlayerState aren't set

[golden nest]

Oh that’s make sense

[thin stratus]

You need to use things like Event Possessed (Server only)

The whole setup becomes a lot easier in C++

Cause then you have access to OnRep_PlayerState

And OnRep_Pawn

In Pawn and PlayerState

But well

[golden nest]

😮

I did not know that

Can I expose those events?

[thin stratus]

Yeah

You can override them in your own class and then just make a BlueprintImplementableEvent that you call

[golden nest]

Ok, I will try on possessed first

[thin stratus]

Something something

virtual void OnRep_PlayerState() override;

UFUNCTION(BlueprintImplementableEvent, meta = (DisplayName = "OnRep_PlayerState")
void K2_OnRep_PlayerState();

void AYourCharacter::OnRep_PlayerState()
{
  Super::OnRep_PlayerState();

  K2_OnRep_PlayerState();
}

[golden nest]

Ok I will try

Cause event on possessed throws not valid errors too 😅

That’s not gonna cause my event “SetHeadBanner” to run on every update and not only once?

Should I run it before a do once?

[golden nest]

What's the meaning on "K2"?

[bitter oriole]

Kismet 2

aka Blueprint

[thin stratus]

Just some remnant of how Epic games calls BP functions that would otherwise have the same name as the C++ one, which doesn't compile

[golden nest]

Oh that's good to know

[thin stratus]

Well keep in mind that htis Onrep from c++ only calls on the CLients anyway

But the Server should have no issue just using the Possessed Event

[golden nest]

And when at the time that "OnPossessed" event is called it's 100% true that my PS its gonna be loaded?

[thin stratus]

Should be as it's created together with the PlayerController

Or rather by the PlayerController

And since you are on the Server here, you don't need to care about replication of it

The only thing you have to make sure is setup properly is the information you wish to display

But I assume that's what your boolean was for in the playerState

Since you will always have a race condition on clients anyway

Either the Character or the PlayerState will replicate first

So the PlayerState has to tell teh Character to update

And if the Character is not valid yet, then you have to catch it the other way round, which means the Character has to ask the PlayerState for info

That way it doesn't matter who replicates first

[golden nest]

Ok, i'll give it a try

Thanks ❤️

Do u know where i can find docs of the order of execution of the BPs?

Like when the GI, GM, PC, PS are created?

[thin stratus]

Hm no

There is a YouTube video that goes pretty indepth about this

I can link that later

[hexed pewter]

https://www.youtube.com/watch?v=IaU2Hue-ApI&t=345s this?

[blazing spruce]

Hey, do you just need to put 'listen' into the options of the open level node? otherwise does anything else look wrong here?

[thin stratus]

Yus @hexed pewter

[thin stratus]

Despite the replicated int being redundant, no

[hexed pewter]

I watch it every day before sleep 🤡 hoping it will make me better at ue

[blazing spruce]

Interesting cause it doesn't work lol I started following Ryan Laley's online sessions series and he did this in the game instance class and made it replicated does that make a difference that it was in the GI?

[thin stratus]

GI and Replication is also redundant :D

GI doesn't hold any gameplay code and only exists locally for each player

There is no replication in it

[golden nest]

you can hold your num of players value in GI until you create a gameplay map and load the value from GI to GS or GM on begin

[blazing spruce]

Okay makes sense lol so other than that theirs nothing wrong with that code cause it wont load the level when i click the host button

[golden nest]

did u check seamless travel?

Seamless travel does not work in PIE

And will print a warning in output log

that could be why the map is not loading

[blazing spruce]

Ill check the seamless travel option but its supposed to be working with steam so i right click on the project file and select Launch Game

this is the host button code too just in case

[thin stratus]

This should be fine

Any errors or warnings in the log?

Do you see the Steam overlay when yo ustart the game?

Are you not finding the session or why?

Could be normal if you use the test ID

[blazing spruce]

The steam overlay comes up, i get the Main Menu load, i click host game and nothing happens, although when i run it in UE as a standalone and press the host button it takes me to the prelobby level just not when i try do it through steam

in the viewport for UE tho

if i actually choose the 'Standalone Game' option it also wont work

[twilit radish]

Is it a bad idea to always have a listen server running and just update the session data to deny people from joining when not wanted? This so that people can instantly join if wanted instead of launching the listen server and creating the session.

And probably a check in some PreLogin event to make sure nobody actually joins.

[thin stratus]

Think in specific games that is totally fine

[elder ravine]

🍉 Can someone help me out🍉 :

How do you guys handle fetching Previous Game Mode variables in a New Game Mode after Seamless travel.

For instance a variable containing a Match Settings Structure > Going from a lobby game mode into a gameplay game mode.

Do you guys save a variable like that on the server's Game instance to acces it in the new Game Mode?
Player controller variables I can simply acces using the EventOnSwapPlayerControllers and cast from the Old PC to the New PC to pass through the neccesary persisting variables..

But how does one do this with variables that exist on the Game Mode and Game State
Anyone perhaps have some advice?

[elder ravine]

So you basically use your listen server as a dedicated server. Totally fine.

[twilit radish]

No? There are big differences between those two, I was simply curious if it's actually needed to keep setting it all up when you can also just always have it running and disable/enable joining when needed. If the client shuts down their game the server is dead, that's not the case with a dedicated server.

[elder ravine]

I know that there's a big difference, but what do you mean by 'Keep setting it up'.

You still need to setup the listen server once right? And then you simply keep it running?

Are you aiming to have some persistent servers online? Hosted from like a virtual machine or something?

Just curious😋

[twilit radish]

With setting it up I mean starting the listen server and switching to the preferred level and also setting up the session so it can actually be joined if for example ran on Steam. If someone wants to join you would need to go through those steps first, I was wondering why you just can't always have it running as a listen server and if someone decides they want people to be able to join open up the game to other clients by updating the session data.

I'm not aiming to have persistent servers, then I would indeed need dedicated servers. I'm simply looking into a quicker setup for people to join, especially switching to most likely the same level when already in it is simply annoying 😛

Unless I missed some C++ 'magic' that can already do this, but so far I've only found that starting a new level with the listen option does this.

[elder ravine]

Ahh ok! 😆 Now I understand what you're doing

Thats a pretty smart way actually of achieving your goal, and nothing wrong with it.

Thanks for explaining it to me, I was just curious

[twilit radish]

No worries, it's difficult to understand things at times without seeing someone. I have had the same problem many times haha.

[elder ravine]

xD

[twilit radish]

It's just a chat program after all, context and seeing what someone means can be difficult 😛

But yeah, it's fine don't worry.

[fading birch]

wait

you're just making a chat game?

[elder ravine]

Exactlyy, so sometimes you can have such a different instance of what someone is trying to say

[twilit radish]

No, as in Discord is just a chat program.

[fading birch]

ohhhh

i misunderstood

[twilit radish]

Yet another example 😆

[elder ravine]

😛

[fading birch]

Generally speaking, when a player decides to start "hosting" you open a new map anyways. Ie Main Menu -> Lobby type map

[elder ravine]

Unless your MainMenu is your gameplay map.. Im assuming Thom has that

[fading birch]

sure, doesn't matter

As far as "opening" and "closing" the map, you can just update the session

and make it so it's not searchable

[twilit radish]

In my case it would be a lobby and a separate game map. People should be able to join other people their lobbies, but should also be able to deny this from happening with some setting. From their lobby they could join the game world, do whatever they want for some time and come back to the lobby / hub.

[fading birch]

that..isn't really possible

[twilit radish]

Why not?

[fading birch]

if you want the client to go to a new map, by themselves, then they would be disconnected from the server

now, if you want a gameplay loop, like Call of Duty for example where its Lobby -> Game Map -> Repeat

that's totally doable

because everyone travels together

[elder ravine]

Yeah players can't be in separate UE4 'Levels'. If thats what you're trying to achieve

[fading birch]

Well..

[twilit radish]

Not by them selves, see it as this: You start the game, pick a save file and join your own hub as a host. From there people can join that host or join other hosts (and then become a client). From that hub the host can start a match and all join the other map.

[fading birch]

technically they could

but that's way outside the scope of this discussion

That's not how listen servers work

[elder ravine]

But this is the standard UE4 Lobby setup. This is exactly what I do in all my multiplayer projects

[fading birch]

This sounds a bit similar to Valheim no?

or Ark

[elder ravine]

Yeah like valheim

[twilit radish]

Why is that now how listen servers work?

[fading birch]

because the "Host" is the authority

[elder ravine]

He meant 'technically they could'

[fading birch]

once you join a host as a client, you follow the host where they go

[elder ravine]

yup

[fading birch]

as long as they open a map with ?Listen ofc

[twilit radish]

Which is exactly what happens?

You simply start the game as a host, but if you decide to join someone else you become a client.

[elder ravine]

But Thom, the setup you are describing is completely normal

Jump in the hangout voice chat with me will you? I can show you the setup

[fading birch]

You edited your message, it makes more sense now

[twilit radish]

Ah sorry 😅

[fading birch]

Basically your flow is:

1. Player Starts Game
2. Player starts hosting a server
3. Player can leave their own lobby to join another player's lobby (what happens to other players in the player's lobby?)
4. Lobby Host starts the Game
5. Start Game opens map with ?listen```

is that correct?

[elder ravine]

Start game seamless transitions Session players to the Gameplay map @fading birch add this to step 5.

Complete?

[fading birch]

oh

sure

doesn't even have to be seamless, but that's obviously preferred

[elder ravine]

@fading birch 6. When gameplay is done, players go back to lobby

[twilit radish]

Yes, players can indeed leave their own lobby to join someone else who is a host or others could join their game. In the lobby people can just look around, mess a bit with each other, look at what the host has achieved so far etc. and then the host can decide to actually start a game on the different map.

[twilit radish]

So this yes.

[elder ravine]

just to save some PC variables perhaps.

[fading birch]

there's more reasons

it's easier on clients

so they don't get hit with a double loading screen

[elder ravine]

yeah i just named one nice example

[twilit radish]

I think seamless would be preferred with this because you go back to the lobby after a 'match', no need to split people apart if you ask me 😛

[fading birch]

that's not what seamless does

[elder ravine]

1. Player Starts Game 2. Player starts hosting a server 3. Player can leave their own lobby to join another player's lobby (what happens to other players in the player's lobby?) 4. Lobby Host starts the Game 5. Start Game opens map with ?listen (This is where the gameplay happens)
6. After Gameplay they go back to the lobby (HUB)
7. repeat from step 4

[twilit radish]

Seamless prevents people from having to reconnect to a listen server or dedicated server after switching to a different map right?

[fading birch]

Seamless travel keeps the clients connect to the server, which allows the hand off of data from 1 map to another.
Non Seamless travel (hard travel) disconnects you from the server, then you travel on you own to it, and reconnect to the server.

Hard Travel is what you do when you first connect to a server, or leave it

[elder ravine]

Well now that we are talking about this topic guys, mind if I ask this following question:

[fading birch]

shoot

[twilit radish]

Yeah, so it would make sense to keep them connected if they swap from the hub/lobby to the game world and then back after some time right?

[fading birch]

yeah, seamless travel is usually preferred

[elder ravine]

How do you guys handle fetching Previous Game Mode variables in a New Game Mode after Seamless travel.

For instance a variable containing a Match Settings Structure > Going from a lobby game mode into a gameplay game mode.

Do you guys save a variable like that on the server's Game instance to acces it in the new Game Mode?
Player controller variables I can simply acces using the EventOnSwapPlayerControllers and cast from the Old PC to the New PC to pass through the neccesary persisting variables..

But how does one do this with variables that exist on the Game Mode and Game State
Anyone perhaps have some advice?

[fading birch]

unless you specifically need hard travel

What info do you need access to?

[elder ravine]

The Match Settings Structure variable that I mention for instance

[fading birch]

game modes and game states shouldn't be used to save persistent data between maps

I would definitely store match settings in the game instance

[elder ravine]

Yep, exactly

I just use the variable in the Lobby Game Mode to For Each loop through my array of player controllers to update their UI with the Game Settings in the Lobby... But I save a copy of this Match settings in the game instance to acces it in the Gameplay Map and act upon it

Fine right?

[elder ravine]

Yep, thanks

[fading birch]

oh actually

you can bypass that entirely

[elder ravine]

How

[fading birch]

and just append it to your open map string

and just parse the string

[elder ravine]

with the option string?

[fading birch]

you only need it from lobby -> gameplay map right?

then it resets?

[elder ravine]

Yea

[fading birch]

when you open a level, you there's an Option string parameter

[elder ravine]

Once in lobby again it resets

[fading birch]

you can just parse that

[elder ravine]

Yeah.. seen that, just not sure how to put the Match Settings in there

[fading birch]

You'll have to format it a bit

probably easier to just go with the struct

[elder ravine]

And save the struct in the game instance and acces it again once in gameplay map right?

[fading birch]

you could serialize the struct into a string

and then deserialize it in the game server

[twilit radish]

That sounds like a really nasty way lol.

The string way.

[fading birch]

but that would require C++, which i'm not sure if you're using that or BP

[elder ravine]

I think im sticking with the game intance way... If it's no problem

[elder ravine]

BP only..

[fading birch]

ah yeah

[elder ravine]

: )

[fading birch]

def game instance then

you could also

[elder ravine]

Alrighty

[fading birch]

make a AInfo actor

and just put it all in there

and add it to the actors to copy list

¯_(ツ)_/¯

[elder ravine]

Yeah could do that..

[fading birch]

many ways to skin a cat

[elder ravine]

But then the Game Instance way still seems easdier for me xD

Yeah

Like, with a Player Info structure i do the followiung

this strucutre contains the username and player profile pic for instance

Player controller variables I can simply acces using the EventOnSwapPlayerControllers and cast from the Old PC to the New PC to pass through the neccesary persisting variables..

Thats what I use to take PC variables from Lobby to the Gameplay map

[fading birch]

you could ALSO go a completely different direction. Setup an entire backend infrastructure, a REST Api, backed with a SQL database and just store the data in that.

😛

[elder ravine]

HAHha

Yeah no way xD..

[twilit radish]

Sounds a bit expensive for just this 😂

[elder ravine]

Or I could make my own game engine

[fading birch]

mine only costs like $3 a month

so not that expensive

[twilit radish]

Sure hosting, but the actual effort to support this all for the very little it sounds like it has to do.. Don't think so 😛

[fading birch]

oh well it was also all be in code

so...

xD

oh actually wait

@elder ravine are you using sessions?

if so, just add it to the session info

then grab it from there when you load into the gameplay map

ezpz

[elder ravine]

Add what there?

Match setting info?

or Player specific Player Info

[fading birch]

The match setting info

The player specific stuff should be handled on the controllers

[elder ravine]

Yeah exactly

Alrighty

Well. If its all fine, which you agreed with me it is, then i keep the match settings in the game instance.

And the player info stuff i pass through with the OnSwapPlayerControllers event and cast from the old pc, get the variable of player info, and pass it into the new pc

[blazing spruce]

I changed the pin on the Create Sessions node from On Success just to the top pin and that worked lmao does this cause any issues it being this way tho that you're aware of?

[thin stratus]

Yeah you will still not create a session

[blazing spruce]

fuuuuuuuuuuuuuuuuuuuu! Thanks lmao gonna keep digging then lol

[graceful falcon]

Hello, So I made an game that has online multiplayer but the problem is I don't wanna use steams subsystem or epics subsystem or some other subsystem does anyone know how I can make it online multiplayer without using steam or epic or any other subsystem? Main idea is to upload the game on itch.io

[bitter oriole]

You only need an online subsystem if you want server browsers, friends, or matchmaking

[graceful falcon]

oh okay but do you have any idea what for subsystem

[quasi tide]

Just don't use it

[bitter oriole]

Do what ? Just don't use those features

[quasi tide]

If you want to be able to connect, you need to do your own STUN/ICE servers, NAT Punchthrough, or Port Forwarding

[thin stratus]

You basically have to create the features that you need from those subsystems on your own

[bitter oriole]

If you do need matchmaking, then you'll need some kind of service - Steam, Epic, or your own

[thin stratus]

Which is not a straight forward task, so using Steam or EOS is def the better choice

[bitter oriole]

To be fair matchmaking / server browser is kinda straightforward, friends less so

[thin stratus]

It's straight forward if you know how to make it

If you have to learn all of that still, it's not straight forward

[graceful falcon]

okay thanks!

[peak sentinel]

Do you guys replicate ammo to owner?

I'm trying to handle predictive automatic reloading when ammo is 0, but between server and client always there is a mismatch

Sometimes server reload 25 ammo, client reloads 30

If I replicate to owner, due to latency, server always corrects the ammo and it looks glitchy on UI

Couldnt find a workaround

[boreal wadi]

Has anyone attempted to replicate the inventory system used in Action RPG? Im struggling mainly because it uses maps to organize and update data which cant be replicated so Im at a loss on how to replicate everything. I have a few Ideas but would like to speak with someone with more networking experience.

[tight glen]

Check out antize inventory. They have a basic ammo shooting system that is replicated and works fairly well. I am using it to create my wip game

[dull lance]

how are you doing your do rep life time thingy?

Also, for this kind of thing you can always have a replicating int32 and a local int32.

Tho how you handle it depends on how you handle fire (whether you do shooting locally then send results to server or do shooting both locally and then everywhere else)

[hollow eagle]

It's a great example of why getting network prediction right is so hard. Seemingly simple scenario - replicate a single number while predicting what it should be - but it gets all kinds of screwy if you go about it naively.

A simple way would be to do what tank said - display a local int32 to the user regardless of what's being replicated back to the client. What I'd add to that is when the player stops firing (or maybe a moment afterwards) you replace the local value with the server-replicated value to account for any desync that may have occured.

[smoky wing]

hello everybody, i wonder how i can make player joins a match when press start or make a new session for him if no empty session. i saw some answered were that i need several servers or if one server i need to use ports. i don't know how i can go with one server approach. also is matchmaking of EOS can solve my problem.. and create matches for players ?

[blazing spruce]

Looks like the reason it wasn't hosting a session was potentially down to a bug with 4.27 that has broke steam subsystem lol

[peak sentinel]

Having a local int32 seems like a good idea, I have a LastShot FVector value with OnRep, whenever client or server fires they replicate this FVector and each connection fire a local projectile from given location by calculating forward vector etc. This is a quite bad design but intended

The main problem is, since everyone creating a local projectile inside of OnRep, when client hits to 0 ammo on primary clip, sometimes server still has 3 or 5 even 7 ammo left on the clip, so while client reloads 30 ammo, server reloads lesser ammo

Probably I need to send the value with RPC

[glacial pollen]

Epic what is the deal with not fixing this since forever now?

[stoic ore]

anyone knows where I can change the MaxSplitscreenPlayers? I just can't find it. It should be available to config files shouldn't it?

[hexed pewter]

Is there any online course or series on unreal multiplayer that I could follow along / use as reference when creating my own multiplayer project?

[stoic ore]

did you have a look into the pins of this channel? There are quite some helpful things

[hoary lark]

You "know this is a bad design" - so you know that replicated variables don't attempt to transmit every change, right?

[stoic ore]

found it.

[peak sentinel]

Thats a bad but only working design for pooled-projectiles in my case, its working very well unless the reloading issue I've mentioned above