multiplayer

[thin stratus]

Keep in mind that for this to work properly across all travels, that your GameMode and GameState need to each have some parent in common across lobby and gameplay

e.g. BP_GameMode_Game which is the parent of BP_GameMode_Gameplay and BP_GameMode_Lobby

And the GameLength stuff should then happen in BP_GameMode_Game

Otherwise you'll possibly lose the length between travels cause you forget to parse it in 15 places.

[spark otter]

Alright

No exaggeration

You've made me cry

I've been working on this, for 10+ hours a day, three days straight

and it's fixed

thank you

[rustic sable]

do actors (replicated) dropped in the level, like say a PCG manger, get a default owner?

[zealous knoll]

When using GameState that is no GameStateBase (because I want to add muliplayer later)
I lost my camera point of view.
I am using Set View Target With Blend
and I am not possessing any character
just using the player controllers

How to use with my setup the Camera point of view?

with a GameStateBase works normal

Point of view goes to 0,0,0

should I replicate the camera view? with Run on server Event?

[thin stratus]

No worries (:

[thin stratus]

Probably not.

[rustic sable]

Yeah, all good tho

[vivid seal]

Hey guys, I'm having an issue with a FastArray property where after some time of constantly replicating items in the array, my client gets disconnected with the error "Array Property Improperly Terminated" inside of ReceiveProperties_r(). Anyone know what might cause this? I'm looking at the function but don't really know what exactly is going on here. Something about the ReadHandle not being 0?

[plucky pewter]

I have a question: For those of you working or have worked on Multiplayer projects using dedicated servers.
What process do you go through when designing?
When your writing code for the server and client do you build up most of the design using the null subsystem and THEN integrate a backend service?
Or do nail down the backend service provider first and then implement systems as you go? piece by piece?

[floral sail]

In what cases do I need to replicate Mesh in Character?
I'm asking because that checkbox fixed one nasty bug where mesh rotation was desyncing under rare conditions. Apart from that bug, there were no issues whatsoever, thats why I don't fully understand why this checkbox was needed for me.

I used this simple function for SetRotation based on Server's data. In most cases it was working perfectly without Component Replicates, but under rare conditions (that I was able to reproduce in game, but not in code) it was leading to desyncing Character Mesh rotation. Actor's rotation was perfectly synced, but not Mesh rotation.
My initial thought was that if Actor replicates, then Mesh replicates automatically, but apparently not?

[bitter robin]

Rotation shouldnt be replicated with RPCs Should have a replicated variable. Why? because if the actor isn't relevant for a person then they wont get the RPC, then when it becomes relevant they wont know its rotation.

[floral sail]

Oh wow thats actually true, thanks.

That wasn't an issue, but a good note, I need to pay more attention to relevancy factor.

Hm turns out when Mesh ComponentReplicates is set to true, the Mesh starts to twitch on the Clients with ping. Guess that solution is bad then.

[lost inlet]

And this checkbox is commonly misunderstood anyway. It'll only replicate component properties that are actually set to be replicated

It won't just replicate everything about that mesh

[ruby lodge]

@meager spade right now if I disable the replication for the weapon mesh, it spawns for the client but it doesn't get attached to his hands

also, it's animations do not play

well, the emitters do get spawned at the correct location etc like before, and the warning isn't popping up anymore, but neither is it attached for the clients view nor is it playing animations. So the server can see everything correctly with all weapons being attached for him and clients and the animations but the client cannot see any weapon animations or anyone having weapons actually attached. Instead they are just spawned at the position they were, well... spawned at, and then stay there

[ruby lodge]

inside of the function called on the second image on the actor component "InventorySystem", it attaches the weapon

Now, I know that it is not attaching it on the clients in any place here so I would say that a repNotify structure variable could be set on "Server_CreateAndEquipLoadout" and inside of it's function it calls create and equip loadout. What do you think?

also regarding the animations, I am playing them locally on everyone now as well

[slim jay]

I’m using the Chaos physics system for vehicles, but the movements aren’t smooth in server. Is it possible to make smoother gameplay on the server without using a plugin? If you think it’s difficult without a plugin, which plugin would you recommend?

[grand kestrel]

@thin stratus @pallid mesa Epic asked me to PR a change to CMC's NetworkSmoothingMode that separates out Translation/Rotation
Exponential is great for translation but Linear is way more stable for rotation
This also means you can conditionally disable interpolation for rotation (only) at the start of a montage/ability, so that it doesn't interpolate it in a wide arc for high mobility abilities, which makes sim proxies significantly more accurate
Hopefully be in 5.5, figured you guys would want to know about this 🙂

[fossil spoke]

Interesting, I noticed this as well between the 2 modes and actually did this for us internally lol

[grand kestrel]

I did it internally and it worked so well that I posted on UDN asking why it wasn't in the engine 😄
Epic agreed and asked if I can PR it

[fossil spoke]

https://tenor.com/view/why-not-both-why-not-take-both-gif-11478682

Happy days

[grand kestrel]

Its a decent quality boost for Lyra too, since it uses Linear to get stable results from TIP/Aim offset, losing out on the exponential translation

[fossil spoke]

Be interesting to see how long it takes for them to merge it though 😛

[grand kestrel]

Since its through UDN hopefully I can just poke them again and speed it up

[twin juniper]

For a Weapon Fire Rate, it must be fast (sometimes a weapon shoot 20 times per second..), would it be okay to verify with the server directly or would it be too slow?

I'm also thinking it should be validated on the client first and if it is correct, then the server needs to validate as well before shooting a single bullet.. If the client says no then the server would have also said no so we can skip the server request and directly say no

Tho I wanted to use shooting predicting but if I use this for the fire rate, the shooting will be slower I would think..

--
Like Client click -> Verify Fire Rate (via Server which is slower..) -> If valid, Predict Visuals -> Trace Hit via Server
Will this slow down and feel bad to the player?

Since my game is coop, would it be possible to just not check the fire rate? let the clients be able to hack and set 0 fire rate..

[short arrow]

It's totally fine to allow some things to be "hackable" and rely on your anti cheat. Fire rate is not one of them.

[twin juniper]

Ok thx

[pallid flame]

I have a small project I'm working on that's working for singleplayer but I plan to turn it multiplayer later
Should I immediately start working on preparations for that or can I worry about it later on?

[fossil spoke]

@pallid flame Multiplayer isnt something you just add on at a later date.

You either build a Single Player or a Multiplayer game from the start.

You will end up redoing pretty much everything about your game to make it multiplayer after it being singleplayer

[pallid flame]

I see
Luckily I dont have too much already established so it's not the end of the world
From what I've heard this is probably a complex topic- but what would I have to begin to do to start that conversion process?

[fossil spoke]

There is no conversion process...

I think you just need to start researching the multiplayer side of UE

Replication

RPCs

Etc etc

How could you hope to "convert" your game if you have no idea what tools even exist to allow you to make a multiplayer game.

[pallid flame]

You're right
And what I mean by conversion is taking what I have and rewriting/recreating it for multiplayer compatibility
Not exactly what it suggests but yeah
Thank you though Ill look into it

[feral narwhal]

Im trying to set a player outline on enemies (any controller with a different teamID), however I am now realizing I cant access the controller from clients on the character. Anyone know the correct way I should be doing this?

[charred island]

is there a way to register event handlers on fields in the player state? I want to update GUI in a race game to reflect the players' positions, which are stored in the PlayerState objects

[zealous knoll]

if I understood you correctly, you are facing what I realized just this morning: Player Controller cant be accessed by other clients.
I am right now re-coding my PC variables and logic to Player State 🥲

I have a question regarding where to put some info, GameState or PlayerState
for my TurnBase game:
-The amount of remaining actions at all (lets say 2 of 4 to choose: walk (and how much steps), jump, attack, use inventory).
-If the player consider he finished his turn (so the next player is allowed to play)

Maybe I track them in Player State but I check them always in Game State?

[lament flax]

Side note: if you make a MP project, you can turn it into a single player game later it needed

With almost no changes

[zealous knoll]

what typical changes would be?

[lament flax]

Depends if you have some custom MP backend or if you are using EOS

If you use plain UE MP with a listen server then you got nothing to change

[feral narwhal]

yeah, still trying to fix it

[lament flax]

Since in singleplayer the playrr is the server

[zealous knoll]

using 2 players standalone everything is fine, Iam switching to multiplayer very early in dev
but
2 clients print Client 0 two times
this is my GameMode, I tried to find some tutorial, cant find how this was made, I did it in the past but cant remember

[pallid flame]

I have so much to learn..

[zealous knoll]

the set up is that the Player Controller doesnt possess the pieces of the board (turn based), just command them as they are Ai

[zealous knoll]

yes, me too

[pallid flame]

Just when I was getting the hang of single player coding
Its that much harder to code for multiplayer than singleplayer, right?

[lament flax]

Look at the basic of MP

A good start is https://cedric-neukirchen.net/docs/category/multiplayer-network-compendium

Here its normal because the game mode only exists on the server

Also, if you test your game in PIE, either play as listen server or all as client (if you want a dedicated server)

[lament flax]

Its in the pie settings

[lament flax]

Yes its more work

• you got race conditions
• have to handle lag
• more optimisation
• prevent cheating

[zealous knoll]

yep Im with that, so far cant see a specific setup of blueprints that says if I spawn PCs or not

[lament flax]

Are you doing BP only ?

Multiplayer on BP is very hard and not ideal

I personally switched to cpp when starting to make my project MP

[zealous knoll]

I would love to learn cpp, but so far I didnt find anything I couldnt do with blueprints, and deadlines on client projects are tight

[pallid mesa]

thats pretty useful!

[pallid mesa]

does linear use some more bandwidth?

[slim jay]

Chaos Physics vehicle is not running smoothly on the server. What is the solution for this?

[knotty bane]

can someone help with this problem, when the server takes the item he takes it succesfully but if the client takes the item the server receives it instead of the client i did switch authority and use a multicast to attach the mesh to the player charcter they both use

still a bit new to the multiplayer scene so happy to hear what is wrong here

[shrewd ginkgo]

I want to make call phone skill for my killer. is it correct way to do it.

Btw all players connected variable contains player controllers

[zealous knoll]

maybe https://discord.com/channels/187217643009212416/966517078834151484

[zealous knoll]

where it is this logic, Player Controller?

Can I detect from GameState who sent data through an Interface? because adding ID the client could cheat.
maybe sending the pawn in the interface?
a different interface for each player ? it will be 2 players only, but maybe this is not good and anyway Im curious how this is made with more characters.
maybe sending the pawn?

the pawn or the player controller ?

[dark parcel]

multicast everywhere 😔

[marsh hamlet]

Hi. I have a PlayFab server running with the correct IP and port numbers. I am trying to connect it with IP and port parameters like "Game.exe 12.23.3.22:30000". While development and test builds successfully connect without issues, the shipping build client can not connect. Any ideas what might be the reason? Or how can I debug it. Basically same client build with everything same, only shipping configurated client fails to connect to server without any errors. Please help.

[blazing spruce]

The reason it works on the server and not the client is because you've marked the event as run on server, so even when a client triggers the event it'll run on the server

You don't wanna use any getters that take in an index like GetPlayerCharacter(0), GetPlayerController(0) ect, if the index is 0 it'll only ever get the first player at the index of 0 every time.. you'll wanna use GetController inside the character class to get the player controller and GetControlledPawn in your player controller class to get your player character instead

You should use a RepNotify instead of the multicast, multicasts don't take into account relevancy whereas rep notify will update players of the change once they become relevant to it

Im not sure how your interaction code is setup up or what class this code is in but i would be passing my player character and controller through the interface so you can access them from every actor that has the interaction interface implemented

and give this bad boy a read - https://cedric-neukirchen.net/docs/category/multiplayer-network-compendium/

[knotty bane]

thanks for the explanation man! makes more sense now🙌

[shrewd ginkgo]

in thirdperson character

[zealous knoll]

if I trigger input "Interaction" and is true "is Murderer"
then I call an event
which executes in all, making a foreach loop of all players
triggering a sound at the location of those who are not murderer...

I am just a noob in multiplayer but I don think you should do this in character

this should be in the GameState or GameMode

I dont know what you mean by "call phone skill", but whatever is this that is triggered by "a murderer" in others that "are not murederers" it should be not made in character

the player trigger this "call phone skill", better through an interface
sending its PlayerController, player state, or pawn, one of the 3, I am not sure which one. I would say PC
then
Game State receives this interface, checks the identity (PC, PS or Pawn)
checking if is murderer
if is true
then in GameState you make the foreach to the others that are not that PC
because also GameState have already Player Array (an array of PlayerStates so if you compare with the sent PC, get PC from the PlayerArray)

I repeat, I am just a beginner, so maybe Im wrong, hope some expert pass by to confirm my approach

[knotty bane]

think i'm going the right direction here but now the interaction is not working as it should do you see a prob here or am i still way of

i included the interaction setup that is inside the character

[blazing spruce]

The interaction input, is that on your character class? You shouldn't need that cast

[knotty bane]

this is inside the character class

[blazing spruce]

You also dont need that Has Authority node either i dont think

[blazing spruce]

Yeah remove the cast, cause it looks like you're casting into the same class that you're already in

[knotty bane]

but that is needed to get the controlled pawn right so the server doesnt receive the item if the clients interact

[blazing spruce]

The controlled pawn is your character class that you're already inside of tho isn't it? the target should just be self

[knotty bane]

alright removed all that and i can interact with the item but its not equipped both on client on server side, the provided screenshots are inside the item that will be picked up

[neon summit]

You aren't specifying parent to attach to

[knotty bane]

even if i use get player character -> mesh to parent nothing happens

[neon summit]

Pass the character into interface event

Set a variable that's replicated and set in interacting actor

[knotty bane]

so a reference to the charcter for the parent to attach to?

[neon summit]

Well the parent would be the character mesh but yeah

[knotty bane]

So what should i change exactly cause i dont really follow

[dark parcel]

This only does it on server

since you have switch has authority

OnRep should be used for clients to receive update

[knotty bane]

ah okay

[grand kestrel]

Net bandwidth, definitely not, nothing is sent after the fact, nor is anything sent at a different rate/frequency, its really just the difference between FInterpTo and FInterpConstantTo (not specifically using those)
But CPU bandwidth? No clue, you'd have to profile, but based on the math I'm looking at it should cost nothing in terms of difference
Its just the math that changes when interpolating the sim proxy loc/rot

[pallid mesa]

iirc they send some extra data for linear

[grand kestrel]

Oh, yeah, I had almost forgot
ACharacter::PreReplication sends ReplicatedServerLastTransformUpdateTimeStamp

[clear copper]

Is BeginPlay called before or after OnPostLogin?

[wary island]

Hello! Has anyone had a problem with ClientTravel only working in a packaged build but not in the editor? We have tried both the function and using the console command and both only seem to be working in a packaged build. We are using Unreal 5.4.3.

[short arrow]

Pretty sure server travelling and the likes regarding seamless travel does not work in editor.

I'm not 100% on that it's been a while. But I'm pretty sure seamless doesn't work in editor

[grand kestrel]

You should expect PostLogin to be called later because it occurs from replication
But I don't think there is a clear requirement for this to be true, so you shouldn't rely on it being true

[clear copper]

That's what I thought

[sour cradle]

I know this is a dumb way to do it but im super rusty with UE. Im just trying to figure out how to pass a variable to the server. So heres my issue. I am working within a widget and I'm trying to pass text to an actor that's in the map. But its not replicating from client to server and in theory it should here's my setup

https://media.discordapp.net/attachments/225448446956404738/1271625071378825307/image.png?ex=66b804a2&is=66b6b322&hm=23d7e8de671c6e1a95861be763465a56921d080667d84c39efff5d1a6e87aaac&=&format=webp&quality=lossless&width=1134&height=706

when I pass that text variable to the actor which contains NewVar 1 text which has replicated selected in replication" It will only show on the client not the server

I forgot to mention the actor itself is also set to replicate

if I were for example to set the variable on the server it would replicate to the client though

[dark parcel]

You don't do RPC in widget, it is not replicated.

Route it through what your client owns. PC or character

[sour cradle]

ah ok dam so I gotta put the replication event in the actor itself then

[dark parcel]

the actor has to be owned by the calling client

or ServerRpc gets dropped

[sour cradle]

hmm ok then so maybe I could just store them in the gamestate then

[sour cradle]

dam my idea didnt work

in the widget

in the gamestate

I expected the variable to pass from client to server but it didn't. I think gamestate may probably be the wrong blueprint class to use

even know I want to store variables there eventually

[sinful tree]

You can't RPC to the server on an actor the client doesn't own. Clients should never own the gamestate.

[sour cradle]

ah ok that makes sense then

if the client has to own it then it gotta be player controller then

[dark parcel]

Read the pinned material on ownership

[sour cradle]

ok will do

[clear copper]

If I call OnPostLogin in my own gamemode, is there any reason to call the parent's OnPostLogin? Is there anything important in the base GameMode's OnPostLogin?

[sinful tree]

Most of the base gameplay classes call separate implementable events from their actual functions... If you've created a GameMode based off of say GameModeBase, then GameModeBases' OnPostLogin would still be called. If you make a child of your own custom GameMode and had functionality implemented in the parent in OnPostLogin and you want that called in the child while also having additional logic in the child's OnPostLogin, then you would need to make a call to the parent.

[clear copper]

That makes sense, thanks

[marsh hamlet]

I am trying to test local multiplayer connection with simple ip (127.0.0.1:7777) port cli parameters in packaged builds. I can not get it to work with shipping builds though. Everything else is just fine like development build or test build. What might I be missing. Any idea?

[dark parcel]

port forward? not sure

not using steam is unimaginable for me

[thorn warren]

Yo quick question, would it be possible to get multiplayer working on two devices running a different engine version?

[sour cradle]

@dark parcel thanks it took me a little while but I got the full grasp of it now. Its a bit confusing at first but its pretty easy once you get it

[dark parcel]

takes a while for it to click to me

but yeah, it isn't hard once we get the grasp

[sour cradle]

I wish there was a sort of warning that would pop up whether or not its not currently owned. I noticed you could also setowner but I dont think its a great idea to use that

[dark parcel]

there should be when your RPC get dropped

scour the log

[dark parcel]

Yes you can setOwner but use with caution and within context. Issue with Set Owner is there can only be one owner

[sour cradle]

yeah I figured that if it were used in a multiplayer instance it would need planning otherwise something like a FPS would probably break the server

[dark parcel]

not to mention exploits etc

[modest crater]

https://dev.epicgames.com/documentation/en-us/unreal-engine/setting-up-dedicated-servers-in-unreal-engine

By default, a dedicated server listens on the localhost IP address (127.0.0.1) at port 7777. You can change the port for your dedicated server by adding the command line argument -port=<PORT_NUMBER>. If you change the port that your server is using, you will also need to change the port when connecting the client to the server.

[marsh hamlet]

Not port forwarding. I simply want to connect to a server instance on the same machine. This is because I had a problem connecting to PlayFab and I wanted to see if that works locally in the first place. Note that development build, test build configurations connects successfully. Only shipping client is a problem.

[marsh hamlet]

Do you mean the shipping build configuration changes ports somehow? Using a development or test build with the exact same IP and port numbers, everything is OK, and the connection is successful. Only the shipping build can not connect in any way.

[sour cradle]

you can change that in the engine.ini aswell cant you?

[thin stratus]

What do your logs says? I assume your server remains as a Dev build?

[marsh hamlet]

It has no mention of incoming connection. And plus I did a network trace by WireShark. And that tells me in Shipping build, there is no request from the client process even.

[thin stratus]

And you don't have Client Logs? Did you consider enabling Logs in Shipping?

You have a Source Build anyway after all

[marsh hamlet]

I didn't do that yet. I first wanted to learn if there is a bug or something lately or if I am missing something. I guess I will have to do that.

[thin stratus]

Not aware of anything.

You might as well make a fresh project with just some UI to connect and to tell you if you are connected and trying that out

That way you know if it's UE or your project.

[marsh hamlet]

I made an empty clean ThirdPersonTemplate project, and that didn't connect as well.

[thin stratus]

Then you'll need to some logging I'm afraid

If you have OSS Null enabled and connect via IP; there isn't too much that can go wrong on UE's side

[marsh hamlet]

Thx for the help mate. I will need to dig down more.

[sour cradle]

@marsh hamlet so I had a similar issue

It was AVG firewalling the connection even though I set firewall rules

Try disabling your firewall and antivirus for a second

And yes it firewalled it on localhost somehow

[molten vine]

Not sure if this is a multiplayer issue, but I'm currently tearing my hair out over this. I'm trying to make a first person killcam system using ue5's demonetdriver recording system. I've got the basic fundamentals of the system working. It records the replay, before loading a duplicate level to play the replay in before returning to the level after the replay is played. In this system, my character is a fullbody character, running no procedural animations(for testing purposes) with no replicated pitch variables (also for testing purposes) And I am setting my view to the view of the killing player in the replay.

However, The mesh of the character lags weirdly in the replay, constantly clipping through the camera and not updating quickly.
Notes:
Animations play fine
Particle effects play fine
The characters do not move glitchily while on the server, so it is not a replication issue. And adjusting network parameters does nothing to help.
What I've tried:
Both of my clients have stable 50fps frame rates.
Both clients are recording at a minimum frequency of 30 and a maximum of 50.
My camera has an interpolation to follow the character's head bone. It is definitely the mesh that is glitching around.

Video: https://drive.google.com/file/d/1g9dwXZu2w16DVN1ZNIWUzHsUk8lbEwUP/view?usp=sharing

[compact flame]

This event works for spawning and possessing but once a client possesses no one else can see the pawn move its just there. even when the player that possessed it is moving

[twin juniper]

can someone help me, this isnt working on the client side
but on the server it works just fine

PossessedCharacter (i.e possessed pawn) is set to be replicated as well

[thin stratus]

I'm not sure you want to preserve the Controller. Cause that has some extra stuff going on in the GameMode

[twin juniper]

got it. The main thing I want to preserve though is the PossessedCharacter though
even on the client, the function's being called, apparently as i'm testing it out but it's just not saving the character

[shrewd ginkgo]

how can I change an variable in ingame gamemode from lobby level (menu gamemode)

[bitter robin]

You make a RPC that runs on the server in the game state and set the variable there.

[shrewd ginkgo]

Can you tell me step by step, I may not be able to do it because I'm a beginner.

this is game mode

I want to change spawn rate from lobby

it doesnt work because I use menu gamemode in the lobby

[thin stratus]

That's not possible that way.

There is only one GameMode at a time.

Why do you need to do that?

[thin stratus]

GameState can't run ServerRPCs...

[shrewd ginkgo]

because I have 2 diffrent game mode for menu and ingame

[thin stratus]

Then you need to either persist the Data outside of the GameMode, or use the OptionsString when ServerTraveling.

[bitter robin]

Oh? I remember it wrongly then, I suppose it would go in the playercontroller. Eitherway, it seems I'm misunderstanding his goal too, I thought he was trying to set the game settings while already in the game. But he is just setting the game settings it seems before the game starts.

[thin stratus]

Yeah, they are in the Lobby and want to set Settings that are used in the Game.

And the easiest way to get some of those settings across is with the OptionsString

[shrewd ginkgo]

like that ?

[thin stratus]

Yeah, you can append more options to that Command

You currently have servertravel <mapname>

You can add more like this:

servertravel <mapname>?<key1>=<value1>?<key2>=<value2>

So e.g. add 2 more pins to your append node.
In one you type ?SpawnRate=

And the other one you connect your SpawnRate variable to.

Then in your Game GameMode, in the BeginPlay function, you can get the OptionsString, which is basically the string you constructed there, and grab the SpawnRate from it again.

Or like this if it's not an int originally

[shrewd ginkgo]

thank you very much, I was very stressed because I couldn't do it

[thick flint]

Hey i have a strange problem, when i attack a other player in multiplayer with my melee combo the player who IS attacking are getting damaged instead of the other player.
I used my system before and it worked fine. But after i had a file loss, i reworked it and it woks not the right way. I can show the bluprints in ScreenShare or Screenshots who ever needs it

(The health variable is Replicated and stored in a component. The Healthbar also works fine. Its just the damage that doesnt get appllied right)

[little pumice]

track down what actor is a target and where it's passed (function argument or "reference to self" etc)

[thick flint]

i fixxed it with the initial Apply Damage node from ue5, then the damage gets dealed right. But the client damaging the host with double damage, and i dont know why

[little pumice]

mb missing HasAuthority check? do stuff on server not on both client and server (not considering client prediction here)

[thick flint]

where would i be check the authority? When overlapping the enemy? BeginPlay? Or when the input is triggerd?

[little pumice]

depends on your "architecture". Looks like you are lacking of "ue client-server networking" basic knowledge

[thick flint]

Oh god damn yes xD

Wow i fixxed it

thanks

it works

[little pumice]

yeah but now client see result with a delay (network latency) it may be expected behavior or may be not (from game design perspective)

[silk nexus]

After adding a player's pawn to the SeamlessTravelActorList and triggering Seamless Travel, that player's pawn reverts to the game mode default. This attached wrapper function just calls the default GetSeamlessTravelActorList(bToTransition, ActorList);

What am I doing wrong?

This results in all listen server and clients getting the default pawn

Is there any more detailed documentation on seamless or server travel? I've read the official documentation
https://dev.epicgames.com/documentation/en-us/unreal-engine/travelling-in-multiplayer-in-unreal-engine?application_version=5.3
And
https://wizardcell.com/unreal/persistent-data/#persisting-data-across-seamless-travel

But so far I don't see a way to solve this problem.

[clear copper]

I'm having an issue with a client accessing a variable. I have a replicated struct variable in my GameState that is just a String and a Texture2D. The host can open a widget and get that struct data with GetGameState to populate its widget, but the client can't. A replicated variable on the GameState should be accessible by every client, no?

[thick flint]

thanks, youre cool

[gray sparrow]

how can i set team variable in my controller before the game start?

[silk nexus]

Where do you store it?

[short arrow]

CMC sends out a multicast about movement information constantly, Does anyone know if the cost is relatively the same to loop through a list of relevant players and just send them each an RPC rather then doing a multicast? I need a way to send specific players information about something. But multicast is not ideal due to the fact that it's based on net cull distance
https://i.gyazo.com/ecadcf517cfb34d1a219412b37918e56.png

[gray sparrow]

idk thats why i ask you

i have a plugin with a c++ function that read very controller and need their team variable.

but the function start on begin play

[silk nexus]

I store mine in a custom player state

[gray sparrow]

its fast enough?

i can read the variable on even begin play?

[silk nexus]

The player state has a variable that stores the associated team, and I also increased the net update frequency

You should always check to ensure it's not null, but yeah probably

[gray sparrow]

and its replicated? every controlelr has his own team in player state?

can you maybe send me the code? or a picture?

[silk nexus]

Just the player state

[gray sparrow]

how do you replciate the varibale to each controller

can you send me maybe a screenshot?

[silk nexus]

According to the network compendium, I understand the player state and its variables are mirrored in the client

For the specific client, that is. So, Client 1 has Player State 1, and the server has a Player State 1 which is effectively the same as the client 1 Player State 1.

[gray sparrow]

? i need every controller has its own team variable choosen in lobby

can you send me a screeenshoot how you did that maybe?

[silk nexus]

https://cedric-neukirchen.net/docs/multiplayer-compendium/framework-and-network

I don't store team in my player controller, only player state

[gray sparrow]

how can i store it in my player controller? -.-

[silk nexus]

You could just add it as a variable?

[gray sparrow]

there is no time

i need to read every controller team variable on level start -.-

[silk nexus]

Why is there no time? Why don't you just add an event that checks on all the clients loading in?

[short arrow]

Turns out the answer to this is, multicast is actually cheaper then individual RPC's due to the way I believe UNetDriver handles sending packets. Without going into detail creating an individual RPC for every actor would bypass some optimization techniques. It's relatively minor but would be less efficient in a large scale game where many factors are at play

If you've got about 10 players in your game and you chose to handle everything through RPC's instead of multicasts it should be totally fine, though not good practice at all. In large scale games though you would likely lose a considerable amount of cpu time

Also wtf
https://i.gyazo.com/74c9e865e441b1e561605de25d94e577.png

[short arrow]

are you not getting errors trying to access player controller 1?

is this local multiplayer

oh yeah so player 1 controls work but player 2 controls doesn't

I remember that being a common problem

I remember it being more involved then that, and also the replicated events your making aren't relevant for co op multiplayer, it's fornaught

until someone comes and offers a more direct solution I remember having this problem years ago and the only way I could get it to work was by following this tutorial
https://www.youtube.com/watch?v=98hu9MPm19c
It used the old input system but it should work the same way if you swap it out

[charred crane]

I have a listen server as my player party, if I wanted to have a global chat for all logged in players (that aren't in game), would I need a server for that? Or is there some other way?

[short arrow]

No matter what you'd need a server, it could be like a steam lobby, or a listen server everyones connected to in game, or a server running off your computer, or something similar. But somewhere something has to host that information to receive and send the chat data

I think a steam lobby is probably your best bet? But I thinkt here's a cap no how many players can be in a lobby

[charred crane]

Yeah sorry i meant would i need a dedicated server

There would be the party chat for the people in a listen server party out of game, the in game chat which is on a dedicated server, and then I want an out of game global chat that could be between parties.

[kindred oyster]

Hey, I have a Question. I Have an Actor Component on PC that should also do Server Events and from there Multicasts. This seems to not work. Isn't this possible?

Ok, the component on playercharacter seems to work

is it true that Player Controler Component cant do Server / Multicast Calls or was the reason a other?

[sinful tree]

PlayerControllers and any of their components only exist on the server and the owning client. You cannot use them to communicate to other clients.

You can send an RPC to the server on a player controller and then have the server replicate back through another actor that is replicated on other clients, but not the player controller itself.

[kindred oyster]

in this case I want spawn an actor RPC to Server

and then Multicast an Niagara on clients

I thought this will work - Maybe the PlayerCharacter is also the better choice for this

[sour cradle]

So I got a pretty unique issue I don't think I'll be able to get around. I am constrained to blueprints and can't install plugins BTW it's part of the ruleset of my dev environment.

I'm trying to find the local session after it's created. Even if you use find sessions it doesn't find the local session

I'm adding that information to a structured array and want to append a GUID to the structure but I can't seem to grab the local session. Information

[sour cradle]

Well I found a funny work around

I could just pass the server name to the player controller and to the server. Have the server run a compare and send the data back to the client

but this in my opinion is not the greatest way to do it

[left heath]

So I have a geometry collection component I have been using for destructible scenery. It works great and how I want everything to interact with other physics objects. It even works over networked servers just fine as well. The only issue is the "WAY" it decides to break is different for each client. I I'm having trouble finding resources that speak on this specific issue, with geometry component parts. Anybody have any ideas on how to approach syncing the broken pieces of a geometry collection across multiple clients?

[dark parcel]

So look at this, every client only have their own PC yea?

What you are doing is running a server rpc from client. So you are telling the server version of your PC to run a multicast event. That multicast event will run on all machine that has the PC except the other client doesn't have your PC so how do you think the other client will run the Spawn Niagara from a controller they never know to begin with?

[chilly haven]

Hi,
About replication.
I'd like send frequency of certain unreliable data to each client to decrease over distance,
i.e. send more updates as an actor gets near a client.
My understanding is that Unreal has nothing like that? It's binary relevance: send at set frequency or don't send.
Is that right? Anyone do anything like this?
Thanks

[hollow eagle]

https://dev.epicgames.com/documentation/en-us/unreal-engine/actor-priority-in-unreal-engine

[chilly haven]

I guess that's the closest but not sure if would give enough control, e.g. does it only kick in when BW is saturated?

[hollow eagle]

it's not necessarily about bandwidth, it's also about server load. But if you have extra bandwidth and CPU to spare why would you want to send things less?

[kindred oyster]

Ok, because every Client has only there own PC. And all clients has all characters (pawn). Right?

I saw a Table where is a Overview need to refind them and save it

[chilly haven]

To minimize costs. Lower BW and CPu means I can run more dedicated servers on a host.

Or, the dedi can support more players

[hollow eagle]

Which is why you set bandwidth limits properly and NetUpdateFrequency.

NetUpdateFrequency is how often an actor is considered for replication.

That doesn't mean it'll actually get sent that often, it's just how often it is checked. And priority will throttle it further if there's a bunch of higher priority actors being considered in a network tick.

[chilly haven]

NetUpdateFrequency is fixed though

[hollow eagle]

yes, but priority isn't

You have to be considered for replication to be able to check a distance and adjust priority.

[chilly haven]

I can experiment with priority but am skeptical it can fit my case

[hollow eagle]

It's literally built for this case.

Net update frequency doesn't make sense to be adjusted based on distance because it's not a per-channel option - it's how often the server evaluates an actor for replication to all channels. And again, you have to be considered for replication to decide whether or not to replicate that tick.

[chilly haven]

For example if an actor is far, I might want to update some data every 2.5 seconds, but if near, every 0.25 seconds, and lerped for inbetween distances. Per channel.

[hollow eagle]

And priority will do that, just not with second granularity. If nothing else is replicating you wouldn't want to throttle that much either.

The engine has controls for bandwidth limits - even per-connection dynamic bandwidth limits.
For CPU you're going to have a better time using something like push model (or even moving to iris) if replication is taking up a big chunk of CPU time.

[chilly haven]

iris is live?

[hollow eagle]

Iris has been available for multiple versions and is beta in 5.4.

[chilly haven]

ok. will look at that too. cheers.

Any idea how much CPU and BW it saves, any case study done?

[dark parcel]

@kindred oyster

[nova wasp]

You could figure this out pretty quickly by just creating a situation with lots of replicated properties to poll and just testing it?

It's more or less a cvar to toggle on and off, but you might need to swap some fast arrays to iris fast arrays

[chilly haven]

great, if it is that easy I'll give it a go with my current project sometime.

[kindred oyster]

Wow yeah thanks

[pulsar meteor]

i'm on unreal engine 5.4.3, and i'm trying to set up local multiplayer but whatever I do I can't get inputs from player 2 to work. its not the hardware, and the player controller exists, but it's just not taking input, anyone know whats going on?

[lost inlet]

Well how is your input implemented?

Gonna need details here

[hybrid crown]

Little question, i've made this modifications in replication source code of AActor :

bool AActor::IsNetRelevantFor(const AActor* RealViewer, const AActor* ViewTarget, const FVector& SrcLocation) const
{

// ...


    return !GetDefault<AGameNetworkManager>()->bUseDistanceBasedRelevancy ||
            IsWithinNetRelevancyDistance(ViewTarget->GetActorLocation());
}```

(Basically, looking for viewTarget location instead of src location). I mind if someone already did the same and wonder about bad practice ? Or issue ? The goal was to avoiding modifing this for every actor of the game for spectator system.

[hollow eagle]

It's a pretty pointless change because SrcLocation is already based on view target.

[hybrid crown]

Hum, this enter in conflict with what Wizard say in his article.

or i miss something

[hollow eagle]

What do you think this conflicts with?

Oh, I see. I don't know if he was looking at an old version of the engine or what, but at least as of 5.4 that change would do nothing.

[hybrid crown]

Hum dunno, i'm in 5.4 but it doesn't look like the view target is taked

only the src loc

[hollow eagle]

SrcLocation comes from AController::GetPlayerViewPoint. If you want the viewtarget to always be the viewpoint then override that function.

[hybrid crown]

will look into it

yeah, cause the issue is the Pawn we are viewing -> replicated. But not the actor around him.

[hollow eagle]

Look at the implementation of APlayerController::GetPlayerViewPoint. It might not do what you want in all situations, override and adjust to your liking.

[hybrid crown]

thanks, will do it !

[pulsar meteor]

Enhanced input

[lost inlet]

yeah that isn't really adding detail, detail would be showing your implementation

[hybrid crown]

so, dunno if you already face that but. As the out location is LastSpectatorSyncLocation
When we spectate, but Spectate is local, so we should like send a RPC from the PC every X second to sync the loc ?

[hollow eagle]

it already does that

[pulsar meteor]

I guess I don't really know what to show. I've got a character, it works, it takes inputs I've set up with enhanced input, I create a local player, but the local play won't take input from additional controllers. What should I show you here?

[lost inlet]

the input events

[pulsar meteor]

It's nothing special, one moment I'll send a pic

[pulsar meteor]

heres the input events

[lost inlet]

and this is on what blueprint? input events aren't networked

[pulsar meteor]

player controller

[lost inlet]

and what happens, did you add a breakpoint to see if it triggers?

what PIE mode is being used?

how do you enable your input mapping context?

[pulsar meteor]

it works for one not the other

[pulsar meteor]

both seperate window editor and standalone

[pulsar meteor]

the default gamemode setup

[lost inlet]

well that'll be a good reason why

since game modes only exist on the server

[hybrid crown]

Thanks

For info this this one : GetFocalLocation()

who is responsable

[pulsar meteor]

i'm only running one client

its a local game

[lost inlet]

yes and clients don't have game modes

[pulsar meteor]

also its the only context I have in default contexts it assigns it automatically, I didn't mean game modes

launches as server, same thing

wait, it works if I launch as 2 clients, now i'm confused

or rather a server/ client

so it detects input if I launch as a listen server and a client, but that's not what I want. so I gotta be missing something, any thoughts?

I also just found out If I set the second player controller to use the first player controllers controller, it swaps properly, but the second player controller still isn't recieving input

[karmic jacinth]

I'm curious if it is possible to only replicate certain properties of a core component? In this case I want to only replicate part of a Capsule component. Should I use a Replicate Property on my parent class (in this case a character) to control the replicated values or is there an other way to do this?

[thin stratus]

Every Class controls what variables are replicated. You'd need to alter the Capsule Component either via Source or via a ChildClass that overrides the DOREPLIFETIME calls.

[hollow bridge]

What are the consequences of running low tick rate on a dedicated server in terms of collision / ai / movement?

[karmic jacinth]

Ok, well I guess it will be just simpler in my case to use a specific parent rep notify variable which will control the capsule component state. Thanks for the info!

[thin stratus]

Correct, that's what one usually does.

[undone needle]

So, easy question, what would be the best approach to create a server side unique ID generator that players can request from and increments everytime a player requests a new ID? Should I simply put in on GameState? Or is there a better solution I am not seeing?

[short arrow]

New GUID creates a new ID everytime you call it

[undone needle]

Forgot about that, but I'm afraid it will slow down my DB if I index it by GUID instead of integer

[short arrow]

Wonder what makes you say that. I think an FGuid is 16 bytes compared to an int32 of 4 bytes. But these days that doesn't mean much

I could maybe see if you're looping an excessively large amount of times through an excessively large amount of FGuids

But is it possible you're worried about nothing?

[undone needle]

for a brief moment I was under the impression that it was 128bytes...

you're right its not that big a deal for my project, will probably incorporate that, thanks!

[short arrow]

That's bits :p

There are 128 bits in 16 bytes

[undone needle]

yeah lol

[gray sparrow]

how can i set """team variable""" from my lobby controller to my player controller?

through level travel

[vagrant grail]

General question : Imagine a player A is shooting to another player B 1 big sphere projectile being really slow and I as player C enters the area of where that happens (as i was not there before) so everything in there loads for me on my client (so the players models, buildings, etc...).

What's the proper way to achieve that so when I enter that area I can see the big sphere projectile being shot at player B as I was not there when player A fired the projectile.

Like if I use an RPC, as I was not there when he shot, that means I would miss the RPC since Unreal would only send the RPC to clients being in the range of that player or projectile.

If I use a replicated property, I guess the starting of the shot would happen again on my client instead of me experiencing the sphere projectile already traveling.

So what's the proper way to handle this situation ?

Please ping me if any answer 🙂

[modest crater]

if the sphere is a replicated actor then a joining client will already see that, if its a locally spawned actor that each client simulates then you need to tell the connecting client that a sphere should exist here going x speed

[vagrant grail]

thanks 🙏

[modest crater]

With the second option you can use some things like clients ping to determine how far ahead of the received position it should already be offset by the time the client receives it (just for more acurate prediction, people do it a lot with animation montages where the start time is offset by the ping)

[ruby lake]

Advanced Sessions suports EOS plus for crossplay?

[modest crater]

GameModeBase.h

    /**
     * Used to swap a viewport/connection's PlayerControllers when seamless traveling and the new GameMode's
     * controller class is different than the previous
     * includes network handling
     * @param OldPC - the old PC that should be discarded
     * @param NewPC - the new PC that should be used for the player
     */
    ENGINE_API virtual void SwapPlayerControllers(APlayerController* OldPC, APlayerController* NewPC);

[gray sparrow]

but i dont want seamless travel ... how it work without seamless travel?

[modest crater]

I don't know.

[gray sparrow]

cant i safe my controller and team varaible chossen in lobby safe it in game instance?

and then ask game instance which controller has which team?

[modest crater]

Of course you could?
But you should store that state somewhere not on the client, otherwise a client can change its value by cheating.

Serializing a value and reading it again is not hard. It's the implementation you chose that affects how it all works.

[gray sparrow]

how can i set the right controller and his right team variable in game instannce?

and how can i ask which player has which team?

[fossil spoke]

Why do you think you dont want Seamless Travel?

[clear copper]

Do all clients have access to all PlayerStates?

[fossil spoke]

Yes

The GameState has an Array of all PlayerStates

[clear copper]

Do they have access to all variables or only replicated ones on a PlayerState?

[fossil spoke]

What do you mean?

Access to variables has nothing to do with Replication

[clear copper]

I have a variable on the playerstate that I want other clients to see for use in their UI when they inspect another player

but i'm having trouble, could just be how im accessing it

just wanted to make sure I wasn't crazy

[fossil spoke]

In order for other Clients to know about changes to variables, that variable needs to be Replicated.

[gray sparrow]

with seamless travel my whole project doesn work anymore...

[fossil spoke]

You probably need to do research on what a Hard Travel and Seamless Travel is.

So you understand the difference

And what their purpose is.

[gray sparrow]

cant i safe player controller 1 = team xx ... player controller 2= team xx... PC3 = team xx

and then when teh game start i can cast to game instance ans ask which team is player controlelr 2 for example?

[thorn warren]

can anyone explain how to access the clients from a listen server to possess a pawn? It seems the normal way you'd do it thru the player index is only meant for local multiplayer

[opaque forge]

What's the best way to test a player joining late in development (for debugging)

When you play with multiple players, they all join at the same time

[opaque forge]

Great!

Then how do you use it?

[fossil spoke]

It literally adds a new Button to the tools panel that lets you Add Client at any time during PIE sessions.

[opaque forge]

cool

[fossil spoke]

Can you explain what you are trying to achieve?

[thorn warren]

I'm trying to setup an asymmetric multiplayer where the server and client have different player controllers

[fossil spoke]

You cant have different PlayerControllers

Are you sure you are using that term correctly?

Do you mean different Pawns?

[thorn warren]

yeah pawns

can't figure out where to tell the client to posses a pawn rn

[fossil spoke]

Clients dont possess Pawns

The Server possesses them

On behalf of the Client

The Client is told by the Server they are now controlling a Pawn

[thorn warren]

ok so where can I do that 🤔

[fossil spoke]

The Controller has a Possess function

Which you can pass in the Pawn to Possess.

This is basic stuff

Which is likely covered in many tutorials.

Online.

[thorn warren]

such as?

[fossil spoke]

https://www.youtube.com/results?search_query=unreal+engine+multiplayer+possessing+pawns

[thorn warren]

dude I already looked that up why do you think I'm asking for help here

those examples don't detail how it works with a listen server

[fossil spoke]

Not sure why you think a listen server has anything different to do with it? Everything is a Server, except for a Client.

Standalone is a Server

Dedicated is a Server

Listen is a Server

[thorn warren]

I have no issues with the owning player possesing pawns, thats just regular unreal stuff

I'm talking about the client

[fossil spoke]

@thorn warren Post the code you have already tried, with which you are having trouble understanding how it should work.

[thorn warren]

I've tried a few different things, right now this inside a custom player controller allows the client to possess the pawn but not the server, despite there being enough pawns in the level

[fossil spoke]

You are possessing the same pawn. Which overrides the previous possession.

Get(0) is just get element 0 from array.

[thorn warren]

I switched it to a keybind to see if I can get 2 different pawns working, but now neither does

I tried switching the default pawn for third person in the gamemode and that seems to work ok, but I still don't really understand how the system is meant to work

[silk pelican]

hey to replicate iti have to add custom events or run on server before branch or after bracn\

hello anybody

bro

[kindred widget]

Bro, you're still being impatient, and you still have not actually worded your issue differently or coherently.

[coral badger]

Usually, when setting up different startup pawns (which I assume you are trying to do because the variable that determines the pawn type is the player controller), you would instead approach this from the perspective of overriding the initial pawn that gets spawned, like so: https://www.youtube.com/watch?v=yfZUMUYFmN8
In case you need this to happen dynamically during gameplay, if you get the above working, this can be further adapted.

[thorn warren]

I'll give that a try later, thanks 🤙

[rustic sable]

Since niagara effects dont play on dedicated server is there any good way to check for OnSystemFinished? trying to avoid doing a server call when this happens on the client obviously

[latent heart]

If you know how long it will take, you could set up a timer.

Not ideal, but yeah.

[white smelt]

this is really bad you know,

[coral badger]

Is it?

[tardy fossil]

i dont suppose theres a way to change the default NetCullDistanceSquared globally huh?

[thorn warren]

I think I solved my issue with a cheeky gamemode bool check

[woeful trout]

for some reason the player revives when the other player is not downed

[twin juniper]

hi guys, quick Q, during seamless travel are playercontrollers persistent by default or do they get destroyed and players are reassigned/spawned new controllers?

[raw drift]

Hey guys, i'm having a problem, i have a platform when a player enter the overlaping box of the platform, it moves, when he get out, it come back to original place. Perfect !
But when he does that and ANOTHER player jump on it again, then it work BUT it has a Very weird behavior and it teleport every second to the place it is supposed to be and try to come back at the same time....
Here is my graph what am i doing wrong ?
Thanks

[undone needle]

Sounds like a rubberband issue where your box position is set on the server but not locally

[lament flax]

if i change two times a OnRep var in one frame, will it rep two times or once on the final value ?

[woeful trout]

Someone help?

[raw drift]

Whereever i fire this, with server, withotu server, in MC or not, it does this

[rustic sable]

First thing I notice why are you doing an authority check followed by a server call? if you are checking for authority all following calls are already on the server.

after the cast to character I would think you would just want a multicast the 'Move Component to' OR just to have the static mesh replicated and just try move component to directly on the server, not sure if the clients would replicate position of a static mesh that way but worth a shot

if it's only moving on the server and not properly replicated it would explain the teleports

[clear copper]

In my GameState I have an variable that keeps track of what character each player has selected. I have it set to RepNotify so that if a player changes their selected character, everyone's UI updates to reflect this change. What's the best way to do this? Should I have the RepNofity function trigger an update event on the local PlayerController or PlayerState?

[sinful tree]

You should likely be storing what character is selected in the PlayerState.
The OnRep on the PlayerState can then get the Pawn of that player using the GetPawn function and have it call the event on the character to update itself based on the selection.
You'll also need to use BeginPlay to attempt to read the playerstate's current value of that variable and again update itself based on the selection.

[clear copper]

The PlayerState only tracks what character the owning player has selected. In the UI, every player should be able to see what all other players have selected. Wouldn't an array of players and their selections be best stored in the GameState?

[sinful tree]

No. Each PlayerState is a reference to each player that is replicated to everyone, is always relevant and you can have variables that are replicated out to everyone. This is usually the best place to store data that needs to persist about any particular player.

[clear copper]

Ah ok, I'll give that method a shot

[sinful tree]

In fact, the GameState itself already has an array of the PlayerStates in the "PlayerArray".

[clear copper]

Yeah I was using that at first

[charred crane]

Does anyone know how I would go about having a dedicated chat server that my players connect to that is exclusively for messaging? Kinda like an MMO general chat that users can connect to while in my front end.

[latent heart]

I wouldn't use unreal for that.

Set up an irc server or something. I'm sure there must be an ue irc integration. Or some custom web thing.

[charred crane]

Yeah I'm just so out of my area of expertise I have no idea how I'd do this

[rustic sable]

platforms like azure already have chat functionality built into the sdk, I'm sure the other big platforms do as well

https://learn.microsoft.com/en-us/gaming/playfab/features/multiplayer/networking/concepts-chat#text-chat-translation-and-moderation

[blazing bear]

Hi, how can I access the HUD from the character class in multiplayer? I need the HUD reference to make changes to its widgets during gameplay

[sinful tree]

HUD and widgets have nothing to do with multiplayer as these are local only. The active HUD object can be retrieved through the local player controller.

[blazing bear]

I'm aware of that, and I'm trying to retrieve it like this but it crashes:

const APlayerController* PlayerController = GetController<APlayerController>();
PlayerHUD = Cast<APlayerHUD>(PlayerController->GetHUD());

How can I get the local player controller only? Or I'm missing something else?

Maybe IsLocallyControlled() ?

[sinful tree]

The trouble is that PlayerControllers are not replicated to all clients, only the owning client and the server will have it. If this code exists within a character, that character can exist on all clients, so when this code is called, GetController() may return a nullptr and the next line is attempting to access GetHUD() from it which causes the crash.

[blazing bear]

Aah I understand

So the getcontroller isn't getting the correct controller of the specific player

[sinful tree]

There's no good path from a character to get to the local player's HUD, unless it's the character that is being locally controlled, but then this would mean that code would only ever execute on the character that the local client possesses which may not be what you want.

[blazing bear]

Locally controlled character means that it doesn't have anything replicated ? The terms confuse me a bit even though I read the docs and stuff xD

Or that other clients or server can't do anything to that character

[sinful tree]

When I play a multiplayer game, I am a client. I have a character that I am in control of. That character is considered locally controlled by me.

[wary ermine]

Hey guys, I've got a question. I am making a Local MP Game, I want each Player to be on its own screen instead of having a splitscreen. I could fine a few links guiding me toward ndisplay plugin but couldnt find a proper documentation or tutorial for games so far. Any idea or a better solution? 🙂

[blazing bear]

Ah got it, well yeah, I'm trying to access the HUD of the locally controlled character, I don't wanna access the HUD of other characters. Each character is in control of its own HUD

[sinful tree]

Ok, so then all you would really need to do to prevent the crash, is check if your "PlayerController" variable you created is valid before proceeding with trying to get the HUD from it.

You may also want to consider having your widgets manage themselves rather than having the character have to tell the widgets to do something...
An example would be that you can create a widget and in its construct event retrieve the controlled character and read the values from it while also binding to events to know when the local controller's character has changed and to know when it should update what its displaying using event dispatchers.

[blazing bear]

Ah so better have them listening to value changes using delegates

Yeah I think that's a more sturdy way of doing it

[crisp shard]

is game instance the only way to carry data from like a main menu to the actual game ?

i want to have a profile creation page prior to the player joining the game but not sure if i should be storing all these variables in the game instance

[leaden bone]

Hey, is TArray replication optimized by default? I mean if I modify only one item on the server, does it replicate the full array to clients or only the diff?

I'm mostly concerned about the bandwidth here

[nova wasp]

With Iris yes, without no

Just use a fast array serializer

It will delta serialize and let you react to individual changes

[leaden bone]

Ok, that's what I wanted to know

Thank you

[viscid tapir]

Hey! I noticed that MoveToLocation does not replicate the movement to the server. Is there any known fix for that ?
Can we achieve something similar to the CMC prediction/replication ?

[dark parcel]

Never done it, but don't see why it shouldnt

Go to your project setting and look for something called allow client navigation

Maybe that helps

[ashen plume]

which one of these should i use for short character speed increases? they both describe roughly the same use case

[dark parcel]

Why would you use either one?

Use the flag to change speed imo

[teal frost]

As far as i know data stored in the game instance can be accessed anywhere in the game.
It's not the only way to move info between levels etc.
You can save and load to/from a save state which can accomplish the same thing while retaining information when the game is closed.
If I'm not mistaken you can retain set values by using async loading as well.

[ashen plume]

what flag? i already modify the character's speed but due to network latency from server to client, the clients get their positions corrected

[quasi tide]

They're talking about extending the CMC and properly adding the change to the SavedMoves process.

[grand kestrel]

The first one means it won't check for client error and send corrections, when it becomes false again, there will likely be a massive correction as a result, it isn't accepting/taking the client's location
The second one means that it will take the client's location and apply that to the server's location
Neither of those are correct for what you're doing

[ashen plume]

they both describe short bursts of movement, I would assume that a short sub second dash or speed change is exactly that

[grand kestrel]

If you really want to allow client to be authoritative during your dash ability, then instead of using that boolean, override the corresponding virtual function instead ( UCharacterMovementComponent::ServerShouldUseAuthoritativePosition )
That way you can check, before disabling it, that they haven't exceeded an acceptable position - basically having the server verify the end result to some degree to help prevent cheaters from teleporting while its active
Cache the start location, and compare it to current location, and return false if its exceeds the max allowable distance

My repo shows how to implement net predicted abilities such as sprinting, that you can use as a template, if you want client-side prediction to prevent cheating without desync properly
https://github.com/Vaei/PredictedMovement/

[ashen plume]

ah, that should help, but then what use case would these flags be for?

[grand kestrel]

The function checks the flag, that's all

The flag doesn't allow you to do server validation, hence the recommendation to override

If you're building a co-op game where you don't care about cheaters at all you can actually set AGameNetworkManager::ClientAuthorativePosition to true if you want client to always have authority

And if you're not, then doing it using client authority is probably wrong

There are valid cases in competitive networked games for doing it, but not for general movement abilities

[sharp hamlet]

Quick question, can we use replication logics (multicast and repnotify) inside level blueprint?

[gray sparrow]

hey , i have trees in my level and when im zoom in the leafes become invisble and only tree trunk is visible -.-

[neon summit]

Get controlled pawn

What did you do?

It depends where you're doing it also

Use event possessed

Probably be alot better to use game state

Probably actually playerstate

[dark parcel]

Game mode only exist on server

[dark parcel]

No, I'm in class

and I don't do homework

I'm still not gonna do your homework

here is something that can help you with replication

#multiplayer message

read it X20 times

[dark parcel]

__

So it seems favoring the client doesn't always produce a nice result. I'm struggling to work out how to do projectile in multiplayer.

in client visually, the projectile will hit an enemy and explode

but with delay in place, the server doesn't necessarily see the same thing and the projectile may miss

or the other way around, the client miss but on server it will hit

what can I do to reconcile these visual difference?

[graceful flame]

Easy: Spawn projectile server only and use large enough particle effect to try and hide the delay.

Hard: Spawn on client and set a network lag based timer to auto destroy while also sending RPC to spawn on server at the same time with a location offset based on the last known position of the now destroyed client side projectile.

End result is a slightly popping projectile but it doesn’t have input lag when firing.

[dark parcel]

Question: How does the size of the particle hides delay?

atm, I spawn on client and server

with the replicated Projectile not visible in the casting client

[graceful flame]

Think muzzle flash with puffy smoke

[dark parcel]

what about a slow moving fireball

cuz that's what I'm doing 😔

There's no input lag when firing visually, as I spawn locally for the casting client

the issue is how the hit is preceived between different machines

(visually)

I'm not at the part where I'm doing any damage

[graceful flame]

With the hard way I suggested the hits are server side and can apply damage. The client projectile doesn’t need to have any explosion vfx when it’s auto destroyed. The server projectile can multicast the vfx.

I used two separate blueprints for the projectiles

[dark parcel]

I want to give the client some leniency (Under 120ms) the client hit result would be accounted for and validated by server

it's probably too punishing when a client hit on their machine but not rewarded with a damage

but no matter how I look at it, there is a cons in every route that I can take

[graceful flame]

The client projectile is short lived based on network lag and is only used for visual purposes the server projectile handles hits. You could even disable all collision for the client projectile. Worst case is when you shoot at a wall right in front of you and it doesn’t explode until after a lag delay since the server projectile is being spawned and explodes right away.

[dark parcel]

Gotcha but how to reconcile the differences? since the projectile form the client would be ahead

even if interpolate it, the projectile would rubber band then?

[graceful flame]

The problem with projectiles is always going to be an issue which gets worse with an increase of network lag.

The solution depends on the type of game you’re making and whatever feels the best vs the drawbacks that come with that approach.

[dark parcel]

that's more option to explore, I will be sure to think about it more

[graceful flame]

If you care more about syncing things than just spawn on server and make sure you have enough servers around the world that players can play without much of a delay.

[dark parcel]

Oh, it's gonna be listen server

with 4 - 6 players max

[graceful flame]

If you care more about input lag then do what I suggested and live with the drawbacks of shooting a projectile at a wall up close.

[dark parcel]

yup, I will sure to test various methods before commiting more into the ability system

[graceful flame]

Listen will have cheaters though so I hope it’s a coop game

[dark parcel]

ty for your time

imma hit the hay

[dark parcel]

Indeed it is, and I am fine with cheaters

[graceful flame]

Ok

[dark parcel]

don't have the necessary skills yet to make competetive mp game

one step at a time, if people cheat, it's their lost

kinda like baldur's gate

I even let them save locally, so there's no point in trying to prevent cheaters

it would be soo damn easy to edit the save file

thought about encrypting but what good will that do, people can just copy each other save file like in Elden ring

my plan is just to have some sort of validation from the listen server, I will not do anything more than that

[hoary spear]

Not if you hash them with a unique id from the pc that made them

Some serial number or otherwise

[sinful tree]

Steam review the next week: "My computer died so I had to buy a new one and then lost my 300 hours of progress as it says my save game can't be loaded!"

[woeful trout]

can someone help please!

[thin stratus]

I mean, that's in the GameMode, so IsServer should always be true cause there is no GameMode on Clients.

You wan to know if any of the PlayerControllers are Client or Server?

Given that it will be 1 Server and x Clients of course

Or is your game 1vs1?

(fyi, your Controller array isn't adding anything)

If you just want to know if the Player that joined is a Client or not you have two options:

• IsLocalPlayerController
• GetNetRole

Idk how the methods are called in BPs

Could also be GetLocalRole

LocalPlayerController will only be true for the Server one in teh GameMode

GetNetRole could be checked against Authority and SimulatedProxy (Server and Client)

[amber merlin]

Hey guys, anyone that have some feedback on Playfab? Looking for backend solution.

I guess my biggest question is if i should do my own server manager for matchmaking or should let playfab do it? Also how do you feel about the the service?

[thin stratus]

Everything aside, all of that will cost you a shit ton of money.

If you are fine with that, then it's really up to you if you want to spent the time on coding that yourself and paying "just" the server hosting cost on some other hosting service, or if you want to skip that and just use PlayFab and pay all the extra fees for that.

[amber merlin]

I am inexperienced with game backend, work as developer (backend developer). Made a csgo replica, gameplay looking nice and wanted to start learning about backend and implementing a matchmaking. Have you any experience with playfab, thinking about the shit ton of money quote

[thin stratus]

I had clients that used it in the past.

I can't put an exact value on it, cause it depends on what you need.

[woeful trout]

hey ahmm sorry if i bother you can you help me for the problem which i have ?

[thin stratus]

But if you get out of the free area, it's gonna be a few hundreds easily. Obviously scaling up the more severs you need.

Which means you usually need some form of monitization.

[pallid flame]

Uhh there could be alot of reasons for this problem but in your code I dont see a check to make sure the player is actually downed and in need of a revive. Is that somewhere else?

//
//
Separate problem:
My clients cant seem to call the Run on Server custom event while the host, of course, can. Any simple reasons this could be happening? I'm very new to this multiplayer stuff and I don't know if there's an obvious fix or if I specifically did something wrong

Code could be cleaner, I know, but the first print string can be called by the client but it never gets to the second one :/

[woeful trout]

i dont think so and this is actually the problem 1st how can i make this check and 2nd in the code "player doing the revive" if you can see i have all the code which is when the player detect the other player if somehow make it to eneble this code after playing the downed anim?? i mean to check when the player is making the down animation then activate all the code but i dont know how to make this if you can help me please!!! 🙂

oh and sorry for my bad english

[sinful tree]

Clients can only send RPCs on actors that they own. I'm guessing that they would not own a "BP Fire Wood Pickup".

[mellow cipher]

In our new update, we have an issue where some clients are getting kicked after joining. Seems like too much network info initially joining because some people fix it by making the host run somewhere else or not talking on voip. We're using steam networking (Not steam sockets) and I can't think of anything we changed to affect this.

Is there a timeout or bandwidth config I can crank up to fix this? This is what the join log looks like:

[2024.08.13-09.33.15:528][403]LogOnlineVoice: OSS: StartRemoteVoiceProcessing(JACOB [0x11...D437]) returned 0x00000000
[2024.08.13-09.33.15:529][403]LogAbiotic: Display: CHAT LOG:  Jooseyadams has entered the facility.
[2024.08.13-09.33.15:531][403]AnimBlueprintLog: Warning: SLOTNODE: 'DefaultSlot' in animation instance class FPArms_AnimBP_C already exists. Remove duplicates from the animation graph for this class.
[2024.08.13-09.33.15:534][403]LogNet: Join succeeded: Abiscuits
[2024.08.13-09.33.16:144][442]LogNet: UChannel::Close: Sending CloseBunch. ChIndex == 0. Name: [UChannel] ChIndex: 0, Closing: 0 [UNetConnection] RemoteAddr: 76561198053306820:7777, Name: SteamNetConnection_2147436908, Driver: GameNetDriver SteamNetDriver_2147450074, IsServer: YES, PC: Abiotic_PlayerController_C_2147436896, Owner: Abiotic_PlayerController_C_2147436896, UniqueId: STEAM:JACOB [0x11...D437]
[2024.08.13-09.33.16:144][442]LogOnline: STEAM: AUTH: Successfully kicked player 76561198053306820
[2024.08.13-09.33.16:221][447]LogNet: UChannel::ReceivedSequencedBunch: Bunch.bClose == true. ChIndex == 0. Calling ConditionalCleanUp.
[2024.08.13-09.33.16:238][448]LogAbiotic: Display: CHAT LOG:  Jooseyadams has exited the facility.
[2024.08.13-09.33.16:238][448]LogOnlineVoice: OSS: UnregisterRemoteTalker(JACOB [0x11...D437]) returned 0x00000000
[2024.08.13-09.33.16:239][448]LogOnline: STEAM: Removing P2P Session Id: JACOB [0x11...D437], Channel: 7777, IdleTime: 0.018
[2024.08.13-09.33.17:393][526]LogOnlineSession: STEAM: Updating lobby joinability to true.
[2024.08.13-09.33.17:745][551]LogOnline: STEAM: Closing channel 7777 with user 76561198053306820
[2024.08.13-09.33.17:756][551]LogOnline: STEAM: 76561198053306820 has been removed.```

Our game is also sublevel based with players logging into a void before teleporting to their last location. I wonder if I just need them to sit in the void for a bit longer?

[dark parcel]

Hmm yeah, maybe rely on cloud save and hash it with steam ID

But still the listen server can cheat anyway, so they can easily change their gold or add item as they please. So what can I do 👉👈

[mellow cipher]

Gamemode doesn't exist on clients

Most of the time, clients can only run "Execute on Server" functions on their controller or pawn

But the client on the player controller is then trying to do "Get Game Mode"

[latent heart]

No

The game mode is not replicated to the client.

The one exception is a listen server which has a server and a client (in simple terms).

[dark parcel]

Ofc, the game mode does not exist on client

As stated by others above

https://wizardcell.com/unreal/multiplayer-tips-and-tricks/

You should take your time to read, what objects get replicated.

Common advice around here is to read it 4 to 5 times and another more if you still don't get it. Mp takes some time to click.

[mental star]

With the projectile motion component, I'm having trouble with collisions

I have a ball and a Racquet that aren't colliding.

[glad robin]

I am definitely misunderstanding something with camera/player view. Inside the ASpectatorPawn, where is the camera that the player is viewing through created? I saw a SetViewTarget() call but how is the whole camera aspect handled?

[modest crater]

If I had to guess, Id say the camera manager

[glad robin]

Im away from computer rn but I was just saw this page: https://dev.epicgames.com/documentation/en-us/unreal-engine/cameras-in-unreal-engine?application_version=5.4 and I only glanced and didn't check any code but it sounds like PlayerController handles initial camera and that makes sense to me aha, I don't know why didn't see it earlier, guess I didn't look hard enough lol.

[hallow dagger]

dumb question
if I print a string in a client, and I see the message in both the client and the server, how does the message reach the server?

• is the message sent from the client to the server?
• or is the logic of the client being also run on the server, and therefor also being printed in the server?

[fossil spoke]

If a PrintString is appearing on both, then both are running it

Your assumption of it being on a Client only is therefore incorrect.

[hallow dagger]

but it I print something when pressing a key (using an Input event), and the message appear in the server and the client, does that mean that the server is of the keys the client is pressing? doesn't seem right 🤔

I dont mean getting a "Client 0: Message" and a "Server: Message"
I mean getting a "Client 0: Message" in both the client and the server

[fossil spoke]

PrintString prints to all windows

In PIE

[hallow dagger]

ah, sorry, yes, I was talking about running in PIE

[bitter robin]

there is only one debug messages list, all windows draw the same one.

[mental star]

^ anyone around that can give me an idea?

Want to make sure it'll work online multiplayer style and I know you can't do real physics online but that's made the collisions between Ball and Racquet not work

[gusty valve]

Hi all. trying to get a better understanding of clients and role authority. In a listen server structured game, only the server (host) player is Role_Authority correct? All the other connected clients would be Role_AutonomousProxy correct?

[fossil spoke]

P2P is a misnomer, dont use that term. Use Listen Server instead.

[gusty valve]

Rodger

[fossil spoke]

Connected Clients would be Autonomous proxy for themselves.

[modest crater]

**only the characters on the hosts instance have authority, so if you had Bob, Dan and Alex and Alex was a listen host he would also see Bob and Dan as authority (locally, remotely it will simulated or autonomous I dont recall, but just remeber there are 2 roles to actors)

Bob and Dan will see everyone as Simulated or for themselves, autonomous proxy

This is covered in the pins and docs tbh in better detail (then what I can "quickly" give)

[gusty valve]

Yeah I'm looking at the matrix right now

I'm trying to understand if it ever makes sense to in a listen server structured game to run code like this

Like this means they are trying to make sure this code is only executed on server, but why are they doing that for critical functionality that a client would need? (This is the open sourced GAS project by Tranek)

[modest crater]

Sure, the clients would RPC to the server to run that and the listen would already be the server and be able to run it. There is no "right" answer though

[modest crater]

because i assume its not predicted and they want server only weapon addition/removal. The client would get the spawned actor replicated to them and usually run a stripped down version in its OnRep

[gusty valve]

is there inherit danger that I put my game in by allowing AutonomousProxies to immediately execute functions like this?

i.e.

[modest crater]

danger how lol?

[vivid seal]

its less about danger and more about making sure the server is replicating these things to everyone

[modest crater]

btw its a case by case basis, how much control can a client have when doing x thing

[gusty valve]

Danger as in cheating

[modest crater]

there is no right answer

[vivid seal]

but also if you let auto proxies do things like this, they could just add whatever to their inventory

maybe thats fine

maybe thats bad

depends on your game

[gusty valve]

Even making games is a choose your own adventure game

Thanks everyone!

[modest crater]

It's all about creativity lol even writing code

[gusty valve]

Just trying to learn best practices for as much as I can as I'm really just starting out

Don't want to slip into bad habits or practices

[modest crater]

be as authoritarian as you can while also reducing lag and taking advantage of client side prediction for simple stuff.

An example is shooting, let a client linetrace and play vfx + the shoot animation but have the server only able to apply damage (and also do some checks like angle checks and visibility checks to reduce cheating)

I'm going a bit much but yeah, its all up to you and how much control you want to give and how much control you can fake.

[gusty valve]

Sounds like good advice. Thank you.

[compact flame]

How do I go about making this work for multiplayer?

[neon summit]

The anim bp doesn't replicate. You'd have to replicate it in the pawn then get it from character and set on anim bp

[compact flame]

Ah

Then that is what I need to replicate

[sinful tree]

Replicate the value through the character. Have the anim blueprint read the value in its Animation Update event from the character and set its own variable with the value so the anim blueprint can run on its separate thread.

[vapid rune]

In the multiplayer listen server (not dedicated server)...can we make a same team save system or not ????

If we assemble same team again then save system show us last saved game ...
Is it possible or not ????

[pallid flame]

How long did it take yall to learn multiplayer coding? Was it hard? Cause ive been trying for like 3 days to get a hang of it and its just a massive headache

[grand kestrel]

3 days? Try like 3 years to be capable of making a release ready multiplayer game minimum, assuming you're doing CMC prediction+GAS or equivalent too

Most of us are still learning in some way or form

Just keep plugging away at it, it will eventually click

Make the smallest games possible, better to have a little win than a big loss, coz you'll look back on your work and think "wow, I knew nothing"

[fossil spoke]

Multiplayer is probably one of the hardest things to learn in Game Dev

Dont expect to become an expert overnight

If you dont think you can commit to years of learning, then it might not be for you

[pallid flame]

Glad to hear its not just me
How long did it take you to get a good hang of it?

[pallid flame]

Thought so.. I haven't even had unreal engine installed for more than 2 weeks and learning everything (singleplayer-code wise) was going smoothly for me
And then I dipped my toes in multiplayer..
And since then ive been almost completely stuck

[upbeat haven]

anyone using mover? Seems like this snippet of code not working on simulated proxies?
if (const FMoverDefaultSyncState* SyncState = CachedLastSyncState.SyncStateCollection.FindDataByType<FMoverDefaultSyncState>())
Im taking it as not everything is properly replicated yet? Animations are broken because of this (downstream)

[vapid rune]

In the multiplayer listen server (not dedicated server)...can we make a same team save system or not ????

If we assemble same team again then save system show us last saved game ...
Is it possible or not ????

[silent valley]

Yes, if the same person is hosting then they can restore their last savegame.

[vapid rune]

Are you sure about

Let's suppose me and my friends play then we save and quit but next time m playing with another teammate ...but after some tym we assemble previous team can we resume over last time save state???

[grand kestrel]

Did you set the replication policy to independent? Its in project settings IIRC

[kindred widget]

You can drill the basics down in a few months which will help you muddle your way through things. But like Vaei said it'll take years to really get to a point where you can do most everything that'll need doing on a heavy multiplayer project. And it isn't necessarily strictly related to multiplayer code either. Beyond just learning specific multiplayer code, you have to understand the flow of everything around it that it affects.

[pallid flame]

Do you recommend I start off with single player games for now?

[kindred widget]

Depends on your needs. I mean if you want to learn Multiplayer it's best to do it in chunks. Do small tasks here and there in a side project to test it out sometimes. I think the main thing is that you can learn the basic tools pretty quick. Replication, RPCs, FastArrays, online subsystems, etc. But applying those takes a lot of time and understanding of the engine. So depending on experience, a singleplayer game can help you simply by giving you a mental map of "How can I translate this to what I've learned about multiplayer code?" And the best part is, if you start making multiplayer systems. Like Inventories, or interaction systems, etc. You don't need to keep separates. Your stuff should also work on a listenserver, which will also work in singleplayer. So you can keep the same stuff in multiple projects as you're going along if you keep them clean enough and don't make them project specific.

[pallid flame]

Yeah you're right
I had a nice single player project going on and then at one point I was like "Oh! I need to make sure to make this a multiplayer game" and then thats when I dove into it all
I tried to brute force it and ended up just watching hours and hours of tutorials n' reading articles online and I still didn't have a good grip on it; It was just really discouraging

[vale haven]

Has anyone around solved the struggle of On-Screen multiplayer interactive widgets... I've got it supposed to be routing through the object in 3D space for replication, but the second a client connects the whole thing breaks, even for the host. The second the client leaves, widget works again.

Editing slider values stops working when a client is connected. Button to tab pages stops working. Not just on the client but the server itself. I tested values inside the widget itself and the widget seems to be reporting incorrect values. I don't really understand what's happening there.

[dark parcel]

@vale haven it sounds like you are not filtering codes that are suppose to run on each machine individually.

E.g. toggling input mode when other player join when really, each machine should handle its own input.

Try to understand how to use is locally controlled, switch has authority. Those 2 nodes are mostly what filter codes that run on what machine.

[lament flax]

why is there a delay before an actor isnt relavant when going out of the NetCullDistanceSquared ?

there is like a few secs

[vale haven]

Shouldn't the values coming from the slate only exist locally though? For example, when I drag a slider before the client connects, the value coming out of "On Value Changed" is as expected. However after a client connects, it fluctuates between expected and zero.

But my understanding was that the widget itself only exists per client, and so the value coming back shouldn't have any way to be influenced by the client.

I understand swtich has authority and locally controlled, but I need this widget to operate both for the local-host and the client.

Should I still be checking for authority inside the widget? I didn't think that would actually gate anything successfully since all the data on the 3D object is being set with run-on-server calls.

It's clear I'm misunderstanding something, I just don't know what.

[dark parcel]

Again, looks like just a classic function that get run on unintended machine

You probably made more than 1 instance of the widget in the same client

Something that get triggered when other people join

I can only guess as much

Did you have something on begin play?

[vale haven]

Yes. Begin play sets up a bunch of things locally, like the controllers settings to use their widget interaction component.

The widget itself isn't being spawned then. It exists already in the scene

[dark parcel]

Well it depends where you call it and if you filter with is locally controlled

[vale haven]

That's too vague to be helpful.

[dark parcel]

For example calling on character begin play is a common mistake when not filtering with is locally controlled

I mean if you know how to filter codes you would know what should run on what machine

It's important part of multiplayer

[vale haven]

I know how to filter code, clearly I

just am not filtering this one correctly. I don't need an assessment on my general expertise, I need advice on widget specific interactions.

[dark parcel]

I mean you said it your self that the value changes when another client connects to the game

[vale haven]

Yes. So why is the value INSIDE the widget, not inside any replicated object, but the widget itself, affected by the presence of a client.

My understanding was that the client has no way of interacting with a widget on the host machine.

The UMG can't be replicated, so how is it able to affect the value coming out of that specific UMG

[dark parcel]

Picture a character begin play without filter that create widget at begin play

Everytime a new player join, you will get a new widget

[vale haven]

We're not creating a widget at begin play

[dark parcel]

3 players = instances

[vale haven]

The widget exists in the world.

[dark parcel]

Well I don't know I can only guess

Nvm anyway

[vale haven]

You don't have to guess, I've already said this.

[dark parcel]

Don't think I can help you

[vale haven]

I don't think you can either.

This value immediately begins to return inconsistent values. But this value should be coming directly out of the slider interaction. I can see the slider adjusting correctly on screen. I can see the bound float value as text updating correctly. The second I let it go, it snaps to 0.

[stoic lake]

Is it possible to open a lobby without loading a level set to listen? I want to be able to open my hideout for other players without respawning in the hideout. The same way phasmo's system works

[vale haven]

The level has to be a listen server in order to recieve a connection from outside, but your matchmaking service does not need to be notified of that sessions existance until you desire it.

Usually you open a matchmaking session/lobby/ticket/whatever it is on your platform of choice, and then immediately call Open Level with a listen option, right?

I see no reason you can't start your initial hideout/level as a listen server, and then simly do your session management inside of the already open listen server.

Just ensure that you do good session/lobby cleanup when that lobby changes or ends.

@stoic lake

[stoic lake]

Ahhh so can I just open the level with the listen attribute before ever creating the session?

[vale haven]

In theory.

[stoic lake]

I think that worked, thanks!

[sonic obsidian]

Hey all ive have tryed the replication graph and had some issues with it is iris any better than rep graph or just the normal replication system i noticed its now experimental in 5.4 should i wait for it to be prod ready?

[short arrow]

Iris is actually suppose to make Replication Graph irrelevant

So I'm pretty sure that means it's better and requires a little less setup

The best documentation you'll get out of it is probably Lyra starter game

[sonic obsidian]

oh cool dident know lyra used iris

thanks

[bright rover]

anyone know when iris is supposed to come out of beta?

[lament flax]

from server, can i know when a variable got sucessfully reped to client (rep notify) ?

[chrome bay]

no

[real ridge]

guys should not be here this HELLO printed on server and all clients too? its inside blueprint pawn, but I am getting print only Server: Hello idk why its like not replicated to all

[rocky mantle]

Is there a way to run console commands in a dedicated server that was launched from the editor?

[velvet current]

when downloading source, should i download the same version as my game file (5.3.2) or download the latest release when I build from source for the purpose of dedicated server multiplayer?

[thin stratus]

Same version

[thin stratus]

ServerExec <consolecommand> in the console

[velvet current]

Thanks!!

[daring wharf]

Hello friends, I’m having trouble interacting with the Advanced Sessions Steam plugin in the multiplayer game I'm developing for testing purposes. Is anyone else experiencing the same issue in version 5.3?

[surreal fox]

How can I get rid of these? I mean when I try to update these booleans in my animation blueprints using custom events, they won't work in mulitplayer even though I use RPCs. Maybe there is a better way than this

[sinful tree]

This is the correct way to do it. You set the replicated variables on your replicated character, the animation blueprint grabs the values on the update animation event and sets its own values so it can then run its stuff on its own thread.

[surreal fox]

yeah it works fine. But it updates each boolean's value every tick or something. I only want to update them when I call any event. I tried doing that, it worked for single player but Idk why it didn't worked for multiplayer. Its a mobile game so I just want it to be optimised as much as possible

[sinful tree]

It doesn't matter if it updates them every frame, in fact, you want it to.... The blueprint update animation event fires every frame because animations execute every frame, and you want your animations to adjust based on the current values for that frame. The animation blueprint also ends up running in its own separate thread from the game thread, so you want those values updated in the animation blueprint when the animation blueprint needs them updated.

[surreal fox]

If the project gets bigger in future and we have around 30 - 40 booleans updating each frame. Is that expensive? or minimal?

[sinful tree]

Extremely minimal.

[surreal fox]

ohh, didn't knew that

thanks man for the help 😃

[sinful tree]

if you're worried about it, you can always test it out yourself too - create a mock up of what you think you might be using (your 30-40 booleans) in an animation blueprint, and spawn hundreds of those actors using that animation blueprint, then profile it and see where the CPU costs actually are.

[dark parcel]

Use enum instead bools after bools

[grand kestrel]

You can use gameplay tag map like Lyra does, that would be cleanest solution
But that implies you're applying tags for each of those states reflected by the bools

[proven pagoda]

I check for tags in my anim instance to set my booleans to swap me between the states

I don't think I'll have 40 different states tho

[grand kestrel]

Yeah that's quite common

Tags are king

I recommended Lyra solution because it looks like they are BP only, and it could simplify that a lot

Lyra solution sucks the moment you need anything in C++

[proven pagoda]

Oh I didn't consider BP only vs C++

[grand kestrel]

Yeah. I would personally never update an anim bp from BP
Because running that in a VM is expensive

For a small game it makes little difference tho

[tribal sentinel]

Why aren't server targets supported in Distribution Builds of UE? What is the reasoning behind that?

[modest crater]

I guess for a smol size, most people aren't doing dedicated server builds so its not fair to make them download that stuff ontop of everything else. Plus if you are going through the effort of a making a game that has dedicated servers, backends and match making then its implied you can clone the repo and wait for it to build, its only intimidating the first time.

The general workflow of working on engine code and gameplay code isnt that different (besides the build times).

[sullen sail]

Hello everyone, I'm having issues with replication. Why is my Blueprint actor's multicast event not being called on the autonomous proxy, but only on the simulated proxy and authority?

The image on the left side is a listen server, the right side is the client 0

[modest crater]

(I didn't read too much into but I can already tell you that it should be a state and OnRep here not a multicast RPC)

PS: An optimization would be to make the initial state NetDormant then when you change it, you just ForceNetUpdate (in BP I think it auto does this when you update a replicated variable when dormant) then all clients will see new state but not waste CPU cycles checking relevency and state.

[sinful tree]

If you're attempting to have a client call that Server Open Barrier event it'll never work unless the client owns the actor.
That's not why you're having trouble though.. Is the Electric Barrier actor itself marked as replicated?

Also, it's probably a simulated proxy, not an autonomous.

[sullen sail]

Yeah, I'm limiting the showBarrier to the localClient and not to the other clients

Oh, now I get it! My client doesn't own the Electric Barrier. How do I make it own it?

[modest crater]

You don't. I am assuming the barrier here is a timed thing like the game starts or mid way through, just have the server set it that state and replicate it to clients like explained here #multiplayer message

If this was a client called event then you would have an RPC which would just tell the server to change its state and it replicates the same way.

[sweet spear]

Have you attempted a fresh project? Just to test you connection? What do you have replicating?

[compact flame]

Hey everyone Im trying to cast to gamemode to get a varuable but it only seems to get it on server when I do it on client it dont work how do I fix this?

[dark edge]

GameMode only exists on server

Read the pins

[compact flame]

Ik I solved it by making a request in the game state.

[spare kelp]

Could I revisit this question?

I'd like to have my sessions independent of the level. As in, I'd like the title screen to be a place where a player can choose to host or join someone else's game. Or simply playing an offline game if they desire. Where every computer is by default hosting, without the user having to choose that option.

Do I have to somehow load that title screen (level) with the 'listen' option before any other machine will be able to see it?
Or, to ask another way, are sessions directly tied to listen servers?

Is there a cost to opening a session in this manner and then somehow closing the listening server side? (How would I do that?)

I have already setup a session create/find pair on the title screen, and using the NULL subsystem, they return 0 found games, despite having two machines on the same LAN. (I turned on the LAN options.)

[vale haven]

The level has to be a listen server in order to recieve a connection from the outside. I'm not sure how much more direct I can be.

If your level was not opened as a listen server, you cannot do Networked multiplayer in it.

[cosmic marlin]

HELP!!
I wanted to replicate a array of UObjects in a actor, If I normally make that UObject using NewObject<>() it works just fine and replciates , but when i try to duplicate it using another instanced object from data Asset , it just doesn't. After some digging i found out because the Duplicated object has the followings flags RF_WasLoaded | RF_LoadCompleted after clearing those flags replications does work. So my question here is , Does removing those flags could be problem by any chance?

[kindred cairn]

Not yet, probably should do the next) However we tried just super basic character class without any logic except moving and standard movement component on a map without anything to replicate (basically just a plane to walk on). Still the same issue 😵‍💫

[sweet spear]

have you tried smooth sync? i've had mass success with that plugin, it's cheap too

Also try both hosting and see if you can notice any difference

[blazing spruce]

Hi, I'm having an issue with my draw system, when the player opens the draw i teleport them to a specific location in front of the draw and rotate them to be facing it properly, but for some reason when the client accesses the draw it doesn't do it, when they then exit and re-enter the draw, it works? Any ideas what could be causing that?

https://drive.google.com/file/d/1JUh4p4NTzrEsAFORXPTC72oVav7xrY0q/view?usp=sharing

[sweet spear]

@kindred cairnIt could straight up be something with your internet, if you're on a hotspot/wireless/4g/5g anything that's not fiber then you're going to have issues

[kindred cairn]

No, will definetely try this. Thanks! It's not because of internet, all players can see this issue.

[sweet spear]

Are they hosting though? and is it local?

[kindred cairn]

No it's the dedicated server on Amazon

[sweet spear]

Have you tried hosting?

[thin stratus]

@kindred cairn is it only the simproxies doing that or does the actual player (the one that controls the lagging SimProxy on their end) get a correction?

[kindred cairn]

Sorry not sure what you mean, if I tried to be host?)

[kindred cairn]

Only simulated proxies

[sweet spear]

Well don't host the game on amazon, try to use your own PC as a test bed

because if it's a new project and lagging, it would suggest it's amazon's server

[kindred cairn]

got it, yes, will try it as well. Good point)

[sweet spear]

if you host the server on your own pc and it still lags it means it's something else

if it still lags get someone else to load the server

[kindred cairn]

yes, makes sense)

[surreal fox]

sometimes when I move my character with timer event of 0.01 sec looping, the client does not move smoothly as the server does. What can be a solution for that?

[halcyon elk]

hi everyone

i am trying to make a custom c++ playerstate class replication working

UCLASS(Blueprintable)
class AMyPlayerState : public APlayerState
{
GENERATED_BODY()

public:
AMyPlayerState();

UPROPERTY(ReplicatedUsing = OnRep_TeamIndex, BlueprintReadWrite)
    int32 TeamIndex;
UFUNCTION()
    void OnRep_TeamIndex();


UFUNCTION(BlueprintImplementableEvent, Category = "Team")
    void OnBPTeamIndexChanged(int32 NewTeamIndex, int32 OldTeamIndex);

protected:

virtual void GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const override;

private:
// Previous value of TeamIndex (not replicated)
int32 PreviousTeamIndex;
};

AMyPlayerState::AMyPlayerState()
{
bReplicates = true;
SetReplicates(true);
TeamIndex = -100;
PreviousTeamIndex = -100;
}

void AMyPlayerState::OnRep_TeamIndex()
{
OnBPTeamIndexChanged(TeamIndex, PreviousTeamIndex);
PreviousTeamIndex = TeamIndex;
}

void AMyPlayerState::GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const
{
Super::GetLifetimeReplicatedProps(OutLifetimeProps);
DOREPLIFETIME(ACrazyPlayerState, TeamIndex);
}

then i derive a blueprint class from it,
if i change the teamindex property on the server the value is not replicated !

on the other side i have tested to inherit from a bluerprint playerstate class and everything worked just fine .

any idea on what's going on please

[high compass]

Okay, I don't understand what I'm doing wrong. Trying to make a custom HTTP request type.
FHttpModule::CreateRequest does TSharedRef<IHttpRequest, ESPMode::ThreadSafe>(new FNullHttpRequest())
but when I do TSharedRef<IHttpRequest, ESPMode::ThreadSafe>(new FMidHTTPRequest())
I get compiler errors because one of the TSharedRef constructors tries to new the IHttpRequest type, which it can't because it has virtual = 0 methods.
But that shouldn't be any different between the FHttpModule case and mine.

[woeful trout]

hey can someone knows how to make an ai replicated system

[upbeat haven]

has anyone managed to profile CMC vs mover? I know CMC is heavy and assuming mover will be much lighter. Wishing it worked with Iris.

Have you managed to understand any reason why Iris isn't working with mover since then?

[honest bloom]

How do I use a fixed tick rate just as mentioned here by this article ?
https://www.kierannewland.co.uk/the-problems-with-unreal-engines-default-networking/

Do I change it in the engine binary ini settings files or .. it has just to do with the blueprint Tickrate thing ?

[fossil veldt]

yes

It's because epic hasn't implemented the iris net serializers for NPP

it isn't a problem with Mover but a problem with NPP

The prediction proxies need serializers, I posted one of them in here at one point that was half written

[thin stratus]

Did you actually implement it fully?

[fossil veldt]

I didn't finish it no but it was something like 80% of the way there

It's not the only serializer that needs implementing either

from what I could see there was 2

[thin stratus]

Are you able to find the message? Would like to have a look at it

[fossil veldt]

I'l go digging

[thin stratus]

Cause I couldn't (Discord Search isn't helpful :/)

[thin stratus]

Appreciated

[fossil veldt]

sec that's really annoying actually

#cpp message

there ya go it has both the .cpp and the .h

[thin stratus]

Ah in cpp. I searched in multiplayer, woops

Thanks!

[fossil veldt]

Yeah so I mostly implemented it for FNetworkPredictionProxy

FReplicationProxy also needs doing, I think if you implement both then it should work

It may honestly work with just FNetworkPredictionProxy implemented tbh

[thin stratus]

Isn#t there a general issue of not being able to properly mark the Proxy as Altered?

Doesn't Iris require MarkDirty?

[fossil veldt]

Well the actual issue is this

That ID there for some reason breaks without a proper net serializer

And that ID is used to setup the entire services

this line here

It never becomes > 0 for clients

[thin stratus]

Yeah I looked that stuff a 100 times in the past weeks haha

[fossil veldt]

ahaha

[thin stratus]

Hm, well but it does without Iris, or?

Could swear the Local Client sets that up properly

[fossil veldt]

Yes without Iris it gets set to > 1

[thin stratus]

Right

[fossil veldt]

but when you turn iris on you get warns in logs about not having a net serializer

and I guess whatever fallback to use the old serializer is broken under iris

[thin stratus]

I hope they do a general fix up of NPP at some point. The amount of crashes NPP and Mover produce is just stupid.

[fossil veldt]

yea would be nice tbh

I didn't actually have that many crashes, but I was using independent interpolation

so maybe that's why I got less

Mover was actually fairly stable for me

[chrome bay]

I come here for therapy don't make me go

[fossil veldt]

I don't think at this point it's worth using fixed interp and doing your own interp because that's something that Justin is seemingly going to fix in the future

Sounded like he might do fixed ticking with automatic interp

[fossil veldt]

Hey man you came to the multiplayer channel for therapy this is on you

haha

[thin stratus]

The last few months of NPP have broken James

Possibly a lot more peeps too.

[fossil veldt]

Condolences

[thin stratus]

At some point you can literally see is mental decline every time the camera went on during standup

[fossil veldt]

hahahaha

[chrome bay]

huffing copium, staring into the middle distance repeating i'm sure it'll be worth it, I'm sure it'll be worth it

[fossil veldt]

timelapse NPP is in my walls

https://tenor.com/view/giygas-cat-melon-cat-psychotic-gif-25770926

God dayum can't believe u guys used NPP at work

brave move

[chrome bay]

you have no idea

I hope, to god, we can talk about it in future

[thin stratus]

Literally NDA'd from crying actual tears in public about it.

[fossil veldt]

fucking lol

I have stopped using Mover for now tbh, until the API is finished I just cba anymore

[chrome bay]

It is incredibly experimental

[fossil veldt]

The fact that you can't actually properly implement crouch yet because the feature to implement it doesn't exist yet makes me sad

[thin stratus]

You can do a lot just fine, but NPP/Mover is one of these things where you only notice how shit and unfinished it is when you already committed.

[upbeat haven]

Gotta be better than cmc at least to expand upon

[chrome bay]

That's the best way to describe it tbh. Until you really get into the weeds with it, you have no idea how much pain it can cause

You'd think

[fossil veldt]

Yeah like don't get me wrong I know you can implement crouch but I just get sad implementing it knowing that I will have to just rewrite it when Justin releases the additional moves feature

and the fact that the mover synchronization ability task doesn't exist yet also makes me sad

[chrome bay]

I am relatively confident that will never exist

[thin stratus]

Honestly, they should just take a step back, look at the whole thing (NPP and Mover) and potentially realize that the core is rotten.

[fossil veldt]

Maybe Justin changed his mind but as of my last talking to him (@ UnrealFest) that was the plan

[thin stratus]

Like, yeah I'm joking a lot with metaphors here, but I literally have a Mover 2.5 Board on Miro by now....

[fossil veldt]

He was experimenting with it essentially so it would syncronize GAS prediction context with NPPs

[fossil veldt]

In all honesty I agree, I think NPP needs to go

and just make a new kinematic liason that takes the good stuff

[thin stratus]

There are several good reasons for having a Streamlined path to prediction. Lots of other Game Engines and Games do that too.
UE is just too cut apart to get that fixed at this point I guess.

Writing "adapter" like code for GAS + NPP is not the solution imo

At that point we could just write that adapter for GAS + CMC and be done >.>

[fossil veldt]

Well the problem is that I don't see any possible future where GAS moves to NPP like was originally planned

[thin stratus]

And beyond all of that, let's not forget the Bandwidth and Server CPU cost of NPP and Mover .......

[chrome bay]

yes

lets absolutely not

[fossil veldt]

It would be great if everything was on the same prediction context

[chrome bay]

bits out the arse

[fossil veldt]

but wishful thinking

[thin stratus]

I'm so happy I'm not part of the optimization team at this point.

[chrome bay]

:):):):):)

[fossil veldt]

Hahahaha

Yeah atm genuinely I think I am going to at some point just completely rewrite a large part of the CMC to fix all the problems I have with it

[chrome bay]

CMC being so thoroughly proven accross 1,000's of games at this point is not to be sniffed at IMO

[thin stratus]

They also further improve it still

[fossil veldt]

Absolutely

[chrome bay]

Like you can tooooootally be critical of it's design, which could 1 billion percent be improved to support more modular features

[thin stratus]

There is async code in it by now. And there is also a lot of new code to handle some nasty smaller things, like jumping on and off a MovementBase, and stuff like that.

Lots of things that Mover will take ages to reach.

[chrome bay]

But NPP being the foundation of Mover is a gigantic flaw IMO, it is so unproven

And has such a long way to go before it's production ready

[thin stratus]

Turning the CMC into something like Mover isn't even that difficult

[fossil veldt]

yea this tbh

[chrome bay]

Yeah for sure

[thin stratus]

You just cut it into Modes and then throw all of it into shitty STATIC functions and ignore people wanting to override the behavior

[fossil veldt]

The main thing I wanted to fix on it is client side perf

That fking find floor function

:|

[thin stratus]

I also still don't get why NPP went away from sending Corrections.

I get that the CPU cost is moved to the Client that way

But the Bandwidth..

[chrome bay]

I think Dave did explain it somewhere a long time ago

But yeah I think the rationale was reducing CPU time on Server, but I don't know if that's ever really been a bottleneck anyways

[fossil veldt]

Also yo I had no idea you were at bulkhead aswell cedric

[cosmic marlin]

Anything on this please?
HELP!!
I wanted to replicate a array of UObjects in a actor, If I normally make that UObject using NewObject<>() it works just fine and replciates , but when i try to duplicate it using another instanced object from data Asset , it just doesn't. After some digging i found out because the Duplicated object has the followings flags RF_WasLoaded | RF_LoadCompleted after clearing those flags replications does work. So my question here is , Does removing those flags could be problem by any chance?

[thin stratus]

Hey James, when will you move your Tank Game to Physics Mover?

[chrome bay]

will I get banned if I tell you to go away with swear words

[thin stratus]

Contractor. I'm everywhere.

[fossil veldt]

Ah I see ;D

[fossil veldt]

lolz

[thin stratus]

No, I would absolutely deserve all of them I bet.

But, I will take a shower now, so you are good to switch to some more relaxing #multiplayer topics.

[chrome bay]

I need a drink

[fossil veldt]

Is the shower related to mover / npp based discussion

[chrome bay]

and a lie down in a quiet room

[fossil veldt]

ha ha ha

[woeful trout]

hey can someone knows how to make an ai replicated system

[weary mason]

experimenting with packet loss for clients and dedicated server i noticed some general components auto activation fails during possession or even initialization and activate/reset must be forced on the owning client for set actor components

[upbeat haven]

Is it not more performant?

[honest bloom]

asking once more, if anyone is willing to help
If my question is too broad .. dumb .. whatever .. please tell me so that I can improve

[thin stratus]

No, but it helped.

[thin stratus]

Hard to tell tbh. I would say "No, not in its native form."

But it also depends on what you are trying to do. As usual.

[honest bloom]

Wonder if a thread for multiplayer beginners could be made on this channel ..
It feels like (I might be wrong) this place is much more used for elites discussions which are not so interested in answering noob questions over and over (and it's understandable, I don't blame)
Maybe this separation could avoid beginners like me loosing visibility for their questions

[sinful tree]

Your question isn't a "beginner" question.

[wispy crown]

Hi!, Does anyone know if spring arm component replicates the locations of components attached to it? I have a sphere attached to the arm but i cannot make it replicate it's position. I've touched every knob i could find.

[spare kelp]

I'm not doing multiplayer in it. I'm trying to setup sessions only.
As described in https://cedric-neukirchen.net/docs/session-management/sessions-in-cpp, like a matchmaking situation.

[latent heart]

If you want noob multiplayer info, the pinned messages are a good start.

And people generally answer any and every question they can, given a chance.

Also, the article you linked had a link under "fix the tickrate" - does that not tell you how to do it?

[upbeat haven]

😅crazy I was here thinking that it would be more performant. Granted I haven't benchmarked anything. But I suppose that is the cost.

But I suppose it would mostly come down to npp for replication performance?

[chrome bay]

Npp has substantially worse network performance out of the box. A lot more data has to go back and forth.

it's just not mature enough. Whether it will be in time.. Who knows

[amber merlin]

Hello, am i seeing correct? EOS has matchmaking for dedicated servers?

[upbeat haven]

I guess that's currently the cost of a generalized predicted system? In the case of cmc just having the optimization of doing absolutely the bare minimum it needs to