multiplayer

[pallid mesa]

but it is indeed more complicated

[scenic bobcat]

hello everyone, i’m making a multiplayer fps and my camera is attached to character’s head, and the head isnt alining perfectly with the forward vector, so whenever i start the game the player controller resets the camera rotation to face the forward vector, the problem is the remote characters dont have a character controller so their camera never gets reset, so their aiming endup slightly offseted,

and the aim functionality which is based on the camera totaly breaks, see the pictures

i tried sending the relative rotation at beginplay to the server and set it but didnt work idk why

feel free to seggest anything cause im getting crazy stuck with this for 3 days 🥲

if im not clear enough please let me know, thanks

[thin stratus]

One usually uses BaseAimRotation for synced rotation for all players

It uses controller pitch for server and autonomous

And a replicated pitch for anyone else

Should be available for pawns and or characters in blueprints

[scenic bobcat]

the pitch is allready replicated through the aim blendspace

[thin stratus]

@dry pebble @digital herald @graceful flame

Some engineer on/from a Client of mine recently looked at GEs for MovementSpeed changes.

The removal of GEs can't be predicted, so that's always a little annoyance. I think they wrote some fancy custom code into the CMC that keeps track of GEs applied via their Prediction keys or so. There was also a small delay between application on server and client when not using the CMC directly (e.g. applying the GE from an Ability).

It all came down to him adding some "threshold" or "slack" where the server waited on the client or so. I sadly can't share the implementation, but it did remove corrections from applying GEs for MovementSpeed changes. Without that we always had corrections at start and especially end of the GE as the client can't predict removal.

(We also went away from using GEs for cooldowns because of that, which is also what Epic did internally)

[thin stratus]

So you are already using BaseAimRotation?

[scenic bobcat]

yeah

i think i fixed it

i wasnt using the camera boom

now that i attached it to the head and the camera as its child it all works fine

[scenic bobcat]

thanks mate

[thin stratus]

Oki glad you solved it

[scenic bobcat]

i think some problem don't get fixed until u ask someone

lol

even if he didnt give u the answer

[thin stratus]

That's more or less the concept of rubberducking

[scenic bobcat]

yeah thanks mate, a lot

[real ridge]

hey guys its again me 😄 i was sick af but today I tried use my thirdperson character as plane with its(movement) but anything I do I mean any move is not replicated either

I moved with my plane and from second client it has same position, maybe is problem in my controls?

also i am doing flying like this

but CMC should be replicated

I have it inside

set it to flying

[scenic bobcat]

did u check the replicates checkbox

on the character movement

and replicate movement on the thirdpersonBP

[real ridge]

yes all are checked

if you mean this

[scenic bobcat]

idk men

[scenic bobcat]

ther is another checkbox called replicate movement

[real ridge]

i have too

[scenic bobcat]

i never used used add actor offset/rotation so idk 😅

try replicating through events

[real ridge]

u mean RPC?

[scenic bobcat]

no just replicate the input event

[real ridge]

i dont understand how

[scenic bobcat]

somthing like this

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

[real ridge]

ah yea do you think its good for replicating movement of my pawn?

[real ridge]

do you know why I am getting this error? I am doing this

[scenic bobcat]

i dont really know 😅 i don't have that much experience yet

as for the warning im not sure

[real ridge]

I am calling it from event tick

[verbal tendon]

This is very simple

you're calling a ServerRPC from a non-owning actor

so your BPDFCPlayer RPC is not being called from the owning client

So in your example you most likely have 2 players, the Tick is being called on each client. And for the non-owning client it'll throw the error

There should be networking basics guides in the pinned messages. Check those out @real ridge

[scenic bobcat]

aw i forgot about that

[scenic bobcat]

no u shoud only check "is locally controlled" before calling the event fly server

[digital herald]

Thanks for sharing. Sounds like custom prediction via the CMC yields the best results.

[real ridge]

and how to fix it?

i am testing it in 2 windows

so thats maybe problem

[verbal tendon]

Don't call RPCs on event tick, this ticks every frame

[real ridge]

but I have update position on event tick where I am calculating position of my plane and he is moving I need have it there 😦

[verbal tendon]

Use replicated movement from CMC (CharacterMovementComponent)

That's literally what it is there for.

[hollow sentinel]

Can anyone please help me out of this!!1

[real ridge]

it's not working I have it there but it is not replicating my plane

[scenic bobcat]

can u clear this up

[hollow sentinel]

Just ago fixed that issue. Thanks for answers.

[hoary spear]

Is a property limited to the replication condition of the actor/component that holds it, or are they individual for all intents and purposes?

[dark edge]

Are replicated variables guaranteed to be in good condition when an actor becomes relevent?

Like say I had a component that gives itself a replicated GUID on spawn.
On BeginPlay, the component registers with a subsystem.
When the actor containing the component becomes relevant, should its GUID be in good shape by the time it registers?

[quasi tide]

I think there is a better place to do that in the Actor lifecycle - I think PostNetReceive or PostNetInit...something like that anyway

[lean surge]

kind of a bump on a question I asked earlier but still;

Anyone know how to turn off certain clients receiving character / CMC location corrections from the server? doesn't matter whether this is done server side, as in simply not sending corrections to that client somehow or client side, just not using the corrected versions that the server gives. Overriding methods like ClientAdjustPosition_Implementation and PostNetReceiveLocationAndRotation to simply just be empty still cause corrections from what I'm experiencing.

[lean surge]

also definitely worth mentioning that this ignoring corrections needs happen on clients that don't control the character

[regal mica]

Hey guys, I'm working on a listen server game where players can do damage to each other, but there is also environmental damage. When setting the owner of the environmental who do I set as an owner of that damage? How do I separate the listen server player from the environment, which is its own neutral entity?

[dry pebble]

Thanks for sharing eXi, appreciate it. I'm surprised something as simple as a proper (no net correction) stamina drain while sprinting hasn't been publicly solved yet, seems like a lot of people would use this.

[thin stratus]

Stamina, outside of GAS, is relatively straight forward

The problem is that the CMC needs a lot of boilerplate code to fully support this

[verbal tendon]

No. Replication to server-state is guaranteed to happen, but eventually.

[dry pebble]

I see interesting

[verbal tendon]

This sounds weird, you might want to elaborate. It sounds like you don't want those actors to be replicated?

[dry pebble]

I am completely lost on how to predict GAS stamina now with sprinting speed change. If anyone can point me in some sort of direction in the CMC, I'd really appreciate it. Back to the source code for me lol 😄

[thin stratus]

I don't think anyone can point you

Either no one solved this or can share it

This isn't every day code anymore

Stamina without GAS, where the Value lives in the CMC directly and is not replicated and only modified via the Sprint Code, is relatively okay

But if you use GEs to modify the value, then you suffer from the problem that prediction can't remove GEs

You'd need to cut the local player some slack for the duration where the server removed the GE and the Client hasn't yet

[dry pebble]

Hmm okay perhaps I'll have "Energy" for sprinting and let that live on the CMC seperate from GAS stamina and just manage it differently. Why not replicate this?

[thin stratus]

There is no need for it

The idea of the CMC is that it does the same on the server as on the client

In the same timestamp at least

If you consume the value during the sprint, it should consume on both ends the same

If you end up having a different value, it will cause a correction, at which point you send the server's value to the client to sync again

The CMC itself isn't even replicated fwiw

[dry pebble]

Ahh I see, and during a replay should I "Save" the stamina value in the FSavedMove_Character? Just locally for the client

[thin stratus]

Yeah, you need to

I learned the hard way that SavedMoves are not only for replays

[lean surge]

I'm aiming to stop the movement replication for a short amount of time to do a knockback client side to not have to RPC to the server and wait for that. Exactly the same knockback will happen on the server and I'm going to re enable replication after it's finished, and probably smooth the client location to the server one during it

[thin stratus]

SavedMoves are also used to send stuff to the Server

while you don't send the stamina value to the server, it can still be that the Client chooses to combine two moves

And the client at that point actually performs the original move twice

So it's:

1. Perform Move 1
2. Choose to not Send Move 1
3. Combine Move 1 and Move 2
4. Perform Move 1+2 (performing Move 1 twice)

The thing that resolves this is that the SavedMove has a method in which it resets the CMC state back to BEFORE move 1

So you will want to save the Stamina value before you perform the move

So you can later reset it

Otherwise the Client will consume too much Stamina when mvoes are combined

Pretty shitty to find out cause Moves aren't combined that often, unless the client is > 60 FPS

At least with default settings

[thin stratus]

You could just use RootMotionSources

But they aren't available outside of GameplayAbilities by default

If you execute those on Server and Client together, it will sync up everything automatically in the CMC

Only thing you need to do is flush server moves before executing them

[dry pebble]

Oh wow I didn't realize it worked like that, that is very insightful, thank you. And yeah that would've been a shock to find out. I hate bugs that happen rarely like that.
And when you say "If you end up having a different value, it will cause a correction, at which point you send the server's value to the client to sync again", is this just automatic because server and client are running the same code or are you saying I need to manually sync this?

[thin stratus]

We have no corrections on 200+ Ping with that

[thin stratus]

The CMC has functions to sync, but you need to override it to send your additional values

Nowadays you make a new Container Struct that inherits from the default one

struct FVRTCharacterMoveResponseDataContainer : FCharacterMoveResponseDataContainer
{
    typedef FCharacterMoveResponseDataContainer Super;

public:
    virtual void ServerFillResponseData(const UCharacterMovementComponent& CharacterMovement, const FClientAdjustment& PendingAdjustment) override;
    virtual bool Serialize(UCharacterMovementComponent& CharacterMovement, FArchive& Ar, UPackageMap* PackageMap) override;

    float Stamina;
};

[dry pebble]

Aha I think I remember glancing over something about that in the source and about that struct too, thanks I'll look into it.

[thin stratus]

UVRTCharacterMovementComponent::UVRTCharacterMovementComponent(const FObjectInitializer& ObjectInitializer)
    : Super(ObjectInitializer)
{
    SetMoveResponseDataContainer(VRTMoveResponseDataContainer);
}

Last line is for setting that

[dry pebble]

oh that must be it lol!

[thin stratus]

VRTMoveResponseDataContainer is a member variable

void FVRTCharacterMoveResponseDataContainer::ServerFillResponseData(const UCharacterMovementComponent& CharacterMovement, const FClientAdjustment& PendingAdjustment)
{
    Super::ServerFillResponseData(CharacterMovement, PendingAdjustment);

    const UVRTCharacterMovementComponent* VRTMoveComp = Cast<UVRTCharacterMovementComponent>(&CharacterMovement);
    const AVRTCharacter* VRTCharacter = Cast<AVRTCharacter>(VRTMoveComp->GetCharacterOwner());

    Stamina = VRTMoveComp->GetStamina();
}

bool FVRTCharacterMoveResponseDataContainer::Serialize(UCharacterMovementComponent& CharacterMovement, FArchive& Ar, UPackageMap* PackageMap)
{
    if (!Super::Serialize(CharacterMovement, Ar, PackageMap))
    {
        return false;
    }

    if (IsCorrection())
    {
        Ar << Stamina;
    }

    return !Ar.IsError();
}

Something like this

Not sure if the Serialize is needed tbh

Just followed what Epic did iirc

I'll have to write something for that eventually, but i'm busy refactoring something that is quite old into something new and shiny and that comes first

[dry pebble]

Ohh interesting that is very helpful, now I can start reading about those methods. appreciate the help exi! 🙂

[dry pebble]

out with the old, in with the new 😄

[thin stratus]

Note though that code above is not all you need. Depends on what you actually do

It might also need a bIsSprinting boolean for example

When you handle the MoveResponse you might then need to start or stop sprinting based on that boolean

[dry pebble]

Ahh okies, I'll keep that in mind when trial and erroring, thanks

[thin stratus]

ClientHandleMoveResponse is the function that gets your move response container

Something something in there const FVRTCharacterMoveResponseDataContainer& VRTMoveResponse = static_cast<const FVRTCharacterMoveResponseDataContainer&>(MoveResponse);

[dry pebble]

perfect knowing all those methods really help, so I can try breakpointing through it and see what they originally do. If anything else comes up you think might help, I'll all ears (or eyes lol)

[pallid mesa]

basically @dry pebble same stuff we said yesterday on stream, you can use an attribute for that and handle the base value yourself.. great explanation from exi with practical code

[dry pebble]

Ah I see, I was able to change the attribute in CMC but not handle it predictively. So like how eXi mentioned using a value stored on the CMC and influenced by sprinting only, this attribute could only be used by sprinting too? E.g currently using "stamina attribute" for dashing ability too, so I assume I cannot combine these for the CMC sprint? Keep it seperate?

[pallid mesa]

Yes you could use your stamina attribute for dashes aswell as long as the dash is also handled in the cmc

the moment you use something that mutates stamina outside the cmc, issues will arise for sure

[dry pebble]

No, the dash is an ability, but uses root motion sources (which is linked to cmc I believe) and has a GE to reduce stamina. So I assume I have to seperate it then

[pallid mesa]

yes unless you have some delays that prevent you from sprinting right after dashing

but its a mess

in fact I'm suggesting to use an attribute but... you are losing the benefits of using an attribute (mutations and such) so... heh

[dry pebble]

I could put dash in the CMC later, but for now for practice, I might try a seperate variable. Any benefit to using an attribute and modifying the base value vs just a value on the cmc?

[pallid mesa]

not many without pulling lots of hair

[dry pebble]

right lol, so I might just try with a value on the cmc

[pallid mesa]

it'd be cool if you can simply apply an instant GE locally which appends tags and such

its possible but you have to modify GAS

which is another deep pit

[dry pebble]

right yeah, I'd prefer to avoid that for as long as possible lol. I'll try tapping into all those methods eXi mentioned and see what I can make. thanks for the help guys!

[pallid mesa]

sure!

[dry pebble]

I'm going to read through CharacterMovementReplication.h, are there any other classes relevant that link to CharacterMovementComponent that I should look into?

[low helm]

Anyone remember how to make a client-side-only pawn send its location updates to server for purposes of the net culling of other objects?

I have to ask every 6 months because I forget

[thin stratus]

The Character is deeply connected

But then again also not

[low helm]

https://tenor.com/view/kill-bill-pai-mei-wise-man-nod-nodding-gif-5291762

[fresh cloud]

SPEAKING OF CMC, i did some prototyping and research

i'm going to, again, try a more basic implementation of INetworkPrediction interface

but, both the version i just finish and stock CMC didn't really respond well to root motion locomotion

it would be fine in an empty space, but as soon as i had collisions and surface sliding, root motion locomotion got too unpredictable and i would get constant rubberbanding under all my tested network emulation settings for both my own work and stock cmc

i'm going to go back to square one, do another solid and simple movement component, but i need to have root motion be only incidental

it's not that bad, i just have to adjust some locomotion animations that are root motion based and normalize them to work with a static movespeed, but after my tests today with stock Character and CMC, i'm pretty sure it's just root motion in networking that is too unpredictable when used for locomotion

again, kind of a "duh of course" moment, but hey i LEARNED something which is always nice

[low helm]

did you try turning on client authoritative during root motion?

[fresh cloud]

oh i was thinking about this, or adding a "trust" threshold after collisions, but the design i had in mind stayed in rootmotion for ALL locomotion

[graceful flame]

I'm still not 100% clear on what saved moves are (even though my code uses them lol). My understanding is that in the simplest terms a "move" is the resulting world location for the character actor after processing all of the player's input which is handled by the CMC. A "saved move" is the vector as predicted by the client and may or may not be used but kept temporarily in a small buffer.

Here's where things become even more unclear for me.
When moves are combined together does it mean the CMC is processing two or more inputs simultaneously?

or does it mean the CMC is processing the first move for input X, then re-runs the code to process another move for input Y and returns a vector all of which occurs on a single frame?

or is it more like the player is pressing W to move forward but the server says no you're pressing space bar to jump and so the end result is both the character moving forwards while also jumping?

[earnest comet]

Guys a general multiplayer question if I may.

In a game I know, many people are experiencing sync issues, such as like lets say you have 2 items in your inventory and you are not the host. You drop item 1 but host sees it as you drop item 2.

So after game syncs you also see that you dropped item 2 despite wanting to drop item 1

However the dev can't reproduce this when testing. What could cause this in general terms?

[hollow eagle]

A saved move is a single "action" taken by a movement component, either on a client or server. It might be a movement vector for walking, or a signal to start jumping, or some other "input". Also most inputs can be combined into a single move, since you can for example jump at the same time that you move in a direction.
It also contains logic for how to apply, revert, and combine other saved moves so that CMC can replay or rollback movement state when necessary.

On clients the CMC needs to retain a saved move buffer because when the server confirms a move the client may have already applied additional predicted inputs, and if the server's confirmation differs at all then the client needs to replay unconfirmed inputs back on top of the server's confirmed state.

As far as combined moves go, CMC doesn't really process things in terms of inputs. It processes saved moves - which may be produced by inputs.

If on the same frame you hold forward and press jump then the result should be a single combined move that contains both

How that's achieved is somewhat irrelevant, but it could be by each one producing a move and then combining them at the end of the frame

Or potentially only at the next network tick

[graceful flame]

Ahhh okay this has helped me a lot. Thank you!

[formal path]

latency, bad framerates, different architectures, network loss, lack of validation, race conditions, the list goes on..

[fresh cloud]

mhmm, basically... the overall flow is tick component on client -> if received client correction, fix here -> replicate to server is called -> create saved move + initial fill -> performmovement -> finish saved move + ending fill -> CallServerPacked -> server unpack and setup -> server side perform movement -> check for error -> if no error, send Ack of good move, if error send client adjustment -> tick component on client -> if receive... and so on

[earnest comet]

Much appreciated everyone. Thats good information!

[fresh cloud]

there's more abstractions beyond that, such as sending an old move, pending move, combining moves that aren't important together, etc. but that's the basic flow for autonomous pawns and the server

[cloud stirrup]

idk wtf is wrong here. followed guide as only 2 steps. click generate file click build. fresh "release" version so should build no issues

[fathom aspen]

Exactly we have #cpp

They will tell you not to look at the error list and instead look at the output log

Just a heads up before you ask there

[cloud stirrup]

im building src tho its not a cpp issue?!? its src itself. anywho im just pissed boput waiting 2 days for the error on something that shoiuld be click build. not midified a thing XD

[dusky yarrow]

it can be cruel over at #cpp but you need to force through all the judging emojies

[fathom aspen]

#engine-source

Glad I could help

[cloud stirrup]

cheers man

[fathom aspen]

You still count 🥈 tho 🕺

[round mist]

Does anyone know if World Partition in UE5 works for listen servers? Our game uses player-hosted sessions that other players can join as clients.

IIRC World Composition doesn't work because the server (our hosting player) handles the loading/unloading, so if the server left a zone in our open world but a client was still there, it would be unloaded and they'd fall through the ground into the abyss. Is this still the case for World Partition? Trying to decide if moving my project from 4.26 to 5.1 would be more work than it's worth.

[fresh cloud]

hm... i know there are functions in place via the player controller where when the server loads a sublevel, the clients are informed and told to load that sublevel as well (i had to override that for a recent project), i THINK there is a flow for the other way around no?

[fathom aspen]

By default all cells will be loaded on listen-server, though in 5.1 there seems to be a couple of cvars you can use to make the server load cells that only have a streaming source, so it's less expensive

Keep in mind this is all still experimental

Link to the thing: #multiplayer message

[round mist]

Good to know. Thank you!

[cloud stirrup]

thnx. its a bp project im trying to build the dediserver. but iv broke it adding c++ starter content to it to try make the vsproj file as it just crashes now 😦 il get src built first from this guide. then try start again

[dry pebble]

Ah yes good point, so those three are pretty interlinked, cheers

[twin juniper]

What would be the best way to rotate a character toward a specified location on a server. I am using GAS and have a custom CharacterMovementComponent on my pawn.

SetActorRotation seems like its not playing well with the movementcomponent and I cant seem to find anything that makes sense in the movementcomponent

[dry pebble]

Would this help on Character.h? virtual void Character::FaceRotation(FRotator NewControlRotation, float DeltaTime)

[twin juniper]

I saw that, but didnt know if I had to go through the movementcomponent

[dry pebble]

I did this to slowly rotate player in that method

        const FRotator SmoothRotation = UKismetMathLibrary::RInterpTo(CurrentRotation, NewControlRotation, DeltaTime, RotationFactor);
        SetActorRotation(SmoothRotation);```

[dry pebble]

Ah not sure, don't remember if I had net corrections doing that, i since changed how I handled the rotation

[twin juniper]

Cause I see that the MovementComponent uses the FaceRotation, but it doesn't seem like there is an explicit way to just rotate the character through it.

I'm think I might need to make something custom

Sorry, as an update FaceRotation wouldn't work. In the game i'm working on we aren't using any controller rotation.

It's all pawn

[jovial charm]

Heyy ghuys I am following the function replication tutorial here https://docs.unrealengine.com/4.27/en-US/InteractiveExperiences/Networking/Actors/ReplicatingFunctions/

Basically there's a collision box in the world, then through the Level Blueprint, logic is setup so when a player runs into the collision box, a "Switch has Authority" check makes sure that the collision is only handled by the server. The server then calls a replicated function with "Run on Owning Client" replication optiion to update a variable's value on the character that ran into the collision box.

How does the server know which player is the owning client? Is it because of the "Character" parameter passed into the replicated function? This is the logic inside the level blueprint.

[dark edge]

Look at how OrientRotationToMovement works

Whatever it's doing, do that I'd guess.

[fathom aspen]

p.NetShowCorrections 1

You edit Engine/Config/ConsoleVariables.ini

[fathom aspen]

Correct. It chains back to the NetConnection for the actor in question (being RPCed on)

Correct

Not project name though

[twin juniper]

I don't see this function

[fathom aspen]

Just Engine folder

There is no Engine folder in your project directory anyways

That's in Engine directory

You could see that if you looked at the top

The one below

That's source code

Is source code part of your Project directory?

Yes just add it

You found the file

I thought you added the file for some reason

[jovial charm]

wow thank you

[fathom aspen]

No

Part of your project directory

Which is obviously not

Sarcasim that is

Laura pls no toxic

[dark edge]

That's a boolean on the CMC, presumably it's used somewhere in the CMC and does what it says on the tin. I'd look at how they do it and try replicate that.

[sinful tree]

To clarify what WizardCell said, it does indeed chain back to the NetConnection for the actor in question, however, in the example you've provided, your RPC's target is "Self" which appears to be a Level Blueprint, in which case the RPC will fail to send to any client. Your "Character" is only an input that would be passed through the RPC but that is not the actor you are RPC'ing on - the target of the RPC is what determines the actor and in this case, your target is "Self" which would be the level blueprint. The only instance this RPC would fire on, even though it's marked to replicate to a client, is the server in a multiplayer scenario.

[fathom aspen]

That slipped under my radar

Good catch Datura

They said they are following the tutorial by Epic. That's why I rolled with closed eyes and just answered the question kekw

Would be funny if Epic did that lol

Oh yeah they indeed did it

Okay I declared it, I officially lost faith in the official docs

Yeah it's indeed my fault for keeping some hope 😔

It goes even deeper, they client RPC to change a replicated property on client

Well I guess I can't trash talk YT/Udemy tutorials after today

Link plsss

I'll believe you considering your hat is not Good Looking

You must believe me considering you made both

[jovial charm]

man I am never following docs blindly anymore 😭 it messed me up more than it helped, I was scratching my head like why on earth would this work....

[fathom aspen]

It is good that you questioned that at least

[jovial charm]

thank you, really appreciate the in-depth answer.

[dry pebble]

Talking about stamina on the CMC with sprinting again, when you say to start or stop sprinting based on a boolean connected to the MoveResponse, what did you mean by this? Is this boolean being set in ClientHandleMoveResponse?

[twin juniper]

The whole issue I'm trying to solve is. We want our Pawn to OrientToMovement, but on ability use rotate toward the mouse cursor.

the kicker with this is the animations that play for some abilities also apply root motion

So I'm trying to get the CMC to understand that I want a instant rotate the pawn toward the mouse then cast an ability.

I'm too sure i'f i need to override something and do custom logic or if i'm just not understanding how it should be implemented

[dark edge]

So look at how Orient to movement does it, and have your ability do that.

[cloud stirrup]

ok that took a long while but i managed to get vscode to play nice and build to a point where i can make the dedi server and client builds. seems u have to start the project with this ion mind for it to not break so start with settign it up for this build env and run from vscode editor not epic editor. fingers crossed i can recreate the project. props to wizard and laura for their help earlier

[obsidian basin]

Experiencing a little bit of lag when I feel like I shouldn't. Basically it's on selection of a character. User clicks, I do a get hit result under cursor for objects. I then send that actor reference to the local player state and replicate it as a variable to the server. However, when I click on an actor, there's about a second of lag before it actually updates.

I'm using mostly blueprint interfaces to transfer information - are they laggy in Multiplayer environments? Should I be casting when possible instead?

[thin stratus]

It's usually set by the server.

In the function where the client handles the move response it should theoretically check if you need to sprint or not and if you are already sprinting or not

And then manually force it to

At least I think so. Always worth checking what epic is doing in the parent class

[verbal tendon]

Are you spawning anything when selecting? Why aren't you simply selecting locally?

There is a very simple philosophy to this, I call it: Local First
If there is anything that does not strictly need to be replicate it, you don't replicate it.

For example UI clicks, VFX from gunshots. If the action affects the game environment and therefore other players, it needs to be replicated. However if the only actions are locally, and it won't out of sync you ... you don't replicate it.

So for the character selection if someone else is supposed to see it, you just simulate locally first for the selection, and the server will update everyone else on your selection.

Simply routing UI clicks through an RPC to the server to then get it later yourself... sounds flawed by design.

And obviously if the action has no visible effect for others at all, it should not get replicated at all

[vivid prawn]

Should I load the content before joining a session or after joining a session?

i see most games start with joining a session and load the content in loading screen

but when I try to use UE default join session, it connect right away, though if the map quite heavy; it hang for a min or so

[gloomy tiger]

So, here's me trying Projectiles + Multiplayer. Most of the solutions rely on Multicast + some filter to guarantee a dummy projectile isn't seen to the owner of it (to compensate for lag). Question: this is a waste, right? In the sense of bandwidth.

[dark edge]

Why would it be?

At a minimum, everyone needs to know that a projectile was fired from X location at X direction if they're meant to see it.

[gloomy tiger]

One way to address "lag" in projectiles is to spawn one locally, then ask the server to spawn dummy ones for the remaining clients. Lots of solutions though suggest doing this technique via Multicast - however, Multicast affects all the clients, including the one that instigated the projectile - which is someone who doesn't care about it.

[real ridge]

Guys if I have Basic Thirdpersoncharacter and it has its basic CMC why when I change it to flying and I am moving with my character in game it's not replicated shouldn't it be like when u running on the ground?

[vivid prawn]

@real ridge is Can Fly checked by default? or you are switching it in the game?

[hoary spear]

Cant you spawn a replicated projectile on server, which has a condition to skipowner

[real ridge]

yes and here I changed position of one and it was not replicated

[vivid prawn]

hmm... the movement in character bp is replicated by default, i assume it's something else

are these 2 are standalone application?

i don't see server/client on them

[real ridge]

then my second approach is using pawn where I replicate movement by RPC but there is also one problem , when I move only little bit on the other window where it is replicated I see much bigger movement

even I replicated it via rpc

so I dont undestand how to do it

[real ridge]

using this settings

but for example I am not replicating moving of propeller and it is replicated

I am confused 😄

[real ridge]

when I try run it in viewport then its replicated properly @vivid prawn i mean this

or maybe do I somehow need use instead this function from cmc and set location there to have my char replicated? i dont know

[vivid prawn]

i see... try to use Add Movement Input instead of moving the actor

that would handle the replication

[real ridge]

but for add movement input is target pawn

this is character

but I will try

[vivid prawn]

pawn has controller and movement as well

yup

[real ridge]

yes but pawns are not replicated

only characters as I was said

many times here

ou shit its doing some crazy shit :DDD

wtf

i just changed that one blueprint and it suddenly react on WSAD EQ

oh my bad only moving up and down is replicated but it's strange he moved to the left

[vivid prawn]

@real ridge just use character blueprint, everything is already there

[real ridge]

I do but you see its working really strange 😄

i just used also that blueprint for roll etc

and its definitely not good controlling of plane

[vivid prawn]

you can roll in CBP

have to turn on Use Controller Rotation Roll in CBP

[real ridge]

also it's not like a plane

what is cbp?

[vivid prawn]

I just checked the Can Fly and set default land movement Mode to Flying everything replicate nicely on myside

[vivid prawn]

character blueprint

[real ridge]

i made one video for you

its uploading

[vivid prawn]

it's just matter of changing the settings

[real ridge]

check this is WS AD QE it's turning weird and it does not allow me turn 360°

[vivid prawn]

my suggestion is not to reinvent the wheel, you will save more time and have more progress

[real ridge]

i am just trying to find the easiest way to use planes in my game 😄 but I have feeeling nothing is working

[vivid prawn]

for rotation, you can turn on delay rotation

so it doesn't snap

[real ridge]

but you see video ? how nonsense moves it is doing ? I made another one where I am showing what moves I need to get

oh no old video..

this is my pawn and right movement

[vivid prawn]

i see... all that actually exists in CBP

[real ridge]

i will try make new project and test it maybe I Fucked something

if u saying

it must work

[vivid prawn]

check Orient Rotation to Movement in Character movement component

[real ridge]

it's ticked

but I have changed inputs

in settings

maybe that's problem

[vivid prawn]

also you can use Pawn Control Rotation in SpringArm

[real ridge]

ticked too

so u saying it should work so I just will try find where I have mistake

[half umbra]

What do you think about Inventory which is based on MySQL database?

[twin juniper]

I actually figured out that I can just use a RootMotion ability task. The CMC is already looking for rotation changes in the RootMotionParams, but none the currently created tasks change the rotation.

[plucky prawn]

Not arguing but how would you go about synchronising said inventory between servers? Like if you had some kind of "server node" set up? Or is that a completely different problem

[outer sphinx]

hello guys, a question someone uses the plugin "MySQL Integration
"?

[timid moat]

Hi!

Are there better options of UGameplayStatics::GetPlayerController to use them developing a multiplayer game?

Thanks.

[silent sinew]

How can I sync a simulated proxy if its late joining the game? Right now I'm testing two windows on a listen server. If I wait for all players to connect then no worries, but if I let the server/ client (same) run around and do something first, then the new player joins , they don't get any updates (unless the property is replicated). In my case I have a TMap (which can't replicate) and if the original starting player adds an element to this tmap I want to be able to tell the joining player - their Simulated proxy (of the starting player) needs to add this elem to the Map.

They weren't in the game when the OnRep for any replicated variables occured and I don't have one that would suffice. I could keep an integar of the number of elems and create an onrep for that, so when the new player begins their int gets the OnRep because it's not the same, and in this I could do something - but it seems so Meh

[timid moat]

Something like instead of GetPlayerController(0) use GetOwningPlayer.. Or APlayerState::GetPawn().

[sinful tree]

For the most part you should be able to get to the player controller from the controlled pawn via GetController, and through GetOwner on PlayerState - both of which would probably need to be casted to PlayerController to do anything useful with them.

[gloomy tiger]

Hey! RE: to Conditional Property Replication (https://docs.unrealengine.com/4.27/en-US/InteractiveExperiences/Networking/Actors/Properties/Conditions/) - any ideas why it's not exposed to BP? What's the rationale behind it?

[quasi tide]

It is exposed to BP

[gloomy tiger]

Is it?

[quasi tide]

It's the "Replication Conditions" dropdown for a variable

[sinful tree]

It is exposed?

[gloomy tiger]

Hm. I'm quite lost, then, geez.

[hoary spear]

Not sure if it was a good suggestion tho as im not very network experienced, but it came to mind

[gloomy tiger]

Your suggestion is actually what I saw everywhere on the webs.

(Thank you by the way)

The thing is - I just skimmed that docs (shame on me), and thought that could be something that would skip the entire Actor from being spawned to the owner of it (missed the second param of DOREPLIFETIME_CONDITION).

That to ask: can I spawn actors conditionally?

In the sense - I want to spawn a projectile to everyone but the owner of it.

(That actually seems to me a pretty common thing to do in multiplayer games when it comes to lagfree solutions. I'm surprised it's so difficult (taking me hours) to get it done correctly, without the need of a multicast.)

[hoary spear]

bSkipOwner

Is for actor replication

In the actor settings

[gloomy tiger]

Wait. Where? 🤔 In the Actor Settings within the Editor you mean?

[hoary spear]

Or avaliable as a property in c++

Yepp

[gloomy tiger]

Supposed to be here?

[hoary spear]

Probably under a replication category

Not in editor atm so cant find it

[gloomy tiger]

Can you point me the docs for this variable you talking about?

[gloomy tiger]

B/C the only bSkipOwner I saw was this one

(Which relates to a variable)

[sinful tree]

Yeah that doesn't appear to be a property of AActor.

[gloomy tiger]

Maybe this? https://docs.unrealengine.com/4.26/en-US/API/Runtime/Engine/GameFramework/AActor/IsNetRelevantFor/

Still not sure how to use it yet.

[sinful tree]

IsNetRelevantFor requires C++.

[gloomy tiger]

Not a problem. Whatever it takes to skip an unneeded multicast.

[sinful tree]

Ok, then it's fairly simple.... One sec.

.h
  virtual bool IsNetRelevantFor(const AActor* RealViewer, const AActor* ViewTarget, const FVector& SrcLocation) const override;

.cpp
bool YOURAPIHERE::IsNetRelevantFor(const AActor* RealViewer, const AActor* ViewTarget, const FVector& SrcLocation) const
{
    const APlayerController* RealViewerController = Cast<APlayerController>(RealViewer);
    if (IsValid(RealViewerController)) {
           // Do whatever checks necessary to determine if the PlayerController should view it or not.  
           // In your case, you'd probably want to return  (controller of the instigator of your actor != RealViewerController) thereby, only those who are not the instigator would return true.
    }
    return false; // Return false if thew viewer was not valid.
}

This would go into your projectile C++ class.

[gloomy tiger]

Testing right away. I anticipate my gratitude 🙂

OK so - doing that would mean that when Spawning the Actor implementing this custom IsNetRelevantFor, the server would spawn it everywhere except at where IsNetRelevantFor would return false. Correct?

[sinful tree]

Yep

So that being said, you may want to add to your condition if the super is true, so any other relevancy may apply rather than just always being relevant for everyone else which it may not necessarily need to be if they're far away for example 😛

[gloomy tiger]

You mean

    if (!IsValid(RealViewerController))
    {
        return Super::IsNetRelevantFor(RealViewer, ViewTarget, SrcLocation);
    }

[hoary spear]

Well damn. You're right, the property is "OnlyRelevantToOwner"

My bad there, mixing it with the cond

[sinful tree]

return that && the instigator/controller part.

[sacred kraken]

I'm working on a two player co-op. You pick a role (there are two roles) and once both players have indicated they're ready, the game starts.

What are the steps I need to take? Abstractly, I mean. I can host a session and I can join, but I don't know when the other player has joined so I don't know when to show them as joined on screen. Should they just pop-up and do I replicate UI? How do I know when to enable the "start game" button?

A "rtfm" is also fine, I just don't know how to proceed.

[hoary spear]

Gamemode keeps track of players joining

Gamestate holdes an array of players

[sacred kraken]

@hoary spear What do I use to be notified of players joining? I have a custom game mode in c++ and I have a blueprint of it as well if that helps

[hoary spear]

Theres an event in bp (in c++) as well

OnPlayerLogin? Or something like that

[sinful tree]

OnPostLogin() is the function in game mode where a player has been granted a playercontroller.

[hoary spear]

OnPost* ah yes

[sacred kraken]

Thank you, that helps a lot.

virtual void OnPostLogin(AController* NewPlayer) override; there she is... If I may be greedy, do you have any pointers on syncing the UI? Player picks a role, and both players connected can see that?

I'm not doing that part until tomorrow, but I thought I'd try my luck 😄

[hoary spear]

Datura will provide a better method than what I did xD

( i may have snaked my way through some super redundant rpc bullshit via the gamemode and whatnot)

[sacred kraken]

I found the other method I need for my first question I think, it's called Logout. I was looking for OnPostLogout like a pleb.

[sinful tree]

Well really, I think it's more about what information it is you want about a player when they join which probably means the Begin Play of the Playerstate may be a better choice as the PlayerState would likely contain that data. The begin play in playerstate on the client could signal something to your UI, possibly by calling something in your HUD class to indicate a player is joining. Your UI would then need to react to that signal, set up any other binds that are required - you may want to read any values and have event dispatchers set up for when changes are made to any OnRep variables (like player name) You can always read the player array from gamestate as well if you want to read the current full list of players and then read their properties and set up binds to their data.

[sacred kraken]

Binds as in umg?

[sinful tree]

Binds to event dispatcher or binds in umg if you desire.

[sacred kraken]

Ah, right, thank you. I'm taking notes, because I need to look up what those are still.

So far I've done the basic map travel, host session, find and join session... That stuff. Now I need to figure out the rest.

[hoary spear]

this was some of my setup

[sacred kraken]

Any docs/tutorials on how this stuff works?

I copied both your messages to notion, so I can go through it using the docs lol

I'll just keep playing around and see what happens 😄 Thank you both

[hoary spear]

whenever someone did anything in the UI i went through the playercontroller to rpc(ignore the S)

which just passed it forward

which ends with the first function i showed, "Server_UpdatePlayerStatus"

this is probably not an acceptable way to do it at all , but it worked for my 4 man lobby x)

[sacred kraken]

Oh, wait, would gamestate then make sense?

Because that's synced, right?

And it's per game mode, so if I have a game mode for the "lobby" then that has a game state I can use to keep track of who's picking what. That information should be available to both players and is a draft until the real game starts anyway

[sinful tree]

It's more about what actor is pertinent for what data. PlayerState is a replicated actor just the same as GameState, the difference being only one GameState exists for everyone. Each player would have their own PlayerState, thereby, any data about a specific player that needs to be replicated to other clients and can be replicated at any time regardless of relevancy should likely be stored in PlayerState.

If it's specific to the state of the game or what is happening and isn't specific about any single player, and again, needs to be replicated to others, GameState makes sense to store that value.

[sacred kraken]

PlayerState lives as long as the controller does, right?

So it can outlive maps

[sinful tree]

PlayerState lives longer - it can stick around and be reassociated to a player that disconnected with a bit of work in C++.

[sacred kraken]

That's good to know

[sacred kraken]

I'm going to tattoo this on my lower back

[sinful tree]

So rather than having the gamestate store what each player picks, which in order to replicate would require a weird structure and/or some array management hell, you can store what the player picked on their playerstate, and then the playerstate can replicate those values to everyone else, and you'd use OnRep properties on the PlayerState so you get functions that are called when those values change so your UI can be updated when those values change.

[sacred kraken]

I didn't know that was how it worked

[winged badger]

Outlive maps... kinda... its going to get reisnantiated with the PC. But you can override CopyProperties to carry the data you need over map transitions.

[sacred kraken]

But clients can change their own playerstate right?

Or is that also server-only?

[sinful tree]

If you wanted to have something replicated, you'd be able to send a Server RPC on the client's PlayerState with the data you want to send, and then when running on server, set the replicated properties you want with the values that were sent through the RPC.

[sacred kraken]

Wait now I'm getting into "rtfm" territory because I am pretty sure the doc I found will cover this

So I need to keep reading

[winged badger]

I strongl, suggest separate lobby and game player state classes with a common base containing all the data you want to persist across levels

Those things tend to grow as you start adding more customization options

[sacred kraken]

I see

Added to my list of messages to decrypt 😄

I'm reading this now by the way: https://cedric-neukirchen.net/Downloads/Compendium/UE4_Network_Compendium_by_Cedric_eXi_Neukirchen.pdf

If there's something else that better explains the concepts I'd love to hear it. I am still finding out who's allowed to change what. But for now I'll go back to reading and being a good student 😄

Thanks again!

[winged badger]

Good choice of light reading material

[hoary spear]

The validation part confused/surprised me a bit

Failing validation results in a disconnect

Is that really how one wants to handle that?

Just disconnect anyone we decide tried to go outside some bounds during some rpc ?

Guess i just expected a rejected rpc, and nothing more

[winged badger]

You can do that, just noz how iz works out of the box

[hoary spear]

I see

[sacred kraken]

I found the answer to my question on literally the next page I had to read. I’m sorry

[winged badger]

Its basically there to kick out cheaters

You can add your custom validation and call it from RPCs _Implementation , for cases where xou dont want to accept what client sent you, but dont want to kick him either

And just have the _Implementation return out eithout doing anything when it fails

[hoary spear]

Ahh right, that makes sense

Thanks

[obsidian basin]

Hey all, I've setup an interaction system - I click on a player and it sets a replicated variable on my player state storing the actor I've clicked on. I've noticed there's a noticeable lag, however of about 1 second between when I click and when it's updated. This is happening on a dedicated server setup.

Anyone have any ideas why this might happen?

If I'm getting this much latency on a local test with selecting an actor now I'm worried what else could be lagging

[graceful falcon]

Quick question, how do server like call of duty or fortnite work? Are those servers dedicated servers?

okay, thanks

[sinful tree]

PlayerState's default NetUpdateFrequency = 1, which means it's only checking for replicated values once every second.

[obsidian basin]

Ahhh, thank you, that explains it. Luckily I don't need it to be faster for my purposes, but good to know why it's doing that.

[obsidian basin]

Does ForceNetUpdate basically say "Update this right now"?

Or is there a way to change the frequency if I needed to?

[sinful tree]

I believe so, not sure as I've not messed with it myself.

[obsidian basin]

(nm, I found it in defaults lol)

[obsidian basin]

Hey, so I need to update an entry in an array. I'm telling the array "Increase this entry by 1". On the server, I find the right entry in the array and go through normal steps to update (Break the struct, set the members and then set array elem). It's updating it locally, but won't update the server.

I assume this is because set array elem isn't replicating; would a better way be to clone the array, make the changes to that array then set the actual array to that? THen it's just a simple set that can be replicated.

[thin stratus]

Yeah that's Blueprints for you

You can try to just call "Set" on the whole Array and pass in the whole array

That might trigger it properly

But that goes for the replication part

You should, even without that, have a correctly updated array on the Server after incrementing the entry. Otherwise you are doing something wrong

[hoary spear]

Is this different in c++, since you say it like that? Would updating an array element in c++ trigger it ?

[cloud stirrup]

if i used loadlevelbp with url/ip how do you know if the level didnt load? would i just add a delay and if im still in the current level when the delay fires i throw up an error dialouge. otherwise iv moved levels and its all good. e.g walk into a tp box to tp from one server to another but if that servers down dont go there and stay where i am. as it doesnt have a success fail output on the bp

[jolly siren]

Is the only way to have a conditional for whether to replicate a property within a ustruct to also replicate a bool and check against that within NetSerialize?
Or can push model be used to control when properties replicate within a ustruct?

[dry pebble]

Does anyone know why the character class disables a replicated property as being not replicated? DISABLE_REPLICATED_PROPERTY(ACharacter, JumpMaxCount);

[thin stratus]

If it's about OnRep, yeah it is different

Is that function called by both?

Also ControlRotation is send from Client to Server

maybe something is going wrong with which ControlRotation is actually being used

ControlRotation is packed and send to the server usually

You'd only need to set it on the Server if you correct the Client iirc

[fathom aspen]

Why the conditional bool property has to be replicated? Couldn't you mark it as NotReplicated?

[thin stratus]

If it needs to be dynamically set, you usually use a bitmask

If it's known at compile time that you don't want to replicate a specific property, you would do what Wizard said

But a boolean is theoretically also fine

We use a bitmask for the GameplayEffectContext

We have multiple inner structs in that and only if someone calls "SetXYZStruct" on the Context, we flip a bit to 1

And use that to check if we need to load/save that part into the archive

I think that's what Epic also does with their EffectContext

[fathom aspen]

I'm looking over at FRepMovement they do something similar. For example they check against RotationQuantizationLevel to know how to net serialize

Though that is not marked as NotReplicated for some reason

Could be that they use it client-side

[thin stratus]

You need to replicate the flag/boolean

Cause you need to know on the client if you need to load the value

You are basically writing it in some dynamic order

[jolly siren]

yeah FRepMovement was the example I was looking at for the bool

[thin stratus]

So the client needs to know the order in which it has to read

[fathom aspen]

That's if you do it dynamically right?

[thin stratus]

Yeah

[fathom aspen]

Yes fair enough

[thin stratus]

Yeah, not entirely sure atm why it would cause corrections

[fathom aspen]

AFAIK Push Model looks for properties by name within the class that you specify, so in theory if you could slap the Struct name in there... then you would be able to control the struct inner properties

But I haven't tried that

Interesting

[jolly siren]

yeah that's what I was thinking too

How does the bitmask method differ? Isn't it the same as the bool method just packed?

[fathom aspen]

Saving those extra bits ^^

But yeah it probably doesn't make a big difference if you're only looking to conditionally replicate one property, but if you have multiple of them then having a bitmask would be a good idea

[jolly siren]

awesome, yeah that makes sense

[obsidian basin]

Just to be clear, once I setup an Event as Run on Server... and this may be a dumb question... everything in that event is run on the server, right?

[quasi tide]

Yes

[fathom aspen]

Potentially run on the server

[obsidian basin]

Potentially

[fathom aspen]

RPCs sometimes get dropped

For reasons

[obsidian basin]

Got it

I wish there was an easier way to visually see player array data on the server

[fathom aspen]

I tried RootMotion last night with the GMC

I have something not working for some reason though, but I like it nevertheless

[quasi tide]

Like the workflow or like GMC?

[fathom aspen]

https://www.youtube.com/watch?v=JPmy2H9Damc&list=PLUYBthaeEmJtsIu81Et9mVLIde9xVx9nR&index=4&ab_channel=JimmyVegas
This is the the tutorial I'm following but FSR sim proxies are not able to see the animation montage playing

[obsidian basin]

I can call a server event from a sever event, right? Like it should know it wants to execute on itself?

[fathom aspen]

GMC

The way properties replicate is different to how you replicate them in a non-GMC environment, so it must be that

I fear it's something with the plugin, but I feel I missed something

[fathom aspen]

Yes, it would then run the second server event as a normal function on server, but a good practice is to know not to mark it as an RPC at all

[quasi tide]

Like it more than the beloved CMC?

[fathom aspen]

To be honest I was not punished enough by the CMC to appreciate enough what the GMC offers, but I can feel the potential the plugin has

[quasi tide]

@whole grove 👆 A light review

[fathom aspen]

I mean I wouldn't program in BP but the fact that you could prototype something really fast is mind blowing

[quasi tide]

How would it be faster than CMC?

Prototype wise

[fathom aspen]

I still dislike for example some boilerplate, so for example you have to tell the GMC owner about the action/axis mappings that you are using

You also have to bind those inputs with dedicated functions and hardcode the names again

But well you can bypass that using the construction script for example so it's not that big of a deal

[quasi tide]

Yeah, that part was not all that attractive 😅. But with enhanced input, you kind of have to do that now anyway. Just asset based now.

[fathom aspen]

But you're eventually going to be doing MP when hired at WizArmy™️

[thin stratus]

I just want a Prediction Plugin Movement Comp

With that sweet sweet debugger

I had to debug Movement shit again

I hate it

you can't log it cause it's obviously not in order when printed

That debugger Dave showed in his youtube video was so awesome

I already thought about just trying to get that to work with the normal CMC

[fathom aspen]

Honestly the dream is if NPP was continued and the CMC worked better in tandem with the GAS

[thin stratus]

Yeah the NPP would just have a general state

A generic SavedMove

With all info you need

;_; UE6 #believe

[twilit radish]

See you in a decade 🥲

[fathom aspen]

That kinda sucks because it means I will be at 40

[fathom aspen]

What debugger is that? 👀

Ah okay I didn't watch the video (I know the video you're referring to)

[thin stratus]

Basically a timeline that shows the "moves"

And if they were acknowledged, or rejected and replayed

And you can click on them to see the state

Like the variables

[fathom aspen]

Wow... this left me speechless

[quasi tide]

Apparently not

[thin stratus]

Blue is predicted iirc

And Red is a correction

[twilit radish]

Did this get scrapped or no?

[thin stratus]

Pretty sure if it still exists it's part of the NPP

Which is still not integrated into any other class that we daily use

[fathom aspen]

How easy life becomes... debugging tools are the best

[thin stratus]

Right?

How easy it would be to instantly see the move that got rejected and compare the values

Instead of printing in random places and having to compare timestamps

cause by default the CMC is like "HEY THE POSITION IS SQRT(3) OFF, GET F DUDE!"

Why? Who knows

Maybe you forgot that the CombineMove function is supposed to reset the CMC back to Move1

freaking hell, still haunts me

[quasi tide]

Cedric dreams in CMC stuff

[thin stratus]

My whole life is a rejected move

what?

That said, I'm actually working on refactoring something that I released some time ago

Not so interesting for you all, cause you already know how everything works

But(!), I'm rewriting it in a way that others can easily extend and update it

[twilit radish]

What are we talking about?

[fathom aspen]

Only one knows how everything works 🐉

[thin stratus]

The Compendium

[quasi tide]

The Compendium V2 - AKA "The Compendium Wiki"

[fathom aspen]

The Persistent Data Compendium?

[twilit radish]

Oh.. That's what I was thinking, but the "easily extend" part threw me off 🤣

[thin stratus]

I'm turning it into a React app with MDX, with a public repo for PRs

[quasi tide]

Yeah - just make new pages on the pdf Thom!

[fathom aspen]

Probably extend it with the Iris stuff? 👀

[thin stratus]

It can still be "printed" into a new PDF, if someone still wants that

[fathom aspen]

I mean me and @whole grove only care about a dark theme

[thin stratus]

But this should make it easier to correct mistakes, update to newer versions and also link specific topics to people

No, Multiplayer is the light in our lives

Dark theme is for Singleplayer

[fathom aspen]

Our opportunity to revamp our #multiplayer learning experience @whole grove

[thin stratus]

Original main reason why I wanted to redo the doc into a website was so I can easier code custom animations, such as highlighting only specific elements if you hover "Server" or so.
But by now I'm happy that I can use Markdown

[fathom aspen]

I already thank you for the effort because I can already feel the potential

[twilit radish]

You're definitely out of the "learning experience" already though lol.

[thin stratus]

Yeah I'm still rewriting it. Lots of the text was cut down due to the limited space I had in the doc before

[fathom aspen]

Finally no more wordpress dropouts? 😍

[thin stratus]

And my lack of webdev skills are also a bit time consuming

[fathom aspen]

Cools dudes use Jekyll (and MM for the extra coolness)

[thin stratus]

I'm even considering moving my guide for C++ Sessions to the same page

Well, other tab, but overall same page

[twilit radish]

Wordpress or custom solution you'll get hacked either way one day lol.

Web sucks.

[quasi tide]

100%. Please save me 😭

[twilit radish]

Get a game dev job 😛
Says the person without game dev job, but you know.

[thin stratus]

I even recreated the damn diagrams as svg

[fathom aspen]

It's funny that I got a mail two month ago from a random about my website exploited. Poor hacker didn't know I have no "real" database

[thin stratus]

And, what is also kinda cool, I can use blueprintUE for the BP examples

I asked the creator if they could look into making it printable (well save to PDF) but I think they didn't get far with that

So I might need fallback pictures -.-

[quasi tide]

I'd like to, but remote is hard to find because gamedev is prehistoric (hard requirement for my situation) and generally the stability and pay is worse.

[pallid mesa]

👀 https://github.com/EpicGames/UnrealEngine/commit/542bc934a28196d6cbf783ea085f78dfa6ec9792

[quasi tide]

I'd honestly even be willing to just take a very small pay cut - but the stability....

[cunning stirrup]

Hello, I'm having issues with location replication and attachments :
I've got a mesh to which I attach multiple actors, all are set to replicate, as well as the root component.
The thing is that i'm spawning and attaching the actors in the same frame, and on the client, sometimes the attached actors get wrongful offsets (not the same as the ones on the server. I'm using attach rule KeepWorld.
Does someone know a fix ?
Btw it's all runtime (runtime mesh and UGC), so unless I code them myself, sockets are not an option as of now.

[fathom aspen]

It's not Iris specifc, amazing 🥳

[twilit radish]

Very relatable, also I suck at everything game dev but relatable. I found a whole one studio in my country that I "know" and that make games, have been considering applying for a QA job and see if I can get anything out of that but not sure yet. But everything international is such a pain.

[thin stratus]

Don't think you need to replicate the root component

Actor Attachment is replicated by default

I even had to turn that shit off cause it was interfering with attaching it to different meshes on different clients..

[cunning stirrup]

yeah but for actors with components it's needed otherwise it just doesn't attach

[thin stratus]

Actors always hae at least one component though

Either way, are you moving while spawning/attaching?

[cunning stirrup]

it's not always a scene comp

[thin stratus]

Doesn't really matter. Actor Attachment is still replicated

[cunning stirrup]

yes, there's a bit of gravity but everything happens in one frame and correctly on the server

In theory, it should still be connected in the same place on the client ?

[thin stratus]

Yeah but the Actors aren't guaranteed to be in the same relative places on Server and Client

Cause they are moving

[cunning stirrup]

Yes, but some spawn at the correct location on the client, other spawn at the location of the component they are attached to instead and so theyu don't get the correct offset

[thin stratus]

Would it be an option for you to, instead, "snap to target" and then set a relative offset?

[cunning stirrup]

Is that possible ?

[thin stratus]

Relative Transform should also be replicated

So if you calculate the relative offset between the World Location and the Attach point, you can snap to target and set that offset as relative location of your attached actor

That should theoretically ensure that client and server use the same offset

[cunning stirrup]

If i've understood correctly, I should use Attachment rule to SnapToTarget and then add an attachment offset ?

[quiet fjord]

How can I replicate an animation in standalone modes?

[thin stratus]

@quasi tide @twilit radish Not to escalate this, but from the POV of the person hiring, I can understand that one doesn't want to bother hiring people across the border. Even within the EU it's annoying to deal with. We do however have three of 5 people work remotely, but within our country.

[thin stratus]

Can you explain what your problem is?

[thin stratus]

For example, yeah

[cunning stirrup]

Ok thanks, i'll try and keep you updated

[quasi tide]

Oh yeah - I totally understand not wanting to remote hire international 😅.

[quiet fjord]

I am trying to replicate an animation of an actor on a map and when I compile and test it on my dedicated server that I run from standalone, the animations are not replicated, I only see them in the actor that runs it but not in the others

[thin stratus]

You'll have to share your code around that, cause this totally sounds like your code is at fault

[twilit radish]

But that's exactly why I'm questioning if I should even bother with game dev despite how much it hurts, imagine I get hired by that one company in my country and something happens then I have literally no or very few other options. My country sucks in terms of game dev jobs 🥲

[thin stratus]

I mean I don't mind hiring someone as a contractor, but not as an employee

[thin stratus]

GameDev is tricky, yeah

[quasi tide]

International contractor is fine. From what I've seen, it is generally, "Hey, here is your money. Figure out taxes on your side."

[thin stratus]

Should probably move it to #career-chat or so, sorry!

[twilit radish]

#BlameCedric 😛

[thin stratus]

Oy, I made sure to help the peeps that asked in between. Otherwise I would be crucified in that feedback thread, which is apparently locked by now (thank goodness).

[quiet fjord]

It does a super weird thing to me, the actor only replicates me when I'm with the other player near the actor who interacted with the object in question to replicate.

all this is for a dedicated server model since the machines are connected by standalone

[cunning stirrup]

It works ! Thanks ! Also, would you happen to know why there is self-collision between attached objects on client but not on server ?

[thin stratus]

No clue. Just make sure to turn off collision on both

And since it's state, preferably via RepNotify/OnRep

[worn wagon]

Uh before I go down a debugging rabbit hole, are there any known issues with ServerTravel in packaged builds for 5.1? I haven't changed anything since the last time I packaged regarding session hosting apart from upgrading to 5.1. I can do it fine in editor, just not when packaged.

[thin stratus]

ServerTravel, as in moving together with Clients to the next map?

[worn wagon]

It basically reloads the main menu when I try it.

[worn wagon]

No just trying to host a session and travel from the menu to the map

[thin stratus]

Ah, that's not ServerTravel

What Subsystem are you using?

[worn wagon]

NULL subsystem for now, hosting lan

[thin stratus]

Then please check your logs

If something went wrong it should be in the log

[worn wagon]

Yeah about to do so

[cunning stirrup]

Nevermind, there's still the same issue : the objects spawn at the parent's location on the client and don't get the relative location applied after the snap.
Do you know if there is a way to replicate data to the object so that it has it on BeginPlay ? that would allow me to fix the issue.

[thin stratus]

Exposed on Spawn variables that are marked as replicated should be available on BeginPlay

Same goes for Deferred spawned Actors in C++

[cunning stirrup]

it doesn't seem to be the case, https://forums.unrealengine.com/t/spawn-actor-replication-of-exposed-on-spawn-variable-values/88774/4
according to that and some testing I did on my end (though that was with replicated variables on a component)

[thin stratus]

Please re-read the thread

Nothing in there says that Replicated Exposed on Spawn Variables wouldn't work

The poster wants ALL exposed on spawn variables to get send to the Client by default

Which is not what I said

[worn wagon]

[2022.12.28-23.17.26:287][372]LogNet: TravelFailure: ServerTravelFailure, Reason for Failure: 'Failed to load package '/Game/Maps/MixtapeMansion''```

[thin stratus]

Guess your map isn't packaged?

[worn wagon]

It always was before. The map is in the same folder as the main menu map.

How do I verify this?

[thin stratus]

Can you try to travel to it via the console?

[cunning stirrup]

yes, but I'm using deferred actor spawning in this instance, so I don't need Expose on spawn ?

[thin stratus]

Other than that, I would manually mark them when packaging

[thin stratus]

Expose on Spawn is the BP version of Deferred spawning (more or less)

Concept stays the same

Replicated Variables that are set before Finishing the Spawning are available on the Client

[cunning stirrup]

So with deferred spawning, the value of the replicated variables should be set on the client when BeginPlay is called, but that's not what I'm seeing

[hardy sluice]

Can someone please explain me: assuming my GameModeBase has valid UserWidget inside it and I call for example thatWidget->AddToPlayerScreen()
Now, I know that GameMode exists only on server, but AddToPlayerScreen() uses local player. How does it work? Will that widget be added to all players' screens? Links with articles and tuts will be appreciated too

[thin stratus]

Are you setting it before calling FinishSpawning?

[cunning stirrup]

and my values are set before FinishSpawning

[thin stratus]

Hm

I'm pretty sure this works. have used that countless of times before

[cunning stirrup]

but my values are on the components of an actor so maybe it's different ?

[thin stratus]

GameMode only exists on the Server, as you said. A Widget Reference in the GameMode also only exists on the Server. Calling "AddToPlayerScreen" on it is not a multiplayer action, so this will still only call on the Server

[thin stratus]

THAT i don't know

I'm only using that with properties on the actor

[worn wagon]

Sorry, but how do I do this? I've never had to do this and I can't find it in the Packaging tab in project settings 😅

[cunning stirrup]

hmm

[thin stratus]

Look for the Session Frontend or so

That thing allows for more advanced setups for packaging

[cunning stirrup]

Thanks for the help, i'll dig in more

[austere burrow]

Hey all, I am attempting to test multiplayer using 2 PIE windows with gamepad input routed to the second window. I have checked Route Gamepad to Second Window in Editor Preferences and Skip Assigning Gamepad to Player 1 in Project settings, but it doesn't work— keyboard/mouse and gamepad get routed to the same window. I am using Enhanced Input as well as CommonUI. Is it possible those are interfering with the behavior? Thanks in advance for any help.

[thin stratus]

Hmmm

Skip Assigning Gamepad to Player 1 could be only for Splitscreen

Not sure about Route Gamepad to Second Window

[austere burrow]

that crossed my mind, but here is the tool tip:

[thin stratus]

https://issues.unrealengine.com/issue/UE-169979

¯_(ツ)_/¯

[austere burrow]

oh lol guess that answers that!

thanks for bringing it to my attention

I can ignore it for now then - not critical thankfully, just inconvenient

[cunning stirrup]

Is there a way to make two non-replicated objects share the same references when going over the network ?

so that both can be referenced by the client and the server without a link existing

[thin stratus]

I mean

You can't send non-replicated objects over the net

You need to create them in both places

The only thing to "link" them after that is using some unique identifier that you replicate back and forth

Like a TMap key

[hardy sluice]

What about standalone network mode?

I ask that bcs according to my understanding of your words there will be nothing for local players however In my singleplayer game localplayer sees that widget anyway
https://docs.unrealengine.com/4.27/en-US/InteractiveExperiences/Networking/Overview/ :

This mode is used for single-player and local multiplayer games. It will run both server-side logic and client-side logic as appropriate for the local players.

[thin stratus]

Standalone/Singleplayer has a GameMode

[cunning stirrup]

Can I exploit unreal's translation to do that ?

[thin stratus]

You can't apply Multiplayer Concepts to Singleplayer

[thin stratus]

I doubt?

You can try and see if an FGUID works

[latent heart]

Why not? Surely it's the other way around. Unreal works the same in SP as it does in Listen Server mode, surely? Just without any remote clients.

[thin stratus]

What I mean is, you can't say "Oh I'm playing the Game, so I'm somewhat of a Client and no GameMode exists, cause GameMode is something a Server has"

Singleplayer has no Server/Client concept. You are basically the Server

[latent heart]

That's just a misunderstanding of the situation, rather than applying concepts 😛

[thin stratus]

A Listen Server that isn't listening fwiw

[latent heart]

Yeah. That's what I mean. ^

You could effectively take a whole MP game and just run it SP, though, as long as it was designed with a Listen Server in mind. So they aren't unapplicable.

[thin stratus]

Yeah, that's just not what I meant

[latent heart]

There may be better ways to do things in SP, though. More efficient.

[thin stratus]

Less restrictive, yeah

[latent heart]

However, there are bonuses to a certain rigidity that comes from MP.

In SP, you could effectively just stick everything in the game mode.

[worn wagon]

@thin stratus Thanks, checked out the Project Launcher tool and made a launch profile where I manually selected the maps to package 😄
Still weird how it suddenly stopped packaging that particular map when it was packaging it in 5.0.3.

[latent heart]

And that wouldn't be good design.

[worn wagon]

Everything working now

[latent heart]

You mean write your own SP subsystem in gmae mode that you can register things to tick in?!

😄

[austere burrow]

@cunning stirrup if you want something to share state over a network, something needs to be replicated. It doesn't need to be the full data necessarily - you can replicated a key to some data that is stored locally

[latent heart]

E.g. when you replicate which mesh to use, you don't send the entire mesh over the network, you simply say, "I am using the mesh at /content/mymeshes/whatever"

[austere burrow]

right

[thin stratus]

Isn't there some #rules to strike Laura for?

tsk

[hardy sluice]

Can I read about that things without deep diving into MP somewhere? Cause now I totally dont understand differences in game behaviour depending on number of local players

[latent heart]

More local players = more player controllers on the machine. About the only difference.... other than the widget/camera space, I guess.

(split screen UI)

I wonder if you can join multiple local players to a server and have it make PCs for thjem all?

(from the same client instance)

[sinful tree]

https://tenor.com/view/well-yes-but-actually-no-well-yes-no-yes-yes-no-gif-13736934

[hardy sluice]

and what will happen in situation I imagined (#multiplayer message ) in the case when there are several local players?

[latent heart]

For each "local" player, there's a ULocalPlayer object (I believe) and, depending on your settings, potentially a unique screen/camera for each player

Each LocalPlayer object gets its own player controller.

I'm not too familiar with it really beyond that.

You might be able to do single camera / split UI as well?

[sinful tree]

If you're talking online multiplayer, a reference to a widget existing in the game mode could only exist if it was created on a listen server. For the reference to the widget to be created, that also means the widget would have needed to be created on the listen server host, as widgets do not replicate.

Local multiplayer, well, then calling Add To Player Screen would likely add it to the screen of whoever was set as the owner of the widget.

[hardy sluice]

thank you for your answer, but I mentioned Im curious about standalone with several localplayers

[hardy sluice]

world can be owner as well as game instance

[sinful tree]

Sorry, owning player.

[latent heart]

GameInstance and World would assume a single local user

UWidget and WidgetTree probably have their own references to the oiwning player somewhere (probably in their owning objects)

And PlayerController would be owned by a specific local player.

Or mabye not assuming a single local player, but maybe the first local player or a "global" ui element.

Probably implementation (yours) specific

[dry pebble]

does anyone know what "custom bookkeeping" Fortnite uses to handle fire rates and cooldowns?

[thin stratus]

I can only tell you that I ended up "custom bookkeeping" Cooldowns for a Client of us a few weeks ago

Cause rapid activation of abilities with GE Cooldowns doesn't work

But "custom bookkeeping" can be pretty much everything

I ended up making it 50% Predicted and 50% Authorative.

• Cooldown is a custom Struct with an Array of another Custom Struct in it
  -- That's so the Outer Struct can handle NetSerializing the Array
• The Inner Struct has the following properties
  -- Cooldown Duration (NotReplicated)
  -- Start Cooldown Timestamp (NotReplicated)
  -- bServerAck
  -- CooldownTag

The "NotReplicated" ones were the headache that had me handle Serialization of the Array by hand, but it's nothing more than custom looping over the new array and updating/removing/adding entries to the local one.

• Client and Server both apply Cooldown when the Ability Commits
• Server calculates a shortened Cooldown Duration (that's why it's not replicated) based on the Round Trip Time (RTT) of the Client, so the Client in theory doesn't suffer from their ping
  -- I had a synced NetClock (so a better setup for Timestamps that also gave me info on the RTT of the Client)
• Client and Server check if the Cooldown is "over", however the Client only removes the Entry of the Array manually if the bServerAck boolean was never set. That's fallback for when the Server had 0 Cooldown (RTT higher than Cooldown...) and generally so the Client can still somewhat predict. Otherwise only the Server removes the Entry. bServerAck is set to true when the Server applies the Cooldown on its side.

Since adding of the Cooldown is predicted, the Timer for UI is too and the Client won't try to reactivate the ability instantly (cause without predicting this, it would have to wait for the Array to replicate back to the Client, which will allow it to try and activate the ability again during that time).

Removing is not predicted (with the exception of bServerAck being false), so the Client will have to wait on the Server to remove the CD. This will guarantee that when the Cooldown is over for the Client and they try to reactivate the Ability, it is also over on the Server.

Because with GEs you run into the problem that the Client thinks the CD is over and reactivates, only to get rejected later. If you play animations in your GA it will start looking really bad for the player :P

I won't go into more detail, as this is theoretically a really simple setup and can probably be improved. I'm sure you can figure this out from the notes above.

[shut lily]

Is it possible to call a server function on an unowned actor? I have a weapon UObject and i want it to call the SetHealth() function on my character but it doesn't work.

[sacred kraken]

I'm still very new to this, but I think it is not possible.

If the RPC is being called from Client to be executed on the Server, the Client must own the Actor that the RPC
is being called on.

https://cedric-neukirchen.net/Downloads/Compendium/UE4_Network_Compendium_by_Cedric_eXi_Neukirchen.pdf page 62. But it shows alternative solutions using the player controller (page 71)

[pallid mesa]

What's the content of the array eXi?

[thin stratus]

The inner struct

[pallid mesa]

Ah so the tag identifies the cooldown identifier for your abilities 😄

[thin stratus]

I think you can get RPCs working on UObjects, but it requires replicating them through an Actor etc.

[thin stratus]

It is the CooldownTag

Not directly the Ability

The Ability might use that Tag for its Cooldown

[pallid mesa]

yeah gotchu 😄

yeah so its possible to reuse cooldowns between abilities, simple stuff, really nicely explained

[shut lily]

how do i do that?

[thin stratus]

https://www.thegames.dev/?p=45

[shut lily]

thanks!

[silent sinew]

I'm trying to learn how to setup TMap replication and I came across some stuff that goes over bool NetSerialize(FArchive& Ar, class UPackageMap* Map, bool& bOutSuccess) When I declare this struct as a UPROP do I still need to add 'replicated'? Or do I manually call NetSerialize when I modify the TMap within and it then replicates to clients with this struct?

[thin stratus]

Quick question, does your TMap have thousands of entries?

I know this isn't solving your replication problem, but I'm asking cause if it doesn't then you could save yourself the headache and just use a TArray and place the Key into the Struct.
Because looping that TArray is def faster than solving the hash function for only a few entries.

You can always write yourself a Getter for an Element of the Array that has the Key as an input, so you don't need to loop in all places

[silent sinew]

No - probably would never exceed 100

[thin stratus]

Yeah then it's probably worse to even use the TMap

[silent sinew]

I found this

USTRUCT(BlueprintType)
struct FStructWithMap
{
    GENERATED_BODY()
    
    UPROPERTY(EditAnywhere, BlueprintReadWrite)
    TMap<FString, FString> StringMap;
 
    TArray<FString> StringKeys;
    TArray<FString> StringValues;


    bool NetSerialize(FArchive& Ar, class UPackageMap* Map, bool& bOutSuccess)
    {
        if (Ar.IsLoading())
        {
            // Move data to Map
            Ar << StringKeys;
            Ar << StringValues;
            for (auto It = StringKeys.CreateConstIterator(); It; ++It)
            {
                StringMap.Add(StringKeys[It.GetIndex()], StringValues[It.GetIndex()]);
            }
        } else {
            // Move data to Arrays
            StringMap.GenerateKeyArray(StringKeys);
            StringMap.GenerateValueArray(StringValues);
            Ar << StringKeys;
            Ar << StringValues;
        }
        StringKeys.Empty();
        StringValues.Empty();

        bOutSuccess = true;
        return true;
    }
};
 
template<>
struct TStructOpsTypeTraits<FStructWithMap> : public TStructOpsTypeTraitsBase2<FStructWithMap>
{
    enum
    {
        WithNetSerializer = true
    };
};```

[thin stratus]

Yeah it's using 2 Arrays

It moves keys and values between the 2 Arrays and the TMap

[silent sinew]

Yeah I know

[thin stratus]

But it's really not worth it if you never exceed 100 entries

[silent sinew]

I agree - but do you know how the NetSerialize works?

Does it require a call to it and then it pushes this to the clients

or do I need to flag the UPROP somehow - and mark it replicated

[thin stratus]

NetSerialize is called automaticlaly due to the StructOps you have below

how that exactly works, no idea

[silent sinew]

Welp I guess I'll try some tests to see if its passing it to the clients

[thin stratus]

If it works like this, then it doesn't need UPROPERTY

However I do remember that struct props that should replicate needed it

Not sure if that also goes for custom NetSerialization, since you control it anyway

[verbal tendon]

Correct

WithNetSerializer means you are using a custom serializer and are taking control of serialization. So whilst the struct instance still needs to be replicated properly from whichever parent scope is replicating it. Anything within its scope of member variables, the engine is now hands-off beyond calling NetSerialize

You do still need to make them UPROPERTY for garbage collection

Unless that doesn't apply

[silent sinew]

So I have it inside a comp like so UPROPERTY(BlueprintReadWrite, EditDefaultsOnly, Category="Overlay") FFw_NetTMap OverlayDataMap; When I add 'Replicated' to the specifiers I get red lines

[verbal tendon]

It's generally a good idea to keep annotating your structs and classes properly even with custom netserializer, in case you ever want to go over them using reflection

[silent sinew]

UPROPERTY(BlueprintReadWrite, Category="Overlay") FFw_NetTMap OverlayDataMap;

[verbal tendon]

I mean it says why 😄

[silent sinew]

Yeah because the struct has a map inside it

So then how does this struct replicate

If I remove it

If I have all the netserialize stuff inside the struct - then everything in the struct will replicate, but how do I get the struct itself to replciate?

[verbal tendon]

Like Cedric said. The easiest way is to use Arrays, and then you don't need a custom serializer

custom serializers are really for niche use cases, this looks like you are trying to make a generic struct to use multiple times throughout your game. That's a terrible idea

You either have a struct that's part of one array, and you find the entry via predicate, or you use an array for keys, use the found index to grab the value. Those are your two best bets.

Because very simply put. if you have a map with 1000 entries, and you change one of them. The custom NetSerialize will send over the entire map of 1000 entries.
Normal replication using arrays will only send over the 1 entry diff

[silent sinew]

Okay so something like this

https://ikrima.dev/ue4guide/networking/network-replication/fast-tarray-replication/

What is going on with this TArray<FExampleItem>

Never seen a Tarray declared like this

[prisma snow]

that is an error of the code parser

the < is the html code of < if I am not mistaken

[silent sinew]

ty

[quiet fjord]

guys in standalone can it be replicated?

[prisma snow]

replicate to whom? xD

[quiet fjord]

I can't replicate animations of an actor when I interact with it. And his status is not reflected in the other players, why is it?

all this when i play on a dedicated server model

[prisma snow]

then it is not standalone xD

[quiet fjord]

clients run from standalone mode

that is, neither acts as a server

[prisma snow]

it doesn't matter, if they connect to a dedicated server they become clients

[quiet fjord]

I will tell you about my exact problem, if you can help me I would appreciate it very much since I have been having the same error for a few days and I do not see what it is due to

[prisma snow]

Giving context would be a good way to go about it xD

Are you using a client-server model or not?

[quiet fjord]

When I start a game, my game mode is in charge of generating some weapon chests for all the players, it turns out that these chests are replicated, when I approach them and try to open it, it opens for the client who interacts with it, but it is not reflected to me for the other clients.

The thing is that I know that the animations have to be executed on the server and then do the rpc for the multicast for the other players but that doesn't do it well for me. To make the animation of the opening of the chest

[prisma snow]

Then your problem is that the RPC is not firing

who does the RPC?

[quiet fjord]

the rpc that executes the opening animation is executed by the actor that belongs to it, that is, the chest itself

I will pass you screenshots of how I have it mounted

[thin stratus]

It all sounds very much like you are executing a server RPC for the interaction inside of the chest actor

[quiet fjord]

I'm just doing that.

what I don't know if I should call the rpc from the pawn that I control

[prisma snow]

if the animation is RPCd by the client copy of a chest, it won´t trigger

the RPC has to be executed by a server-owned actor

[verbal tendon]

There is a network example level that show cases this. I forgot what it's called. Maybe Advanced Networking?

It's in the starter kit I believe. It shows chest opening, network relevancy how it relates

[verbal tendon]

GameMode only exists on the server, and thus would only spawnon the server and replicate the actors

[verbal tendon]

Presumably your RPC is on the chest actor, which is a non-client owned actor. Therefore the Server RPC only executes locally

[quiet fjord]

Yes, of course, my actors are all replicated, that's not the problem, the problem is that the states of my actors are not updated when I interact with them from the clients

[verbal tendon]

The solution is to have the server-RPC on the playercontroller

Or one of the other ways that are in pinned messages here in this channel

It's very simple to debug those things, put print strings into your BP logic to see what is and isnt being executed

and fromwhere

I strongly suggest reading more networking guides and materials before working on the game

having a strong grasp of the basic concepts will be more fruitful than continuously making beginner mistakes

especially RPCs can be tricky when you're just starting out with them

[prisma snow]

yeah but he stated that the chest actor made the RPC, not the game mode

[verbal tendon]

Literally this: https://discordapp.com/channels/187217643009212416/221799385611239424/1058038858194886758

[prisma snow]

yey exactly 😄

[dry pebble]

Thank you so much for your explanation eXit, you clearly know your stuff. I'm going to read it over and over to let it sync in.

[sacred kraken]

I'm stuck again. What I am trying to accomplish is:

1. Two players. One runs around doing stuff (VR), the other has a side view of the same map (PC). These are two pawns with their own cameras.
2. The build of the game should somehow dictate which player role you have. This never changes.
3. The correct pawn should be assigned based on this player role.
4. Once both players are ready (meaning PC connected to VR and both pressed some button) the game starts.

I don't know what the order of things should be and where to put them. I don't know where to decide the player role. I don't know where to assign the player role. I don't know where/how to assign a pawn based on the player role. I don't know where to create/assign even the UI.

Does anyone have the patience to, abstractly, help me through this? I've learned quite a bit about the functionality, I know roughly which methods are available and all that... I just don't understand what goes where in what order yet.

[quiet fjord]

I think I got it guys thanks a lot 🙂

❤️

in the end the rpc launched it from the pawn that has a connection

[wooden plover]

Is there anyway to check and see if all players are loaded/valid in the level? I’m thinking of holding the number of players, and then incrementing a variable once they are valid in the level

[verbal tendon]

That is an easy and valid approach

[worn wagon]

You guys having any issue with anim notifies in shipping builds? I know it's bugged in 5.1 but this convar (a.EnableQueuedAnimEventsOnServer=1) fixes it in the editor, but seemingly not in shipping builds, at least for me.

[worn wagon]

(for the listen server host)

[clear island]

its a known issue https://issues.unrealengine.com/issue/UE-170093

one of the many reasons I'm avoiding 5.1

you'll have to wait until 5.2 for a fix

I didnt know about that console command but if its editor only, I guess its not a solution

I dont know why they didn't decide to do hotfixes like they did for the 5.0 release

some of these bugs are pretty critical

I'm still on 5.0.2 but I'm using a source build

I was like:

seems like 5.0.3 has a few bugs, I guess I'll just wait for the 5.1 release and stick with 5.0.2 for now

meanwhile 5.1 releases and its even worse 😄

so now I'm like: I guess i'll just wait for 5.2

[worn wagon]

There's no way they don't fix the issue until 5.2 right?

I mean how long will that be

[clear island]

inb4, 5.2 gets worse

[clear island]

yea we have no idea

I think its going to be a while

[worn wagon]

anim notifies not firing in multiplayer for listen hosts isn't some minor issue either

[clear island]

yep I know

theres even worse issues in 5.1 than that believe it or not

I'm not touching it

[clear island]

the bug tracker says 5.2 so I dont think they're fixing it before that

[quasi tide]

There is a setting you need to turn on for it to work

Trying to find it now

[worn wagon]

Are you talking about the convar?

[quasi tide]

Yeah - the one you have to put in a .ini file if I recall

[worn wagon]

Yeah I have that, it fixes it in editor only

[quasi tide]

Lovely

[worn wagon]

I packaged a development build and it make it better than it not being on at all, but some anim notifies aren't getting fired still

it's just a mess idk

[short arrow]

Me still on ue 4.26. That's craaazy

[clear island]

I get the impression that 4.27 was the most stable version, alot of the issues I find, I often find comments like: oh yea that used to work but stopped working since 5.0

[quasi tide]

5 will be solid in 5.27

[clear island]

hopefully 😄

[sharp yarrow]

Hello Everyone! I am having a hard time understanding how the Gameplay Message Subsystem works for Multiplayer in Lyra. I have a widget that broadcasts a message through the GMS and a component attached to the LyraGameState that receives the message and stores it in a replicated variable. What I want is for both the server and clients to update the variable. However, when I run the game it does not work as expected. The host updates the variable on the server and all changes are seen by clients, but the clients only update the variable for themselves. All the tuts I have seen on this involve setting up custom events on the Player Controller and passing those through to the game mode but in Lyra all is done through components. This messaging system seems to be the proper way of doing this in Lyra. Could someone please let me know what I am missing?

[winged badger]

Havent looked at lyra or the gameplaymessagesubsystem

But i can tell you that subsystem cant use server rpcs

Subsytems typucally dont replucate

[obsidian basin]

Question about non-player controlled actors. What's the best way to store replicated data for them? For example, let's say I have a game that's PvPvE - obviously for players I'm storing stats like health on the player state so it can be kept in the player array on the server.

How/where would I store that data for mobs?

[winged badger]

So send a server rpc with y payliad that then broadcasts the message server side

Why, PS health id only really uaeful with multiple pawns thst share hp

You can access pawn via playerstate

[obsidian basin]

I have other stats that need to persist through player death, so I'm just keeping everything on PS to make it easy

[winged badger]

Slightly awkward, but ok. Mobs hp on their pawns

[dark edge]

Why not just make death not be a deletion of the pawn

[winged badger]

You can add an interface to keep access cobdistent

[dark edge]

pawn stats on playerstate just feels gross

[winged badger]

Consistent*

[dark edge]

the State of the Player is their score. The state of the pawn is the pawn's HP

I don't have the HP, my pawn does

[obsidian basin]

How do I ensure I'm damaging the right mob, though? Again with players, I can just get the actor's owning player state and then pass the information through that, but all actors have different ids on each client, right? Or is that only for player owned actors?

[winged badger]

Each actor that is net addressable has a unique NetGUID

in other words you can send an actor pointer through a RPC

[obsidian basin]

Is that available in blueprints or just c++?

[winged badger]

Bp as well

You just add inputs to RPC event

[sharp yarrow]

Is it being replicated if the messages sent by the server (host of the session) are being replicated which seems to be the case?

[obsidian basin]

Ok, I'll have to look a bit more into this, thanks!

[winged badger]

Not neccesarily

Your listen node binds to a delegate (event dispatcher), which lives in a replicated object that receives the delegate then broadcasts

Your node is likely a full object that has a handler function that then broadcasts messahe received, which fires xour exec pin

Cant tell xoumore from s m9bile phone though

But that is a standard pattern for znreal engine

(Cant help typos, small buttons, large fingers)

[prisma snow]

I think znreal engine means unreal engine

[winged badger]

It does

[prisma snow]

[quasi tide]

Nah - it's really "Zlo's Unreal Engine"

[prisma snow]

lol where I can dowload

does it work with ChatGPT

[winged badger]

I barely ever modify it!

[prisma snow]

can it make game with brrr and AI

[winged badger]

Objects need an ActorChannel to replicate, and subsystems typically dont have an Actor as an Outer

So they tend to not replicate

[dark edge]

Have subsystem spawn an actor to use as a telephone on world begin play?

[winged badger]

You would have to also rename it to change outer

Which would kinda break it as a subsystem

[dark edge]

huh? I'm talking about the subsystem just talking to the actor

subsystem not actually replicating anything

just using the actor as a fax machine

"Hey Mr Actor here's a copy of my new state, replicate it plz"

"Hey mr subsystem, I got some new state for you"

basically the subsystem's secretary

[winged badger]

Actors dont like replicating objects unless they are also objects outer

You could do it indirect

But in this gameplaymessage scenario, you alsi need an actor owned by pc

[dark edge]

ooh yeah hadn't thought about ownership. So it could work one way but Client -> Server RPCs wouldn't work

[rose egret]

has anyone ever used ActorSpawnParamter.CustomPreSpawnInitalization ?
I want to set some properties before BeginPlay , I was using bDeferConstruction but saw this callback now

[sharp yarrow]

I thought the playerstate component was doing the replication because that is where the replicated variable lives.

[winged badger]

Even if the object is replicated, it would still need to be wired to always server RPC everything

For it to just work

Not near PC so cant check whats under the hood

[leaden sparrow]

i am trying to make the platform looping back and forward but its not synced can somebody tell me what is going on

[wooden plover]

Look at your replication settings. The server has the correct path because it knows all. However, the client doesn't know its exact position because its movement isn't being replicated correctly via code or settings

BRY has a good series on the basics of multiplayer

Question - I am trying to have a countdown timer that is ran on the host(server) that gets replicated to the clients. However, the countdown only works on the server. I have the option for replication checked for the variable. Any advice?

[prisma snow]

the funniest explanation of manager actors I've read

also it is totally what I am doing

[obsidian basin]

Ok, so how does one get the Unique NetID for an actor? I put a variable on the player character and then replicated it, but I'm not sure how to access it. @dark edge I'm looking to you since you originally suggested making this change lol.

[leaden sparrow]

yeah exactly but how do i replicate that. checking the options doesnt work

[thin stratus]

Well, the most basic way is to tick the Replicates and ReplicatesMovement checkboxes

But that wouldn't be pretty

Cause that will cause it to literlaly just set the location to the one the server sends

And that is not something happening often enough to look smooth

So you would need to code some interpolation to smooth between previous and new location

That's more a c++ thing though (daily reminder that Multiplayer without C++ is basically not working out one way or another)

[leaden sparrow]

thats my moving object blueprint

[thin stratus]

Yeah that's pretty wrong for Multiplayer fwiw

[leaden sparrow]

oh damn

[thin stratus]

BeginPlay calls when the Actor spawns on the Client

At that point the Timeline for the Server is already running

This will never sync

[leaden sparrow]

sooooo changing it to custom event would work?

[thin stratus]

Well

[leaden sparrow]

noooo

[thin stratus]

Again, you can mark the Actor is ReplicateMovement