multiplayer

[dark edge]

ok back up, what is the base class of Prayers?

Do you have prayer classes or anything like that or just images?

[glacial moat]

Only images, I havent got to the point where I want to store anything in playerstate yet

It should be just updating an image at this point

[dark edge]

ok lets assume your goal is to sync an image

do you have a replicated onrep variable of type image in your character?

[glacial moat]

I can make one

[dark edge]

what class is this code in?

Why is the variable called Prayer 22

[glacial moat]

Made a 2d Texture Variable

Assigned it what image i want

to see if it will work

set the variable to replicates

[dark edge]

Here's the general form

Input -> ??? -> run on server event //happens clientside
Run on server even -> ??? -> set replicated variable //happens serverside
OnRep_Variable -> change stuff in response to that variable changing //happens everywhere

[glacial moat]

alright I set it to rep notify,

What am I doing wrong now?

[dark edge]

you aren't setting Prayer 23 and you're not USING it in the onrep

what do you want to do when Prayer 23 changes?

wait do you have a variable per prayer? Do you have Prayer 1 through 23?

just have CurrentActivePrayer

[glacial moat]

currently this

[dark edge]

ok no there's a much better way to do this

why not make a class of some sort called BasePrayer, probably an actor

give it a variable PrayerIcon

maybe text PrayerName

then what you can send around is WHICH PRAYER YOU SELECTED

by class ref

right now your enum is sorta acting as that

[glacial moat]

So Make a new actor, give it a 2d texture component, refrence that actor, then set image?

[dark edge]

not component

just a variable

[glacial moat]

then make variable public?

[dark edge]

you don't need to instantiate prayers yet, you just need something to pass around to talk about what prayer you're concerned with

[glacial moat]

Alright, sec

[dark edge]

Then the variable you''ll be repnotifying is of type BasePrayerClass MyCurrentActivePrayer

[glacial moat]

Like this?

That variable is from the new actor

inside BP_ThirdPersonCharacter

[zealous wigeon]

Hi how strong the replication system is against cheating?

I would expect a multiplayer game to send movements inputs as "w_pressed", "space_pressed" etc, but it looks like it's convention to send directlty the position of the player, however we know we can't trust the client

how does this work?

thanks

[lament flax]

replication by default has nothing than, replication

you as the dev have to handle how you send data to the server and other users

[zealous wigeon]

Could you rephrase that, I have zero experience in networking through Game Engines, I only know how it works in multiplayer games made with frameworks (for example raylib)

from scratch

I watched some explanation of replication system

but still not really into that

[dark parcel]

You can't really stop the client from sending invalid data.

What you can do is check on the server machine if the input is possible

[zealous wigeon]

yes exactly

[dark parcel]

E.g. in shooting game, client may send data on which actor it hits.

The server will then check if the shoot is possible at all

[zealous wigeon]

however if I structure the game to send my position to the server, it's easy to understand that anyone can easily cheat the game and send fake positions to the server

so anyone can teleport themselves

[dark parcel]

Yes and that's been done

But you can always do some counter measure

[zealous wigeon]

so I would expect the client to send input events instead

[dark parcel]

Again by validating on server side

If the move is invalid, roll back

Or kick the player for cheating

[zealous wigeon]

isn't it harder to check if the movement is invalid? compared to record on server side the movement since "w_pressed" til "w_released"?

[dark parcel]

If you look into character movement component. It already have networked movement.

It have client prediction movement but server authorities. Players can move ahead, wrap the movement data and send to server.

Server validate the move, if they don't sync, correction will be made

Why do you need to check if a client press w or released?

[dark parcel]

You can look at character movement component. Or watch a video by delgoodie for the break down.

[zealous wigeon]

because doing so removes the need to validate data, which isn't always that easy (depends by the game I guess)

[languid finch]

checking inputs is no safer than checking location, if you check inputs then cheating tools will just simulate the inputs to reach a given location. which would be fairly trivial to fake. instead you send less data back and forth between the client and server by just sending location data and verifying whether that is within safe margins.

[dark parcel]

Not at all

[zealous wigeon]

mhh, I mean simulating w press for a given time is exactly like pressing it phisically, you still need time to reach location and you have to avoid obstacles, teleporting is worse imo

however, the question is, how does the server work in ue

?*

[dark parcel]

Don't understand the question but you can read the pinned materials in this channel

They hold the best source to learn basic replication

A server is just the host computer/machine not sure what the question is about

And speaking for my self, since I never publish a mp game and it's my first project.

I'm not gonna reach too hard, let cheaters cheat.

It's harder to cheat if you have dedicated server

Then just validate important bits on server side

Don't overthink cheating, if you are not making competitive games

[zealous wigeon]

in a game made without an engine I would just make an external program listening to a specific port, parsing data received from clients and perform the critical game logic,

but in ue there's just blueprint components with replication checkbox, will I have to write an external program as well? or does packaging the game provide the server as well? etc etc

sorry for the nooby questions but I can't wrap my head around ready-to-use stuff

[quasi tide]

You're making this way more difficult than what it needs to be

[sinful hawk]

You have to build the server separately

its a build target you setup. last i checked you had to do it from c++ in the ide but maybe theres a way now in editor

Well not specifically in c++, but from engine built in source

[dark parcel]

Dedicated sever need source build

[zealous wigeon]

in case I would build the server in my own, but what should I expect to receive from ue clients? xml? I mean I can't really underatand how all this premade stuff is not confusing to anyons

[dark parcel]

You are making it sound harder than it should

Just look at pinned material and get comfortable first imo

[sinful hawk]

For the most part you don't have to think about it just click the replication box and make sure its setup to broadcast to the correct people with 1 of 2 (or both i think) options

[quasi tide]

It is confusing to a lot of people. That's why help exists. That's why there are mountains of documents and tutorials covering this stuff.

You're just making it way more difficult

[dark parcel]

Written tutorial for multiplayers are tend to be helpful

[sinful hawk]

For the built-in stuff like movement, I'm assuming the built-in character movement is built to industry standards, so you probably don't have to think about all that. But I do get your question.

Videos like this made it click for me pretty easy: https://www.youtube.com/watch?v=OVeo3cVTIcU

[dark parcel]

Soo many harmful videos on YouTube tho

Like many is just straight up wrong

I would only recommend the pinned material and a written tutorials

[sinful hawk]

Thats true, you just have to go into it understanding that, watch for something that doesn't seem right and find another source to double or triple check, like anything in life

[dark parcel]

Yeah but people can't tell if someone doing the wrong thing when they just start

Legit saw a video spawning with multicast

And thousands of viewers thank him

Lots of victims

[sinful hawk]

ChatGPT is a godsend for me learning things even though it can be wrong half the time it usually says some keywords I can research more. But I already know how to code so its easier for me to notice things that are obviously wrong

[dark parcel]

It's just written tutorial are made by thoughtful people with the goal to educate

Youtubers are there for view imo

So they don't give a flying f if they say a total bs

Not saying all anyway, I found some video very helpful. Would be lost in cmc without delgoodie videos

[thin stratus]

I don't think that YouTube videos in the form of tutorials are usually meant to just generate clicks. If they are bad or teach wrong stuff then usually because the person simply learned it wrong and doesn't know better. Maybe they already learned it wrong from a different tutorial.

Most of those are probably actually convinced that their way is correct due to working and not having caused any issues, yet.

[dark parcel]

I do have bias or straight vendetta, seeing too many avoid casting and bad mp info on youtube

[zealous wigeon]

So the base idea was to use ALS for the main character

and a simple blendspace for the enemies

(that would actually see ALS in their screen)

this shouldn't be a problem if the hitbox of the chars is big enough to cover both the ALS version and the blendspace animations

what do you think

first of all ALS is only for singleplayer, and second it would be still too heavy to replicate over the net

also I can't use community replicated ALS

I switched to my old laptop lately and can't get C++ build tools to work the right way

[glacial moat]

I'm struggling

[hoary sandal]

I´m spawning these items only on the server, but there are disparaties between the clients, how can I solve this ?

The spawner is already placed on the level so unsure who does it belong to and if there are different isntances per server client

[lament flax]

are the pickable actors set to replicate ?

[hoary sandal]

It was a weird one so essentially I had to replicate the static mesh comp because I was setting a visual representation with the data asset on the construction script

[keen adder]

Heya dudes, how can we get the client's Number/Index/ID?

PlayerState.PlayerID gives me the total number of players created. So after a while in the editor it's 460. Just looking for player index 0, 1, 2, etc.

[kindred widget]

Why do you need it?

[latent heart]

Find their index in the game state's player array?

Though I don't think that's guaranteed to be the same everywhere or even in join order.

[kindred widget]

Referencing players by index never ends well.

[latent heart]

Indeed

[keen adder]

Yeah this should work. It's just for spawn positions

[daring gorge]

UPROPERTY(ReplicatedUsing=OnRep_Driver, EditAnywhere, Category = "Seating")
ACharacter* Driver;
UFUNCTION()
void OnRep_Driver();
my onrep function doesnt call? am i missing something? im setting the driver variable through a server RPC and did replicate the variable in getlifetimereplicatedprops

the variable does set too

[quiet yarrow]

I must be missing something obvious. Client to server and server to client is working. But client to client my physics constraints isnt replicating

[ripe lotus]

does unreal sends a network packet as soon as i trigger replicated code (e.g. moved something replicated). or does it waits till end of frame ?

[kindred widget]

All replication is end of frame. Assuming it gets past consideration. Replication can also take multiple frames before it's sent.

[daring gorge]

so the repnotify only triggers on clients when i change value through blueprints?

[ripe lotus]

oh interesting. thanks a lot! do you know if ue does some .. "optimization" before sending (like compressing the data or discarding multiple changes to the same value in one frame?)

[ripe lotus]

im sure it does on cpp. since ive used it.

[daring gorge]

yeah i tried but it doesnt seem to work, the onrep doesnt seem to trigger through cpp until i actually call the onrep function when i change value and even if i do unless im setting the value from bps the func is not getting called on clients

[ripe lotus]

have you also set the variable as replicated by oerriding virtual void GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const override;

[daring gorge]

yea

[ripe lotus]

also i vaguely remember reading some doc that says that either on rep or a server/multicast behaves differently on cpp than bps. on one of those it doesnt trigger on the server. sorry i cant remember.

[daring gorge]

its all good, it does seem to be behaving weirdly, im doing the same attachment code i did in bps yet it doesnt seem to work as it did in bps

[kindred widget]

You set state, once or hundreds of thousands of times in a frame. At end of frame objects are considered for replication. If that object passes consideration, it will check for changed replicated properties. Changed properties are sent and when sent they have a function ran on them that allows you to pack stuff however you like if you choose to override it for the data type.

[ripe lotus]

https://wizardcell.com/unreal/multiplayer-tips-and-tricks/#3-be-aware-that-blueprint-only-multiplayer-is-limited

[kindred widget]

Regardless of C++ or BP. OnRep will run on the client if the server sends a value, and when that client receives it, it is different than the value the client had when receiving it.

[ripe lotus]

thanks so much. thats really helpful. :)

[kindred widget]

For server though, in BP it will run the OnRep when setting it. In C++, you have to call the OnRep yourself manually when setting something.

[daring gorge]

right im yet to fully test my func, i did get it to fire func but i see that i do have to set the value through bps if i want to

[daring gorge]

did this too

[daring gorge]

and yes ive gone through this article before

[kindred widget]

You are saying that if you set the value in C++, you do not get an onrep on the client. But if you do it in BP, you get an onrep on the client?

[daring gorge]

yeah

[kindred widget]

You're 100% sure you're setting the value only on the server instance of the object?

[daring gorge]

yes

i know has authority can return client but im using an actor which isnt owned by a client and am setting the variable only after checking if local role is authority

also i dont think the function is running as it should or it did in bps

[kindred widget]

Is this the same value or two different ones? Like you're setting the C++ defined property in BP?

[daring gorge]

same value

yeah

[kindred widget]

That's a new one. O.o

[daring gorge]

and the function was just attach actor to actor at some socket, it doesnt seem to actually fire up on client

it worked in bps

the same exact code

[kindred widget]

Worth noting that actor attachment is replicated. You don't actually have to set it on clients usually. This is why Unreal Tournament uses a FPS and TPS mesh in it's weapons. Cause it can't easily override the attachment behavior.

[daring gorge]

but when i attach only using a server RPC my character isnt attaching like properly. it jitters and lags behind the actual attachment pivot. when i attach using on OnRep for clients, atleast when i did in bps it would work properly and smooth and actually attach

what im more confused about is why isnt this attachment firing up on client side as it should/did in bps

[ripe lotus]

(good to know )

[daring gorge]

is there a way to check if this attachment is actually being fired on the clients? or force it to fire up on clients because im sure it isnt

[daring gorge]

nvm i figured it out, cpp is indeed a bitsy weird though

[reef flume]

Hey all, new to the multiplayer scene and having a troubling time with a networking/audio problem.

I have an audio manager on clients only (no server as audio only can be spawned on clients)

I would like to send a message from my audio manager(B_AudioManager) to a different server bp (let's call it B_Score).

Basically saying:

When all clients send you a message saying their audio timer is done, do a thing.

But I can not figure out how to send said message. If, on my B_AudioManager I

• get the client version B_Score
• Then try to call the event, CS_DoThing,
• • which then calls SC_DoThing(replication RunOnServer)

the server version of that event never calls.

Hopefully that makes sense. I've tried watching a few different YT's on multiplayer replication, but I still can't seem to get my head around sending info from a client to a server. I do know that in general the server calls the shots. So it is a bit backwards to have the client tell the server what's up. Bare with me, and maybe I am just approaching this from the wrong angle

Thanks for the help!

[dark parcel]

Where is this bp?

[reef flume]

The B_Score is located on the GameState as a component

[dark parcel]

That's not what I asked

The image you posted, what bp it's in

[reef flume]

Ahh, that makes more sense. It's in B_Score

[dark parcel]

Can you just take a full screen shoot of #blueprint message

This bp

Especially include the top right corner that shows what class it's derived from

[reef flume]

I can only grab some of it, NDA

I do have component Replicates enabled

[dark parcel]

For a start client don't have ownership of game state

Calling server rpc there will just get dropped

[reef flume]

ok I think that make sense. Gamestate only ever lives on the server right? Then info is replicated to clients. So a client can have a non-owned GameState? not sure the lingo here

[dark parcel]

Not true, everyone have a copy of the game state but only the server owns it.

[reef flume]

Ok, that's what I was trying to make sense of thank you.

[dark parcel]

When calling RPC you need to be aware of ownership

In general only the controller and character are owned by client by default.

So you will probably have to route the rpc there

[reef flume]

Ok that's good to know. Is there a way to tell who owns what? Or is it a bit more of an abstract concept that you can' t really check? Follow up Q, how do you apply ownership, if I want my client to own the AudioManager?

[dark parcel]

You use set owner node (have to be done by server) but it's not recommended to do that.

Normally always limit what client can have ownership on

Soo far, I just use my character and controller or component that lived in either of the two

[reef flume]

is this a saftey measure kind of thing?

[reef flume]

hmm I see ok thank you

[dark parcel]

Security is one of the reason

Also only 1 owner can be set to an actor

So who's gonna own the Audio comp? The server? Player 1? Player 3?

When you think about it, not very useful

[reef flume]

Fun thing about audio, server can never own audio components. They must live on clients

try and spawn audio on server and instant error

[dark parcel]

Not aware of that, I will look at it later maybe

Like what audio comp? The kind you attach to actors?

Like why not?

I would be surprised if I crash but I will take your word until I try it

[reef flume]

Both. So either a SpawnAtLocation or SpawnSound2D or SpawnSoundAttached.

Crash is a stretch. more like you will get an error saying invalid and no sound plays

[dark parcel]

Nah, why wouldn't they work

Server is just another computer, that is happend to be the host

And I used those nodes too, don't see any problem

[reef flume]

Idk what to say, just tried spawning a sound 2d via a server specific event and it never played, putting an isValid on it says not valid

[dark parcel]

The error you are talking about is it accesses none error?

Server rpc = hey run this on server version of the actor

[dark parcel]

So like it must be what you are doing 100% maybe share the code for others to look at

[reef flume]

Let me set something up quick to show here. I'll recreate in a fresh project

[reef flume]

Ok pardon the quick slap together. Just threw an actor component on a GameState

[dark parcel]

@reef flume just tested on my end, works and no issue

what is your Net Mode?

[reef flume]

client. Sorry not sure if I screen recorded that

[reef flume]

yeah standalone and listen will work as they create the client version locally

should of specified that to start, my bad

[dark parcel]

wait what

Play as Client will work too

[reef flume]

?

wait I think I see what you are saying. Yes it will still play a sound on the client since the actor component is on both

[dark parcel]

Game State exist in every machines

[reef flume]

but we were talking about having a spawned audio component on the server

[dark parcel]

hmmm

I didn't use component

just do something on the begin play of the game state

[dark parcel]

regardless of spawning something, the print string should just show if it work or not

Yea still work

no problem what so ever here

[reef flume]

got ya. So in this instance. the server owning version can not spawn audio. Which is fine. I only ever want it on the client. but it means in order to avoid errors I would have to always put in HasAuthority checks

So the owning server can't have a cashed version of the audio component.

So if I played a sound from the server, and wanted to AssignOnAudioFinished. The server owning version would never occur. The client would, but the server no

[dark parcel]

in the case of audio comp you seems right actually

gonna do some test

[reef flume]

For example, this does not work on the server

[dark parcel]

actually nvm it work for me

but I found something interesting

the game is mute for the first few seconds when running multiple window

when the client joins

[reef flume]

what does your bp look like?

[dark parcel]

it's a comp that lives inside the game state too if that helps

[reef flume]

I get this. This is straight on the GS

[reef flume]

ill try this quick

[dark parcel]

I moved it straight on the GS, no issue either

[reef flume]

You are in client net mode as well with 1 player right? I must be missing a bool somewhere

[dark parcel]

im on listen server mode

[reef flume]

ah that's why. try client mode

because the server in listen server is also the local client it will play it

[dark parcel]

I see

@reef flume well if you are playing as client net mode, you are aiming for dedicated server?

[reef flume]

correct

[dark parcel]

because there would be no point in playing a sound in a headless machine

[reef flume]

makes sense, no speakers lol

[dark parcel]

it's all just processing and output text, no render

yea no audio either

I just crashed after changing it to client mode

[reef flume]

gotta love those

[dark parcel]

but prob make sense, why play sound on headless machine 🤷‍♂️ , maybe someone that actually knows can clarify tho

[reef flume]

so then allll the way back, and sorry I should of said dedicated server, if I want to have my audio on a client, tell a score counter on the dedicated server, how do I do that?

[void juniper]

This Looks Cool

[dark parcel]

what's the relationship between audio and the score counter?

[reef flume]

now that I think about it, it doesn't have to be audio. could be any event.

I have a audio count down that is driving a score counter via Quartz. so really it's just an event

[dark parcel]

Server RPC is the only way for Client to communicate with server

[glacial moat]

Is this the proper way to do rep notify?

[dark parcel]

Rep Notify gets called when the variable value gets updated (On Server and Client in BP), (Only on client on cpp)
"proper" is very subjective, that image really tells nothing

though I don't know why you are over complicating it.
On_Rep Emoji -> Update widget

why do you need event dispatcher there

[reef flume]

So then in how would I send info from client only to the Gamestate, as per photos

[dark parcel]

Route it to something the client owned

controller or character

[reef flume]

Hmm ok so then really it needs to go

AudioManager->PlayerController->GameState

Even though the AudioManager is a component on the GameState

[dark parcel]

AudioManager->PlayerController->Server rpc there

[glacial moat]

To update the widget?

[dark parcel]

I would just have a direct reference to the widget and update it

anyway the idea is widget just read the replicated variable

OnWidgetInit-> Read the variable -> Display

OnVariableReplicated (OnRep) -> Get Widget -> update widget -> Display

[glacial moat]

I guess I don't know how to update it without an interface or event dispatcher, casting?

[dark parcel]

No, just grab the reference to the widget

[dark parcel]

Scores should live in player state

if each players have individual scores

[reef flume]

yeah that was a poor example on my part. should of just said, it's a thing on the gamestate for "reasons"

[dark parcel]

@reef flume It can be as simple as this

if you need to access all the player states, lets say to display the score of all players

you can go.
Game State -> Get Player Array

those are your player states

gtg, gl

[reef flume]

Take care and thanks for the help from a fellow RedPanda

[glacial moat]

So this works now (except that it doesn't replicate) and I get these errors along with it

[dark parcel]

You are trying to access a widget that don't exist

Need to point the reference to an actual instance in the world

You are leaping top far diving to multiplayer if you don't know how to use reference. The difficulty is way harder because you will need to handle not one but multiple machines

[glacial moat]

It gets made at run time (the widget)

[dark parcel]

At the time when on rep called the widget ref points at nothing

Hence the error accessed none

Also need to be aware of race condition here

[glacial moat]

How is it able to update then?

[dark parcel]

If the variable replicate before the widget is created then you will get the error

So have is valid check

Simply don't update widget when the widget is not created and it is not yet set

OnRep-> widget valid? Update widget

Else do nothing

[glacial moat]

is valid removed errors, still works

[dark parcel]

Race condition it is then

There is latency in multiplayer, you mpst likely haven't even test in a battle tested environment

0 ms is fake multiplayer, you will need to add some latency and address race condition when working in mp

[glacial moat]

Havent even got to the point to know to address that yet :/

I'm still stuck for days trying to get am image to replicate. I figured out how to replicate some static meshes with tutorials and documentation you recommended before. And I understand the basic concept ( I think). I just want to learn how to do this one thing so I can apply it to everything else

[dark parcel]

Simply marking the variable e.g. texture 2d as replicated will make the variable replicate from server to client.

If client need to change the value, do server rpc
If server need to change the value, just set it right away

If client need to react to the update , use on rep

Just try to replicate a texture 2d, forget about your widgets and these event dispatcher and enum

Some common advice is to read the pinned material 8 times , practice, fail, repeat

But once you understand replication, it's actually very easy when it click.

Unfortunately replication is probably the easiest concept to understand in MP. There are many other challenges ahead

[glacial moat]

Don't feel like I'm going to get that far if I can't figure this part out

[dark parcel]

Practice with changing a color of a ball or something

That's how I start

[glacial moat]

I will do this and then get back to you, sounds easy

[dark parcel]

Make the client and server able to change the color. Then make sure everyone see the same state (color)

Do not use multicast

If you are stuck with that share your code here

[glacial moat]

hmmmm, working with multicast, need to do more research, might take me longer than I thought, thank you

[rough dock]

does anyone know how to add an impulse to a client? whenever i add an impulse on a client it just corrects no matter what even when doing a multicast.

[glacial moat]

Alright : bottom (component overlap) easy peasy
Top (Event Dispatcher) only working on server and not updating or changing on clients (besides server client combo and only when it calls it itself)

[dark parcel]

Don't need event dispatcher

Also you can just use input

Like pressing the V key

[glacial moat]

The event dispatcher is bound to the E key

Only works on the server/clinet combo

[dark parcel]

V key pressed -> if server-> Set the material variable

If client -> server rpc that set the material variable

On rep update material

[glacial moat]

switch has authority?

[dark parcel]

You can use that to filter host vs client in most cases

Client can have authority if the actor it's in, are spawned by them self.

[glacial moat]

😮

[dark parcel]

If it's replicated actor and spawned by the server then it's fine to use switch has authority

[glacial moat]

Okay, all of that makes sense to me, mostly (I think)
Trying to think how that applies to my 2D texture dilemma

What node(s) can I use besides has authority to tell if its a server or client calling

or is it just this?

[fossil spoke]

An RPC marked as Run On Server, will only ever run on the Server...

You dont need a HasAuthority to check if a Run On Server RPC is being called on the Server...

[glacial moat]

Yep, just read that on the forums. I'm going to pull up something that I got to replicate properly. Then ask why it doesn't work on anything else.

Maybe what I labeled each of these things is not what it actually does and I don't understand it properly

[fossil spoke]

SetIsReplicated just marks an Actor/Component to be considered for replication. Calling that function doesnt actually replicate anything.

[glacial moat]

If I remove that node, it doesnt change on the clients

[fossil spoke]

Sure, im just speaking more to how you have the comments

Update Clients of Server change

[glacial moat]

🤔

[fossil spoke]

Technically speaking, thats just a byproduct of calling SetIsReplicated

You should be able to just set bIsReplicated to true on the Add Static Mesh Component node.

In the details panel

[glacial moat]

So things can replicate on the server without seeing the results of it being replicated?

[fossil spoke]

No, again, you are confusing terminology.

[glacial moat]

Having issues with details panel, going to keep reading what you posted and read more on the forums

[dark parcel]

@glacial moat

[glacial moat]

ohhhhhhhh so you do use cast XD

[dark parcel]

what's wrong with casting?

[glacial moat]

here

[dark parcel]

yea I never said anything about casting, what I said was why do you need event dispatcher

[glacial moat]

maybe you were replying to something before that post

[dark parcel]

you asked for an overhead icon

I did above with a few lines

don't make it overtly complicated than it should be

though I think the problem boils down to not knowing how replication works

you should attack the pinned material again

[glacial moat]

I will check it again, but the things you posted are golden, I thought you were saying to set it without casting, interface, or event dispatcher, which is why i posted the only other thing I could think of

[dark parcel]

you are still using dispatcher in your post tho

im only casting because im using widget component

because the getter node return generic type

[glacial moat]

this one

but I guess it still uses an event dispatcher to get to that point

[dark parcel]

last time you tried that you have accessed none error

[glacial moat]

yeah, but i made it like that because I was trying not to use cast or event or interface

[dark parcel]

using cast or not is not the issue

you can certainly do what you have above

but your issue was you didn';t set active player widget ref

or there might be race condition happend

e.g. widget created after on rep is called

casting is just a type check

[glacial moat]

is valid fixed that one

but still didnt replicate properly,

[dark parcel]

no error doesn't mean it's fixed

it can even be a silent bug

the point is since order is not guaranteed in multiplayer

you need to know how to address incoming data

[glacial moat]

I guess I only know some of what I don't know at this point. And trying to learn a bit at a time. This is defiantly going to help me understand /know more of what to do/when to do it (I'm hoping). So thank you again, a ton. 😊

[charred lark]

Hey Guys! I have a problem with the replication? I Guess?^^
Ich have a multiplayer game. and i want to set the selected player meshes on start.
Only the player itself sets the mesh so every player on his own machine...

I mean the meshes only get refreshed locally… client 1 can’t see the new mesh of client 2 ^^

My BP_Player is replicated. All needed variables too…

[dark parcel]

Don't use Multicast

Set the Struct

OnRep(Struct)-> Set Mesh

or if you don't need those info and just need to set the mesh in the client, make the mesh replicated variable
Server : Set Mesh,
Client: OnRep(Mesh)-> Set Mesh, that's it

[charred lark]

Oke ill try it this way - thanks 🙂

So the server sets the struct variables...and onRepNotify it should set the mesh

so server calls this:

thats the method that gets called on the player:

Thats the RepNotify:

same result ^^

[dark parcel]

If you used multicast everywhere, you might want to start refactoring

don't use multicast for any stateful behavior

this may account up to 95% of the casses

or more

[charred lark]

No i do not but i tried so much stuff 😄

[dark parcel]

Break your S Curr Character

Get the mesh

Set the skeletal mesh from the mesh inside the S curr character

[charred lark]

WOW!

it works 😄

But can u explain why its working that way?

even if i set the custom event rpc to not replicated it did not

[pseudo wagon]

So you are not understand RPC and replicated at all.

[dark parcel]

#multiplayer message
you can see some example here

[charred lark]

I already refactored so many things with this authority calls and stuff...im getting better...but still a noob I guess 😄

But thanks...I already did some tutorials and explanations about rpc calls and thats everything is better than multicasts ^^

[dark parcel]

its not about the question of better but the context it is used

If you need to do something stateful, don't use multicast

if you want to do something fire and forget where it wont matter if some players don't replicate the behavior then you can use multicast

Like a chat message, where you just want to broadcast your msg to the players currently in the game

[charred lark]

Yah cosmetics etc. that isn relevant for the game

for example

But Thank you!

For the quick help! 🙂

im gonna refactor everything now where I use an RPC call..if its necessary 😄

[tacit pine]

Hi. I have a question. Is it possible to force the server side to render a specific shader or Actor? I am working on water in Unreal and as you know, the standard Unreal Engine plugin does not support multiplayer and synchronization due to the lack of water rendering on the server. Therefore, I am considering options such as using server rendering, so that some information can then be transferred, for example, Fluid textures - simualtion textures, to the client side, and then use this data to calculate physics.

[pseudo wagon]

Server does not have GPU, so I don't think it is possible.

[tacit pine]

Lets say i can buy GPU on server or something like this.

• if this is not possible, then how does Pixel Streaming work? Some hack?

[charred lark]

I have another question. When I call a function from the server that calls a method on every player … the player should call a dispatcher that is executing for a example a hud update… but I don’t want to replicate my local widgets and I only render my widgets on client side. (Which is the common way I hope?) What’s the way to let the players call their dispatchers and refresh the hud when the server did the main call?

Because the server has nothing to do with it - it’s only client sided … is it like calls from server -> rpc owning client -> refresh hud?

[tacit pine]

Or, which in my opinion is more correct - Server Call Update Dispatcher -> client recive event- client call self dispacher ->hud recive event.

[pseudo wagon]

I am sure that Pixel Streaming will require Server has GPU.

[charred lark]

Like so?

GameMode -> Call „dispatch yourself“ on every player controller

PC -> Receives call from server -> Calls Dispatch yourself (owning client rpc) ?

does the pc has all of its local components when it’s „wrapped“ in an owning client call?

[dark parcel]

widget don't replicate, so you can't even if you want to

also widget just strickly READ

dont even put any shared information in it, widget just read the variables from else where

Why does the server need to tell the player to refresh their hud?

sounds like design problem

[charred lark]

hmm

[dark parcel]

HUD update when HUD update,
e.g. when client array of item structs get updated for example (the variable lives in player character/ player state for example),
on repnotify -> Update widget

[charred lark]

Ah ok 🤣 I think there was a complete misunderstanding on my side 🤣

[coral badger]

I've not seen anyone mention Online Beacons in a while. Anyone here using those or are they perhaps deprecated or something?

[thin stratus]

Not a lot of people get into the situation of needed them

They were originally a concept to allow Players to register to DedicatedServers before actually joining them.
Something something Unreal Tournament.

[chrome bay]

ye used them in HLL for that + server queues

[thin stratus]

Then people started to use them for MainMenu Friend Invites.

I assume Fortnite also does that or at least something along those lines.

[chrome bay]

only matters if it takes an eternity to load your map

[thin stratus]

For the Server queue?

The Friend Invite stuff is more of a feature than a solution.

[chrome bay]

For reserving space in a server I mean

[thin stratus]

Yeah okay

[chrome bay]

server queue was just a feature we added

[thin stratus]

Yeah I only ever had to use them for that Friend Groups that queue up for Games, like Fortnite, CS, Overwatch and what not

#online-subsystems should have pins that help with getting started with them @coral badger

[coral badger]

Yehh I've used them for a pre-server game Lobby system as well. Was just wondering if there are other use cases.

[chrome bay]

anything where you need a light connection to a server I guess, and want to transfer data via replication. That's it really

[dark parcel]

Anyone can throw some wisdom on fast array?

Regular struct does delta replication right? While fast array would replicate the whole object.

If that assumption is correct, why do I want atomic replication for large data like items?

Wouldn't that be more performance heavy to replicate the whole thing instead just replicating the difference?

[chrome bay]

Structs, TArray and Fast Array all do delta replication

Fast Array also does delta replication of the internal structs by default (you can turn it off)

The main advantage of fast array is per-item callbacks, and that you can change the order without causing a massive delta, which is what you'd get with TArray

TArray can still be faster and cheaper. Plus custom delta serialization prevents you using any shared serialization, so FastArray can be slower with POD types and lots of connections

Calling it "fast array" was a mistake

[lament flax]

i thought Fast Array would always be faster that TArray, since i learned that an array will replicate all entries after the modified index

[hoary spear]

would checking server connection be a valid choise for this? I was planning on testing ot to get a sense of the server ping before commiting a full join

[chrome bay]

nope, untrue

[lament flax]

how worse is fast array replication performance ?

[chrome bay]

TArray calculates delta by comparing elements. The problem is that when you move/delete an element, usually every element after that will then be "deltad"

[lament flax]

my whole inventory and other systems use those

[chrome bay]

Depends(TM)

Faster in some cases, not as good in others

[lament flax]

but it wont be "way worse" right ?

or should

[chrome bay]

If you're using POD types and your array doesn't change size/order, TArray will be massively faster and cheaper

[lament flax]

fk me

my inv array doesnt (for now) change size

[chrome bay]

If it doesn't have UObject/FNames in it, you could benefit from shared serialization with lots of connections.

could being the operative word

[lament flax]

but yeah, on a OnRep of an array, how do i know what changed ?

[chrome bay]

There are no hard rules here

Compare it with the previous state

[lament flax]

i have to iterate the whole array to compare ?

yeah

[lament flax]

i have a UObject in it

[chrome bay]

no shared serialize 4 u then

[lament flax]

im doomed then, i dont want to remake all of it yet

[chrome bay]

Profile it, find out if you are doomed or not

[lament flax]

yup

[chrome bay]

Problem is people assume fast array is better, but it's not always the case and unless you look at how it actually works under the hood and understand it, you can't make the best decision.

[lament flax]

but how can i know if it can be improved ? for know i can only guess its bad if i get lag spike

[chrome bay]

fast array for inventory is probably fine

[hollow brook]

Quick question about replicating movement using standard MovementComponent inside PlayerCharacter. I am teleporting players on the server only, but this does nothing with the Client, ie. Client is not teleported AND on the server, the client's position goes back where it was before the teleport (client overrides the movement). I am using just the standard setup, anything obvious here, what am I missing? Does teleport need to be handled on clients, as they are the authority of the character? I am so used to that Server has to do everything.

[lament flax]

are you 100% sure you use TP on server ?

[hollow brook]

Yes I am 100% sure. Inside the Actor, that handles the TP logic, I have a if (!HasAuthority()) return; and also the Logs suggest that the TP logic is run on the server (when the players enters certain collision box)

From the Server POV, it looks like the Client teleports for a frame and then goes back to where he was (like the Client overrides the position)

SetActorLocation should replicate by default right? I mean if I set a player position like that on the Server, it should update on the client? Works like a charm for non-player actors 🤔

[dark parcel]

Instead set actor location, isn't there teleport node?

[hollow brook]

Does not make a difference

[hexed pewter]

How are pointers to actors, objects ect sent through in context of multiplayer / replication / rpc. Are these sent in some form of ID?

[chrome bay]

ye

Servers/Clients create mappings between those IDs to the local pointers so they can identify objects

[lament flax]

when are those created ?

my guess is:

• server knows the UObject exists
• created netid
• sends netid to client (with class instance data ?)
• client recreate its local version of the uobject with the class instance data
• assigns it to a map with the given netid

[chrome bay]

for a replicated actor the server sends the ID with the actor spawn packet.

For objects which can be addressed by their path name, you just use the path

[lament flax]

what is the type of the actor spawn packet ?

so ican check what is inside

[lament flax]

the path of the class def ?

[chrome bay]

or the path of the asset, or the object in the level, whatever it might be

[lament flax]

okay

thats kinda smart

idk what other possibilites there was to rep UObjects

[hexed pewter]

What about SoftObjectPtrs / SoftClassPtrs. These are just paths to assets as FStrings so there is nothing unsual about sending them through net, right?

[hollow brook]

So in fact, what worked is that I am sending a Client RPC from Server to the Client, inside the PlayerCharacter actor, that teleports the player. I still do not understand why doing this on the server (without Client RPC) does not work.

[lament flax]

nope its kinda small

[lavish wigeon]

im making a multiplayer racing game and have the player select their vehicle in the main menu then it loads them into it when they create the session, but when i have the second player join the session it doesnt seem to spawn the vehicle pawn, does anyone know what i can do to fix this

[dark parcel]

Good to know, ty

[lavish wigeon]

Heres avideo of the issue

[glass crescent]

hello,
one window is both client and server and another is client only. On Spawning the objects (using game mode), i m giving possession to the player controllers iteratively. But for the (server and client ) person , how can check out of the two spawned object which one is possessed by it?

[lavish wigeon]

so i need to tell the gamemode to spawn a seperate pawn for the other clients?

[glass crescent]

no game mode is spawning all the players together one by one

when the host clicks the start button

[lavish wigeon]

so what is the solution?

[glass crescent]

its my question , i m not answering your's problem😅

[lavish wigeon]

oh, you should use a question mark lol, its also very similar to my issue i just posted

[glass crescent]

oh yeah just changed it

are you spawning the vehicle on server?

@lavish wigeon

[lavish wigeon]

i was doing it in the gamemdoe

mode*

[glass crescent]

send ss

bleuprint of game mode

[glass crescent]

what is happening , if you start game after joining the session

[lavish wigeon]

what do you mean start after joining?

[glass crescent]

on clicking play button only you are spawning ?

i think you are spawning only on clicking the play button , and when user clicks on join its just switching your level without spawning the player

you need spawn player on joining

[lavish wigeon]

yeah i think you are right

[glass crescent]

anyone help me with this ?

[lavish wigeon]

what is the alternative? sorry im an artist.. lol

im surprised iv got this far

[glass crescent]

ohkay

well i m also new to unreal , but i understand some logics

[lavish wigeon]

you think i should look into how to spawn multiple players?

[glass crescent]

the alternative is , you need to send an RPC event to server on joining succesful

[glass crescent]

yeah that you can look into

when server get the rpc event , it will spawn player for you and gives you the possession as you already did

[lavish wigeon]

ok thanks

[ruby lodge]

Why is the niagara effect not visible on the server? This is the multicast event called by an run on server event.

I, again, feel like this is a fairly stupid mistake I am just overlooking.

[dark parcel]

multicast only works if it's called by the server

[ruby lodge]

It is

[dark parcel]

and don't forget the receiving end

well I don't know, you gotta show proof that it's called by the server

show the code maybe

[ruby lodge]

it's called by a run on server event. It's working for the client, the server also runs through this and prints correct values inside the macro at the end

it's just not visible for him

[lament flax]

what costs more between an RPC each tick or a onrep var change each tick

[ruby lodge]

inside the macro the server is printing correct values here as well

[glass crescent]

I m stuck at this problem , please help , if you know😅

one window is both client and server and another is client only. On Spawning the objects (using game mode), i m giving possession to the player controllers iteratively. But for the (server and client ) person , how can check out of the two spawned object which one is possessed by it ?

[dark parcel]

I think there is a misconception

the 1st window is the server

not both client and server

it's simply the server

[lavish wigeon]

isnt there a "get possessed" node

[glass crescent]

okay , but isLocallyControlled must give true for that

[dark parcel]

isLocallyControlled will check if the actor is locally controlled or not in respective on whos calling it

[lament flax]

this one is true for the liste nserver

[glass crescent]

i mean for host , which is also a part of game

[dark parcel]

Don;'t see how that connects between client / server tho

isLocallyControlled just check if the actor is locally controlled by the machine that's calling it

[ruby lodge]

this here is the macro

[dark parcel]

Players normally have a pawn they posses, for the pawn they posses, isLocallyControlled will return true on the machine that owns the pawn/actor

[ruby lodge]

The material change and timeline are working for the server. Just the niagara effect is not visible, although it's valid

[glass crescent]

here i m assigning playercontrollers, but it is giving true for client , which is correct, but for host it is throughing false for both object

this is the loop

[ruby lodge]

Oh now I see. I set the particle size to 1000 and apparently the server is spawning the particles in the center of the map although it's set to snap to target :/

so nvm, It's not a multiplayer issue then

[keen adder]

In my experience no attachment rules ever really work lol. So i always set the position again after attaching

[lament flax]

top left: client
bottom right: server

any ideas why the camera rotation is replicated from client to server (screen 2), but not from server to client (screen 1) ?

none of the camera spring arm and camera is set to replicate

well anyways i think i can use RemoteViewPitch from GetBaseAimRotation since its reped

[lavish wigeon]

is game instance client side?

[lost inlet]

there is no networking element to game instance at all

[lament flax]

so its server only ?

or local

[lavish wigeon]

im trying to set a vehicle of the players choice in the menu, that theyll spawn with in game, but currently both players spawn with the hosts choice of behicle

the variable was stored in the game instance and cast to by the game mode

id like this to be per player

[lost inlet]

it's both but they're not networked

a game state is networked

[lament flax]

so its some kind of pure local

[lost inlet]

?

[lament flax]

its local and isnt networked

i personally call something local when its running locally on a machine (so client + server)

[vivid seal]

Is it possible to get PreDestroyFromReplication for an object you hadn't received from the server before? Like the initial bunch for that object was just its destruction? I had a crash as client joining a game in progress, and the crash was inside PreDestroyFromReplication, and the initialization for that object hadn't run at all yet (its triggered by an OnRep)

[glacial moat]

It's finally working! thank you everyone that helped!

P.S. the texture that I was testing everything with was corrupted so I wouldn't have gotten it without your code ColdSummer

[half umbra]

I have Pawn, and a camera in it, when the player rotates the camera, it changes the Mesh rotation in this Pawn, and I would like the Mesh rotation to be the same on the Server and clients

someone can help?

[upbeat basin]

Both pawn and camera component have options to adjust their rotations according to controller (which is what actually being rotated when you use AddControllerXXXRotation function). You need to select the ones you need according to what you want to achieve

[half umbra]

I also have elements in the actor that cannot rotate

with this option the entire actor is rotated

[upbeat basin]

Pawn's Use Controller Rotation X options directly apply the selected rotation axis to the Pawn actor itself yes. But the result should be the same on all players. What is your issue here, not wanting a component in your pawn to rotate with the pawn?

[half umbra]

I'm creating a tank

[magic vessel]

Could use GetControlRotation and retrieve the X component?

[half umbra]

some ideas?

[upbeat basin]

Then you wouldn't want your pawn to use any part of the controller rotation. I haven't mingled with vehicles before so there is probably a better way to do this but you need to rotate your barrel and turret part according to base aim rotation's pitch and yaw respectively

While your rotation inputs still adds rotation to controller and movement inputs using add movement input with your world direction being the forward of your actor

That way everyone can update your tank's instance themselves according to base aim rotation

[quiet yarrow]

Anyone know why chaos wheeled vehicle component causes a crash when running server but not standalone?

[meager spade]

Never crashed for me

So nope

[zealous wigeon]

Hi, I'm trying to open a map from client1 on button click

however the map doesn't load

this is what clicking on the button prints on the server side

tag me for answer please

thanks

[brittle ledge]

Happs u forgot adding player start?

[brittle ledge]

https://tenor.com/view/starwars-han-solo-tag-youre-it-stormtrooper-gif-20240479

[zealous wigeon]

not in L_Grid

I have two player starts there

mh but wait

I think I understood

basically I'm launching the server saying that L_Lobby (that doesn't have player start) should be the default one

how do I prompt the client to start from a specific level?

[brittle ledge]

The default level is the one client will launch

Make sure it has a player start

[zealous wigeon]

no it doesn't

and doesn't need to

it's a lobby

with join button

i need to launch the client to a specific level instead

[brittle ledge]

There is server default level and the client default level. When u launch the game it will launch that level.
U can then open a different level though.

When u connect to a server u open that servers level

[zealous wigeon]

no no okay I managed to do it, just passing the level name as argument
but now when the map loads, the input doesn't work on the client, so the player is not moving, and the server prints this

[2024.09.12-19.55.01:530][565]LogNet: Client netspeed is 100000
[2024.09.12-19.55.05:679][654]LogNet: Join request: /Game/Levels/L_Grid?Name=DESKTOP-4K9SVM7-65C0AA104C4C4ACBDB68B88512B914FA?SplitscreenCount=1
[2024.09.12-19.55.05:690][654]LogNet: Join succeeded: DESKTOP-4K9SVM7-65C0
[2024.09.12-19.55.06:105][663]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:107][663]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:150][664]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:198][665]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:249][666]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:251][666]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:254][666]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:291][667]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found

[2024.09.12-19.55.06:292][667]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:338][668]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:340][668]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:385][669]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:388][669]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:432][670]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:480][671]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:481][671]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:526][672]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found
[2024.09.12-19.55.06:527][672]LogPhysics: Warning: COLLISION PROFILE [ALS_Character] is not found

[grand mica]

Hi!
I am trying to get OnRep_ReplicatedMovement() this called for my custom pawn.
I am trying to do this on the server side code but still this doesn't get triggered

FRepMovement& repMovement = PawnOwner->GetReplicatedMovement_Mutable();
repMovement.Location = m_position;
PawnOwner->SetReplicatedMovement(repMovement);
PawnOwner->ForceNetUpdate();

here, for ref

    /** Used for replication of our RootComponent's position and velocity */
    UPROPERTY(EditDefaultsOnly, ReplicatedUsing=OnRep_ReplicatedMovement, Category=Replication, AdvancedDisplay)
    struct FRepMovement ReplicatedMovement;```

according to what I have learnt - when ever the replicated object gets manipulated then the OnRep_ method gets called. This is not happening in this case and I am debugging this on the client's exe.

[grand mica]

or basically I am trying to get OnRep_ReplicatedMovement on the simulated client by changing its value in the server

[brittle ledge]

Best advice if no one has given yet, would be to add print strings so u understand the problem

Cuz it could be many things like server not knowing about your input, or there being a non-multiplayer related issue

So like first know if the server knows of the input, then add like breaking points like that to know where the issue happens

[zealous wigeon]

i fixed that

but the client now does not handle input

[brittle ledge]

[zealous wigeon]

yes but anyways I think i will drop ue for this project

ue with dedicated server for my project feels like a spaceX rocket to travel 5km

makes no sense

ain't no way im downloading +200gb engine source code and compiling it from scratch just for this

[brittle ledge]

What's ur project? & For what?

[zealous wigeon]

there is a grid 16x16, two players search for a match putting each 100 coins, fight with Pump, AR and fortnite builds and who wins takes all the coins

you can then cash out the coins into real money

for example 1€=100coins

this may not be compliant to UE rules so I will adapt it with some workaround like gift cards and tickets instead of a virtual currency

what you think?

[brittle ledge]

U can do it with ue though u could also do it with other engines. I was wondering if it was a game or just an app. I guesh do what u think is best.

Though if u intend to make more games, id recommend regardless of decision start installing the source build

Worst case scenario u'll have it ready for a future need

Even if u end up using a diff engine for this one

[zealous wigeon]

yes for sure I can do it in ue

but it's too much stuff forna relatively small project

[lament flax]

Well thats a bit dumb to stop for so little

But do as you want

[zealous wigeon]

no dude trust me, there is no way I can manage to download all that stuff

trust me you don't know my internet provider

anyways thats not the only thing

[ripe lotus]

good day, quick question. if i have an actor that's owned by the server, then the server reparents (attachtoactor) to the pawn. would that object become an autonomous proxy on the client for that pawn?

[lament flax]

Attaching doesn't change anything on ownership

[ripe lotus]

thanks, oh for a moment i thought the parent and the owner where the same thing. maybe for components?

[lament flax]

To find ownership components go to there owner (the actor holding them)

But its only the case for components attached at compile time (95% sur)

[twin juniper]

owner = ownership
parent = attachment
(95% sure)

[quiet yarrow]

any common reason why client to server replication is fine, but client to client replication is not working?

[dark edge]

because that's not a thing

Variable replication is Server -> Clients only

[quiet yarrow]

I mean the server and a client both see it, but the other client doesn't get notified

[dark edge]

show code

[quiet yarrow]

replication was the wrong word there

[dark edge]

The general form is that a client informs the server of something through a run on server event, and the server sets a replicated variable, which eventually makes it to everybody

[quiet yarrow]

maybe im lacking that variable

[dark edge]

show code

[quiet yarrow]

sorry its sorta a mess atm

[dark edge]

that is very cursed

[quiet yarrow]

lol i've been trying everything I can think of

[dark edge]

so I'm guessing you want to hitch something to something else right?

Press key -> if close enough, hitch

[quiet yarrow]

yeah pretty much

using a physics constraint

[dark edge]

Networked physics is cursed enough on its own but it's doable

First off, don't try predict the hitch. The client side should just be input -> tell the server something

Input -> I wanna hitch (run on server)
I wanna hitch -> is there something close enough to hitch to? (get overlapping actors) -> yes -> hitch to it

Now whether or not setting constrained components on the server is enough is neither here nor there

[quiet yarrow]

right. But when I try that I get worse results than this method oddly enough. Lemme retry and show you the results from that method

[dark edge]

How are your vehicles moving to begin with?

[quiet yarrow]

vehicle movement component

[dark edge]

It might be that the fact that the 2 things are constrained is not replicated

is the constraint component replicated?

[quiet yarrow]

it is

[dark edge]

Check that everyone agrees what the 2 constrained bodies are

tick -> get constrained components -> print them

[quiet yarrow]

idk why I havnt thought of printing that out of all things lmao

[quiet yarrow]

so are you suggesting something like this?

[dark edge]

It's been a while since I've done this but it is doable

[dark edge]

get rid of that on component overlap node

the fact that it gives you anything useful at all is a stroke of luck

you don't care about the last thing you began overlapping, you care that you're overlapping something hitchable at the time you press the button

[quiet yarrow]

right right

yeah that was giving me issues in the past

so how should I check if something is overlapping without that?

[dark edge]

get overlapping actors

for each -> is it a wagon? -> proceed

[quiet yarrow]

I honestly forgot that was a method of getting overlapping actors

[dark edge]

there's basically an array of overlapping stuff hanging around and the events fire when it changes

[quiet yarrow]

I was scratching my head thinking I dont remember overlap being this weird lol

doubt this will fix my issue, but it needed fixing nontheless so ill give it a try

[dark edge]

If I were doing this I would at start with making sure everyone agrees on what's constrained (and the ref frame for it)

then I'd look at the physics replication settings of the wagon and possibly the car. Make sure everyone agrees on everything. Do you know for sure that your car is replicated correctly?

[quiet yarrow]

for sure, no. but from all my testing it they have been extremely stable with no issues

[daring gorge]

if i have very simple use case of max 6 elements to be put in an array, i do want this to fire up OnRep func whenever the item is added, does it makes sense to use fastarray or should i just stick to normal TArray replication

[quiet yarrow]

okay I cant figure out how to check if they all agree on whats connected. But I did setup the overlapping actors check like you suggested. Now it seems the client that is pulling it is experiencing the wagon lag behind by a large margin

[short arrow]

If the array is going to be relatively small then no you don't need to take the extra steps in optimizing that one single thing

a normal Array is just fine

as always, if you want to be sure everythings okay it only takes about 2 minutes to pop open the network profiler and see

[opal shore]

where can i host a free unreal server build? its for learning, it will have aproximately half CAU

[twin juniper]

on your machine?

[opal shore]

mmm, could be, but im looking for cloud mainly

[twin juniper]

then you need to pay or use some free tier

[opal shore]

i think i will self host, otherwise aws. thanks erererererer

or unity multiplay i have to look at that

[daring gorge]

its just going to be 6 elements at max, im sure of it, i do think i can just use a normal array, atleast the more i think it seems more viable

[short arrow]

there's nothing wrong with using a replicated TArray if the number of elements are relatively low. I assume you may be worried about the network traffic. If you want to keep costs to a minimum while not overcomplicating things, I would consider making your actor dormant, and making use of force net update.

[daring gorge]

my actor is a bitsy important so ive set it to always be releveant and yes i was worried about network traffic and reliability in general.

[rough dock]

does anyone know how to add an impulse to a client? whenever i add an impulse on a client it just corrects no matter what even when doing a multicast. please help

[verbal vapor]

Looking for locomotion guide

[lament flax]

Whats your issues with MP & locomotion ?

[verbal vapor]

I am just trying to get the idea how can I build my own locomotion from scratch and handle replication

I know that Epic released their locomotion system but it's quite advanced

XD

by the way, how can I export their animations from the locomotion project - exported i mean it use the manny skeleton and mesh instead of the UEFN one

[hoary spear]

Is there any considerations to replicating a UDataAsset reference? My understanding was that they would 'instantly' replicate fully, as they exist locally already ?

[lament flax]

I dont fully remember, i remember having issues with that.
Anyways my recommendation would be to not store a DA at runtime (for example as a Inventory Item), but instead use them as static data that is used as a initer

[hoary spear]

So create some method to grab this data on init , instead of storing a reference to it?

My current setup just pointed to these like this;

    UPROPERTY(BlueprintReadOnly, Replicated)
    USqsQuestLine* QuestLineDefinition;

While it seem to 'work' I'm seeing some weirdness but it could ofcourse be elsewhere

[lament flax]

Thats my preference yeah

I mostly do that because i want to store more data at runtime then in the DA

So instead of editing the DA i edit my runtime object

[hoary spear]

i do the same, but separate them in the instance so to speak

[lament flax]

It also depends how heavy is you DA compared to its potential runtime version

[hoary spear]

SqsQuestLine is DA (static for all intents and purposes)
SqsQuestLineInstance holds a ref to the DA, + whatever runtime data i have

[lament flax]

IMO if i had a quest system i would only replicated specific data like the quest title and description

And a soft ref pointing to a location ping actor for eg

[lament flax]

Well you can test how it goes with that

There is a lot of differente ways of doing

[lament flax]

And to complete/add peogress to the quest use whatever source to do a server RPC

[hoary spear]

The only issue atm is that some stuff dont update in the UI, while if i inspect the reference at the time, it got the correct data

[lament flax]

weird

Can you show how you rep that to UI ?

And the supposed good value at runtime

[hoary spear]

during inspection

(currently mid refactor, so this is just all testing)

when hovering the variable it's "out of scope",

if i print its value, it's correct

[lament flax]

Yeah thats a BP limitation

You are forced to hover the original struct/object var

[hoary spear]

hoooold on

im a dumbass

[lament flax]

Sounds like its not replicated

[hoary spear]

the TB_Description was collapsed -.-

[lament flax]

I had this issue when i first tried a inventory composed of DAs

[hoary spear]

the sub textblock was visible.. making me think it was the TB_Description

yey, it works!

[lament flax]

Didnt understand

Oh you are talking about the text blocks

[hoary spear]

yeah

the "bug" was only wrong visibility

sorry about that

[lament flax]

So is the DA ref replicated ? Or do you only need the texts here

[hoary spear]

yes, everything replicates as it should

the DA contains all the static info about everything related to that quest line

[lament flax]

On your screenshot i dont see any usage of the DA

[hoary spear]

QuestLineDefinition is the DA
Quests also holds a QuestDefinition to a Object inside same DA .. (one could say its redundant, but its for ease of access in widgets)

and Objectives/Failconditions yet again holds a definition. plus the runtime data

[lament flax]

its weird that here its showing null

[hoary spear]

which part?

[lament flax]

oh im dumb

i was looking the quest reward

[hoary spear]

ah haha yeah that's invalid at this point

the quest got no reward 😛

[grand mica]

no idea about this anyone? 😦

[lament flax]

so inside your OnRep_ReplicatedMovement you got no calls ?

[nova wasp]

you do not need to call SetReplicatedMovement here

you already changed it

[grand mica]

i was just trying out if this could call it out but no!

[grand mica]

nope. It doesn't get triggered. I think in CMC it gets triggered through some physics but I am writing my own simple system.

[nova wasp]

is this actually being called on the authorative client?

[lament flax]

maybe its just not changing ?

did you add it in GetLifetime... ?

or is it already

[nova wasp]

is bReplicateMovement true?

[grand mica]

I have been trying to change the value on the server and kept a breakpoint by using the client's application

[nova wasp]

this is not physics related

[grand mica]

yes

[nova wasp]

you can just test this in a single application in multiplayer PIE, make sure you actually watch the play in editor context string too

etc

{,,UnrealEditor-Engine.dll}GPlayInEditorContextString

is this a replicating actor at all? is it even created on the client?

[grand mica]

APawnAgent::APawnAgent()
{
    // Set this pawn to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
    PrimaryActorTick.bCanEverTick = true;

    SetReplicateMovement(true);
    SetReplicates(true);
    bAlwaysRelevant = true;
    

    defaultSceneRootComp = CreateDefaultSubobject <USceneComponent>(TEXT("SceneRootComp"));

    RootComponent = defaultSceneRootComp;

    // Create and initialize the skeletal mesh component
    SkeletalMeshComponent = CreateDefaultSubobject<USkeletalMeshComponent>(TEXT("SkeletalMeshComponent"));

    SkeletalMeshComponent->SetupAttachment(RootComponent);

    PawnAgentMovementComponent = CreateDefaultSubobject<UPawnAgentMovementComponent>(TEXT("PawnAgentMovementComponent"));
    //MaxJumpHeight = 5.0f; // Desired maximum jump height
    //Gravity = -300.0f; // Gravity
     // Calculate initial jump velocity based on maximum height
}``` 
I have set the things in the ctor

but I am trying to change the value from the movement component but on the server

[nova wasp]

what's the point of defaultSceneRootComp here if it's the same type as teh root component already...

besides the point I suppose

[nova wasp]

cool, I asked you if you are doing that now

is this code actually running on the server?

[grand mica]

the code that changes the FRepMovement& repMovement?

[nova wasp]

    UE_LOGFMT(LogTemp, Log, "{WorldString} Set repmove here", GetDebugStringForWorld(GetWorld()));

yes

[grand mica]

yes that's running on the server I am 100 percent sure

[nova wasp]

this dumb logging thing should help show which context it is being ran in

okay, I'm not 100% sure lol

[grand mica]

it done in server rpc

[nova wasp]

Is the object also replicated to the other client as well?

[grand mica]

that object is in Actor.h
it's replicated yes

[nova wasp]

Is it actually being created on that client?

I'm not asking what checkboxes you pressed, I'm asking what is ACTUALLY HAPPENING

could be as simple as a missing Super:: call somewhere

[grand mica]

basically I want void APawnAgent::PostNetReceiveLocationAndRotation() this to get called whenever the position of the actor changes and I can update the position for the simulating client

[nova wasp]

you can actually override OnRep_ReplicatedMovement interestingly enough if you want to

[grand mica]

i did not override PreReplication or anything. It was getting triggered on the client yes

[nova wasp]

what is getting triggered on the client? I'm confused

[grand mica]

yeah but still I guess it won't get called if its not getting called for the parent

[grand mica]

PreReplication method on Actor.cpp

[nova wasp]

also LocalRepMovement.bRepPhysics being true precludes a call to PostNetReceiveVelocity

can you just breakpoint AActor::OnRep_ReplicatedMovement ?

Or override it just for debugging purposes

[grand mica]

i have the source code. I can put a breakpoint there

[nova wasp]

unsure if it will work without debug symbols

[grand mica]

i am running it on Debug Editor build

[nova wasp]

that's not what I mean, I mean debug symbols for the engine

a rather large optional download you need if you are doing any non-trivial C++ stuff

[grand mica]

isn't downloading the source code and building it enough to create the pdbs for the engine?

[nova wasp]

or you can just do the simple thing and override it to see if it's called

[nova wasp]

yes, but you never mentioned you are on a source build?

[grand mica]

here 😛

[nova wasp]

sorry, I assumed you were on the binary launcher build

[grand mica]

no issues 🙂

[nova wasp]

having the source code does not preclude it being a binary build

both of them have the source code...

[grand mica]

yeah ofc. Yes but i did build the whole engine here

[nova wasp]

okay, just breakpoint it then?

you don't need my permission to try to solve the problem lol

[grand mica]

one moment. So to get the breakpoint triggered i think i have to run it under one process.

also, i am getting this warning when I run it
ensureMsgf(!NeedsInitialization(), TEXT("SetIsReplicatedByDefault is preferred during Component Construction."));

would it matter for now?

[nova wasp]

unless you want to get that ensure literally every time you run the game then leave it?

SetIsReplicatedByDefault appears to skip the extra call to UpdateReplicatedComponent

[grand mica]

yeah everytime i run the game through VS this pops up

[nova wasp]

then... why didn't you just do what it says?

Just use SetIsReplicatedByDefault ...

I'm not certain if it matters for this but it's definitely skipping a lot of extra work

[grand mica]

thought i could do it later. Bleh. Wanted to test out stuff

SetIsReplicatedByDefault where do i need to call this?

[nova wasp]

This is just a change to the source file? this is a file you are changing anyways 😛

[nova wasp]

This is the part where I tell you to just... look at the error

[grand mica]

no it's my custom movement component

[nova wasp]

yes, that YOU WROTE

look at the callstack of the ensure

[grand mica]

it must be coming from where i wrote

[nova wasp]

I think it would be really beneficial for you to figure out what a callstack is and what it means because otherwise C++ debugging will be quite difficult

next time you see the ensure, look at WHERE it is coming from and what could change

[grand mica]

anyways, I am not sure what do we need to fix first. Keep a breakpoint in OnRep_ReplicatedMovement here or fix the warning?

xD

[nova wasp]

both

[grand mica]

yeah i know lol.

xD

[nova wasp]

also you never proved it's being created on client and server with anything

if you are compiling with the editor open or something do not do that (Unless you know what you are doing, live coding can as a rule of thumb can change cpp stuff)

[grand mica]

this gets triggered but only on the first few frames and I highly doubt its getting triggered because of my code

[nova wasp]

this is not a callstack

[grand mica]

one moment

[nova wasp]

ensures are designed to only cause a breakpoint the first time they are triggered each run

this is to avoid being stuck pressing f5 forever on "bad but not a crash" kinds of errors

yeah, this is a received bunch

It would be easier to override this to see if it's being called

as this could be any replicating actor

you also hid which actor it's for... I don't understand how I can do this seeing only small pieces of isolated things at a time

[grand mica]

ok i am overriding it and dioing super::call in it

[nova wasp]

also please just fix the bad SetReplicates call now rather than ignoring it

[grand mica]

sure.

one moment

[nova wasp]

Also make sure you didn't miss any Super:: calls in your overrides, like beginplay etc

[grand mica]

yes sure!

[grand mica]

in the mean time i want to ask. I think you made your own rollback netcode right?
How did you manage to deal with packet loss?
I have seen unreal has done it with acknowledging the moves and sending back to the client but the new moves are sent regularlary and with regular packet loss the gap between the last ackd move and current move would increase. How did you manage this?

[nova wasp]

I'm not an authority by any means, I don't think I have something viable yet

with packet loss you just... spam moar packets lol

[grand mica]

I don't want the server to acccept whatever the client has done in those packets which were lost

[hoary spear]

https://tenor.com/view/fuck-working-with-boxes-gif-10055506

[grand mica]

so there must be a solution?

[nova wasp]

a server correction?

I think the reality is eventually you just have to correct the client to be where the server expects them to be... if the server missed some old unreliable move RPCs then oh well

[grand mica]

yeah but that would make the client to keep on sending the new moves and the server is still processing the old moves. With more packet loss - older moves and so on 😦

btw overriding didn't help either

[nova wasp]

I didn't say it would help, I said it would let you see if anything was calling it

[grand mica]

no, didn't get called. Let me show things are happening on the server

[nova wasp]

I still haven't seen a simple output log showing the object existing on both other client and server

[grand mica]

these are my logs in the server code and server logs

[nova wasp]

none of this shows the client's log

just... run in editor to avoid the headache here

[grand mica]

what exaclty you want to check?

[nova wasp]

UE_LOGFMT(LogTemp, Log, "{WorldString} Set repmove here", GetDebugStringForWorld(GetWorld())); I gave you this exact line here to pasta in (If this doesn't compile my b, I think it's accurate though)

add this log to the pawn's BeginPlay as well

[grand mica]

okay one min

UE_LOGFMT it says its undefined?

cant i do it with normal UE_LOG?

[nova wasp]

sure, you can

UE_LOGFMT is just fancier

[nova wasp]

missing include

[grand mica]

uhm. Doing it with normal log. Running it

[nova wasp]

Is there a reason you need to run it outside of the editor here? I personally prefer just doing stuff like this in PIE

it's not a perfect test but it should be more than good enough for stuff like "does this replicate at all"

[unkempt tiger]

Can I switch a player's APlayerController instance mid match? To perhaps a difference type?

[dark parcel]

What would be a good use case to do something like that?

Sounds like a pain to me

[nova wasp]

the player controller is more than just "what buttons you push", it's kind of the object that owns the connection to the server

[unkempt tiger]

I want to let players spectate the match if they're dead
I figured maybe changing the controllers to a spectating controller would work

[nova wasp]

it's not simple to swap out from what I can tell and I have never seen a project that needed to

[unkempt tiger]

Makes sense, I figured it wouldn't be trivial

[grand mica]

those the logs kept inside On_RepReplicatedMovement() and BeginPlay()
PIE means another window for the client and not in the editor itself?

[nova wasp]

Spectating does not require changing the player controller at all, by default NAME_Spectating actually just spawns a spectator pawn (defined by the gamemode) locally and partially possesses it

[unkempt tiger]

Oh right, doing it via a pawn makes so much more sense

how do you mean partially possesses it?

[nova wasp]

it's possessed but not THE pawn of the player controller, it is actually the spectator pawn of the controller

the server doesn't know or care about it

[dark parcel]

Makes me wonder how fog of war works in multiplayer

[unkempt tiger]

Ah, gotcha

[dark parcel]

I guess what can be seen must be defined by server

[nova wasp]

If you want to do things the ~unreal way~ you can do this to start spectating (dot his on the server to the player that starts spectating)

// start state "spectating"
            MyPlayerController->ChangeState(NAME_Spectating);
// make sure to yell at the client too
            MyPlayerController->ClientGotoState(NAME_Spectating);

[unkempt tiger]

woah

that is bizzare to me

[nova wasp]

there is nothing stopping you from just making a new flying pawn and possessing that to make spectating a thing, spectating (the unreal player controller NAME_Spectating state) is entirely optional

it is techinically used when joining before you get given your pawn etc in the default case I think?

but in most cases this will be like a brief stutter before you start walking around

[unkempt tiger]

I would guess that at the initial couple of seconds before the pawn is spawned for the client the controller is in a pawnless limbo

gotcha

[nova wasp]

the unreal setup is fine except for a few omissions in spectators not being respected as the current pawn ( PlayerController->GetPawn() does not return it, but GetPawnOrSpectator does)

[unkempt tiger]

That works, thanks a lot for directing me to pawns

[nova wasp]

I feel like I need to take a step back here, lol...

learn what a pawn is first... please read the getting started docs

[unkempt tiger]

I was about to actually use this system I wrote some time ago that I called 'player experiences' which was just an input controlled camera that became the player's view target, potentially letting the original pawn still get inputs

i don't like this multitude of options

[nova wasp]

the alternative is to ignore those options

your setup is actually probably a pretty good idea, the view target + input is all you need in reality

but it might omit some key things like the server knowing where your viewpoint is from the possessed pawn (distance based relevancy?)

[unkempt tiger]

exactly my thoughts

[nova wasp]

I would highly recommend at least possessing a real pawn while playing

[unkempt tiger]

yes ofc

[unkempt tiger]

thankfully all of my actors are always net relevant so this will never have horrible consequences 😅

[nova wasp]

also if you want... you CAN add actor components complete with server RPCs + replicated properties to a player controller

if your concern is "why do I have to stuff all of this darn stuff in the player controller" or something

but the pawns are there for a reason I guess

[grand mica]

sorry to bother you again but here are the logs

showing where things are called.
The call on the clients come from begin play and On_RepReplicatedMovement which I think is being called only when I play the game. Not when the values are changed

[nova wasp]

How on earth are you getting a -1 client ID?

are you passing in a nullptr?

ah, no read the ternary wrong

I guess -1 is the pie instance of standalone processes

[grand mica]

yeah. It happened because i launched it on PIE yes

[nova wasp]

I suspect something else is overriding the repmove here (the value I mean, not the function)

I would just launch it all under one process for stuff like this (just to make it faster to test, no it is not an accurate test that way)

try setting the position of the root component rather than manually changing the rep move

I think it's gathering movement and seeing the position hasn't changed

[grand mica]

let me try

[nova wasp]

See AActor::GatherCurrentMovement

which is what fills out ReplicatedMovement

you can actually make a seperate property for your own replicated movement if you like and disable the old one if need be

[grand mica]

right. I noticed in high ping

These are the values of the local client over 10 frames

local client - 1,2,3,4,5,6,7,8,9,10
server - 0,0,1,2,3,4,5,6,7,8,9,10
remote - 0,0,0,0,1,1,1,4,4,4,8 etc
so the remote client is getting the update in a bunch rather than receiving every single update. This seemed weird and I tested the Third person template in Unreal and they were updating the values regularly even on high ping using PostNetReceiveLocationAndRotation

I am not sure what was happening here

thats why i was looking into it

[nova wasp]

is it changing anything in the onrep? Is it set to Onrep_always?

[grand mica]

no i changed things on OnRep when I noticed the simulated client isn't getting regular updates. I didn't use it before when I noticed this issue

anyways its weird. I'll try this stuff on a different project now

At this moment I think i need to focus on how to deal with packet loss