multiplayer

[torpid lantern]

Super stuck on this one, but maybe I have a fundamental misunderstanding of client/server object refs.

Here's my attempt at a proof of concept, but it's failing - the temp var that I want to store a ref to the serveractor appears to be a ref to the **client **actor, which returns none after the actor leaves net cull distance.

In this poc: I press 1 and that sends an server event which uses an interface; which goes to the UnitBP (on the server?), which stores a replicated ref (ServerUnitRef) to itself

I press 2 and the game grabs the ServerUnitRef and saves it to TEMPServerRefStorage on the player controller

[I walk the actor out of cull distance, and they are removed from screen]

I press 3 and my expectation is the TEMPServerRefStorage still has a ref to the server object and should be able to get its location.

All prints are firing data, but #3 returns 0,0,0 when the client actor is out of cull distance.

My backup plan is to store a GUID on the actor and then use a "get all actors of class", then filter by GUID - but that feels super heavy for what I need (the location of a single actor who is outside cull distance).

[prisma belfry]

Hey yall

I have a game where you fight with melee weapons. I want some accurate collision detection so i use a plugin for tracing along the weapons movement^
Problem is that dedicated servers dont run animations so they dont actually move the weapon and the traces dont move at all
So I see 3 options:

• Client authorative detection, seems like a bad idea for obvious reasons
• Enable animations when not rendered (if i could find the damn setting), generally not adviced, it will also affect clients and i use some expensive als animation blueprints
• Bake the sockets relative location during the animation and replay it as a sort array of vector positions, but this tedious and it makes it impossible to do some dynamic aim adjustment stuff i wanted

Thoughts?

[sinful tree]

The reference wouldn't be valid on the client to get the location from if it's outside of the cull distance. The reference goes invalid when it gets culled.

[lost inlet]

RPCs work on replicated components, you just would need to make sure the client owns the owning actor

PS is an odd choice unless other clients need to know the complete inventory

But the PS is owned by relevant player controller

Well the PS is owned by the player controller, so that player should be able to call RPCs on a component that is owned by that PS

The output log does show failed RPCs

[cobalt pollen]

So to allow navigation on my moving ships I setup a proxy/ghost ship on the server side with ai characters mirrored there and it works. I can move the ship around and the ai proxy characters can use navigation move commands. I'm currently setting the relative transform of the "real" character on the ship to match the relative transform of the proxy character (just a character with a capsule) on the proxy ship. I'm doing this on the real characters tick... this might be fine but any ideas if there's a better way to sync up the movement of an actor to another one? Especially that take advantage of any magic netcode in charactermovementcomponent?

[hollow eagle]

The expense of CMC has nothing to do with being autonomous.

The expense is in the spaghetti that is its movement calculations.

I don't know why you're talking about netserialize

it has nothing to do with this.

It would not.

I don't know why you keep mentioning random parts of the networking framework without understanding what they are.

NetSerialize is not the same as generic property replication

it is a specific method to serialize things in a custom way.

CMC is already based on both property replication and RPCs.

Maybe, it depends on what you are doing and where the expensive bits are.

There's no hypothetical answer to this.

You profile and find out.

I don't know why you're talking about network profiling

it's not what I'm talking about.

The cost of CMC is not primarily with its networking.

interpolation yes, position and movement no

there are already callbacks for when actor movement is replicated, storing that off and interpolating is up to you if not using CMC.

it depends on what you are doing

[clear island]

#multiplayer message

yea they really arent

animation will hit you first long before that

then after, CMC floor checks

and then maybe delta property comparison for replicated stuff

well the server has to track bone positions on the skeletal meshes

because you need that info to acurately detect hits from line traces for example

also from what I've heard, transform updates are slow in UE

as in, more than other engines

the technical reasons I could not say, but its been mentioned on #cpp a few times I believe

its really depends on what your game is doing

but most of the time if you want to detect stuff like hits against the mesh you wll need up to date information about the pose the mesh is in, which is usually driven by animation, so thats why the server needs that info

100 player cap on "default" UE is definitely not happening

[hollow eagle]

ehh, it is

that's what fortnite is

not for a solo project though

[clear island]

yea

[hollow eagle]

that's a team of engineers. They're not twisting the engine in weird ways, all the tech they use is available.

[clear island]

yea what I mean by default is: not using rep graph, iris, ABA, etc..

[hollow eagle]

hey even epic isn't using iris yet

it isn't something enabled by default

and it requires configuration

you cannot use repgraph with iris

[clear island]

I thought they were using it already I guess I'm confusing it with something else 🤔

[hollow eagle]

and you should absolutely not use iris if you haven't worked with unreal multiplayer before

[clear island]

ah actually I think its the push model

I believe they're using that

[hollow eagle]

it's possible I missed them saying they've started to use it, but afaik they said they weren't using it on fortnite back in 5.0-5.1 and haven't said otherwise since.

[hollow eagle]

yeah push model is stable

all the more reason to not use iris

iris does not change the basics of how you interact with replication

[clear island]

mostly CMC and animation yes, although once you optimize most out of those 2, then yea networking is probably next

[hollow eagle]

iris does introduce complications in terms of setup, configuration, zero documentation existing aside from a single high level overview page, and bugs that basically no one will be able to help you with unless you have access to UDN.

[clear island]

yea I'm currently using push model too

[clear island]

rep graph is kinda the same, in terms of almost no docs except for shooterGame

[hollow eagle]

yeah, but at least that's stable. Or more so than iris.

[clear island]

yea

I'm not touching iris either, for now I just settle with push model, the network stuff is currently not even my top offender when it comes to performance

I wouldnt replace the CMC if I were you, thats an ungodly amount of wheels to reinvent there

just subclass it and make changes where necessary

from what I've heard the GMC is not necessarily lighter, it just has more features

also navmesh will probably hit you too when it comes to performance if you're thinking about having AI

I dont have GMC so I'm not the best autority on its internals but I believe I've seen it discussed here in that manner

it depends, usually moving pawns should not be set to affect navmesh generation because navmesh gen is expensive, but then you need to look into RVO and theres many edge cases

I'm just using the default features, selectively enabling/disabling "Can ever affect navigation" in a combination with RVO

theres actually good official docs on this

[lucid badger]

So i'm switching my items over to data table rows. Before they were BP Classes subclassing the ItemData class. That was just temporary when I had like 6 items lol.

But when they were BP classes, I could call Construct Object of Class and the Class identity was part of the object itself, meaning when the object was replicated on client side, it started with knowledge of what type of item it was implicitly.

Now that I am using data table, I'm guessing there's absolutely zero way to get the same functionality? I have to have a RowName on the object and replicate it, and do setup for the item in OnRep_RowName?

[vagrant grail]

I'm watching a multiplayer tutorial on how to do sessions, and the tutorial guy wrote his code using variables to save the value of his UI elements (input box and checkbox), while in my case I directly inputted the value of those UI Elements into the "Create Session" node, is what I'm doing bad / wrong and could lead to issues compared to his setup ?

There are some differences in my setup compared to his as I use a slider to get the the value for "MaxPlayers" while he's using an input box.

[copper pendant]

🤔 .. any idea how to fix it? i dont understand this error

[hollow eagle]

quite frankly you need to stop looking at random lists of features and start actually making something. The decisions you are making are based on nothing but your own wild guesses.

And the only way to fix that is to forever sit around asking questions and never actually build anything, or to get experience and figure these things out as you go.

[plucky prawn]

It means you used the wrong player controller on a widget. I'm guessing this is running on a listen server and are iterating or otherwise referencing a player controller that is not yours for a widget

[copper pendant]

thank you

[copper pendant]

can you tell me how to get client player controller index number? is his index player 1 or 2 or... ?

[plucky prawn]

dont use index

[copper pendant]

im trying to understand how to make this: Client presses button in his widget and this event is get send to the Server and Server is replicating this event to all other Clients (Any Client->Server->All Clients)

[plucky prawn]

use GetOwningPlayer on the client with an RPC through the player controller

then the server would iterate over all player controllers and do a new RPC

[copper pendant]

thank you! ill try that

[copper pendant]

this?

[plucky prawn]

if its going from client -> server you want Run on Server

otherwise if its going from server -> client you want Run on Owning Client

[copper pendant]

this helped with error, but i cant make my URL var get replicated

[plucky prawn]

🤷 this doesnt make sense and i dont see the callsite for UpLoadButton

[plucky prawn]

is it supposed to be an RPC?

because right now UpLoadButton is called on the client

[copper pendant]

changed it to be multicast rpc event still nothing...
oh.. this multiplayer stuff is so confusing🥴

i managed to make: when server change map its changing on the client with ReplicatedActor before that (Server->Client) 👍
but it didnt worked when Client tried to change map (Client->Sever)🥲

Now i tried to remake it with PlayerController hoping that it would just works both ways (Client<->Server) but it get even worse cus now its not even sending button events from (Server->Client)😢

[plucky prawn]

The client needs to send an rpc to the server through its player controller (or other actor it owns but let's focus on the player controller) for any action it wants to execute on the server. The server should verify the action then in your case iterate over all of the other player controllers and execute a client rpc on them. Don't use multicast for this

[copper pendant]

thank you, ill try that little bit later

[copper pendant]

if possible with screenshots could you please show me a very simple example how that structure would look like? then i would understan it much faster

[plucky prawn]

i dont have unreal open at the moment. i would highly recommend you look at the networking compendium in the channel pins

[cobalt pollen]

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

[copper pendant]

Thank you, i would look in to pins and this man tutors

[cedar lagoon]

Hi what is the correct way to add a mapping context to for a player controller using the Enhanced one.
I have a pawn on server, i then as a Client send an RPC to possess that Pawn which does, then in my code (pawn) I do:

void ACustomPawn::PossessedBy(AController* NewController)
{
    Super::PossessedBy(NewController);

    if (const APlayerController* PlayerController = Cast<APlayerController>(NewController))
    {
        if (PlayerController->IsLocalPlayerController())
        {
            UEnhancedInputLocalPlayerSubsystem* Subsystem = ULocalPlayer::GetSubsystem<UEnhancedInputLocalPlayerSubsystem>(PlayerController->GetLocalPlayer());
            Subsystem->AddMappingContext(InputMapping, 1);
            GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, TEXT("Added mapping context"));
        }
        else
        {
            GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, TEXT("Not local player"));
        }
    }
}

And of course there is something wrong with the IsLocalPlayerController() because it alaways goes to the "Not local player" which makes sense Ikr, but i'm lost using the enhanced input system with mumtiplayer setup

Yeah I might add that this does work for a Listen server but only for host, if playing as a Client it does not work

[tardy fossil]

you should set up all your input bindings by overloading the APawn virtual function: SetupPlayerInputComponent(UInputComponent* PlayerInputComponent)

[twin juniper]

RPCs can only return void, right?

[tardy fossil]

also virtual void Restart(); is what you want if you wanna do stuff on a client on possession

[tardy fossil]

correct

[cedar lagoon]

Hum yeah thanks, I don't even know why i didn't try that..

[rain condor]

Simple question. shooting traceline has to be replicated only on the server and vfxFireEvents on multicast?

[inner cove]

Yeah line trace should run on server but can also run on owning client for client-side prediction for stuff like hit marker (hit marker is not really client-side prediction, but depending on your project's requirements you might have things that client-side prediction can be applied) to feel instant instead of waiting for the server's response to know if they client hit anyone, this will be very noticable with high ping

[silent valley]

Is it possible to speed up the sending of unreliable RPCs?

I am seeing a case in PIE where server triggers GC and sends one of my game RPCs in the same frame.
The GC rpc is received 2 frames later on client.
The game RPC is received 29 frames after that?

The ASC sends the GC rpc as unreliable

ok, seems calling ForceNetUpdate(); on the actor with the RPC makes the unreliable RPC send immediately 👍

[inner cove]

Maybe increasing the Frequency helps?

Nvm thats probably only for replicated variables

[chrome bay]

Is it a multicast?

Unreliable Multicasts get buffered and sent similar to properties IIRC

[silent valley]

it was multicast, yeah. ForceNetUpdate() seems to do the trick though 👍

[solar stirrup]

Keep in mind ForceNetUpdate() doesn't force anything

It asks the engine to consider the actor for replication asap, but if your network conditions are pretty bad (i.e. saturated bandwidth and such) the engine can still push back replication

[forest reef]

If I move my gun barrel around with an animation but then try to call the location of said barrel on the server. Would the server know where the barrel is or does it ignore the location in an animation? It almost seems like its getting the location from my default pose.

[solar stirrup]

I don't think animations are generally played on the server

So you'd have to pass in the relative position of the gun, probably with some light server-side validation to avoid cheaters

[forest reef]

yeah im thinking thats why my barrel tip is in the wrong spot. maybe the client has to send that location over when calling the server function? Then I just need to validate it to stop hacking?

oh you beat me too it lol

[solar stirrup]

haha

but yeah exactly

[thin stratus]

@forest reef SkeletalMeshComponents have a setting to only process Bone and Pose updates when being rendered.

If you have something that requires the Update to also happen when not rendered (ListenServer not looking or DedicatedServer), you'd need to set that setting to always update the poses and bones.

Guns being moved by Aim Offsets and similar are a good example for stuff that would need this, otherwise Server ends up with a different Location.

[forest reef]

I'll have to check that out next time I get a working example going! Thank you

[forest reef]

@thin stratus so something like ```cpp
BaseCharacterSMC->VisibilityBasedAnimTickOption = EVisibilityBasedAnimTickOption::AlwaysTickPoseAndRefreshBones;

[thin stratus]

Yop

Usually done on the BP or in the Constructor I guess

[forest reef]

oh yeah, oddly i found the cpp code before i could find the option in the BP

[tardy quarry]

Looking for some advice with respect to working with the replication graph. I understand that it can save a decent amount of CPU server-side when you're working with a lot of actors AND connections, but is it worth spending the time diving into it if I'm only planning on 16 players or less? (Bonus question, with UE5 and Iris in it's experimental phase is it worth bypassing replication graph all together in favor of Iris?)

[latent heart]

Iris is a pain unless you're willing to devote a lot of time to it. So I hear.

But a few people are using it successfully!

[slate basin]

hey, is there something like route gamepad to second window for VR HMD?

[vagrant grail]

Simple question : If an actor (let's say a simple cube for example) doesn't have the "Replicates" property on the actor set to true, if I create a variable in that actor and set it to replicate, would it replicate that variable?

[keen hound]

trying to redo the random character system I had, it's spawning the character but not possesing them. any help?

Okay it's possessing them but it's not allowing input

[hollow eagle]

no

[vagrant grail]

Thanks, another question : If I have a big map like a battle royal, and someone on the other side of the map breaks an object (like in Fortnite), the destruction of the object will instantly be replicated to all players to update their instance of the game, or will the game rather use the repNotify part and wait for the player to be in the range of that object (so the Squared Distance property) to give him the updated state of that object and destroy it ?

Because to me the second option would be better in terms of performance to avoid people receiving updated states all along during the game which could create lag, but the thing is when the object is destroyed, it doesn't have its "sphere collision" detecting when a player is in range of the object to send him the new state of the object as the object itself is already destroyed, so I'm kinda confused 🤔

[hollow eagle]

if an actor isn't relevant it won't replicate

[vagrant grail]

true but what about the second part, how's that possible to replicate when he becomes relevant but the actor is already destroyed, so there should be no detection for relevancy as the actor doing that is already destroyed 🤔 ?

[hollow eagle]

if the actor exists on that client then destruction will be sent, if it doesn't then it doesn't matter because the client doesn't know about the actor in the first place.

an actor that isn't relevant does not exist on the client

[vagrant grail]

Ohhhhhh that's why then, it makes sense now. Because in my mind, I thought it still spawns the objects even if they're not relevant at first but will destroy them on the client when he becomes relevant to the obect if that object is already destroyed on the server. But it makes sense in terms of performance of why it's like this. Thanks 🙏

[past flicker]

Is anybody using state machines? I looked through the marketplace and the plugins are really lacking on the network side. Some have replication but with pretty big drawbacks, and none have prediction support.

[spice gorge]

I'm using the PhysicsControl setup to attach an object to a player actor (The reason for doing this and not just attach actor to actor is because I want to attach the same object to two actors). Now I did this in a project last year and it worked. This current project is setup differently however so I can't just copy and paste the code directly.
The issue I'm having is that clients don't recognize other clients or the server when they get attached to an object. Example: If the server picks up an object the connected client observes it move into position and then just continually fall to the ground then pop up again.
If the client attaches to an object they see themselves ok and the server sees everything as intended.

I've been trying to debug this and figure out what steps aren't replicating. The code is run through an Ability in GAS and the attach code is a Task. I thought that those things were replicated as default so I guess there's something specific I'm missing and I'm not sure what.
Is there a component I might need to flag and replicate or force each connected client to call a function locally to replicate state?

[past flicker]

If the server picks up an object the connected client observes it move into position and then just continually fall to the ground then pop up again
That sounds like the position of the object is replicated but the constraint is not. I searched the entire PhysicsControl folder for "replicate" and see nothing, so is it even replicated?

[pure oar]

i want to switch teams in a 2vs2 game in a 4-player lobby, with Team A and Team B, but I couldn't find any resources, and I couldn't switch teams because I couldn't retrieve the Steam usernames correctly. If anyone has a source, could they share it?

[spice gorge]

I'm fearing not. I suspect that marking the compnents as Replicates won't do anything (and didn't in my quick test). So I'm wondering that I did in the old project to achieve this result.
Noob networking brain here: Would this be a case of getting the server to NetMulticast to each client and get them to establish a Physics connection locally to essentially replicate the state?

[oblique arrow]

Guys will spawning weapon and assign it to the Weapon variable should replicate this variable to the client?

[past flicker]

What may have happened in your previous attempt is you had replication so frequent that it just looked like the constraint was working because position was updating so fast. As far as your "noob" strategy goes network physics is complicated, so unless this PhysicsControl is deterministic your clients will just desync. If you want PhysicsControl replicated you're gonna have to replicate it in all the ways Epic didn't, probably for good reason (it's hard).

[spice gorge]

That could well be the case. Looking at the old build (checker box) it looks pretty stable. I'm wiggling the character here to rotate the box. In the current project you can see that the client just wants to settle the physics to the ground. I'd expect that in the old build even with a high replication frequency there'd still be noticeable jitter.
The intention here isn't to use the physics part, the box should stay ridged, it's the only solution I could find for attaching multiple actors together.

[past flicker]

Why not AActor::AttachToActor?

[spice gorge]

Because I have two players being able to attach to the box at the same time. I believe AttachToActor parents it, which only works with one, unless I made the box the parent and each player the child. I don't know what Unreal would do in that situation.

[past flicker]

Oh no. That definitely sounds like a physics interaction. Party Animals is the only game I'm aware of that has done something like that over network recently.

[spice gorge]

In the previous prototype, the advantage I got from using the PhysicsControl component was the force vector, which I can use to change the movement input vector. This did put more stress on the Physics system in the multiplayer setup. It worked well as players would only be able to move if they were both syncronizing their movement as pulling in opposite directions would cause the force of the physics control to neutralize their movement vector.

My intention with this prototype was to get it setup the same basic way (hooked up via PhysicsControl) but just use the players movement vectors against each other and ignore the box part. Though I can't get to the point where the attachment works 🙂

[past flicker]

Actor has EPhysicsReplicationMode but I'm not aware of how it works and a lot of it is marked WIP. My guess is you're on the hook for a lot of custom code to support this.

[spice gorge]

Certainly could be. Though I'm just exploring ideas. This will be stuff for smarter brains than I.
Looks like EPhysicsReplicationMode is a 5.3 thing. We're still on 5.2.
I'm going to try and rip through the code of the old project to see how that's managing to work so well. I don't care for shippable code, just enough to present potential.
Thanks for taking a look!

[queen escarp]

https://gyazo.com/428f382cfdb0595897fb9ed86cff716f'

[spice gorge]

Ummm. So it looks like I did it. The boxes in the current project were set to simulate physics by default, but in the old project they weren't, instead physics sim was switched on during the creation of the Physics control part. So I just replicated this setup and it all seems to work now. There's no jittering on the client.

[queen escarp]

hey guys this is a common problem i have with all my projects, the damn "rubberbanding" or whatever its like that by default when i start a new project even

any tips on what i can do to make it betteR?

[spice gorge]

I think I understand more of what was going on here now. Prior to my fix I added code to log when the physics connection happens and noted that the server got two events, self and client, but clients would only get themselves. So clearly they weren't seeing the networked state.
Switching sim physics on the box now shows two events on the clients. So I guess the clients were failing previously when trying to establish a physics control connection.
I'm sure this is all still bad in terms of performance and good code, but it helps prove the target concept out.

[past flicker]

I don't follow. You're saying you turned simulate physics on at runtime instead of default and that fixed your problem? You now have perfect replication of physics between 2 actors manipulating a third actor?

[spice gorge]

yup

I'm guessing the default physics state wasn't replicating or something was going wrong. As physics was on players could walk into the boxes and push them around and that all replicated, but maybe it was just replicating movement and position and not really physics because it wasn't correctly on.

Adding that did magic thing.

[past flicker]

I'm still stuck at Unreal having fully replicated physics out of the box. I don't see anything online about this. Can someone more knowledgeable chime in? Unreal just has automagically replicated physics? Since when?

[spice gorge]

I think I'm probably getting things in a setup where each client is doing something that looks like there's replication going on but they're all just doing their own thing.
I though Iris was supposed to be the Unreal solution to Networked physics, and I'm certainly not using that here.

[thin stratus]

Not sure Iris would allow Networked Physics any more than what we currently have

[past flicker]

Have you tried turning on network emulation? Set it to bad and we'll see what's up.

[thin stratus]

Physics Replication is not really a thing in UE

At least not to a point that it can be used for Gameplay

The max you could achieve is have something server auth bounce around that you smooth locally

But Client controlled is pro bably not a thing

The CMC for example boots you out of you enable physics on the character

[spice gorge]

Ah, I'm misremembering Iris, I thought it was adding some level of physics, but I see not.

[thin stratus]

Not sure, afaik Iris just replaces the overall replication stuff of UE with something fresher

[hollow eagle]

All unreal does is replicate basic movement properties, there's no true physics replication.
There's an experimental physics replication mode in chaos but it is nowhere near stable and it's off by default.

[thin stratus]

Something that ties in ReplicationGraph etc.

Chaos has some phys rep stuff, afaik, yes, but also not for gameplay in that regard

[hollow eagle]

It is afaik

it's fully predicted physics

it just isn't finished

[thin stratus]

Yeah that's what I meant ,sorry

Should have added "in its current state"

[hollow eagle]

ye

[past flicker]

Alright dagger, so this is confirming what I thought. I don't know what you've achieved here, but it probably isn't gameplay ready multiplayer physics.

[thin stratus]

It depends on what the goal is

Just enabling PhysicsSim is not gonna achieve much

[hollow eagle]

I mean, basic movement replication is "good enough" for some things. And horrible for others.

basic interpolation and no prediction may even work well enough for some

[thin stratus]

I don't think bone location is synced or?

[hollow eagle]

oh is this about ragdolls

[thin stratus]

Idk

[past flicker]

I think the main goal is dagger wants two actors to attach to and share another actor.

Like a tug of war over a box

[thin stratus]

Sounds a lot like these physics brawlers

Gang Beasts etc.

Human Fall Flat

Bla

But none of those are done in UE iirc

They are probably Unity

Or custom

[hollow eagle]

unity doesn't have physics replication either afaik, it's all going to require a bunch of custom work regardless

it doesn't require a different physics engine but it does require replicating physics state data and reconciling it with predicted physics yourself.

[past flicker]

Unity has Netcode for entities which seems to have some physics stuff. Party Animals is the most recent game with this and is Unity.

[spice gorge]

Well the goal was just to prove out a gameplay concept. The final "how it's actually done" is something to be figured out if the prototype proves itself.
I ended up using Physics Control because it let me attach two players to an object (Two people carry a box). I don't really care for the simulated physics part as the intention is to make things more deterministic. This seemed like a quick way to prototype the idea out for a LAN multiplayer setup.

[dark edge]

There's physics replication

it's not predicted but it's there

[past flicker]

The plot thickens. I don't know what to believe now.

[spice gorge]

I just had a quick test with Bad network emulation and it looked acceptable. There was lag, but no more than the lag that the client player movement also had.
As this is intended to just be tested via a LAN setup I think it's fine to prove the point out.

[past flicker]

How poorly documented is this engine when some of the most knowledgeable people on this discord can't agree if UE has physics replication?

[spice gorge]

I feel like I walked in here with two cans of gasoline today 😄

But were they replicated cans of gasoline?

[past flicker]

I guess we'll find out if the client catches fire.

[dark edge]

btw that typo has been there FOREVER

physic(sic) error correction

It actually works pretty well if you don't need prediction

[hollow eagle]

...which is just the basic movement properties I was talking about

[dark edge]

I mean what else do you need replicated besides the physics state?

[hollow eagle]

it's not the full state first of all, and there's no real reconciliation to handle prediction on clients.

[dark edge]

Clients see what happens on the server due to physics, that's physics replication. Not great for a game that needs prediction but that's pretty much it

It sends enough state to be smooth and consistent, just the default settings are crazy strict

[hollow eagle]

it's really not that smooth or consistent

[dark edge]

Good enough for a space game or something of the sort but I wouldn't want to make an F1 game with it

[past flicker]

I'm pretty sure those Unity games don't have prediction either. I've felt noticeable lag just controlling the character in Party Animals.

[hollow eagle]

it's barely good enough for throwing a single physics object around without clients wildly mispredicting

proper replication and prediction requires a degree of determinism that unreal doesn't do by default.

and is experimental, and didn't even exist before chaos.

[dark edge]

I haven't tried stuff on a super small scale but I tuned it to behave great with my vehicle system, ramming each other at full speed felt butter smooth.

just had to loosen up the error margins a lot to make it behave at the scale of vehicles

[hollow eagle]

with how much ping and packet loss, though

I also question whether the various vehicle systems in the physics engine follow a different code path for replication anyway.

[dark edge]

oh idk i made my own

@past flickerhttps://github.com/EpicGames/UnrealEngine/blob/072300df18a94f18077ca20a14224b5d99fee872/Engine/Source/Runtime/Engine/Private/PhysicsEngine/PhysicsReplication.cpp#L358 if you want to peruse the code. It's simple but works good enough if you don't need prediction. IDK if I'd try do a Gang Beasts with it but it all depends on what you're trying to do.

[past flicker]

Thanks for confirming that. I'm not even using physics for gameplay, but maybe it would be nice to have a ragdoll land roughly the same place on all clients? IDK.

[livid jetty]

Does UE5 have complete solution for server authoritative networking including non-humanoid characters?
I mean client prediction, server reconciliation, interpolation, lag compensation.
Or i need to implement it myself ?

[wanton bear]

what are the drawbacks of running a dedicated server locally vs playing as listen?

i did my logic as clients only and im starting to wonder if that was a bad decision for a coop game

[solar stirrup]

Not for non humanoid characters

You'd have to implement it yourself

[livid jetty]

So humanoid characters have reconciliation and lag compensation? How i can achieve that?

[solar stirrup]

CharacterMovementComponent

Lag compensation no - you'd have to implement yourself

missed that one

[dark edge]

If it's meant to be one and the same machine then just do listn

If you're testing and the game is intended to use dedicated servers then do that

[dark edge]

https://docs.unrealengine.com/4.27/en-US/InteractiveExperiences/Networking/CharacterMovementComponent/

[livid jetty]

This looks like replication, not the rest i mentioned

Prediction is mentioned, i guess reconciliation and interpolation might be there

[hollow eagle]

all of the above is in there

characters have full prediction, reconciliation, and interpolation.

[livid jetty]

nice

thanks

[twin juniper]

Naming question: I have a function in PlayerCharacter that is called on both PossessedBy and OnRep_PlayerState, so that the PlayerState would exist.
What should i call it for the sake of clarify? I currently use "WhenPlayerStateAvailable" but it feel vague.

[vagrant grail]

Guys I was following this tutorial, and when trying to press the "Leave Session" button like him, it froze the engine for like 5 to 10 sec, then crashed unreal. Does anyone know how to solve this issue please ?

The tutorial (with timestamp) : https://youtu.be/7OdruBNGOM8?t=1916

I will try to relaunch the engine to try again and see if it crashes again.

[twin juniper]

Idk why my action FInputActionValue is always 0 when i sent it to the server. I literally bind it as a normal bind function.
Anyone knows?

Is this even the right approach to move the character though?

Because, you know, if i let the player move client-side, they may teleport and stuff

[hollow eagle]

it is not, because FInputActionValue is not at all intended to be sent over the network

just send a vector if that's what you need

[twin juniper]

interesting, where can i read about what is intended to be sent over the network and whats not?

[hollow eagle]

Nowhere? It depends on what the thing is.

There's nothing that's going to give you a list of types.

If it isn't a basic type and there's no evidence of it being used for networking at all then it's probably not used for that.
Or you read the source of the type and see if it is even remotely setup for replication.

In this case the underlying value isn't a UPROPERTY and there's no evidence of custom network serialization. So nothing useful will be sent by it.

[twin juniper]

How do i read the source and know that the type can be use for networking? Wdym the underlying value isn't a UPROPERTY too? God this is confusing

Do i really need to know that too, or just try to send basic type and that's fine?

[twin juniper]

Even though my input is ok now, somehow my character won't move on the server

Ok imma go checkout Lyra now because i have no idea what i am doing

[crisp shard]

im having trouble getting other** clients to see an attack VFX.

i have client side VFX firing fine but when i do the multicast, it fires but i don't see anything and im not sure why.

is there anything wrong with this flow of logic?

[cursive steeple]

Other than the obvious one that the non-local path isnt connected to the effect function call? My first guess would be that the "PointOfFire" isnt properly replicated, whatever purpose that one has ^^

[crisp shard]

the owning client shouldn't see/hear any of this, it's firing so that everyone else see's/hears it

that's why i have that check, so the player firing doesn't expericne the multicast

there is a client side evenet before this that is working for the player firing. but i want that effect to be played for all other players and the event does in fact fire but i don't see any visuals/hear anything

[crisp shard]

point of fire, would that need to be set to "replicated" ? it's basically a scene componenet ref

this is the event that calls the multicasat btw , so you can see where those varaibles are coming from

[cursive steeple]

If it's a local component then why pass it as a parameter? Let local clients select their own component based on that replicated IsAim bool (or pass the bool if the variable isnt reliably replicating fast enough).

[crisp shard]

ahh i could probably do that, i guess i was thinking to get the variables on the server since it's being called there, but i could probaly just get them inside that mulitcast itself

if that's what you mean

[cursive steeple]

Im not a hundred percent sure, but in my mind object refs as parameters through rpcs would only be valid if the object is properly replicated, I'd imagine that otherwise you'd get a null ref and all your effects would be spawning at default 0,0,0 location. Happy to be wrong tho.

[cursive steeple]

Yes c:

[crisp shard]

let me print the locations and see real quick

it's getting the same location as the client so it does seem to work

well, it gives the same location

so, it should be in the right place, but it isn't seen by the other clients for some reason

[cursive steeple]

Alright then since it's a preexisting comp, it's an exception, thanks for the confirmation

There's still the part where you branch on the locally controlled pawn, which obviously stops other clients from spawning the effect, right? Or that was just disconnected/checked for debug or?

[crisp shard]

that event fires every time there is a "fire" from a weapon and it does that multicast but i don't want the player that fired the weapon to hear/see anything, so i had that check to make sure it only fires on OTHER clients

[cursive steeple]

Nvm my bad im tired, ignored the negation

Yeah

[crisp shard]

it legitmatley fires and is getting the correct location/etc im not sure why i can't see or hear anything from other clietns

[cursive steeple]

Im out of ideas currently (sorry), but if you figure it out soon, I'd love to know the cause

[crisp shard]

thanks yea, not sure why it's not working. it's firing, and the locations are the same, and im doing legitamtely the same kind of logic on another bp and it works fine. but i just can't see this VFX on other clients. not sure if doing it on the characters would be better, but i really don't think it would matter, as i would do the same logic

[thin stratus]

Did I understand correctly that the multicast prints fine for everyone

Or does it not even reach other clients

[scarlet radish]

I'm spawning an actor using a blueprint (authority switch), the actor only spawns on the server and doesn't spawn on any clients, what am I missing here?

[lost inlet]

the actor is not replicated then

[scarlet radish]

I have bReplicates = true;

Is there anything else I need?

They replicate correctly if I spawn them in the editor, just not at runtime

[chrome bay]

relevancy perhaps? How far away is the client from where you put it

default relevancy distance is 150M

[scarlet radish]

Stood on top

[chrome bay]

is it actually spawning though?

[scarlet radish]

It's spawned on the server (top left)

[chrome bay]

Can't see anything on either screen

[scarlet radish]

All the items are all over the floor at the top

[chrome bay]

oh right, yeah

Are they blueprints of your C++ class? I'd check the BP has replicates checked

[scarlet radish]

Better view

Purely c++

Things spawned in the editor are replicated (the little apple)

[chrome bay]

are they physics objects or something?

IDK, something is off

[scarlet radish]

They have physics yea

ikr

[chrome bay]

I suspect then, they are spawning on the client then immediatelly getting yeeted by collision

Do you have replicated movement turned on?

[scarlet radish]

yes

[chrome bay]

Cus if not, the two sims will diverge

No idea then.. I'd start breakpointing

[scarlet radish]

I always get stuck on shit like this

Random bugs no one has ever heard of lol

[chrome bay]

It'll be something obvious

[scarlet radish]

It always is

This is the blueprint I spawn them with

[chrome bay]

What does ConstructItem do?

[scarlet radish]

NewObject<UItem) I believe

Just creates the object

[chrome bay]

Cus atm the only part of that which is actually replicated is the spawning of that actor

[scarlet radish]

OOHHH

It's being spawned, but the properties are replicated, so I cannot see it

Because the model hasn't loaded

[chrome bay]

ye

ConstructItem looks a bit odd tbh

[scarlet radish]

Every dropped item has an item on it

[chrome bay]

Problem is, that won't replicate

Certainly not out of the box

Can't a dropped item just store a reference to the class of item? Why does it have to have an instance of it?

[scarlet radish]

Because it has properties specific to that item

Durability, stack size

[chrome bay]

That's fine but that all lives in the item class

Also are those items data assets? You don't usually make isntances of data assets

The point of them is they are static data

You jsut use them directly

context will not be given

[queen escarp]

hey im trying to destryo session when the "host leaves"

[chrome bay]

well now you ruined my joke

[queen escarp]

it works but it also destroys it when clients leave ./&?

[scarlet radish]

My Item UObject has a reference to its static asset, which contains the static info (name icon model etc)

[queen escarp]

"is server" condition is what i want instead?

[chrome bay]

OnLogout is called for any player logging out

So whoever logs out first will kill the session

[queen escarp]

yeah but i dont a check at the end =

switch on authority

[chrome bay]

SwitchOnAuthority will always be true in the Game Mode

It only exists server-side

[queen escarp]

yeah and this wont work either

[chrome bay]

That will also always be true

[queen escarp]

maybe i should check for active player controllers instead ?

[chrome bay]

Use IsLocalController instead

Probably not where I would manage sessions tbh but if it's Blueprint only then meh

[queen escarp]

AYE

[frozen rune]

When I download a megascan, it can be like 20 Gigabytes, will it be that big when I upload it on steam, or will it compress?

[chrome bay]

It'll be cooked and compressed when you package

Megascans includes all the source data IIRC so you can export it all

Also 20GB for one asset lol no thanks

[scarlet radish]

Can you replicate UObjects??

    UPROPERTY(Replicated, EditAnywhere, BlueprintReadWrite, Instanced)
    TObjectPtr<UItem> Item = nullptr;

I have this, but it's not replicating the actual item.

[chrome bay]

Not just by doing that no, they need to be replicated through an actor

[scarlet radish]

That is on my actor

void ADroppedItem::GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const
{
    Super::GetLifetimeReplicatedProps(OutLifetimeProps);
    DOREPLIFETIME(ADroppedItem, Item);
}

And that

[chrome bay]

https://jambax.co.uk/replicating-uobjects/ Bit out-of-date but it requires a lot more than that

Also Instanced has it's own problems RE replication

The key distinction is that marking an object property replicates the value of the property, not the object it references.

Instanced replicated objects had problems with GC last time I checked. Might be resolved in newer engine versions but IDK

[scarlet radish]

I notice you use inline functions in your guide

For GetLifetimeReplicatedProps etc

When do you use inline vs on the cpp file

[frozen rune]

Aight thanks, you seem experienced. Freind request?

[chrome bay]

It's only in the header to make it easier to read in the post, not needed for the actual code

Also it is old

[scarlet radish]

Understood

[chrome bay]

You can skip things like ReplicateSubobjects() and use the replicated subobject list now for instance

[scarlet radish]

I'm replicating my object using AddReplicatedSubObject(Item); and still don't see it replicated 😦

[oblique arrow]

Guys this variables will replicate to a client? im spawning actor on the server and asigning it to this variable and i need to use it on my client

[chrome bay]

Assuming the actor class replicates yes

[oblique arrow]

It is but im still getting null on client

[chrome bay]

Either the weapon class or the actor storing them isn't replicated

Client_BindWeaponDelegate looks hugely unsafe

No garauntee that weapon actor will be valid by the time the RPC is called on the client

[scarlet radish]

Any ideas? i#'ve just been staring at this for 2 hours now..

    UPROPERTY(Replicated, EditAnywhere, BlueprintReadWrite, Instanced)
    TObjectPtr<UItem> Item = nullptr;

virtual void GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const override
    {
        Super::GetLifetimeReplicatedProps(OutLifetimeProps);
        DOREPLIFETIME(ADroppedItem, Item);
    }

AddReplicatedSubObject(Item);

Why is Item not being replicated

[scarlet radish]

bReplicateUsingRegisteredSubObjectList = true;

[twin juniper]

Show the part that the item is not replicated

[steep wolf]

follow jambax tutorials for replicated uobjects

you require special function overrides

uobjects by themselves dont replicate by default

[scarlet radish]

I've followed it

I've also followed the 5.1 replication changes docs

[scarlet radish]

Okay I'm a step closer

How does replication work with data assets?

I have a data asset which contains information about my Item

UPROPERTY(Replicated, EditAnywhere, BlueprintReadWrite)
    TObjectPtr<UItemTypeAsset> ItemType = nullptr;

Assertion failed: Object->IsSupportedForNetworking()

[crisp shard]

Yes it’s printing it says “server” but not sure why I’m not able to see the fx. The function is set to a multicast

[thin stratus]

Only Server?

Shouldn#t it say what you put into the prints

And also print that on everyone?

[crisp shard]

It’s a multicast so when those fire im not sure if what the print says but I’m pretty sure it just does both (depending on who is receiving the event). The client fires false (as designed) but the other clients aren’t getting that multicast event. Unless I’m missing something obvious

For the record. Player fires gun, fire server event, that fires a multicast event that checks the local player controller, which should only fire for the other clients and not the owner/player firing

[queen escarp]

hey, how would i make an object "server side to rpc sound and effects :/ ?

[thin stratus]

And for that same record you made sure that all the RPCs etc. are calling where and when you want via Print Strings?

Server RPC works, and Multicast calls everywhere?

[crisp shard]

Server RPC works and the multicast is printing both on client and server (which would only happen if it’s firing both true and false which would only happen if other players are receiving the event correctly).

[crisp shard]

And yea, the final print at the end of these VFX fire both on the owning client (player firing) and also on “server”

Server as in multicast

It just doesn’t say “multicast” on the prints tho

[thin stratus]

You can't easily do that without being on the Server in teh first place. For the ServerRPC you need to have the local client own the Actor.
To own the Actor, the Server needs to set it as the Owner. I'm sure you know Ownership by now.

If you need this to happen when a Client interacts with the Actor then you need to RPC elsewhere.

[thin stratus]

It wouldn't

It only prints the Player + the Message

E..g Server: Bla

And Client1: Foo

[crisp shard]

Right yea, just making sure

Is the logic I’m thinking correct?

[thin stratus]

So with 2 Clients and Server

It prints 2 times True

And 1 time False

False for the Local Player and True for the SimProxy and Server

[crisp shard]

Yes exactly

But that other client does not see the VFX

[thin stratus]

Can you please debug print teh Location on everyone, as well as DebugDraw a Sphere at the location

You might be not seeing it cause it sits at 0,0,0 caue that component there isn't valid

Or something along the lines

[crisp shard]

Yea I checked this actually and the client and server print the same locations

[thin stratus]

Can you still draw the sphere

Sanity

[crisp shard]

Would this just mean a sphere drawn at locations like here the VFX should print?

Show*

[thin stratus]

Yeah the Sphere should show where the VFX would play

@crisp shard

[crisp shard]

ok finally back on the comp, will test

[queen escarp]

@thin stratus

so basicly this would work right ?

the same logic if i just set the owner ?

but i need to set the owner "server side" *

[thin stratus]

@queen escarp If "Event: Use" calls Server side, yes

But if that already calls ServerSide, then you can just Multicast from there, right?

I hope you see the "problem" in this

[crisp shard]

incredibly, i am seeing the debug on both client and other client. only the owning client is seeing the VFX tho.

[queen escarp]

yeah yeah

[crisp shard]

it makes me feel like the VFX are like not replicated somehow but i know they work just v confused

[thin stratus]

You are just referencing an asset, so that should be fine

[crisp shard]

right, im very confused. is it possible the event is getting dropped/

even tho it's firing lmao

i am testing w latency emuluation at all times

[thin stratus]

RPCs can be dropped if you test with PackageLoss

PackageLoss is something I would only really test with if I want to know if my game softlocks locally

Cause lost packages aren't really "fixable"

It just shouldn't break the game entirely

Ping should not cause it to drop though

[crisp shard]

interesting. so when i test w packetloss i shouldn't expect my game to run like that?

[thin stratus]

But given you see the prints, and even the debug draw, I'm not sure if that's the issue

[crisp shard]

i've been going insane testing w packet loss lolol

[thin stratus]

PackageLoss is a very bad thing

[crisp shard]

yea it makes me very confused

[thin stratus]

Even small percent, like 1-3, are already causing issues

It just shouldn't cause a lockup

[crisp shard]

yea i have it at 1

[thin stratus]

If the game works well afterwards, it#s fine

[crisp shard]

yea ok dope that makes me feel way better about things lol

[thin stratus]

But you NEVER get the VFX

So that's not the problem

[crisp shard]

but yes, the VFX

lol

[thin stratus]

Can you play anything else there?

Anything to confirm that the VFX is not the issue?

as stupid as it sounds

[crisp shard]

well the same exact event is being called on the owning client so that VFX is working itself it just doesn't seem to spawn on other client

should i send the flow of logic real quick?

i should mention, this worked completely fine when i did everything via multicast, but i implemented client side prediction (sorta)

[thin stratus]

I assume you call a ServerRPC on a Client-owned Weapon

[queen escarp]

@thin stratus when setting owner dosent it require me to set the controller as the owner somehow not the chracter right ?

[thin stratus]

And then in that ServerRPC do a Multicast

[crisp shard]

yes

[thin stratus]

The thing is

If you put a Print into the VFX function

And that prints on everyone but hte local client

But you don't see the VFX on the Sim Clients, then something is odd

[thin stratus]

You can use the Character fwiw

Ownership is a chain usually that gets checked recursively up to the UConnection

[crisp shard]

ok well at least i know im not insane, yet

[thin stratus]

It's theoretically also better to use the Character, so Relevancy can take over for stuff like Weapons if the Owner of the Weapon is the Character

I would assume, without testing it, that using the PlayerController as an owner for a Weapon and setting the Weapon to use OwnerRelevancy, might not replicate teh Weapon to other clients anymore

But yeah, it's fine to use the Character as owner

It's just not so common to set an Owner on an Actor that is in the Level that multiple people can use at the same time

Caus then it break

[thin stratus]

I would try some other stuff

Play a different VFX. Or do anything else locally that yo ucan use to confirm that it's generally workign

[crisp shard]

i'll give it a go, and update

[crisp shard]

changed the VFX and works fine on owning client but again, doesn't show for multicast

[thin stratus]

Yeah then not sure atm. I would double check all the RPCs, all the Locations, Print and Breakpoint.

[queen escarp]

if im playing as listen server is it my upload speed or download speed that affects the server ping

its the upload right ? has to be

internet *

[halcyon sparrow]

Hello! I am having this weird bug on a replication shooting event where once a client shoots (and I call Server_Shoot) Even if the Server event is empty the client is kicked out of the session and opens a new level. Does anyone have any ideia on that? or is that somewhere I can post a video of it?
Using UE5.2

[mystic estuary]

It should be both. If you're not fast enough to get the information clients are sending, you're going to wait longer to start handling that information.

[mystic estuary]

You should look at the output log. Most likely it will tell you what the issue is, and what instigates the travelling upon shooting

[queen escarp]

aye okey, and what would ideally be a required speed to be able to host "lag free" *

100/100 250/250 500/500 1000/1000 ?

[mystic estuary]

It solemnly depends on your game. A chess server requires less Internet speed than Fornite.

[queen escarp]

ofc but lets say a PubG game with 5 players

for instance*

[mystic estuary]

Honestly, I'm clueless about the actual servers. However, someone like Cedric will be able to answer that in a better way 😛

[queen escarp]

ah okey, il just wait for an answer from him then 🙂

my contract is running out next month and i got 100/100 today, wich is slow but im not sure if its worth the extra money for more speed,

100/100 works "fine" for everything u need tbh,

[halcyon sparrow]

thank you! It seems that the issue is related to this: Client attempted to create sub-object

[mystic estuary]

What do you mean by that?

I know that you can replicate objects using subobject list, but I don't know what a subobject is

[thin stratus]

Is this via C++?

[crisp shard]

ok so i set the weapon to "always relevant" and that works, not sure if this is the best option but it works correctly now

[scarlet radish]

If I'm using static data assets, how do I replicate those across the network?

[thin stratus]

They replicate on their own via the Path

[queen escarp]

Cedric

got any thoughts on the internet speed thingi ?

[thin stratus]

What are you setting the owner of that weapon to?

[scarlet radish]

I thought they did, but I'm getting a crash saying object type cannot be replicated

[crisp shard]

the player charcter

"self" when i equip

[thin stratus]

What are your Replication Relevancy settings for that Weapon?

[thin stratus]

If you have a DataAsset Type Variable and set it to replicate it should replicate just fine

[thin stratus]

Eh not now, no

[crisp shard]

not sure exactly where i'd find those, is it this section in the bp?

[scarlet radish]

Like this?

UPROPERTY(Replicated, EditAnywhere, BlueprintReadWrite)
    TObjectPtr<UItemTypeAsset> ItemType = nullptr;

class FACTORYSURVIVALGAME_API UItemTypeAsset : public UPrimaryDataAsset

[thin stratus]

If AlwaysRelevant fixes it, then the Actor might not be relevant on the SimProxy Clients

Which is a bit weird

[thin stratus]

That should be fine imo

[halcyon sparrow]

Nop, Blueprint
Again, the server and MUlt event are empty, I am not sure why a sub-object is being created

[crisp shard]

the damage functions all which are within the same blueprint and flow of logic is firing correctly

[scarlet radish]

It might not be the data asset, its failing here

[chrome bay]

Why does it feel like you're still making instances of data assets?

An asset implicitly has a stable name

[scarlet radish]

I don't think its the asset actually

It's the UObject

I incorrectly assumed it was the asset

[thin stratus]

The inly thing I remember for this is either the Validate in C++ returns false or the Actor that you call a Reliable Multicast RPC in doesn't actually exist on anyone but the owning client, e.g. the PlayerController.

Not sure why the second case happens though

or if it still happens

[scarlet radish]

Overriding

virtual bool IsSupportedForNetworking() const override
    {
        return true;
    }

Fixes it, but I feel like its not the correct solution. How can I make sure my UItem is stable?

[chrome bay]

It won't be, but doesn't have to be

[scarlet radish]

So I have to override that function on everything?

[chrome bay]

The only thing you need to do is add IsSupportedForNetworking(), spawn the item on the server, and add it as a replicated subobject. That's it

And I suggest making sure the "outer" of the object is the actor also

[scarlet radish]

Okay thanks

How does AddReplicatedSubObject work with Arrays?

Do I need to itereate through the array?

[thin stratus]

You'd probably add it when you create it

I don't see the need to loop the array if when you add/create the object you could also add it to the sublist

[scarlet radish]

I'm currently using a struct to represent each inventory slot, would this need to become a UObject if I wanted to replicate it?

[thin stratus]

No, a Struct replicates fine

I don't quite get what we are at by now

Are you instancing UObjects and trying to replicate them or not?

Cause the DataAsset shouldn't need this

[scarlet radish]

Sorry, I should have mentioned, that seems to be working now.

I'm currently trying to replicate an inventory

[thin stratus]

So different problem?

Structs replicate fine

[scarlet radish]

Do I need to AddReplicatedSubObject ?

[thin stratus]

The properties of the struct follow the same rules though

If you have UObjects in that struct that aren't assets, yes

The struct itself and any network support asset and type don't need that

[upbeat basin]

Is setting character to use controller yaw and camera to use control rotation the only way to replicate base aim rotation to other clients?

Also, why does giving controller yaw input snaps the character mesh back to it's default rotation value on simulated proxies while it keeps the custom rotation value on server and owning client?

[wanton bear]

In game state, on begin play ive got a branch checking if its the server, then setting a repnotify variable. shouldn't this work as i'm not making a RPC? doesn't seem to.

[upbeat basin]

What doesn't work? OnRep function?

[wanton bear]

replicating variables in game state. im not using rpc, its on beginplay

[scarlet radish]

I have this on a component and it isn't being replicated, am I missing something?

UPROPERTY(Replicated, EditAnywhere, BlueprintReadWrite)
    TArray<FInventorySlot> Slots;

[upbeat basin]

I'm still not sure what is not working, is it not changing the value?

[wanton bear]

begin play -> is server? -> yes -> set w/notify -> only sets it on the server

[upbeat basin]

Where do you read the value on clients?

[wanton bear]

i assume this must be an intentional way that game state works

im printing on the notify and it only prints for the server

[upbeat basin]

Are you setting it to it's default value?

That wouldn't trigger the OnRep on blueprints

[upbeat basin]

Are you adding/removing elements or changing the elements inside the array?

[umbral tangle]

blueprint of shame; how I handle the playerstate not being replicated yet on a player-controlled pawn... anyone have any greate ideas on how to handle it in a better way? afaik I can't a RepNotify on the PlayerState variable, which is what I'd ideally want to have I guess

[wanton bear]

ah that was it, thank you

[scarlet radish]

Changing

[upbeat basin]

A change in an array element object shouldn't trigger the array's replication

[scarlet radish]

What's the solution here then?

[thin stratus]

So, C++ in theory

Cause C++ will have proper OnReps for the build in replicated pointers

In BPs, you can try to move the call to PlayerState itself, cause then you know it's valid

But that depends on the logic

[umbral tangle]

I was not aware of that, thanks!

[thin stratus]

Just keep in mind that C++ OnReps are proper OnReps

Meaning they call Client side only

[umbral tangle]

I can't on this instance, because sometimes the playerstate spawns before the pawn

[upbeat basin]

Actually, now that I'm trying it, it seems like changing the value in the struct seems to be replicated to the clients as well

I do remember I was setting the struct element again to make it replicated to clients but I'm not sure now

[queen escarp]

https://blueprintue.com/blueprint/fn-xe732/

Cedric why is this not working on the client :/ its changing the ownership correctly

its not printing'*

the startEvent / ServerEvent are RPC*

done on an actor*

or anyopne*

[thin stratus]

Why are they RPCs

You are already on the Server in EventUse

If you aren't then you can't set the owner

Owner is only settable on the Server

You must RPC in a Client Owned Actor before calling Use

There is no cheeky way around this

[queen escarp]

gah mkeyy

[haughty ingot]

Does anyone know how to renable property replication when a property has been marked as "DISABLE_REPLICATED_PROPERTY"

[mystic estuary]

Look for RESET_REPLIFETIME_CONDITION macros. The DISABLE one only changes the replication condition to COND_Never. It might be enough to set it to something different, and the property will replicate.

[haughty ingot]

Thank you

[nimble sky]

anyone able to help me understand what i should be adding to my game I have steam advanced sessions plugin i have a UI I can simulate a connection and all is fine but if i want a Dedicated server like so that way a user can choose host local so ppl can play together and if i want to have Dedicated servers that I pay for where players can connect to what do i need to be following im getting lost on the information any help would be awesome

[upbeat basin]

I'm trying to give some relative rotation to the character mesh on runtime. However on simulated proxies, as soon as owning client gives rotation input, mesh rotates back to it's default relative rotation value. Is there a way to disable this behavior? Only solution I could figure out is setting the rotation of the mesh on tick but, well I would prefer one without using the tick

[bitter swift]

In general, if the server Multicasts a function on a replicated Actor, and that actor hasn't been initialized yet on a client due to packet loss, what happens then if the client receives the RPC multicast?

For instance, let's say I have a replicated variable called CurrentWeapon in my character. The weapon is an AActor and it contains multicast functions. What happens if the server multicasts to a client who didn't update CurrentWeapon yet due to packet loss? In this case, CurrentWeapon might be nullptr for the client.

[hollow eagle]

RPCs targeted at objects that do not exist on a client will be dropped.

or not even sent in the first place.

[bitter swift]

Perfect, in that case I don't need to worry about crashes or otherwise

[scarlet radish]

How do I replicate an array that isn't mutated (its children are)

[solar stirrup]

Show code

[scarlet radish]

UPROPERTY(Replicated, EditAnywhere, BlueprintReadWrite)
TArray<FInventorySlot> Slots;

Slots[Index].Item = xxx;

etc

I don't think the UE knows the array was mutated, I need to somehow manage this manually

Or take a different approach

[solar stirrup]

Push Model

But normally it should detect it

[scarlet radish]

I tried that but it didn't work

[solar stirrup]

What does your struct look like

[scarlet radish]

USTRUCT(BlueprintType)
struct FACTORYSURVIVALGAME_API FInventorySlot
{
    GENERATED_BODY()

public:
    UPROPERTY(BlueprintReadWrite, EditAnywhere)
    TEnumAsByte<ESlotType> SlotType;

    UPROPERTY(BlueprintReadWrite, EditAnywhere)
    TObjectPtr<UItem> Item;
};

[solar stirrup]

Is your item a replicated subobject

Also you don't wanna use TEnumAsByte for your own enums

use enum class instead

UENUM(BLueprintType)
enum class ESlotType : uint8
{
  Your,
  Values,
  Here
};

[scarlet radish]

Not sure

Someone said you don't need to mark structs for replication

[solar stirrup]

UObjects do not replicate by default

[scarlet radish]

How do I replicate the UObject on the struct?

[sinful tree]

If the object itself is replicated through the replicated subobject list of some actor, then the reference in the structure would be valid I imagine.

[scarlet radish]

Feel like I'm nearly there

Should my Inventory slot be a UObject instead of a struct?

[scarlet radish]

Anyone ?

[thin stratus]

That's up to you. Struct is fine. Doesn't need to be a UObject.
Unless you need it to be one.

[rancid wren]

I lose control of my pawn after a seamless travel, I am lost on where to fix it.

could i get some help with this?

[fossil spoke]

@rancid wren Most actors are destroyed during travel, including Pawns.

[rancid wren]

i've marked it and it does load to the next level

[fossil spoke]

What do you mean you marked it?

Also the PlayerController has likely lost possession of it.

You may need to repossess the Pawn

After travel

[rancid wren]

marked as in for the getseamlesstraveactorlist

I'd take a look into the possessing

[nova wasp]

my assumption is something that ISN'T being travelled is cleaning stuff up and knocking your stuff out of place

[steep wolf]

do i ever have to do anything for data asset replication

for example softload

or is it fine to just replicate dataasset*

[fossil spoke]

@steep wolf Any package that is referenced from disk is safe to pass across the network as it will be directly resolved.

[steep wolf]

so for example, if i have a UPROPERTY(Replicated) UMyDataAsset* containing some asset references within it, they will automatically non-blocking softload on client if i change it on the server?

[chrome bay]

Any hard references will be loaded when the asset is loaded, always

Replicated references to objects will only be async loaded if net.AllowAsyncLoading is true. Default is false because it obviously adds latency to the networking system

[steep wolf]

hmm thanks

[queen escarp]

hm since clients cant access the game mode

where would i store player deaths ?, for instance my game has 4 players if all die then game over =

where would i best do that logic ?

game state* ?

[chrome bay]

If you need clients to know the number of deaths then typically yeah

[queen escarp]

hm

well if i only want the server to know then how would i do that since clients cant get game mode ?

[scarlet radish]

When does it need to be one?

[chrome bay]

If the client doesn't need to know why do they need the game mode?

[queen escarp]

well when the player dies i have to send the information to the game mode :/ ?

but i cant do that since i cant access the gamemode right

[chrome bay]

But player death should be entirely determined by the Server anyway

[queen escarp]

well yeah, but still i need to send that information to the gamemode :/ ?

[chrome bay]

Yeah, but you're doing that on the Server - so it has access to the gamemode

[queen escarp]

oh thats true

[chrome bay]

Clients don't tell the Server when they died, otherwise they could do that at anytime

Or worse, do it for other players

[thin stratus]

If you want to use one

You are asking a question that has no clear answer

This is completely up to you and how you design your inventory

Either you use a Struct or a UObject. Or something else. Up to what you need.

[scarlet radish]

Is there not a general rule of when one is preferred over the other? I'm quite new to c++ and unreal

If they both work in this scenario

Like what differences are there

[thin stratus]

UObject allows for Inheritance fwiw

[scarlet radish]

I've found so far, that I cannot use them [structs] as pointers, which is causing me problems rn

[thin stratus]

Cause the Struct, even if you inherit, would object slice

You could use FInstancedStruct to wrap the struct I guess, but at that point one could use an Object

[scarlet radish]

Also I cannot use structs as data assets which is a shame

[thin stratus]

Sure but your Struct can have a DataAsset pointer

[scarlet radish]

If I use FInstancedStruct it makes net replication easier than UObjects?

That's the end goal after all

[thin stratus]

Never used it for replicating an Inventory. Jambax added those iirc.

I think most people in the end use a FastArraySerializer for their Inventory

And UObject is probably preferred if you need Items with different properties and function overrides.
While that is also possible with Structs, again they object slice iirc

[scarlet radish]

"Object slice" ?

[thin stratus]

So if you want to be on the save side of features, a fast array with UObjects is probably gonna be a good call.
But you also only really need Structs or UObjects if your Items have a state.
If they are just plain data that never changes and each slot has only that one item, then you could just have an array of DataAssets fwiw.

[chrome bay]

FInstancedStruct would be pretty expensive for inventory tbh

a) it replicates atomically and b) it's really more suited to RPCs than properties

[thin stratus]

struct FItemStruct
{
    int32 SomeInt = 0;
};

struct FItemStructChild : public FItemStruct
{
  bool bSomeBool = false;
};

If you have an array TArray<FItemStruct>, you wouldn't be able to put FItemStructChild into it

You'd lose the bool

So if you need inhertiance like that for your items, UObject it is

[scarlet radish]

Okay so I don't need UObject here, the only problem with structs, is I cannot have the null value when an inventory slot is empty.

FInstancedStruct doesn't even exist for me

And I cannot use pointers apparently

[thin stratus]

Not sure what you mean

You are also never really providing any code

[scarlet radish]

I tried making an "Empty" item, but I'm not sure what combination of & and * I need

static const FItem* Empty;

[thin stratus]

Yeah no

[chrome bay]

Part of the problem here is confusing the item data with the item slot

[thin stratus]

You won't be using pure C++ with UE

[chrome bay]

My slots look like this, in a nutshell:

{
    UDataAsset* ItemDefinition;
    uint32 StackCount;
    UObject* ItemInstance;
};```

[thin stratus]

Naked pointers are pretty shite

If at all you'd use a TSharedPtr<FItem> but even that is wrong for the array

Just TArray<FItem>

And if you need to know if Items[Index] is empty, add a boolean to FItem

[scarlet radish]

So far I have

UPROPERTY(EditAnywhere, BlueprintReadWrite)
TArray<FInventorySlot> Slots;

[thin stratus]

Or if you have an ItemDefinition like Jambax, put that to null

[scarlet radish]

USTRUCT(BlueprintType)
struct FACTORYSURVIVALGAME_API FInventorySlot
{
    GENERATED_BODY()

public:
    UPROPERTY(BlueprintReadWrite, EditAnywhere)
    TEnumAsByte<ESlotType> SlotType;

    UPROPERTY(BlueprintReadWrite, EditAnywhere)
    FItem Item;
};

[thin stratus]

Yeah and what's the problem with that?

[scarlet radish]

For example, I cannot do this

FItem UInventory::GetItem(const int32 Index)
{
    if (Index < InventoryData.Slots.Num())
    {
        return InventoryData.Slots[Index].Item;
    }

    return /* nullptr ? NULL ? FItem::Empty*/;
}

[thin stratus]

bool UInventory::GetItem(const int32 Index, FItem& OutItem) const
{
  if (InventoryData.Slots.IsValidIndex(Index))
  {
    OutItem = InventoryData.Slots[Index];
    return true;
  }

  return false;
}

[scarlet radish]

Hmm I could do it that way

How could this work? this is used as a predicate

bool CanItemFitInSlot(const FItem Item, const FInventorySlot Slot)
{
    return (Slot.SlotType == ALL || Item.ItemType->SlotTypes.Contains(Slot.SlotType))
        && Slot.Item == FItem::Empty;
}

[thin stratus]

Doesn't give you a ref though, but for a ref you'd need to ensure the entry is valid anyway

Your FItem need something to identify it as empty

A boolean, a pointer to a DataAsset

Something that you can set to later check if it's valid

[chrome bay]

Could returns pointers instead and return null

[scarlet radish]

I can't use struct pointers right?

[chrome bay]

So long as you don't expose to Blueprint you can

[thin stratus]

Struct Pointers are fine. What I meant earlier is that you shouldn't do new FItem()

At least not without using a SharedPtr

FItem* UInventory::GetItem(const int32 Index)
{
    if (Index < InventoryData.Slots.Num())
    {
        return &InventoryData.Slots[Index].Item;
    }

    return nullptr;
}

You can do this fwiw

But again, not usable in BPs

[scarlet radish]

How about something like

// FItem.h
bool IsEmpty() const
{
  return ItemType == nullptr;
}

ItemType being

UPROPERTY(EditAnywhere, BlueprintReadWrite)
TObjectPtr<UItemTypeAsset> ItemType = nullptr;

[thin stratus]

Yeah I mean that's what I suggested 2-3 times now

[scarlet radish]

I based it on this yep

[thin stratus]

Yus

[scarlet radish]

I wasn't implying it was my idea, was just showing relevant code to double check we were on the same page

[chrome bay]

If this is how it's going, why can't the inventory slots just be a TArray<FItem> instead of needing a wrapper type?

Just index into it using the enum

[scarlet radish]

Because inventory slots have the slot type too

HEAD, PRIMARY, OFFHAND, CHEST etc

[chrome bay]

But those slots always exist right? They just might be empty

Or can you have more than one etc. of each type

[scarlet radish]

You could have more than one, an inventory could take any shape

2 days and we made it

Okay great, so my next issue now, is.......

I have an Equipment component, that updates when the Inventory changes (via events)

But Equipment is a client side component, Inventory is a server side component, so it doesn't receive the neccessary events.

I feel like I could fire the event from the OnRep function, but I need to know the index that was updated

[scarlet radish]

🫡

[thin stratus]

That's what the FastArray stuff is usually helpful for

cause you get per element callbacks

Not necessary but helpful

[meager spade]

@chrome bay are your item instance replicated?

i highly recommend FAS for the callbacks on client side

[lilac lance]

does SetActorLocation Replicate in c++ or do you need to set up an RPC for that?

[solar stirrup]

Has to be done on the server, then yes

I think you need bReplicateMovement enabled for that

not entirely sure

[lilac lance]

Im just changing the position of a static actor (e.g. barrel, chair, table)

[solar stirrup]

Actor needs to be replicated

And it needs to be movable

[hollow brook]

I am dealing with the following issue:

• On a server, I generate tiles. All the tiles are stored in a TArray: TArray<FMyTileStruct> Tiles which is pretty huge (30k+)
• When a tile is generated, an Actor that replicates is spawned (Tile Mesh is spawned on Server & Clients)
• I have a mechanic of Building for clients, which works as usual, you pick a building to build, camera zooms out and you are presented with a trasparent preview of the building position
• The color is Red or Green depending on if you can build on that tile or not
• This is resolved via checking the TArray of Tiles, if the Tile at that position is "free" (so no collisions checks etc)

On server, this works fine, but on client, I would need to replicate the Tiles array from Server to Client, which is not a great idea as the Tiles array is pretty huge (would need to chunk it). Also I am not a fan of it replicating realtime. So I was thinking about using a Server RPC call from Client that would work like "Is this tile free?". However, with this approach, there would be a slight network lag, for example if you would move the building preview to a new tile, you would first need to wait for the Client RPC from Server to tell the Client if that tile is free, which could break the game fluidity.

What would be the usual/standard solution to solving these kind of issues with replication/lag/prediction?

I guess you misunderstood my issue. The issue is, when a Client would want to know, which tile is free or occupied, he would need to send and then wait for RPC telling him the outcome, which would result in a slight lag, as the information presented (green building preview = good, red = occupied) is realtime.

[chrome bay]

Usually yeah, but doesn't striclty have to be

[hollow brook]

I am not using Fast Array. So with that, the entire Array would replicate to clients and I would not need to do the RPCs, if I understand correctly. I'll look into that, thanks for the tip!

[chrome bay]

But it's either usually an actor instance or some existing subobject that stores additional data per-item etc.

[solar stirrup]

Ever since FInstancedStruct released and was made net serializable, my items instances stopped being replicated subobjects heh

The only replicated UObject I have is inventories, since that way I can move inventories around actors without copying the inventory array and having to replicate the whole thing again

(also has the bonus of the new replication condition for subobjects, I can hide inventories from players as needed)

[thin stratus]

If I have a replicated property on an Actor that a freshly spawn, do I have any function where I could set that variable before it initially replicates?

[solar stirrup]

probably PostInitProperties()

afaik that'll call before initial replication

[thin stratus]

Talking about a Struct with "ProjectileData" that is replicated and fed into the Actor when spawned.
One of the values in that Struct can be set from the Actors SpawnLocation.

Hm

[solar stirrup]

Replication is always one of the last things done unless i'm mistaken

So you can set it after spawning the actor

[cobalt pollen]

I know in blueprints you can set properties to expose on spawn. Maybe equivalent in c++

[thin stratus]

The equivalent is a Deferred spawn but that's not what I mean

[cobalt pollen]

Not sure how that interacts with replication

[thin stratus]

The actor already has the variable exposed

[solar stirrup]

Yeah don't need to defer, pretty sure the game loop always runs before replication so if you spawn it and then set data, they're guaranteed to be there when they get replicated to clients

(assuming no prop is a replicated UObject obviously)

[cobalt pollen]

Just grasping at anything because it's rare to see you asking the question instead of answering 😅

[thin stratus]

The problem is that the Actor calculates a Direction from StartLocation to TargetLocation.
When first spawned, that StartLocation is basically the spawn location/actor location.
The problem comes when it respawns after not being relevant for a few seconds.
Cause then it will recalculate the direction but on the Client the StartLocation is now the one where it "respawned".

I want to have a value that remains the initial spawn location that the Server spawned it at, but I need to make sure that it's set before begin play calls

And yes, I could just replicate the Direction itself, but StartLocation is used for a lot of things

[solar stirrup]

If you set it after spawning the actor, clients are guaranteed to have it when BeginPlay() calls for them

It's one of my favorite guarantees, replicated properties (POD) are guaranteed to be replicated when the actor spawns on a client

[thin stratus]

"After Spawning" being PostInitProperties or similar I guess?

[solar stirrup]

Pretty much any time between spawning and replication occurring

[thin stratus]

Does Properties call before Component?

[solar stirrup]

Could be SpawnActor<>() -> MyActor->SetStuff()

[thin stratus]

(PostInitXYZ)

Let's try it I guess

void ACustomProjectile::PostInitProperties()
{
    Super::PostInitProperties();

    if (HasAuthority())
    {
        ProjectileData.StartLocation = GetActorLocation();
    }
}

[solar stirrup]

There's also OnActorSpawned

nvm it's a delegate

[thin stratus]

Was just about to say

I will try this first

If it works I'm fine with it

[solar stirrup]

this should work

pretty sure the engine would init props before replication

makes no sense if it didn't heh

[thin stratus]

It's a weird case, cause the project got NetRelevancy setups later on

So now some stuff that wasn't an issue if the Actor is relevant from start to end becomes issues

.>

[solar stirrup]

oof

[meager spade]

i create the Instance locally, and it gets filled in from the data provided by the FastArray

so i don't replicate instance and fastarray entry

[thin stratus]

PostInitProperties doesn't seem to work, but that more due to GetActorLocation seemingly returning 0,0,0

With the assumption that I need to wait for the Components to be init

So will try PostInitializeComponents

[solar stirrup]

ah possibly yeah

since it's the root component that gives location

the actor lifecycle doc doesn't say when post init props calls >:/

[thin stratus]

:/

[thin stratus]

Works with PostInitComps

Cheers

[burnt hinge]

How can i set the right character ref when i have a multi seated vehicle?

[sinful tree]

Have your seat store a ref to the character that is sitting in it / interacting with it.

[burnt hinge]

okay but i have enter / exit events that use the character ref to play animation and set location etc. i can't use multiple ref's for that. this is getting way too complex lol

it would be easy if i didnt use animations. just teleporting

[crude comet]

Hello everyone! Does anyone know why morph target names (FName) do not exist on the server? I used two different methods (one from USkeletalMeshComponent and the other from USkeletalMesh), none of them are sufficient.
GetMorphTargetCurves and GetMorphTargetIndexMap. On the development build TMap was empty. Are there any other methods to retrieve name on the server? I do not want to RPC names from the client or something like that. It seems that I'm missing some checkbox or something which will allow me to get these names straight on the server side.

[lucid badger]

I must be misunderstanding you because this is not consistent with my experience

Every single time that I spawn an actor or an object and set a value that is replicated I have to use the on-rep not begin play because in the beginplay the value is not yet repped

Like 100% of the time

[solar stirrup]

What kind of value are we talking about

[lucid badger]

Anything. Pointers, ints, structs, floats, bools

That's what I've replicated so far off the top of my head

[solar stirrup]

POD is guaranteed to be there

[lucid badger]

What's pod

[solar stirrup]

plain old data

[lucid badger]

Well that's not my experience

[solar stirrup]

Pointers are special - you replicate a reference to a UObject, the UObject isn't guaranteed to be available on the client

It's weird because that's definitely a guarantee

Another guarantee is that, on a frame when an actor is replicated, all of it’s changed properties will be sent at once, and the client should receive and apply these changes within a single frame (with the exception of unmapped properties). However, there is no guarantee made regarding the order in which properties will be received or the order in which OnReps will be called. Any order is considered an implementation detail that should not be relied upon. If the order of an actor’s property replication is important to your game, you may need to implement OnReps to track which properties have been updated on a frame. After the replicated values have been received and their OnReps called, you can handle the changes in the PostRepNotifies function. You may also need to save certain received values in their respective OnReps until they’re ready to be used.

https://forums.unrealengine.com/t/replication-ordering-guarantees/264974

[lucid badger]

Where/when are you setting the value? If I set something immediately after calling construct or spawn, the object replicates "naked" first

And beginplay fires without the value up to date yet

What you just quoted doesn't say that they're all guaranteed to be there by the time beginplay fires

It just says changes all come together if in same frame

[solar stirrup]

im trying to find the actual place where I got that guarantee

Okay so it's probably better to do it in PostRepNotifies()

instead of BeginPlay()

[lucid badger]

Why not just do it in an on-rep? that's where I ended up

[solar stirrup]

Or that

[lucid badger]

If multiple things need to be repped at the same time I just put them in a struct

And on-rep ig

[solar stirrup]

But the basic guarantee is that when an actor is replicated to a client (initial replication) all replicated properties will be available clientside (except unmapped props)

yeah, just make sure that if you must have everything in your struct arrive at the same time, mark it USTRUCT(Atomic) or override net serialization

I do have on reps call before BeginPlay() sometimes so it's annoying, but yet another race condition to keep in mind working with replication i suppose

[lucid badger]

Maybe this applies if you like spawn the actor WITHOUT replication and then set the values, and then turn replication? So the values are set before? If I set them in the same frame I create the object this doesn't hold true

[solar stirrup]

nah

Replication is handled at the end of a frame

Your game loop generally fires before that

So whatever you do between spawning the actor and the end of your ticks, will (normally) be replicated

No need to disable replication, and for deferred spawning. The only time I'd use deferred spawning is if I need properties set before the actor's lifecycle starts

[lucid badger]

I wish we had a separate term for when the existence of the object is replicating

Like co-spawning or something

Versus properties on it

My understanding is that BeginPlay (on client) is called the moment the item "co-spawns"

And for me that happens 100% of the time before any uprops have replicated

Every uprop is always default value for the class at that moment

And it sounds like what you're saying contradicts that

[solar stirrup]

Nah so

the props are there just probably not set

I need to double check but iirc BeginPlay() gets called when the actor is added to the world

the world has begun play so it calls begin play

You're guaranteed that on the frame your actor got created on the client, they'll have all the (pod/mapped) props

OnReps/PostRepNotifies() will work fine for that

[lucid badger]

What exactly is POD? Just primitive types? int bool float?

[solar stirrup]

yep

numerics, strings, structsm anything that isn't a UObject* generally will be there

[lucid badger]

Yeah that's not my experience

That's why I had to move everything to onrep

Gotta wait for the properties to show up

[solar stirrup]

UObjects require mapping, so while the reference to it might have replicated, it might not exist on the client yet and you'll be waiting for the UObject itself to replicate and be mapped to your prop

[lucid badger]

Because they're not ready yet

[solar stirrup]

Yep you do wanna use OnRep

[lucid badger]

Like FGuids

Are not valid

At the moment of co-spawning

[solar stirrup]

It's just that on the frame your actor begins play, the props will be there. Maybe not on begin play, but they're right behind that.

[lucid badger]

Oh

Okay I think I was just getting confused by the semantics

[solar stirrup]

Yeah nah like, I wish BeginPlay() got called after props got deserialized

[lucid badger]

By there I just meant like, ready to go

You mean like network traffic wise

They have arrived but are not yet ready

[solar stirrup]

I meant that I wish the engine only called BeginPlay() once the replicated props were set

[lucid badger]

Yeah that'd be lovely

Cramming every value into a struct and repping that seems to work fine though so

btw hwat's Atomic I never seen or used that

[solar stirrup]

Right now it can call BeginPlay() even though the replicated properties are right about to be set on your actor - they are there, they will be set on the same frame as the BeginPlay(), but yeah

Atomic makes your struct always replicate all properties at the same time

[lucid badger]

now I got you

[solar stirrup]

No delta replication

Let's say you have FMyStruct with int32 A and int32 B

[lucid badger]

I thought... that was already implied. I'm guessing I haven't needed this yet cuz I haven't done testing with latency yet

[solar stirrup]

You set A to 5, and replicate that

next frame your set B to 10 and replicate that

However, the packed with the update of A got dropped

Your client only receives B's update - your struct is (temporarily) desynced

With Atomic, if you set A to 5, the engine will send A & B to the client

If you drop the packet, you drop the whole struct update

[lucid badger]

Oh hum

Yeah that makes sense. I didn't know it was only diffing

[solar stirrup]

Saves bandwidth especially on large structs

[lucid badger]

But I can't picture a situation where I am replicating changes to a struct where I'd be okay with some changes being dropped

[solar stirrup]

let's say player scoreboard stats

kills, deaths etc

it's fine if the kill/deaths/points get desynced temporarily most of the time

[lucid badger]

So it'll just get fixed on an upcoming frame? Without requiring another change?

[solar stirrup]

yeah replication is "eventually consistent"

the server sends update after update and the client will "eventually" be synced

[lucid badger]

I can't remember the specifics now but i Had a situation where a value was getting desynced and would only correct when the value changed again on the server

Like the client changing their value to a wrong value didn't get the server to correct it until the server changed its value

[solar stirrup]

If the client modifies the local value, it's on them

[lucid badger]

Ah

[solar stirrup]

They'll be desync'd until the server sends another update, it won't if it doesn't know it needs to

Which happened in your case

[lucid badger]

But when it's the other direction it can tell

And eventually get it right

[solar stirrup]

Yeah iirc clients send acknowledgements of property updates they receive

If they don't receive a property update, the server will send it again

[lucid badger]

good stuff thanks

[solar stirrup]

Or of course if the server's value gets updated again

[lucid badger]

That Atomic thing was probably going to cause some truly nightmarish bugs when I started testing with latency Although I guess I'm usually changing the whole struct at once in my current uses but still

[solar stirrup]

Latency isn't the issue

It's packet loss

If you modify both A & B in a non-atomic struct, it'll send both props in one update

[lucid badger]

sure

[solar stirrup]

So you're rarely gonna notice a bug if ever

If you modify A but wanna make sure your struct stays synced, then yeah make it Atomic

[lucid badger]

Yeah I'm not taking any chances. If the struct is meant to sync as a unit then I'm putting Atomic just as a best practice

[solar stirrup]

Weigh the pros and cons when you do that, if your struct is huge you're gonna be sending a big chunk for every potentially minor property update

[lucid badger]

That's what I mean. For the structs where the whole struct represents a set of data that changes all at once, i.e. where the Atomic addition wouldn't change what's getting sent because it should be getting all changed together anyways

I don't have any structs yet where I'd be changing singular values in a frame

But to protect if I accidentally do that without thinking

Boom, atomic

[solar stirrup]

[weak copper]

Someone should remake Front Lines Fuel of War... and let me be part of it.

please 🥰

[quasi tide]

See I would - but that game was extremely boring to me.

[weak copper]

first game with full drones in multiplayer ... RC bomb car RC attack helicopter and RC mini gun tank... the multiplayer was way ahead of the curve before BF3 and COD and i believe it was 32 player?

and fight the chinese ...

[rocky kestrel]

Hello! I have online game that worked well with 20 players on server but on playtest with 60 players servers started lag (delayed movement, shots, etc) what things could help and is there any way to simulate 60 players on server on backaged build?

[fossil spoke]

Use the profiling tools.

Identify areas that are causing performance bottlenecks

Optimize those areas

Profile again and start the process over until you reach your target performance metrics

[dusty river]

Blueprint: Is there some general way for a client to execute some logic, then tell the server to multicast it to everyone but the client who called it?

Would it be absurd to pass the player controller who called the RPC as a condition to check when performing the multicast function?

[twin juniper]

Where should i put my inventory in an average multiplayer game, PlayerState or PlayerController?

[quasi tide]

No

[quasi tide]

Depends on the game and your goal. Should everyone be able to see the inventory? PlayerState. Should only the owning client see it? PlayerController

[twin juniper]

If something like PUBG then PlayerController right?

[quasi tide]

That'll be fine. Or the Pawn.

[thorny saddle]

what is the best way for pass actor from client to server?

[quasi tide]

What do you mean? If it exists on both, then just do a server rpc with the actor reference

If it doesn't, then you need to tell the server to spawn it and have them match up with NetAddressable shenanigans (if I recall correctly)

[thorny saddle]

void UPCSBuildingActorComponent::Server_SpawnFromPreBuild_Implementation(AActor* Target)
{
    blah blah
}

something like this ?

NetAddressable what is this ?

[quasi tide]

Yes, something like that.

[thorny saddle]

im in ue4

[quasi tide]

Okay

[thorny saddle]

its won't work btw

server can not find the refrence