multiplayer

[winged badger]

like right after spawning

[jolly siren]

Hmm I never knew that they were replicated in the same bunch

[winged badger]

95% sure it would work that way

if not you can OnRep_AutoEquip

it does make sense that the Actor would send all its replicated properties in initial bunch that spawns it

otherwise, you'd have chaos with what arrives when

[jolly siren]

Right, it makes sense. I'm just not sure if that is how it works

[winged badger]

i can't say i explicitly tested a scenario where i spawn something, then immediately set its variables

but that is probably because i never had trouble relying on it

as for other cases of multiple variables replicating together, they will replicate in DOREPLIFETIME order

that i did test

[jolly siren]

@rough iron Can you confirm that setting a replicated property directly after spawning that actor will always result in that property and actor being replicated in the same bunch?
In other words, can you rely on the values of replicated properties in BeginPlay?

[wary wyvern]

Hey guys, I'm trying to spawn replicated actor, which has a replicated child actor inside. That child actor spawns on server but does to appear on client. What my be the problem?

[winged badger]

it is easy enough to test @jolly siren

just set the bool to not its default value, breakpoint BeginPlay and read it from there

(you'll hit twice, you're interested in one with ROLE_SImulatedProxy)

[jolly siren]

Right, yeah I know. It's the intermittent issues I'm worried about. But I'll test with lag

[rough iron]

@jolly siren not 100% sure but it all depends how much you need to replicate, if the netcode decides to chop all your data in smaller parts some will comein later, I remember that exposed on spawn values are valid in BeginPlay, others I wouldn't rely on it.

[winged badger]

NetDriver shouldn't send any Actors before it evaluated the entire traffic for that frame

[jolly siren]

Hmm okay, it seems like it isn't common knowledge then if it is true.
I would think that if the bunches were chopped up, they would be reassembled before UActorChannel::ProcessBunch

[winged badger]

it is my current understanding, ExposeOnSpawn also need to be set under the hood

before the blueprint construction script runs

but i never found the time to read the entire net code

[jolly siren]

Okay, just read a long write up by an Epic dev.
Answer: They try to ensure that BeginPlay is called after replicated properties are received. But it is not guaranteed in all cases.
And we should use PostNetInit instead.

[jolly siren]

Both UT and Moss's Twin Stick Shooter example have places where Client rpcs are called immediately after spawning a replicated actor on the server

hmm

[winged badger]

does your FActorSpawnParameters have something related to PC as the Owner ?

[jolly siren]

No, I don't set the owner with FActorSpawnParameters. I am setting the owner to the Character within GivenTo

So really it looks like this

AGun* NewWeapon = GetWorld()->SpawnActor<AGun>(DefaultInventoryClasses[i], SpawnInfo);
NewWeapon->GivenTo(this, i == 0);

void ABaseGun::GivenTo(APortalWarsCharacter* NewOwner, bool bAutoEquip) {
    ensure(NewOwner);

    Instigator = NewOwner;
    OnRep_Instigator();
    SetOwner(NewOwner);
    MyPawn = NewOwner;
    PrimaryActorTick.AddPrerequisite(MyPawn, MyPawn->PrimaryActorTick);
    ClientGivenTo(Instigator, bAutoEquip);
}

void ABaseGun::ClientGivenTo_Implementation(APawn* NewInstigator, bool bAutoEquip) {
    Instigator = NewInstigator;
    SetOwner(Instigator);
    MyPawn = Cast<APortalWarsCharacter>(Instigator);
    PrimaryActorTick.AddPrerequisite(MyPawn, MyPawn->PrimaryActorTick);
}

[thin stratus]

As long as the Owner is set before you RPC it should be fine

[jolly siren]

So the client rpc can't beat the actor (AGun) replication?

[meager spade]

https://gyazo.com/e93af512afaee5d7bdacbae26348834c

anyone know how i can make the muzzle flash more conistent looking

it plays on the remove client longer than it should

remote*

[bitter oriole]

Can't really say without knowing more

[meager spade]

so the muzzle flash is a GA cue attached to the muzzle of the gun

when i fire local is fine, muzzle flash plays properly, on remote the muzzle flash carries on for quite a while

before stopping

and looks really odd

after i stop firing*

think ill handle the firefx outside of GAS

it seems to be hit and miss on replication times

[winged badger]

@jolly siren you can't call a client RPC on it before you call the GivenTo, as it has no NetOwner at that point

[jolly siren]

@winged badger ClientGivenTo is called within GivenTo after setting the owner on the server

[winged badger]

it didn't look like that from your first snippet

you spawned it, then called ClientGivenTo directly there

[jolly siren]

sorry, yeah the 1st snippet was a simplification

The 2nd snippet was meant to show more

[winged badger]

if your RPC arrived before the Actor on the client

your client would DC

[jolly siren]

oh really? I didn't know that

[winged badger]

it happens every time NetGUID resolves into a null reference

multicasting from PC or GameMode

or calling a Server RPC on an object thats no longer there

all result in client disconnecting

[jolly siren]

The same goes for client rpc?

[winged badger]

while i never managed to make that happen by accident

pretty sure it does, there should be no difference from Multicast

(in a way the RPC is resolved, the difference is in to whom its sent)

i did have the situation recently with InventoryItem (ActorComponent) with no cooldown - result was if you spam fast enough when your stack is 1 server would destroy the component, and client would send another RPC before it got that information from the server

which would result in attempting to call a function on a component that was no longer there and client disconnecting

[jolly siren]

ahh okay, yeah I think I'm going to remove the rpc for now

[twin juniper]

Does anyone have jitter when walking on a terrain in multiplayer that they don't have when walking on flat ground?

[meager spade]

maybe you need to adjust the replication settings

in the CMC

to make it smoother

[twin juniper]

How?

[meager spade]

think there is some smoothing settings

or something

not get editor open atm

https://gyazo.com/b1263fb05a306a1afd7a3df9e07b7dc6

maybe need to increase replication frequency?

lots of things can cause jitter

[twin juniper]

It seems like it may have something to do with vehicles. I have AWheeledVehicle pawn, it replicates fine but it seems to get very jittery

[jade gazelle]

Is it advisable to replicate a timer from server to client or would it make more sense to just set the timer on server and then simultaneously set a timer on the client via RPC? The client timer is just for UI purposes, there’s no functionality on the clients end

I guess what would be the least expensive from a bandwidth perspective is my question

[jolly siren]

I have my character's mesh pose not ticking on the dedicated server. Therefore, when I drop weapons they come from the tpose location instead of where I really want to drop them from (the animated location). Is there anyway to tick the pose for a single frame before dropping the weapon on the server?

I thought calling RefreshBoneTransforms would work, but it's not

[opaque forge]

What can a cause of getting this error when trying to replicate functions be? 1>C:\Users\Sam54123\Documents\Unreal Projects\TVStudio\Intermediate\Build\Win64\UE4Editor\Inc\TVStudio\VideoSwitcherComponent.gen.cpp(47): error C2511: 'void UVideoSwitcherComponent::ServerSetInput(const TScriptInterface<IVideoSystemInterface> &)': overloaded member function not found in 'UVideoSwitcherComponent'

Full code: https://pastebin.com/mjQ7pQzF, https://pastebin.com/zfZpR5gn

[sharp pagoda]

const TScriptInterface<IVideoSystemInterface> &input
TScriptInterface<IVideoSystemInterface> input

Signature mismatch

[opaque forge]

I get rid of the & and it complains about a signature mismatch though

[sharp pagoda]

const

[opaque forge]

void UVideoSwitcherComponent::ServerSetInput_Implementation(TScriptInterface<IVideoSystemInterface> input)

That still seems not to work

1>C:\Users\Sam54123\Documents\Unreal Projects\TVStudio\Intermediate\Build\Win64\UE4Editor\Inc\TVStudio\VideoSwitcherComponent.gen.cpp(40): error C2511: 'void UVideoSwitcherComponent::ClientSetInput(const TScriptInterface<IVideoSystemInterface> &)': overloaded member function not found in 'UVideoSwitcherComponent'

[sharp pagoda]

void ClientSetInput(TScriptInterface<IVideoSystemInterface> input);

Same issue

This time for the client RPC

[opaque forge]

?

This is my first time networking btw

But to my knowledge I followed the wiki exactly

Obviously swapping function names

[sharp pagoda]

It's just the same issue with the server rpc function, you have a signature mismatch in your client rpc

ClientSetInput_Implementation

Change the parameters of that to not be const ref

[opaque forge]

It's not

void UVideoSwitcherComponent::ClientSetInput_Implementation(TScriptInterface<IVideoSystemInterface> input)

I fixed all of them at the same time

[sharp pagoda]

"UVideoSwitcherComponent::ClientSetInput(const TScriptInterface<IVideoSystemInterface> &)" (from your error)

Are you sure?

[opaque forge]

new code: https://pastebin.com/R9mzJjwW

[sharp pagoda]

What's the error?

It can't be the same thing

[opaque forge]

It looks the same, I haven't changed anything since I posted that, but here's the whole compile log: https://pastebin.com/vHx0aABg

I may have missed someting

[sharp pagoda]

Line 38 use GetOwnerRole(), there is no Role since this is a component, not an actor

[opaque forge]

Is that the cause of the entire fault?

[sharp pagoda]

Might be, hard to tell if the other errors are false positives or not

[opaque forge]

Well, it's not compiling. Not intellesence's falt

[sharp pagoda]

New error log?

[opaque forge]

https://pastebin.com/67zhdeqe

[jolly siren]

https://answers.unrealengine.com/questions/859609/view.html

[sharp pagoda]

@jolly siren I would try TickPose() then RefreshBoneTransforms(), you shouldn't need UpdateComponentToWorld

[red ledge]

Hey guys, I was looking into the best way of replicating an inventory

something like the fortnite or pubg ones

my idea was to have a list/database of items with item ids

and only replicate that

not the struct that holds all the info

but what are other ways to have a proper working inventory? all tips are welcomed

I heard something about FastReplication as well but i have no idea what is that, can't find anything on google

[jolly siren]

@sharp pagoda I tried that too, it isn't working

GetMesh()->TickPose(0.f, false);
GetMesh()->RefreshBoneTransforms();

The location I am trying to use after doing that on the server is
Weapon->getMesh3P()->GetComponentLocation()

[hasty adder]

Not sure where to post this but anyone familiar with discord’s richpresence ? Is this at all something to use for dedicated servers so if client sees client b is on dedicated server and requests to join etc or just peers to peer stuffs

[thin stratus]

Pretty sure how you handle the join request is up to you

If it's done right, they send you a request with payload

That payload should be info about the session you want to join

Shouldn't matter if Listen or Dedi server

[hasty adder]

Hmm might have to review my ded server setup. It makes sessions but it’s using nulloss I always get log messages for no session to join etc even tho it works

[jolly siren]

@red ledge replicating IDs is the best way to go imo

[hasty adder]

Unless this is normal for dedicated non steam server..

[thin stratus]

You can make Sessions but with NULL OS they are only local

NULL OS Dedi Servers would need connection over the internet via IP

[jolly siren]

@sharp pagoda Okay so the following is partially working.

So I'm doing the following from character right before dropping the weapon

GetMesh()->TickPose(GetWorld()->GetDeltaSeconds(), false);
GetMesh()->RefreshBoneTransforms();

This seems to start off in the wrong location (tpose location) and gradually get closer and closer to the correct animated location the more I drop the weapons. Any ideas why this might be?

[warm summit]

Hi, does anybody know a good tutorial to make LAN Multiplayer? Because with Advanced Sessions, the LAN Tickbox doesn't really work; I can't join another session in my own network (except for PIE

[red ledge]

@jolly siren thanks!

[jolly siren]

np

@winged badger What is your understanding of how long after SpawnActor a replicated property can be set and still come over in BeginPlay(really PostNetInit)? Is it any property set within the same frame that the SpawnActor was created?

[keen thorn]

@jolly siren I think is is because the pose/animation have a transition time, so when u tick it with certain deltaseconds, it will use that to interpolate the pose to the correct one

@jolly siren try setting the delta seconds to something big like 1.f

cus then i believe its enough time for it to do instant transition to the current pose

[jolly siren]

I tried setting it to 100.f. But yeah using a 0.f delta seconds caused it to not work at all. I'll try 1.f now

[keen thorn]

or 100.f didnt work?

what happened on 100.f

[jolly siren]

It acted the same as with GetDeltaSeconds. I'll try again tho

[keen thorn]

worst case u gotta call it lots of time, but i believe there should be a better way, not too familiar with this functionality :/

[jolly siren]

A lot of times with different delta time each time? Yeah I was thinking of doing it in a loop and incrementing delta time

[keen thorn]

but im not sure if that may work, the pose transition may be hard bounded, gotta experiment i think

[jolly siren]

Yeah with 1.f it is still gradually getting lower

I'll try a really really high number

[keen thorn]

ye, i checked the source code and nothing clamping the deltaseconds

[jolly siren]

yeah even this still has the issue

GetMesh()->TickPose(999999.f, false);

Moving to #animation

[severe nymph]

Anyone on 4.21.1

?

using the createstaticmeshcomponent or instancedstaticmeshcomponent seems to be busted across networking

LogNetPackageMap: Warning: FNetGUIDCache::SupportsObject: StaticMeshComponent

Logging this when testing with multiple clients

animation blueprint wont properly replicate movement velocity when touching the mesh created with the node

Maybe its base movement returning null …. not sure

Its almost like it doesn't know how to cook these actors that call this node anymore

https://blueprintue.com/blueprint/br_ajew9/

Copy of my construction if anyone wants to see if they can reproduce

[hasty adder]

Client> Saves Setup to savegame
Client> Joins Server
Server> Creates PC - Sends RPC to Client to send info back.
Client> Loads savegame data, Sends to Server Values to set on PC server side
Server> Server Sets PC -> PS character setup
Server> Spawns Character - Exposed var from PS for what body parts.```
Will the values for each part of the character be replicated correctly or will it just spawn defaults?

This is my workflow theory of setting up say int for what Head or arms etc should be used as a character, customizable char over multiplayer

[fossil spoke]

If the Server is setting the Meshes it should replicate fine, though typically you would want the Client to update it locally as well for instant feedback.

Also using a Client Side savegame to set values on the Server leaves it open to Players modifying the Save and potentially gaining access to content they shouldnt have access to.

Are you using BP or C++? @hasty adder

You should look into the ClientTravel function and the Options you can append to the connection URL that gets sent to the InitNewPlayer function on the GameMode if your using C++

[hasty adder]

Unfortunately bp so I need to call back when pc is created. Luckily latency is ok because you still have to choose team from a spec state

[severe nymph]

here is what happens when walking across meshes created with that node. To work around create the static mesh components in the actor and set them using the set static mesh node instead of using the create static mesh component node..... unfortunately this means instancing is completely broken over networking until this is fixed.

[hasty adder]

I’m gonna give it a try tonight or tomorrow depending on my wife’s schedule lol.

[meager spade]

yo

LogNet: Warning: UNetDriver::ProcessRemoteFunction: No owning connection for actor BP_WeaponAK47_C_0. Function ServerRemoveAbilities will not be processed.
LogNet: Warning: UNetDriver::ProcessRemoteFunction: No owning connection for actor BP_WeaponScar_C_0. Function ServerGrantAbilities will not be processed.
LogNet: Warning: UNetDriver::ProcessRemoteFunction: No owning connection for actor BP_WeaponAK47_C_1. Function ServerRemoveAbilities will not be processed.
LogNet: Warning: UNetDriver::ProcessRemoteFunction: No owning connection for actor BP_WeaponScar_C_1. Function ServerGrantAbilities will not be processed.

the weapon has an owner though

[fossil spoke]

Are you sure?

Does it have an Owner with a NetOwningConnection though

IE something connected to a PlayerController

[meager spade]

yeah the PlayerState

even if i set the pawn as onwe

owner*

its saying that

[jagged garden]

do IsLocallyControlled check before you call the function

its weird like that

[meager spade]

yeah

i think its running on another client

and thats what is throwing the error

[fossil spoke]

Make sure its not a remote clients version of the actor calling the RPC as they wont have a PC that they own to make the call for them

[meager spade]

@fossil spoke that is what my investigation through locals just confirmed

the pawn calling it has no Owner

so i need to do IsLocallyControlled before calling the Server rpc right?

[jagged garden]

yeah

[meager spade]

    {

        if (!OwningPawn->HasAuthority() && OwningPawn->IsLocallyControlled())
        {
            ServerRemoveAbilities();
            return;
        }

        UAbilitySystemComponent* ASC = GetPawnOwner() ? GetPawnOwner()->GetAbilitySystemComponent() : nullptr;

        if (ASC)
        {
            ASC->SetRemoveAbilityOnEnd(ReloadAbility);
            ASC->SetRemoveAbilityOnEnd(SecondaryAbility);
            ASC->SetRemoveAbilityOnEnd(PrimaryAbility);```

like that?

now im hitting a check if i put IsLocallyControlled

check(IsOwnerActorAuthoritative()); // Should be called on authority

oh i think i need to return out if not IsLocallyControlled

and screw them

hmm now i have no abilities at all

thats cause i !IsLocallyControlled is bailing the server, mmmmmm

so what is the best prcatices

for handling ListenServer and dedicated server?

in RPC calls?

[severe nymph]

RPC calls should always come from an actor with owner set

Has authority or is server branch

Why would a pawn calling it not have an owner?

If the pawn is ai it should be owned by the server ai controller

If it’s a player it should be owned by the player once the ak actor is equipped or gripped(vr)

Set owner on equip

[meager spade]

right

so the player switches gun, OnEquip is called

OnEquip calls GrantAbilities

but that should be server only

so non servers get bailed out, and it calls Server to call that function

fixed it

i was just derping a bitg

[severe nymph]

👍🏼

Awesome 😎

[quartz heart]

in a multiplayer scenario with a dedicated server, is there any way to use Level Streaming such that the server has all of the levels loaded in the world, and all of the actors active, but the clients only have the levels loaded they can 'see' or care about, and only tick actors and get replications for the actors in those levels?

last thing i read about this was from 2014 and basically was 'no if the server loads a level all the clients do it too'

trying to cut down on the number of actors each client has to worry about.

[grand kestrel]

If you're just worried about actors considered for replication then that's what the replication graph is for

Released in 4.20

[fleet fiber]

can anyone explain what im doing wrong here? I have a Pawn_blueprint. In that blueprint I have a G pressed event. When G is pressed the event calls (RunOnServer) which calls (MultiCast) which spawns actor from class. I am not running a dedicated server. Client1, the listen server, presses g and the actor spawns on all clients. Client2 presses g and the actor only spawns on his own client. Why is it not spawning on server? https://gyazo.com/1329ac8dfeb44d0c79d9fe3905ad9a3c

[winged badger]

it is spawning it

just not where you'd expect

[fleet fiber]

lol whut

[winged badger]

as it will spawn under hosts (listen server scenario) or first player that logged in (dedicated server) cursor

sorry

you can't use GetPlayerController[0] in this scenario

[fleet fiber]

when i call this on listen server, it is spawn on server and client, when i call it on client its only spawned on owning client

[winged badger]

your Actor should be spawned server only

and replicated

[fleet fiber]

yes, thats why i use ron on server on client, and then multi cast

[winged badger]

and you should send the HitResultLocation as an input parameter on the ServerRPC

because that will return a different location on each machine

[fleet fiber]

so I have to replicate the hitresult before sending it?

[winged badger]

as it is now

no, click on red event node

add input in details panel of type vector

and connect the pins

that way vector is sent with the RPC

multicasting is a terrible choice here

as any player outside NetRelevancy range, as well as any player that joins later won't have that Actor

[fleet fiber]

Players cant join later so that doesnt matter:P

[winged badger]

it matters for relevancy, and its really bad practice

[fleet fiber]

https://gyazo.com/5d87660c78b9dcd18a2d42b003de6b24 you mean like this with the vector?

[winged badger]

not quite

you plug those 3 nodes into the first server RPC

both server and multicast should have the vector input

is the door replicated?

[fleet fiber]

yes

its stattic mech sompnonent is replicated as well

[winged badger]

that explains why it "works" when server does it

[fleet fiber]

XD

[winged badger]

so

your HitResultLocation is evaluated when Spawn is called

and each machine has a different idea of what is PlayerController[0]

[fleet fiber]

wouldnt the pawn return its own playercontroller ?

[winged badger]

so each machine takes a different location for the spawn

no, GetPlayerController is static

it doesn't use Pawn as context

so on your client PC 0 is its local controller

[fleet fiber]

so im basically returning the listen server playercontroller everytime?

[winged badger]

and on server its the host's controller

when your server spawns a door

it spawns it under its cursor and it replicates, so clients see it where it should be

clients however spawn an additional door wherever unreal figures out their own cursor is locally

and if you are using multi window PIE, that can result in some interesting numbers

bottom line

replicated Actor should be spawned on server ONLY

[fleet fiber]

So multicast is not needed?

[winged badger]

and you need to push the Location (because its dependent on local controller) through the ServerRPC

no, its not

server has no clue where the clients mouse cursor is

ever

or what buttons a client is pressing

unless you RPC the info

[fleet fiber]

so how do I get the local controller?

[winged badger]

you don't need to

your SpawnDoorRPC has vector input

when its called it will evaluate the location locally

and then send the result to server along with the RPC

basically saying "spawn door at this location" instead of 'spawn door"

[fleet fiber]

https://gyazo.com/474bba905fe101dcaf08132d5480d94c

So I made a replicated vector variable, it gets the vector from the hit result, which it sends to the run on server

and this seems to work fine

@winged badger would you consider this a proper set up?

Also, thanks, been stuck on this for days 😛

[winged badger]

almost

you don't need an authority switch

or a variable Vector

otherwise, yes

also, http://cedric-neukirchen.net/2017/02/14/multiplayer-network-compendium/

[fleet fiber]

Yeah I left the switch cause im lazy :P, I thought I'd have to replicate the vector so I made a variable. Gonne try without it.

[winged badger]

it would not do anything, as client setting variable locally wouldn't replicate to others

and clients would overwrite whatever server sent when they press G

the RPC carries location with it now

[fleet fiber]

lulz, Guess I got a lot of bad info on youtube xD. Thanks a lot, now I can finally continue my project

[final thicket]

Hey guys what would you say is the best way to handle knocking back a character in a way that is server authoritative yet also without a noticeable delay?

[jagged garden]

maybe try add impulse

[jolly siren]

Interesting bug found by TheJamsh https://issues.unrealengine.com/issue/UE-67695

[opaque forge]

When I call a net multicast function, does it run on the server as well?

[jade gazelle]

Yes

[fleet sluice]

Interesting bug indeed

[opaque forge]

Is that intended?

Should I make use of it?\

[jolly siren]

yes, it is intended

[chrome bay]

I posted that issue to Answerhub too with code. Got a reply from engine team which says it is a bug, got a guy on it.

General limitation with how the rep layout is generated.

Note that if you manually create a NetSerialize() override, the previous value is correct

[jolly siren]

Ahh okay cool, yeah I came across your udn post on it

[chrome bay]

Ah cool cool. Yeah I'm surprised it hasn't been found sooner.. makes me wonder how many people are using that functionality. I find it really handy

[jolly siren]

The old value with OnRep is sort of a hidden feature

[chrome bay]

I guess the other workaround is to just store a shadow copy locally and update it in the OnRep function, but.. kinda annoying

Yeah for sure

[jolly siren]

I've had issues with it before too. Can't remember the specifics, but it definitely isn't rock solid

[dense spindle]

Someone encounterd FPS problems with 4.21? In our Multiplayer FirstPersonShooter you start to lag when you pass 180FPS...

[chrome bay]

Clamp to 120 :D?

Willing to bet the net driver is just choking on RPC's / data

[dense spindle]

Hehe, well thats our workaround for now, but we arent sure whats going on. You dont want to limit the FPS.

I wonder if someone else has this issue

[chrome bay]

Yeah not ideally. How are you testing it? In PIE?

[dense spindle]

The error isnt in PIE when i understood correct.

[jolly siren]

Looking through my code it looks like I was having issues with the OnRep previous value when it was a TArray. Might have been fixed by now tho

[dense spindle]

Our game can create also Listen Servers, when you play on them the problem dosnt happen. Means it only happens in Online Mode. Lan is fine. Its weird.

Also difficult to find out what is cuzing it...

[chrome bay]

I hope it's been fixed as I rely on that sometimes too haha

[dense spindle]

[opaque forge]

Do server functions have to be called by a pawn or can they be called by any replicated actor?

[jolly siren]

https://docs.unrealengine.com/en-us/Gameplay/Networking/Actors/RPCs

It depends on ownership

See the rpc chart on the link i provided

[opaque forge]

Is there a way to make an actor dropped into the level able to call server functions from the client?

[jolly siren]

https://docs.unrealengine.com/en-us/Gameplay/Networking/Actors/OwningConnections

[opaque forge]

I'm trying to make a very moddable game with replicated components that can be easily put in any actor and I don't want to custom code the player pawn to individually find all the actors that might contain a component and try to replicate them every time the function is called

[chrome bay]

A client has to be the net owner of an object to call an RPC on it. Only way

Whole networking system is built around that concept.

[opaque forge]

How do you recommend implementing a system where a player on a client can press a button (in vr) on an actor and it calls a server function?

What's the best way to pull a variable from the server into a variable in a server owned client variable without always replicating the variable?

[jolly siren]

Without always replicating it? So you want to replicate it once only or multiple times that you have control over?

[opaque forge]

Never mind

[opaque forge]

Does anyone know what to do when the compiler complains about inconsistent dll linkage when implementing GetLifetimeReplicatedProps on a compoent?

My code: https://pastebin.com/cY37mYDx, https://pastebin.com/Mgp46A0h

[jolly siren]

Lots of problems there

should be void UVideoSwitcherCompnent::GetLifetimeReplicatedProps

And you aren't calling Super::GetLifetimeReplicatedProps

[opaque forge]

Just following the wiki

So what am I doing wrong

Shit, I'm an idiot

Didn't read that I wrote UActorCompontnt::GetLifetimeReplicatedProps

[jolly siren]

yeah I just said that

[opaque forge]

I guess the wiki was confusing when it uses AActor as a placeholder for your class name

Now I'm getting 1>C:\Program Files\Epic Games\UE_4.20\Engine\Source\Runtime\CoreUObject\Public\UObject/Class.h(3032): error C2039: 'StaticClass': is not a member of 'IVideoSystemInterface', but I think it's unrelated

[opaque forge]

What are the potential causes of an property outright not being replicated? I have it marked as ReplicatedUsing=[function], it's activated at the bottom of the file, my component and actor are set to replicate, and Blueprint even says it's a replicated property, yet when I update it from the server, my function isn't called and my property isn't updated.

Code: https://pastebin.com/HRb9t97v, https://pastebin.com/BWSCCgs3

Okay, I figured it out. I forgot to put const at the end of GetLifetimeReplicatedProps, which led to it trying to define a new function.

[grand kestrel]

Has anyone ever returned false from a _Validate (RPC)? Maybe ever in the history of UE4? Genuinely wonder where you'd actually handle failed validation in that manner

[sharp pagoda]

Returning false in a validation will boot the client, so you can do so if you believe the client is attempting to cheat based on their inputs.

[chrome bay]

Yeah I've used it once or twice, but very rarely

[grand kestrel]

@sharp pagoda I mean compared to dealing with it in another manner, I know what it's for 😀

Any cheat detection I've put in hasn't been in the validate methods

But I guess I can see some edge cases that might catch an excessively blatant cheater

The real problem is cheaters who do minor adjustments like reducing recoil, hiding foliage, etc

[chrome bay]

I've only ever had one use case for it, but it was pretty unique... client sends through reliable RPC's with a "Handle" - and the handle is always just incremented from the last value. The handle is used to seed RNG, so if a client "knows" a particular handle that generates good RNG for them they could just repeatedly send it. The server verifies the handle first by checking its the "next" one, and kicks them straight away if not

But tbh.. chances of anyone figuring that out anyway are pretty much slim to none

[stray patio]

Anyone here who hase experiences with replicating things on servers with many players (e.g. 64)?

[twin juniper]

Anyone have any movement jitter when walking on hills? or on specific surfaces?

[grand kestrel]

@stray patio Yes, but I'm not gonna sign up to answer any questions, the one piece of advice I'd give is to learn the engine inside out so that you know how to replicate the least amount of information possible and don't double up on things that are already replicated out of the box (this is extremely common with newer devs)

[halcyon abyss]

how do I identify a client on the server_

?

clients can have multiple player controllers on the server

[meager spade]

no

clients have one controller on the server

and one controller local to them

so the server has a copy of everyones controller, and a client only their player controller

[halcyon abyss]

sorry

what I meant

is that I have local and online multiplayer mixed

So they have multiple local controllers

and I wanted to know if there was a way to tell by the player state or the player controller... What client they belong to

I can always of course just send the info from the client to the server so that he knows how they are grouped

I jsut wanted to know if there was a client ID

aready

[lethal depot]

I want to test my build locally between more computers

for some reason I can't join with 127.0.0.1

but using the exact ip address works

(local one)

any idea why? 🤔

[halcyon abyss]

and this issue https://www.reddit.com/r/unrealengine/comments/5y9qw8/making_a_player_join_screen/

how can you do this without having all player controller instantiated?

[jagged garden]

@lethal depot 127.0.0.1 is local machine

so it would only work on that computer

[opaque forge]

are non replicated actors always ROLE_Authority, even on client machines?

[lean river]

no

only server owned actors has role authority even if the actor is not replicated they have authority role as i remember

[opaque forge]

If a scene component is replicated, does it automatically replicate location?

[opaque forge]

If I have an actor with a static mesh as it's root that's supposed to be replicated, do I have to set the static mesh to replicate as well?

[livid barn]

anyone seen the syptom where you suddenly lose movement speed when using acceleration curve in multiplayer as a character approaches maximum speed?
narrowed down the problem, but this issue has been a massive road block for months now for me 😦

More info here https://answers.unrealengine.com/questions/860045/sudden-loss-of-movement-speed-when-using-accelerat.html

[opaque forge]

I have a server variable that is updated a lot by the server (like every frame) but is only used by the clients once and a while. What's the best way to implement a system where the value is only sent to a client if it requests it? The client may not be the owner of the actor.

[livid barn]

@opaque forge of the top of my head, possibly instead of the client directly trying to pull down the value (since it updates so often) have a chain of RPCs or something, whereby the client requests the server to send the value.
Then the server can do a single event for that client with the variable you want updated only then and there.

[opaque forge]

What if the client isn't the owner of the actor?

It's for a media player synchronization across all clients.

[livid barn]

handle it the same way as you would with a widget running a function on the server or something. You need to do a chain of events that goes through the player controller, then to the server

[opaque forge]

Okay

Also, quick question when an rpc has a return value, what's the client's protocol for waiting for the return value to come back from the server?

[livid barn]

not sure off the top of my head. Have you read http://cedric-neukirchen.net/Downloads/Compendium/UE4_Network_Compendium_by_Cedric_eXi_Neukirchen.pdf ? If not thats may get you more int he head space for how data flows from Server to Client and back again

[grand kestrel]

It doesn't work that way

If you want it to send something back use a client RPC

[opaque forge]

Can you send a client rpc to just the client that called the rpc?

[grand kestrel]

Client RPC send to the owning client

[opaque forge]

We're not sure it's going to be the owning client though

The server RPC will be sent from the actor to the player controller to the server

[grand kestrel]

If there is no owning connection you can't send rpc

Need to use replication

[opaque forge]

'The server RPC will be sent from the actor to the player controller to the server'

[grand kestrel]

There are no player controllers on clients for simulated players

The server has one for every player then each player has only their own

[opaque forge]

I know

[grand kestrel]

You really should read the compendium that was linked

[opaque forge]

Each client will use their own

Or if there's a better way to do what I'm trying to do, I'm all ears

[grand kestrel]

The compendium will inform you how to make any solution for anything

[livid barn]

heres an example from my game. I have a widget button which spawns a NPC into the world.

• On the Widget Blueprint when button is pressed... Talks to Player Controller Ref to run event there
• In the player controller ref, the Event "Executes on Server", then it runs an event in the Game State
• In the game state the event Executes On Server. and does all the required stuff to spawn the NPC

From that chain, the client sees the NPC spawn into the level

[opaque forge]

I'm trying manually request a value from the server from on the clients because the server updates it so often, it's impractical to update it on all clients every time

And it's more of a master value that, theoretically, the clients should be individually simulating

We just need to check in periodically that it's correct

And when a new client joins, of course

[livid barn]

do what I did above, but instead of spawning a NPC. The server just sends runs an event on the Player CHaracter that requests the value from

[opaque forge]

But how do I get a return value from that?

How does the rpc system deal with return values?

I can't find much documentation

[grand kestrel]

What documentation, you were linked the compendium, if you read it you'd know how to make it

[opaque forge]

I'm planning on it

[livid barn]

remember, the player characters LIVE on the server. The client only has a puppet that essentially controls them. Replicationwise its up to the server if it wants to send data back to the client to show the client whats really happening witht he player character

[opaque forge]

Can we do it on the player controller?

[livid barn]

so you would store a replicated variable on the player character or whatever, but its ONLY gets updated when the event on the server is trigged becuase the player requests it so

yeah player controller or whatever.

I'd suggest possibly making a widget button that maybe does something to your character which the server does. Just leaning how to request the server to do something from a non owned source will help it be a bit clearer

[opaque forge]

I get the function calls to the server

That makes sense

Just how do you handle the return value in rpcs

And waiting for the server to give you the return value

[grand kestrel]

Again.. you can't

[livid barn]

i think you're in the wrong mindset to what you're expecting it to to.

[grand kestrel]

You're expecting something to happen in a way that it simply doesn't

[livid barn]

think of it this way. How can the SERVER version of your character get the data you want only at certaintimes?

cause when that SERVER version of your character gets it. It'll propogate back down to the client

[opaque forge]

Ooooh, that makes sense

[livid barn]

yeah its one of those weird wacky things unreal does which if you've ever leanred networking programming it throws ya off a bit 😛

[opaque forge]

Will that turn into spaghetti code because of the fact that the component I'm trying to replicate has absolutely nothing to do with the player/player controller, and there might be multiple of them?

[livid barn]

first make it work, so you understand it; then make it better 😃

[opaque forge]

Will do. Also is there a printer-friendly of that compendium?

[livid barn]

the text is pretty big on those PDF pages, you couyld probably just open it up on a tablet or a phone

[opaque forge]

Okay

[livid barn]

what you'll find is that EVERYTHING lives on the server. And if you were to have your own pawn (without the unreal special Movement Controller) you'd notice that when you send control inputs to the client in a high latency environment; it will take a noticeable amount of time before the server actions it and send you the update that the client moved position

anything client side is essentially like "please server, can you make my character do this please?"

[opaque forge]

Yeah

I've done a little bit of networking

I'm actually trying to figure out how to replicate a media player

The server would keep track of the time the media is supposed to be at, but we can't constantly replicate that to the client

Especially since the client will theoretically keep at the same time

But there might be occasional buffering, etc

[livid barn]

you'd probably have a StartTime in world seconds that the media is playing at

so 5min video starts at 12:04:03
and if its 12:05:06 then video is at 1m 3sec into playing

[opaque forge]

Of course

Why didn't I think of that?

The server will have the option to pause it, etc, but we can always math the start time out of that.

[livid barn]

yep pretty much. Saves having to spin an update time each tick

the less you have on EventTick the better

[opaque forge]

That's my problem, I get single minded and try really hard to solve my problems instead of finding ways around them

[livid barn]

oh we all do. I'm STILL banging my head on this charactr position reset problem I've had for months in my game

[opaque forge]

Oof

It's probably an engine level bug

[livid barn]

https://answers.unrealengine.com/questions/860045/sudden-loss-of-movement-speed-when-using-accelerat.html <-- thats it there in its most pure form after whittling down the issue more and more over the months

[opaque forge]

I read that when you posted it earlier, and had no idea how to awnser it

[livid barn]

😭 i hope someone out there sees it and can atleast point me in the direction of a good work around concept or something 😦

[grand kestrel]

Lol that's certainly not an engine bug

[opaque forge]

btw, will using start times like that get screwed up with timezones?

[livid barn]

use UTC clock in unreal. MUCH better

also you can also use Server time to base the position off rather than trying to match UTC time across clients

[grand kestrel]

@livid barn that's not a bug at all, you need to integrate anything that modifies movement into the existing code so the prediction uses it

[livid barn]

so server started 1000 seconds ago, video starts at 1000 seconds... etc

[grand kestrel]

You can't do it in BP

[opaque forge]

How well are the clients synchronized if I use server time?

[grand kestrel]

You'll want to override and copy/paste then modify CalcVelocity in Character Movement component

[livid barn]

@grand kestrel i thought I had done that, as I've attempted to do it in C++ with a custom movement controller and everything. Still not change.

This issue seems to happen occasionally also. Which makes it even weirder. Like I have done frame by frame velocity checks and at some point the server just goes "nah fuck it you're slowing down for no reason at all" then after about a frame or 2 resets the position. The issue seems to happen i think just before the reset

[opaque forge]

Anyway, going to bed. Marry Christmas, if you celebrate it!

[grand kestrel]

@opaque forge if you send an rpc to the client and save the current time, then the client sends an rpc back, the current time when the rpc is received minus the time it was sent gives you the clients ping

And from there you can solve the time offset between server and client

[severe widget]

technically speaking (TimeRecieved - TimeSent) /2

[grand kestrel]

Yeah

It's hard to type on phone

[severe widget]

And just because you've got a custom movement component doesn't mean you're doing everything CMC gives you for free (as part of character movement)

CMC can be like 4 diff components, really

[livid barn]

yeah im reading through the source now

[severe widget]

CMC is like.

wut.

but also CMC was before components could directly RPC

so its not even as good as it can be

[grand kestrel]

Look at the CalcVelocity function

Override it

[livid barn]

but yeah i feel a bit lost from this; as Im not really seeing what BP or C++ wise Im doing wrong as it works for many many frames, and then suddenly shits it self almost randomly. And i cant seem to trace it back to what makes the server go "nah time to use different values"

[grand kestrel]

Also don't use set walk speed

[severe widget]

its not obvious.

[grand kestrel]

Override GetMaxSpeed

[severe widget]

Also yeah, don't do that.

[grand kestrel]

Crap this is a mission on a phone

[livid barn]

SetWalkSpeed is set once. Im not updating it

[severe widget]

vaei its cool I'm here :akppa

imma leave my emote failure.

[grand kestrel]

In that case you can just set it on the component

[livid barn]

if you get a chance have a go at the steps to reproduce the issue that i have in the link above. Like I've been hammering away at this for months trying all sorts of approaches. The symptom is not consistent, despite how I attack it.

[grand kestrel]

I've already modified CMC immensely, last time I made it use a spring algorithm for acceleration, I've also made it move naturally along a spline without setting it along the spline

I'll have a look when I'm home

In four days

Just @ me around then

Or I'll forget

[livid barn]

cheers 😄

[grand kestrel]

@livid barn https://streamable.com/a8570

Found it, that's using the spring algo

[livid barn]

and thats over network?

[grand kestrel]

Yeah

Everything I make is network capable

I don't do single player systems they're a waste of time

[severe nymph]

Has anyone found a way to fix the issue with the add static mesh component node not assigning netguid to the component properly for multiplayer

https://blueprintue.com/blueprint/v5u_cb_4/

Test with 2 clients and server doesn’t send velocity or handle client movement properly

(Name=0x00000112655a4bd0 "NODE_AddStaticMeshComponent-0")
This what's failing the NetGUIDLookup in PackageMapClient.cpp

but its very strange because at first this value comes across
+ NetGUID {Value=23 } FNetworkGUID

it breaks here

    if ( NetGUID.IsValid() )
    {
        return true;
    }```
result
```[16] = {0x00000112298a8800 (Name=0x0000011266e192d8 "StaticMeshComponent0"),{Value=23 }}```

Any insight on a fix would be awesome.... only 4.21.1 bug keeping me from migrating

[grand kestrel]

@severe widget BTW can't you see your PMs?

[next falcon]

Hey guys
so i replicate a Object inside of a Component and i replicate a string inside that replicated Object in cpp and it works fine, but if i create a String in the blueprint child of that object and replicate it, it doesn't work
is there a way how i can replicate Blueprint Vars in a replicated Object ?

[bitter oriole]

So, any reason my local (same machine) client gets 30ms ping - scaling with the server framerate, so basically two frames ?

I'd understand one, two seems weird

[austere veldt]

Hey, do you know if there's a possibility to decrease replication frequency and accuracy with distance? Let's say that I want other players to be in perfect sync within 50m around player, but players distanced at 200-300m aren't relevant so they can replicate even once per 5 seconds just to show their presence?

[thin stratus]

@austere veldt UE4's replication graph system would allow that

It's what Fortnite uses

[austere veldt]

@thin stratus thanks, that's exactly it. So I do assume that I could design dedicated nodes prioritizing different activities in the game like for example melee fights. If fight between players is detected then the actors will be routed to this dedicated node which adjust their update frequency. Am I right?

[versed socket]

I notice that when I want to have a client-triggered action to multicast to everyone in the server (e.g. swapping their current weapon), I find that after a while of doing this over and over I end up with a bunch of dummy router helper methods in my PC or in my GS that are only just passing on the word from Owning client to Server and then to Multicast.

Is this the right way to go about implementing this? It seems to work fine afaik but I still wonder if I'm doing it the "right" way.

[lean river]

yeah you doing "right", however lot of options exist for weapon change..
you dont have any other choice to start this since the beginning of this happening on client..
after you forwarded this to server you can use multicast to trigger animations or you can use replicated state enum variables etc.
but multicast is also fine.. personally im using replicated weapon state so i can fully ignore multicasts

[heady scroll]

What's the "right" way of processing input from clients?

For instance, when a client presses a button I want to set a variable on their controlled pawn, but I want the server to do that as well

Will I just need to do a multi-cast event call and have an extra event for that single set node?

[thin stratus]

Client->SetVariable
Client->ServerRPC
ServerRPC->SetVariable

Multicast only makes sense for fire and forget things

Would rather mark the Variable is Replicated

@austere veldt Not 100% sure how it works but the graph system puts actors into groups

These groups are more or less important

[heady scroll]

Wouldn't just the ServerRPC and following SetVariable be enough?

[thin stratus]

I guess you define rules on which group an actor belongs to

[heady scroll]

Because the owner would get the replicated value back anyway

[thin stratus]

@heady scroll Yes, but then the local client has to wait 2xping to get the update

[heady scroll]

Right

[thin stratus]

or 1xping? well delayed

[heady scroll]

Yeah, 1x ping

But the point stands, if you're playing with people in the US while you're in Europe, that sucks

[thin stratus]

You will feel it even with 30ms

That's why movement for example is simulated on the client

[austere veldt]

@thin stratus yeah, it's a bit complicated and based only on C++, but the idea is great. It's too bad that it isn't documented... What interests me the most is the possibility to dynamically route actors to specified nodes basing on their actions, like for example fist fights

[thin stratus]

I think there is a blog post about it

And that's it

https://docs.unrealengine.com/en-US/Engine/Networking/ReplicationGraph

That's all or so

not sure

[austere veldt]

allright, I guess it's time for experiments then

thank you for your help!

[heady scroll]

Also, as a primarily SP dev, thanks for the compendium @thin stratus

The third about GameStates and that sort of thing is making my life a lot easier in singleplayer things as well 😛

[twin juniper]

"SpawnActor","2.356 ms","100.0 %","0.049 ms","0.1 %","0.0",

Why does spawning an actor take 2.3 miliseconds

[jade gazelle]

Is there any built in functionality in the engine for transmitting specific data from one dedicated server to another? Like if I had players that were “grouped” and they bounced servers to another map, sending info to the new server to let it know to regroup those players?

Otherwise I think I have to use a database solution which I guess is fine, but not idea

Ideal

[thin stratus]

@twin juniper Depending on the Actor, it can be pretty heavy to spawn one :P

@jade gazelle Doubt, cause UE4 is build for games like UT.
While you can also use the whole Engine for tons of other games and setups, it's still limited to that base idea of having one Server and playing one match from start to finish and which then goes to the next map.

If you need Servers to talk to each other, you have to add your own solution

[twin juniper]

@thin stratus I am trying to spawn a new actor every 15 seconds

It's an AI zombie thingy

[final thicket]

Is, 'Set Ignore Look Input' server authoratative ?

and 'Set Ignore Move Input'

[keen thorn]

@jade gazelle theres no built in system, but there are plenty of free plugins to aid do what u need.

[low gate]

http://prntscr.com/lzg55a http://prntscr.com/lzg67s spawn sewer mesh im not appearing by other player how ı can solve this. -sorry for my bad english

[tropic snow]

Anyone know why I can't reconnect to the same server after disconnecting? This is my game info instance:

[hasty adder]

@tropic snow Crazy. I bet you may have followed a tutorial for lobby? Find your network error handling

There might be a branch for is server

You do not want server to destroy its session on error. And if it’s the tutorial I’m thinking of it has a branch true or false both kills the session on error

[jagged garden]

@tropic snow look at events like on logout or something along those lines

if you wanted auto reconnect

[twin juniper]

Anyone here have experience with the steam inventory?

[severe nymph]

https://blueprintue.com/blueprint/v5u_cb_4/

Anyone else having issues over multiplayer with the add static mesh component node?

21.1 regression

This worked fine in previous engines

[opaque forge]

Can I put ustructs in a replicated uproperty?

[glossy moth]

Hello there! So I'm having a issue with replicating the projectile to either client or server (I can see the player shooting but not someone else), I'm new so would really appreciate advice!

[thin stratus]

Why do you have two ServerRPC behind each other?

And what is calling "PlayerFire"

And where are you calling FireProjectile?

[glossy moth]

thats a very good question, i set server fire to multicast and i call the fire function in the rifleBP child blueprint

[thin stratus]

That seems rather wrong

The correct order is:

Input(Client/ListenServer)->ServerRPC (ServerFire)->CheckIfCanFire->Fire

Your base weapon should implement the FireWeapon already

[glossy moth]

okay ive put the fire proj in the master BP

and now it looks something like this

and could you explain the input/rpc/fire a bit more for the beginner? im just very new to everything still and i know how frustrating it can be pointing out the obvious

[meager spade]

your naming is a bit odd for starters, i would get confused calling a Server RPC PlayerFire

[glossy moth]

i noticed that now, its supposed to be a normal event because its the player character that does the shooting action event "presses button" and should go > Server > Multicast IIRC?

heres the correct way i believe

[meager spade]

a non authority can't multicast

so your PlayerFire is invalid

PlayerFire -> ServerFire -> Multicast no need for the authority switch, only issue is your multicasting the projectile and projectile spawning

which is not needed

Server should spawn the projectile and just multicast the effects/fx

the projectile should be replicated and will be visible to all players when spawned on the server

[glossy moth]

So i should put multicast in between reduce ammo and play sound?

Aka after fire projectile

But still in the same exec so to say?

[meager spade]

what does CanFire do?

checks for ammo?

[glossy moth]

CanFire checks ammo, you spawn with 30 default

[meager spade]

so, client calls ServerFire, ServerFire checks for ammo, if true, it spawns projectile, and multicasts the sound and effects

ideally i would check for ammo locally

if you can that value locally which you should be able too

[glossy moth]

Well this is the master blueprint for weapons which is going to have child actors

[meager spade]

PlayerFire -> Check for ammo -> ServerFire -> Spawn Projectile -> Multicast

[glossy moth]

Oo I see

[meager spade]

i mean my projectiles, the server does more sanity checking before firing it

but start with basics first

[glossy moth]

I read your networking document @thin stratus and found that my dumbass didnt replicate the projectile itself in its own blueprint

[normal hatch]

Hey there! I'm here from a guide on how to make a dedicated server from unreal engine. I have successfully made my dedicated server! I want to host my server on Amazon GameLift. I have added the Amazon GameLift plugin. So how would I package my server so it could be hosted by Amazon GameLift? Thanks!

[meager spade]

how can i hide a spawned actor on the server that is replicated from the owner

[tall maple]

How do servers work if I wanted my games servers to purely community run kinda like how valve do it? Can I just package up a server executable and make it public? Is it safe to do that?

[graceful cave]

@tall maple yes

not hard to do if you dont already know how it works

but requires engine built from github source

not that you need to modify anything, visual studio just wont create a server binary otherwise

[hoary lark]

I'm trying to work on fall damage for my game... right now the server is auth over all damage (engine default), this means the client hits the ground and locally nothing happens, then they hit the ground on the server, then the server tells the client they should take damage or die. the delay is a bit jarring and I'm wondering if it might be common practice to implement clientside prediction for receiving damage (maybe only for self-inflicted damage), similar to how clientside-prediction and server-checking of movement is done? would "pro" games ever build a saved state system that could be rewound and replayed for health just like saved moves? or do they just make the client able to apply self-inflicted damage to itself and broadcast up to the server? (does that open an avenue for cheating somehow, even if I limit it to damage events only and not healing?)

[calm plaza]

Anyone have much experience with Advanced Sessions Plugin? Trying to figure out how to best utilize the Search Sessions Filters Struct. Any points are welcome.

[grand kestrel]

@hoary lark apply any effect locally, the actual damage deduction done server side

If you're using CMC it's predicted so the result should be nearly identical

[hoary lark]

My question comes from the fact that if only the server applies damage, death/ragdoll gets that delay

And the change to your health bar but that's not as important

[grand kestrel]

I guess you ultimately have two choices

First, process the death immediately on client, revert it if server disagrees

Second, process the death immediately on client, and notify the server that it received fatal fall damage and the server can just kill the player

[hoary lark]

That's not a bad idea actually

[grand kestrel]

Since you can't really cheat by falling to your own death

It should be ok to take the clients word for it this one time

[hoary lark]

Simplifies things and doesn't create too many nasty loopholes. I'll put that into the team for consideration. Thanks!!

[grand kestrel]

Not for fall damage, specifically only for dying from it

If there's a way to heal other players it could potentially cause an issue if they were healed immediately before hitting the ground but it would be rare and they'd just think they were too late. You could refund any cost of the heal with some good logic

Logic is basically -> client says they died -> saved by that heal on my end -> refund

[hoary lark]

Yeah it makes perfect sense. I can cope with a delay receiving some damage from falling, it's when you land and keep running and then suddenly fall dead it sucks. 😄

[grand kestrel]

Another way depending if it suits your game is to add a tiny stun from fall damage

Though might still not look great

[hoary lark]

It's pretty fast paced, I don't really need to handle it much otherwise... Some local fx from the impact that don't really do anything, and forcable death, will be perfect. I'll have to implement a little logic to prevent double playing fx and stuff but... Liking it more the more I think about

[ocean geyser]

question. im doing server/client travel to connect multiple instances together. i can host on one client, and join it on another by connected to my local ip address just fine. the problem is when i port forward(im 100%positive the port is good) and try to join through my external (11.111.111.111:1234) for example with clienttravel, it does not connect. is there something im missing here? or is it related to me trying to connect with it with that ip/port from a local machine?

[thin stratus]

@ocean geyser Are you trying to use your public ip on the same PC?

Cause I'm half sure that's not working.

Public IP works for connecting from outside of your LAN though

[fleet sluice]

When you try external/public connections between processes running on the same machine, you are "vulnerable" to router hairpinning. The technical explanation doesn't matter since you can't control that, but the effect is that some routers will prevent that kind of connections

Stick to LAN or separate WANs

[meager spade]

how can i get projectile to act smoothly on client?

[meager spade]

https://gyazo.com/10cbfa44f058451122b1c4086a22bff4

you can see the issue here

the frst non wobbly one is local only and the wobbly one is server

[twin juniper]

Is there a way to "Bake" NPCs into a map

so like, they spawn in groups, instead of just one SpawnActor() at a time?

[thin stratus]

Each actor has to be spawned through the SpawnActor code

You can preplace them

Or loop in one and the same frame to spawn multiple ones

[twin juniper]

Is there a way to spawn a group instead of just one? SpawnActor is a very expensive operation

[thin stratus]

Nope

If you have a lot of Actors that have to be spawned, you spawn them at the start and make sure to pool them

[twin juniper]

What is pooling? :o

How do I do that

[thin stratus]

You keep an array of your actors

So basically spawn 100, keep an array of the inactive ones

When they die, you don't destroy but mark them inactive

If you spawn one, you take an inactive one from the pool

[twin juniper]

I know that the engine is capable of handling 1000s of actors in multiplayer, because of what was shown in Fortnite. However, I seem to have issues just spawning a number of zombies on a timer

Oh so you would just spawn a few thousand of them on load, but then move them to where they would be spawned? Instead of actually spawning new ones?

[thin stratus]

Correct

[twin juniper]

I see

That would make much more sense actually

In theory, you could spawn a few thousand actors on load

and then move them as needed

[meager spade]

issue with 1000 actors on load is memory

[twin juniper]

Well, the issue I have is basically trying to figure out how to have different sets of actors in different locations. However, I need to have them based on the zone/city/area they are in.

I tried to spawn them using a timer, however, there is lag whenever that timer event goes off

[meager spade]

yeah cause your instantiating a bunch of actors same tick

[twin juniper]

Large numbers of NPCs, based on different zones, seems very complex to do. Manually placing them wouldn't work either because we need to be able to respawn them if they die

[meager spade]

so either space your spawns

or pool and spawn

you will still get a tiny hickup when spawning the actor, but if you spawn an actor every .1 second it will help reduce the amount

[twin juniper]

How do games like Fortnite spawn all of those items for example?

There's like 3000 items, each I assume is an actor randomly spawned, not even mentioning the chests.

[meager spade]

the map is pre-populated

before clients connect

and all chests etc are spawned during this initialization

[twin juniper]

What about Conan Exiles? They have thousands of NPCs, with unique interactions and quests!

and then the npc's even spawn, but no lag

w<

[meager spade]

they probably use pooling

[twin juniper]

or uh

what's that other game

[meager spade]

for the actual actor and adjust his quest

once unpooled

[twin juniper]

https://github.com/riperjack/ue4_object_pooling

Is this a good example to look at?

For how to do this

[meager spade]

not really my pooling manager is better

[twin juniper]

link me

[meager spade]

and allows for pooling of any object, it is c++ only

o_0

mines not released

but

ill share it as its quite simplistic but good

well any actor not UObject

just to clarify

[twin juniper]

yay

@meager spade where is it? you going to dm me?

[normal hatch]

Hey there! I'm here from a guide on how to make a dedicated server from unreal engine. I have successfully made my dedicated server! I want to host my server on Amazon GameLift. I have added the Amazon GameLift plugin. So how would I package my server so it could be hosted by Amazon GameLift? Thanks!

[jolly siren]

Is PktLagVariance supposed to affect ping?

I'm trying to test very large lag spikes. Looks like PktLagVariance is clamped at 100

I'll see if I can do it with clumsy

[river hazel]

Its a percentage i believe

Anyone have any experience with getserverworldtimeseconds? Im seeing it not sync up properly from server/client

[twin juniper]

Does ARK use object pooling to spawn 25,000 actors within a few milliseconds?

[fossil spoke]

@twin juniper Might be better to ask that on an ARK Discord? Unless there is an ARK dev here with that knowledge its anyones best guess.

[twin juniper]

Is there anyone who has been able to have 25,000 NPCs and mass spawn them on map load?

[jolly siren]

Definitely don't spawn them all at once

[flint plover]

Quick questions. I’m working on a small multiplayer game, 6-16 players. My graphic card fried this week and I’m waiting on a replacement so I don’t have much to do on the computer so I figured I’d start a open conversation about replication graphs. Going to shoot a few questions out and see if anyone feels like answering. Would I even need one for a smaller project like mine? Would I benefit much from it? How hard would it be to implement into an existing project? And what kind of results have you had if you have used it?

I can tell from some of the above conversations, some devs may benefit from replication graphs when trying to spawn increasing amounts of npcs or items

[trail dragon]

Can I replicate arrays and if so is the entire array replicated upon change?

@flint plover Doubtful. Replication Graphs were only introduced to handle 100 players and thousands of replicated actors for Fortnite

It just gives you finer control than "distance" to what is relevant to your players

[meager spade]

you can replicate Array's but not TMap

and yes it will replicate entire array

if you want to be smart you can use a FFastSerializer

[trail dragon]

I should break down and read a tutorial on multiplayer inventories then instead of trying to roll my own it sounds like

[meager spade]

to only replicate what changed

[trail dragon]

Not that tutorials always follow best practices

[meager spade]

FFastArraySerializer < sorry]

[trail dragon]

Can a UObject be replicated if it is created on the server and assigned to a replicated property?

[meager spade]

a UObject would need some stuff added to it to make it suitable for replication

by default they wont replicate

UActorComponent is a good place to look for replicating UObjects as its based on UObject

AActor aswell is

[turbid heron]

ok question i am confuzzled

how do I check if the pawn that has had its variable replicated is actually being possessed by the client?

void Client_UpdateHealthWidget();```

i thought that this would only be fired on the owning client?

[trail dragon]

Aside from your actual problem, it's probably better if the player broadcasts an event when his health is changed, and the health widget is registered to that event and updates it

That way you can create the widget locally only for the pawn you possess and any time that pawn's health is changed the UI automatically updates without having to manage specifically telling the client to update their UI

[turbid heron]

yeah the UI is client-sided, and no I dont want to bind and poll for the health on tick, i would rather an event-driven UI

[trail dragon]

"broadcasts an event when his health is changed" = event-driven

[turbid heron]

but that's what I am already doing, except it is broadcasting on all characters whose health change

my original question is : how can I tell which character the listen-server/client is owning?

ex:

CharacterA (listen-server is possessing this character) damages CharacterB

it triggers a server RPC to change CharacterB's health

it then runs a client RPC to update the widget (this part needs a check if the character is the one the client/listen-server is possessing)

would it be just a matter of getting the character's controller, and seeing if it is the same as the first player controller?

that seems convoluted, there should be some flag for ownership somewhere...

omg

im stupid haha

i was damaging CharacterA instead of hitting CharacterB, so that was pretty awful of me

[turbid heron]

IsPlayerControlled() && IsLocallyControlled()

this is what should tell you if the pawn is owned by the local player authority

(or networked client)

[severe nymph]

Has anyone found a resolve to the 4.21.1 add static mesh node in construction script bug?

a commit or something?

1. create a new FPS template blueprint project.
   2)create a new actor and add the following construction script.
   https://blueprintue.com/blueprint/v5u_cb_4/
2. make sure the collision is block all on the add static mesh component node.
3. test in editor with 2 clients and walk over the actor mesh.

Listen server wont send movement data to clients

Doesn't matter which template you use... its the engine itself. Something got messed up with the GUID on that node.

This bug is literally holding me back from migrating from 4.19.2

[trail dragon]

@severe nymph Is it because each client is creating their own uniquely named instance which aren't linked to each other so anything that tries to replicate it fails?

[severe nymph]

It’s not marked replicated

It’s just a net load on client in map actor with add static mesh component node

Works fine in 4.19.2

[trail dragon]

Right but looking at the error in the console

"could not resolve the new relative movement actor base, ignoring Server CorrectioN"

When the player walks over it, the player controller sets it as the movement base, and it doesn't exist on the server/client (as a same/linked entity)

[severe nymph]

Oh yeah it seems they are both creating their own instance

(Name=0x00000112655a4bd0 "NODE_AddStaticMeshComponent-0")
This what's failing the NetGUIDLookup in PackageMapClient.cpp

but its very strange because at first this value comes across
+ NetGUID {Value=23 } FNetworkGUID

it breaks here

    if ( NetGUID.IsValid() )
    {
        return true;
    }```
result
```[16] = {0x00000112298a8800 (Name=0x0000011266e192d8 "StaticMeshComponent0"),{Value=23 }}```

[trail dragon]

Maybe you can say the StaticMesh component has Replicates Component enabled? I'm not sure if that would cause them to link properly or not 🤔

[severe nymph]

So it’s two versions of the node component

I tried that

It clears the warnings but server still doesn’t send data

It appears something is wrong with GUID on this node

[naive stump]

Guys,
do I need to configure my router for dedicated server to work over steam?
Adding inbound and outbound rules doesn't helps

[severe nymph]

@trail dragon so I would have to now replicate any actors that use static mesh component nodes and set the components to replicate also?

That seems a bit strange considering that if you add a static mesh component to the actor and set the mesh with construction it behaves like it should.

It only has this issue when using construction scripts to add the static mesh component.

[trail dragon]

@severe nymph Is the construction script run when the map starts, I don't remember. I think it also differs in editor vs. packaged builds.

[severe nymph]

Construction scripts are ran on actor compile

Built before init play

[bitter oriole]

On actor creation

Not compile

[severe nymph]

In previous versions it cooks properly in map build

[trail dragon]

They get re-run after a compile (because they get re-created, but still 👀)

[severe nymph]

Not in 4.21.1 it seems

[bitter oriole]

Construction script is basically an extension of the C++ constructor, so it will run everytime you create an object

Compiling a blueprint will recreate it so yeah

[trail dragon]

There were certainly changes to networking between 4.19/4.21 because Fortnite... if the construction script is only run when editing the map (and not before Begin Play) you should see why the server/client think they have different instances?

[severe nymph]

My roads, stairs and sidewalks are all modular using this public var system to construct different types

[trail dragon]

ie: There's a "Stream Sub-Levels during Play in Editor" checkbox in the Level Editor - Play that might make a difference

[severe nymph]

If I replace the node with an actual component it works but I have to destroy components not set by vars

And it’s simply a ton of work to redo my entire map actors

Plus having actors with components just to destroy them is bass akwards

The add static mesh component node is practically useless in multiplayer now

[trail dragon]

Try changing that setting and/or try packaging

See if it works then

[severe nymph]

I’m using persistent map

No Sublevel

[trail dragon]

If you disable "Use Single Process"?

[severe nymph]

According to that debug editor c++ breaks I was doing the node isn’t passing the check. I’m not sure how previous versions of the engine handled the node but something tells me that it was simply overlooked

Primarily because if you tick component replicates on the node it clears the warnings even without actor rep ticked

Which does nothing if the actor isn’t replicated

[trail dragon]

Might be worth a bug report then

[severe nymph]

If I replicate the actor and the component then it seems to work

But I shouldn’t have to do that on a net load on client actor

Static mesh component at that

It’s like saying you have to replicate a landscape

Or a house floor

Chews up bandwidth for nothing

There should be no difference in behavior between a constructor static mesh component and an aactor with a child component when parsed by mapbuild.cpp

Packaged behavior is no different than editor

https://cdn.discordapp.com/attachments/525953948448849920/526247268194713600/PlayerHUD.gif

Dude just slides

Haha 😂

[trail dragon]

You've made an ice skating hugging simulator

[severe nymph]

Apparently 😂

My project is already heavy on bandwidth due to it being VR with transform data for IK

About 5kb per client not including voip

Aiming for 35 clients on dedicated on 100mb fiber

Anything I can do not to have garbage replication data the better

[trail dragon]

To be fair, they only replicate once.

[severe nymph]

I hope epic overlooked this and isn’t expecting us to rep this manually

Maybe they replicated it by default in previous build and ripped it out for fortnite

But that still doesn’t explain why placing a static mesh component in an actor that isn’t replicated yields different results

Vs using the constructor

The client should understand it’s walking on a non movable static mesh component baked into the map

Technically the server should understand

It errors for listen server client as well

So it’s definitely a server issue

Locally everything is fine the movement just doesn’t make it anywhere

[trail dragon]

The PlayerState isn't valid on the client when their Player Controller is first spawned right

If so, how can you tell when the Player State has been replicated and the player is ready to actually set up 😦

[naive stump]

no one?

[severe nymph]

@trail dragon you run an isvalid loop break

Until valid

Or write a c++ function to give you a playerstate valid event

And expose the node to bp

[twin juniper]

@jolly siren Any idea of how other games handle the saving and spawning of NPCs?

How do people spawn 25,000 NPCs, and then save them in the same position, with the same stats, and when the player leaves the game and comes back, the NPCs have the same stats, health, etc

Calling SpawnActor<>() and then setting the stats causes too much lag

[bitter oriole]

Very few people spawn 25,000 NPC @twin juniper

Nevermind saved NPCs

[twin juniper]

ARK does it every time you load into a single player map

I think Conan Exiles does it too

but i dont know how

[jade gazelle]

If I have a widget component nameplate attached to all players that gets updated and set via OnRep, what would be the best way to implement a client side “hide nameplates” option? If I run a function on the client to hide all nameplates that would work until a new person joins and then the function would need to be run again to remove the new persons nameplate

Should the OnRep function maybe check to see if the player has a bool set for nameplates on/off and then function accordingly?

[twin juniper]

Is it possible to spawn 25,000 actors in under a minute?

with zero lag

[naive stump]

@jade gazelle Using OnRep would hide it for sure and it would not need to be hided when a new player joins

[severe nymph]

@twin juniper batch he spawning

Create a spawn manager actor with a que

Spawn with a deviation so it happens randomly between frames. Will reduce the hit

[twin juniper]

That doesn't work, tried it

Calling SpawnActor()

is just not going to be an ok solution

[severe nymph]

I can spawn 50 per frame random delay loop over the first minute and get 10000 no issues

If your not delaying 10 seconds after map load it’s going to hurt

Spawning NPCs during map load is a bottleneck

[twin juniper]

Are these just basic actors? or are they complex?

I need to be able to spawn NPCs

which are complex

[severe nymph]

My NPCs are ai

3rdperson character base

Are you handling with a grouped controller?

Or are you spawning 25000 controllers also

Might want to modify your behavior tree to group your controllers for like NPCs

Cause truthfully 25000 NPCs with a controller each is 50,000 actors

You can use crowd manager or write your own ai controller class to control a group of NPCs either way

@twin juniper

Also if your using some plugin for sql or MySQL and not using vars then that will be much slower

[twin juniper]

Yea

There is no SQL

But it is spawning controllers.

@severe nymph

But I don't think the controllers are the issue

[severe nymph]

You’ll be surprised how much the ai controller instance slows things down

But delay on your spawn manager to allow map load to finish ... spawn actor in loop up to 50 then random deviation on the timer handle to recall the spawn event

You should see much smoother performance

@twin juniper

The actual spawn actor should have a random .2-.5 delay in front of it

Keeps it out of the same frame

[twin juniper]

@severe nymph Could you show me an example of how you are using a single AI Controller to control thousands of NPCs?

How does that work when they are all going to be moving in different locations

[severe nymph]

You get all actors of class set controller

The logic is handled by behavior tree

[tall knot]

Hey!
I'm making a simple multi stealth game and I'm doing the Hosting a session and Joining a session with blueprint. I have a bit of an issue, I'm using "Find Session" and it returns a blueprint session result array, which contains IPs I assume, but I want to let the guest choose from different available sessions in the Joining a session menu, but I can't figure out how to print those values in my menu so the player/guest can choose. Well I kinda did print it to screen, but either I get 0 when I fail to find a session, or 1 if I do. I got those numbers by checking the lenght of my blueprint session result array so I know there is a value there, but I can't print it to screen (with print string).

I'm a bit new to this, so please bear with me.

[bitter oriole]

Sessions aren't an IP address

They're not printable

Dunno how that's exposed to Blueprint, but you should be able to get something like a session name, or the names of joined players, etc

[tall knot]

How would I set the session name? When I use "Create Session" I don't have that option

[severe nymph]

@twin juniper in the controller the only difference between a single ai and multiple would be to loop through the pawns to perform the behavior tree logic

Move to ... attack ... whatever. The services you used in behavior tree should execute for each casted pawn object you pass in

Crowd manager is good for really dumb NPCs but for anything with meat to it your going to have to write a custom class

Also I’d recommend a c++ or nativized class as blueprints are a little slower handling this but it is better than 25,000 controller instances

[tall knot]

@bitter oriole I can get the name of the server who's hosting the game, how do you think I should do this?

[twin juniper]

@severe nymph You do know a Controller can only possess one pawn at a time right?

lol

[bitter oriole]

@tall knot I haven't done this, so I don't know. I use sessions for friend matchmaking, so I never list sessions in a menu.

[turbid heron]

sessions have names

[twin juniper]

@severe nymph Do you know what I mean

[severe nymph]

Yes but your misunderstanding

In your controller

Loop through the actors

All actors of class

Pass in the pawn to behavior tree

Do service logic

Technically it’s not possessing them all at the same time

But once they perform the action the service timer has to execute meaning the controller moves on to the next pawn

[tall knot]

@bitter oriole thank you for your help tho 😃 have good day

[severe nymph]

There are tons of examples on google and YouTube of custom group ai controller classes

Just study what they are doing and work out the logic on how you want to do it for your situation

[naive stump]

Guys,
do I need to configure my router for dedicated server to work over steam?
Adding inbound and outbound rules doesn't helps

[severe nymph]

I’m using a single controller for ai horde logic I loop through all the zombies pass the pawn to the blackboard run the service to move to and move on

Just depends on what you need. If you want them all performing complicated unique behavior then instances will probably be the only way (remember a single controller shares variables across all possessions) so most vars will need to be in your pawn in this setup

@twin juniper

[twin juniper]

@severe nymph yes but the pawn needs a controller to possess it

pawns must have controlers that possess them

otherwise behavior trees dont run

[severe nymph]

lol

I feel like your not reading what I’m saying

You possess them on get all actors of class -> loop -> body -> possess

In the controller

You can have a pawn in the world with no controller

You pass the pawn cast into the object in your behavior tree so it knows which pawn to run the service for

Object key

[severe nymph]

If you don’t want to worry with that then write your service to loop through the actors @twin juniper

Have 1 controller behave as the logic for all actors but still have an ai controller instance on each

Really there is so many ways to skin this cat

You’ll need the subclass of the controller not run the behavior tree in this situation

With 100- 2500 NPCs it’s fine no big deal but if your seriously trying to do 25,000 then your already pressing the cpu and memory to some extremes then throwing a behavior tree and service tick on top

It’s going to be costly

[twin juniper]

You know as soon as you call Possess() on another pawn, it stops the behavior tree on others right? @severe nymph

Like, what you are suggesting just is not possible to do

[severe nymph]

I don’t know what to tell you other than it’s how I’m setup

You have to be mindful of your returns service timers and loop timers

It’s all just timing and math

The using ai controller subclasses with a parent class maybe easier for you to get your head around and use as a “leader” but I can assure you that you can indeed control groups of pawns with a single ai controller by being mindful of your logic and possession/action timers

@twin juniper

Just because something isnt fitting into the way your thinking about it doesn’t mean it’s not possible. It’s just that it’s not “done for you” you have to write the logic all the way from the controller -> possession -> pawn -> service-> action return variable to control the next event call in controller

[twin juniper]

https://hastebin.com/uyobaqawiz.cpp

@severe nymph

So you are saying I should just do this manually?

[graceful cave]

is there a reason bHidden on actors is replicated?

seems like it should be clientside only

[severe nymph]

@twin juniper that’s a great start yes but you would need an event to call it once the previous pawn completely returns its actions

If you want to have a horde behavior then you’ll need to think about a parent controller with subclass for possession

So you can control group movement and actions all at the same time but with a single controller logic

Basically a “leader sensing”

[twin juniper]

@severe nymph I think ARK has a custom "SpawnActor" node as well

[trail dragon]

I highly doubt either of those games are actually spawning 25,000 NPCs

[jolly siren]

If I spawn replicated actor B from replicated actor A, is there anything in the engine that guarantees replicated actor A will be created on the client before B?
A is the owner of B

A is Character in this case and B is a Gun

[lean river]

in theory.. yes..
if you spawn actor a then you spawn actor b from actor a straightforward server would create a before b
but this not means actor b would be created on clients with proper owner of actor a
this is why all of the actor has onrep_owner in case if owner is not replicated at the moment when created on client

[jolly siren]

Well I'm talking about 100% guaranteed, not theory. I'm not really worried about the owner pointer itself

I'm worried about if actor a exists on the client when actor b hits it's PostNetInit

[lean river]

im not sure about this, but i think actor b and actor a both can be valid at same time (or actor b can spawn before actor a ), so order is not guaranteed..
owner rep is the final step in replication which happens after client spaned those actors

[jolly siren]

yeah the problem is that I need to have the values of multiple other replicated properties on spawn on the client. Which is why I am using PostNetInit because it apparently guarantees that

[lean river]

of course actor replication is modified by netfrequency or distance

[jolly siren]

    /** Always called immediately after spawning and reading in replicated properties */
    virtual void PostNetInit();

Set Owner should be valid in PostNetInit, however if the character that Owner points to hasn't been replicated yet then it will still be null

[lean river]

yup its weird but i run in this problem several times..
actor was replicated properly, their base properties also was replicated properly

but owner was not

seems owner is always in late and replicated after that actor is created on client

but sometimes owner was replicated before everything else :D
im not sure postnetinit is a safe point

[jolly siren]

Argh, I'm not sure what else to do besides packing everything into a struct

[lean river]

well for weapons im replicating weapon state
its a workaround but im using onrep function for weapon state and check for valid owner

if owner is invalid im skipping everything

also im checking state in onrepowner function if state is replicated i call what i need to call