multiplayer

[fringe dove]

If an actor is destroyed within an RPC, will additional RPC's for that actor get dropped, or does every RPC need an is pending kill guard?

[meager spade]

GetPing() * 4

thanks for stepping in @hollow eagle 😄

i read the comment like an hour or go ore more

[hollow eagle]

ran into that myself a while back, it's not at all obvious you need to do that until you look at the code...

[meager spade]

but working all day, i am kinda burnt out

so i am forgetting things

[twin juniper]

Anyone online available to maybe help

[summer tide]

@winged badger Hi

[meager spade]

don't ask for help, just ask your question

i wouldn't randomly ping people korvax

[spare mortar]

Are Reliable RPC's guarenteed to maintain order recieved?

[meager spade]

nope

[spare mortar]

RGR that

tnx

[meager spade]

only guarentee is they will arrive

😄

[twin juniper]

well i have some decent experience in this engine but trying my hand at something multiplayer, pretty much trying to get a TPS character to posses a car as well as the client im not sure what i should be doing for the client to be able to take control

[meager spade]

ill give you a hint, a lot of games do not possess the vehicle

instead they attach the pawn to the vehicle, and pass inputs to the vehicle, whilst still possessing the pawn

anyway its 5am and i am tired 😄

[twin juniper]

so not technically possessing the pawn via the node but just passing inputs?

[meager spade]

yes

having a pointer to the vehicle on the character

if its not null, pass inputs to it

[twin juniper]

hope u rest well dude ty for your hint 🙂

[meager spade]

and set the view target on the PlayerController to the vehicle

to use the camera on the vehicle

that is how Fortnite do it, if you ever seen or played it

[twin juniper]

super interesting i goto do some more digging into this!

[fringe dove]

@spare mortar they are guaranteed order within the same actor channel

[spare mortar]

Neat, thanks

[fringe dove]

mostly means two reliable RPCs on different actors could arrive in any order, but on the same actor it will normally be the same

I think when a pawn is possessed it uses the owning player controller's actor channel to send to server though so there may be ordering preserved between pawn and player controller as well

most surprising thing that bit me bad is reliable multicast is not reliable

it has a shorter timeout than the client timeout and can just straight up drop messages

or did in the past

[summer tide]

In multiplayer steam game, does it require a standalone mode as well. The player could use the multiplayer option and play by himself right

[past sonnet]

Hi,
I have a problem.

When I move the client character IT update the animation but I can not see IT on the server

But if I move the server character IT update the animations and I can see IT on the client.

[fervent yacht]

That's pretty normal, server is the only real place.

[past sonnet]

But I should see the client animations on the server I think

[twin juniper]

yeah they can host and play alone

[summer tide]

@twin juniper does it downgrade perf?

[rich ridge]

for example root motion tasks of GAS is entirely constructed over CMC, so if I switch to network prediction and replace CMC then those tasks won't work.

[sly violet]

Hey Slackers. When performing Seamless travel, is it right to expect all Widgets and references created by a character controller and attached to their viewport to persist through travel?

I am experiencing the opposite. Before travel I create a loading screen widget, being travel with server travel console command, and OnPostSeamlessTravel the character controller has no reference to the Loading Screen widget it created before.

Should I have to save that variable to Instance before travel?

[rich ridge]

@sly violet There are only few actors which persistent the travel.. umg is client only so it won't persist.

GameMode, PlayerState and PlayerController are persisted. else everything is Garbage collected so that your main match level plays smooth.

[sly violet]

Interesting. Thank you!

Saving it to Instance then collecting it after travel has solved my issue.

[winged badger]

PreClientTravel is an excellent place to do cleanup, particularly leftover UI

btw

[rose egret]

anyone knows whether ACharacters move toward their velocity in server or they are just move when position is arrived from owning client ?

[twin juniper]

When i move a replicated uobject pointer from an actor component to another actor component ( both of them owned by the same actor that is replicating them through its channel ) some time it works but most of them times become nullptr

[winged badger]

@twin juniper define "move" and what's the objects outer?

[sage creek]

how do i do that

[twin juniper]

@winged badger i'll try to explain

i have a UObject* inside a FFastArraySerializer struct, and a base actor component with an array of that struct marked as replicated
then 2 actor components inheriting from that base actor component . (first component : a, second component: b)
for example if i instantiate that uobject on (a) then add it to the array and mark the item dirty,
then if for example i press X to transfer that uoject from (a) to (b).. i get the Uobject by index, add it to (b) mark the (b) item diry, then assign nullptr to (a) on that index and mark it dirty.

sometime it works but most of the time its nullptr for some reasons

[winged badger]

you're using postreplicatedadd?

[twin juniper]

@winged badger nope to visual that on uumg i just broadcast a delegate from PostReplicatedChange with the index that have been changed

[winged badger]

depending on your ReplicateSubibjects override

Change might fire with null UObject

needs to be checked

i still don't have a clear mental picture of your setup though

you have 2 identical fastarrays on 2 actor components on same actor

the fastarrayitem has a (weak, not weak?) pointer to a replicated Uobject the owning actor itself replicates over its channel

at this point im guessing inventory and quickbar/belt or some such

[twin juniper]

Correct inventory / actionbar,
No the fast array defined 1 time in the base class component im just re-using it in childs
i tried to debug but it's tough it hits
OnSubobjectCreatedFromReplication when instantiating object
and when doing the transfer sometimes it does, sometimes not

bool bWroteSomething = Super::ReplicateSubobjects(Channel, Bunch, RepFlags);
    if (Channel->KeyNeedsToReplicate(Items.IDCounter, Items.ArrayReplicationKey))
    {
        for (auto& Slot : Items.Slots)
        {
            if (Channel->KeyNeedsToReplicate(Slot.ReplicationID, Slot.ReplicationKey))
            {
                bWroteSomething |= Channel->ReplicateSubobject(Slot.Item, *Bunch, *RepFlags);
            }
        }
    }

    return bWroteSomething;

[winged badger]

there is no subobject created from replication

or shou;ldn't be

on transfer

the object itself is not destroyed, therefore it doesn't need to be created again

if you don't have a strong pointer keeping it alive on clients though

the GC will get to it

in my opinion, you are overcomplicating the design

[twin juniper]

depends on the quantity if transferring the whole slot quantity to the other component, i just assign the same uobject ptr to the other component then assign nullptr to the source

i didn't find any easier way

[winged badger]

assigning a null to the UObject pointer does not destroy a UOBject ncecessarily

i would run the entire thing from a single fast array

[twin juniper]

that's what i do the fastarray exists only on the base actor comp

the childs inherit

[meager spade]

can i ask why you are transfering stuff?

rather than inserting and removing?

[twin juniper]

i just this function to empty the slot
Item = nullptr;
Quantity = 0;

[winged badger]

struct FInventorySlot
{
  ESlotType SlotType;
  int32 SlotIndex;
}
struct MyFastArrayItem
{
  TWeakObjectPtr<UObject> InventoryItem;
  FInventorySlot InventorySlot;
  int32 Quantity;
}

pseudocoded ofc

[meager spade]

it feels weird your replicating the object via ReplicateSubObject

[twin juniper]

@meager spade because its slot based, and i don't want to lose the order in replication

[winged badger]

PostReplicatedAdd adds the poitner to the not replicated TArray of inventory items

[meager spade]

but your slot can be a index

[winged badger]

that keeps them alive

in the same component that has the fastarray

post replicated change broadcast changes

and post replicated remove removes a single pointer to the item from the TArray

or if you prefer having 2 UObjects for split stacks

then you don't have to bother with that

[twin juniper]

@meager spade
this is my slot struct

UPROPERTY(EditDefaultsOnly, BlueprintReadOnly)
    int32 Index;

UPROPERTY(EditDefaultsOnly, BlueprintReadOnly)
class UItem* Item;

UPROPERTY(EditDefaultsOnly, BlueprintReadOnly)
int32 Quantity;
    
UPROPERTY(EditDefaultsOnly, BlueprintReadOnly)
class UActorComponent* Owner;

@winged badger i think its the same since the pointer of uobject is handeled by GC

[winged badger]

i never use my fastarrayitems to manage lifetimes

[meager spade]

nor do i

then again i dont replicate the UObject item

i create it client side via the PostReplicatedAdd

😄

[twin juniper]

what if the item has something replicated inside like a value?

[winged badger]

replicating UObject item is okay if there is a reason for stuff to replicate via that object

[twin juniper]

that is why i have to replicate it from server

[meager spade]

@twin juniper i don't so i had no need

[winged badger]

but basically

jugglign several fastarrays

when you can do it all with one

just complicates your life

you just need an enum for slottype in the item to avoid it

that makes you not transfer items from array to the next

[twin juniper]

that would be pain to handle for splitting

[winged badger]

dropping an item from inventory to action bar is just change the enum

no

you create an extra item anyways when splitting

so whats the difference there from what you're doing now

none

[meager spade]

my quickbar/hotbar is a seperate fastarray, but it just holds ItemGuid to slot mapping

it pulls the item using the guid

from the WorldInventory array

[winged badger]

i also allow for local mapping of slots to items

so client can drag and drop and rearrange the ivnentory

without RPCing anything to server

[meager spade]

same in my pet project

client just sends the GUID

when it does stuf

stuff

[winged badger]

indeed

you can even choose not to split the items on server at all

because it makes no difference in the grand scheme of things

if client has stack of 20 rocks, or 4 stacks of 5 rocks

[twin juniper]

i mean i don't get the problem of having the same fastarray in childs its gonna be separated and the same one?

[winged badger]

as long as quantity is synced

[twin juniper]

im not using different ones

[winged badger]

its an extra step

extra step means extra points where your code can break

and you don't really gain anything by it

always go for simplest possible design

with least amount of network actions

what you're using now is not it

[twin juniper]

so let the client handle moving items?

[winged badger]

as you can see you have to add defensive code for your object being destroyed seemingly at random

as long as server enfoces "you have 13 rocks"

it doesn't matter how client slots them locally

its just for his UI/Controls

[twin juniper]

the problem with that is with split u might be duplicating none existing items

[winged badger]

if he throws a rock, the effect is the same, no matter which slot it was in

[twin juniper]

i'll show you a .gif of what's happening in ui

[winged badger]

there are many approaches and nuances you can take

i strongly advise one component, one fastarray

[meager spade]

^

[peak sentinel]

I deleted last question, realized problem is different. Is it normal that this function prints on server?

    if (GetOwnerRole() == ROLE_SimulatedProxy)
    {
        ClientTick(DeltaTime);
        GEngine->AddOnScreenDebugMessage(-1, -1.f, FColor::Green, FString(TEXT("Client Ticking")), true, FVector2D(1,1 ));
    }

[bitter oriole]

Looks like PIE, so it's probably normal because there's only one engine instance

[peak sentinel]

Understood thanks

[bitter oriole]

You should print the current role to your logs

[kindred widget]

That's one reason I like Kismet's version of PrintString if you're going to use Onscreen messages. It'll add the machine's name to the beginning of the print.

[unkempt tiger]

If in my ustruct A, I have a uproperty that's another ustruct B which I want to be delta-serialized automatically by the engine, is there any operator I should override on ustruct B?

For example:

USTRUCT(BlueprintType)
struct MY_API FStructA
{
    GENERATED_BODY()

    UPROPERTY()
    FStructB SomeProperty;

    UPROPERTY()
    FStructC SomeOtherPropertyOfAnotherType;
};

[meager spade]

it should be serialized fine

if its a UPROP

[unkempt tiger]

Yeah but how do I make sure it's delta serialized?

[meager spade]

make your custom serializer

[unkempt tiger]

But a custom serializer would prevent the engine from using delta serialization

[meager spade]

you can make your own delta serializer

[unkempt tiger]

Do I need to override NetDeltaSerialize?

Reading on it, thanks @meager spade 👍

[normal matrix]

Hello! Does Origin rebasing works in multiplayer?
it works

[unkempt tiger]

I'm looking around for the same kind of thing right now, did you happen to come by any examples?

[unkempt tiger]

Wait, given the above example, if FStructA is a UPROPERTY(Replicated) on some actor... and recently only FStructB SomeProperty changed... will only that be replicated by default, without having to write any custom net serializer, delta or not?

[meager spade]

you dont use Replicated inside a struct

[unkempt tiger]

Yeah I meant if I have SomeActor and in it a member UPROPERTY(Replicated) FStructA SomeStruct

[meager spade]

yes all UPROPERTIES will replicate

unless you mark them "NotReplicated"

UPROPERTY(NotReplicated)

[unkempt tiger]

Yeah but I mean

Suppose only FStructB changed (inside of the struct)

Will only FStructB be net serialized during replication?

To save bandwidth?

[meager spade]

not sure how struct serializing works tbh

it probably will replicate entire struct

[unkempt tiger]

Hmmm

[meager spade]

test it?

you have NetProfiler/Insights

you can check

[unkempt tiger]

Yes, I will do that and report back o7

[chrome bay]

I did not I'm afraid

But yeah NetSerialize sends everything you write to the archive everytime

Regular property rep is off when you do that

[unkempt tiger]

Yeah, and I assume UPROPERTYs are also automatically delta serialized if no serializer is overridden

for structs that is

Like in this example ```USTRUCT(BlueprintType)
struct MY_API FStructA
{
GENERATED_BODY()

UPROPERTY()
FStructB SomeProperty;

UPROPERTY()
FStructC SomeOtherPropertyOfAnotherType;

};```

Where FStructA is a UPROPERTY(Replicated) member of some actor

[chrome bay]

Yeah so only the changed items would be sent

[unkempt tiger]

Phew

Btw I found this: FGameplayDebuggerNetPack::NetDeltaSerialize

It's doing some intense stuff and I'm not really spotting any arrays involved

[chrome bay]

Oh interesting I'll check that out at some point

[unkempt tiger]

It's apparently using FNetFastCategoryBaseState pointers for state handling

DeltaParms has an OldState, a writer etc, I'm guessing those states can be cast to the type of the relevant struct?

[chrome bay]

Yeah I think generally delta serializing is something you need a lot of prior plumbing for

[unkempt tiger]

Now that I think of it though, when 'dynamic' properties are mentioned in NetSerialization.h:

and how those can't be handled by the ::Recent buffer etc, he really does mean dynamic types that change in size

If my structs however aren't dynamic - that is, eventually they are broken down to atomic properties, it will fit inside the ::Recent buffer nicely!

Which is very good for my sanity

[summer tide]

How does the loading a saved game works in a steam multiplayer?

[regal sand]

I got some weird breakpoints when building a dedicated server; It did not build, which is odd; as it is based on a template. Can you guys take a look at this error log to see what is wrong with it? https://pastebin.com/FTnJrSmp

[hollow eagle]

However you want it to... steam doesn't dictate how either save games or multiplayer works because it provides neither.

[austere snow]

To my understanding, any code/bp in an actor runs on server and clients, right?

[lost inlet]

that's an incredibly broad question

some actors aren't on the client but are on the server (like the game mode)

[austere snow]

@lost inlet Sorry, i meant like a pawn or a character.

[lost inlet]

well you said "ANY" code, so it that can still go either way

something on a pawn in a tick function that doesn't have authority checks? yeah

[austere snow]

Yea, for example, begin play->print string, will print the string on the client and server.

correct?

[lost inlet]

that specific example, yes

[austere snow]

Technically won't any function/event in a pawn without authority checks run on server and client?

(Sorry if my wording is off, still learning)

[lost inlet]

well input functions won't be run on the server

[austere snow]

Ah, forgot about those.

Thanks for the clarification. @lost inlet

[summer tide]

@hollow eagle I meant what are the steps in loading a multiplayer saved game. Let’s say you invited ur steam friends then played the game then saved it. When you what do you do? Do you meet in a lobby then load the game?

[hollow eagle]

Again, the answer is however you want to do it

You could do it that way

you could save the game to everyone's client, you could save the game just to the host's client, you could pull a halo and only save basic mission progress but no mid-mission checkpoints, you could save everything to some server you control instead of the player's clients. And then there are numerous ways to allow loading in any of those situations.
You're asking a very generic question and there's no one answer.

[summer tide]

In Steam multiplayer one of clients will host

So the host will save the game in his computer

[hollow eagle]

Ok... and? Is there a question there? It sounds like you already know what you want to do.

[summer tide]

It’s similar to the game grounded. I have to see how that game loads in multiplayer

Trying to see what goes behind the scene

[hollow eagle]

to my knowledge there's nothing special about how grounded or similar deals with saves

it's exactly the same with singleplayer or multiplayer - someone loads a game, other people join

joining from a lobby doesn't change anything - they just join immediately rather than after the host has been playing for a bit

[summer tide]

Ok so each client have to load the game not only the host

[hollow eagle]

The save? No, only the host loads the save... other clients learn the state of the game through normal replication

I guess you could seed client state by sending the save over... but that's basically what initial replication does anyway so that's a bunch of extra work for no benefit

[summer tide]

You still have to create session let’s say for 3 ppl which the game was saved for before loading so that other 2 clients could join

[hollow eagle]

I'm lost, what does any of that have to do with saving the game

[summer tide]

I guess I have give it a try and see how it really works

[ember osprey]

Given that ISMs do not replicate, how can I store transform data of ISMs (Instance Static Mesh) in an array/struct, Replicate array and have clients draw ISM?

[shut gyro]

Can I dm someone about playstation OSS setup? Having some trouble

Someone who is a playstation developer of course

[heady python]

How can I make networked movement in BP so that I avoid stuttering on the server and rubberbanding on the client?

[round meadow]

Hi every! This exciting time for the multiplayer community! We have developed a server system that is unhackable! We can not wait to give back to the community so they can use this system to reduce server cost. Internet , in house server and power is all an indie dev needs to get started hosting an MMO RPG!

[hollow eagle]

unhackable
🤔

gonna have to qualify that statement bud, there's no such thing as unhackable.

[round meadow]

it works through chat system on third party streaming services

example https://www.twitch.tv/mizkif

this eliminates connections to any server tied to your mmo rpg.

our system takes information from all in house servers so that players can join each other

no downloadable client needed. good luck ddossing twitch haha

[dark edge]

Would it work for a science-based, 100% dragon MMO?

[round meadow]

yes we are working on integrating an x box controller so players can move around

any game type you want to create in unreal engine will work with our system

you can program it to be single player to

no need to program it for multiplayer

[dark edge]

I only have a guitar hero controller, that work? I got a kill in halo with it once.

[round meadow]

if it works on your pc yes

[summer tide]

So when you load a multiplayer lan/steam game and you had 3 players, do all the players need to be present in the lobby prior loading

[hollow eagle]

No. Again, this is up to you to implement. You can make people join a lobby first or allow join in progress.

[hollow eagle]

So you're describing something like stadia/xcloud/luna/psnow/etc. Maybe more on the side of stadia/luna.
My (and every potential client's) first question is why your system is any better than what google/microsoft/amazon/sony have done.

[round meadow]

we give it away for free?

[hollow eagle]

Good luck keeping that sustainable...

[round meadow]

devs can make their own games?

thanks !

[plush lagoon]

Is there a way to get a export of all associated packets for a build?

like tcp/udp packets :X

anyway to reference them at all?

[hollow eagle]

What do you mean by "all associated packets for a build"? Like get a packet capture from a live game? Or do you mean a list of all the different types of packets the game can send? Or something else?

[plush lagoon]

Well I'm trying to make a connection Service within kubernetes, that allow accept UE4 Connections, and relay the packet information too a Pod which will manage/maintain a virtual map utilizing a exported navimesh.

[round meadow]

wireshark might help the counting process. But you need to look at and count your custom events

[plush lagoon]

:X Trying to make scaling connections I'm not trying to hack a game, or anything

I am making one XD lol

The idea is Micro-Service(UE4 Connection Handler) -> Validation of Connection -> Direct Connection too Pod -> Pod Accepts Data -> Relays it back to UE4 Connection Handler in that play, I have a few micro-services that are managing functionality for specific events. But mostly i'm focusing on the Connection Service and Replication on a Map. For now :X Cost me like 1000usd @.@ testing a UE4 Instance on AWS/EC2 LoL

XD trying to come up with a better way, less money. LoL

UE4 Connection Handler -> Level Pod -> UE4 Connection Handler more or less :x

[round meadow]

its nice that will all go away for us. We use twitch validation for client authentication. Our servers are in house and streamed to users so reduced server costs.

[plush lagoon]

oh nice :3 rock one!

[round meadow]

streaming will be the next cloud gaming solution

[plush lagoon]

I'm trying to build a large scaliable Level.. but I realize that running UE4 as a Server itself, is just well uses alot of everything. LoL

So i'm like well. What if UE4 wasn't a single service, what if it was a collection of services that communicate via tcp/grpc/etc and if you did it that way, you would only need 3-5 services in total.

Control Service
Connection Service
Map Service
Action Service
Event Service

At least that is my concept.

[round meadow]

yea you have it set up nice

keep at it!

[plush lagoon]

so I'm working on just that.

Going to open source it when i'm done. :x

[round meadow]

omg now I love you!

[plush lagoon]

but yeah back to what I was asking, anyone know a way to dump all associated packets by chance?

the idea is to use those as whitelists for validation, of packet structure, and relay that via custom interface.

[round meadow]

you might need to dump them as they are received then set up a function to parse through the packets.

[plush lagoon]

hmmmm damn 😦

[round meadow]

I know it sucks

[plush lagoon]

❤️ thanks @round meadow ^_^

i'll look into it :3

[clever plinth]

If I replicate variables that are only valid on the server, will clients be able to access these variables as readonly?

[fossil spoke]

The fact that a variable is replicated has no bearing on its access properties.

That question makes no sense.

Can you reformulate it?

Just to note, Clients cannot modify the value of a variable on the Server directly.

They can only modify their version of that variable.

The Server can modify (through replication) a replicated variable on the Client though, when its value changes.

[meager spade]

if you don't want clients to access/read a property, then don't use it on client, if the property can be used by client and server, make a getter function and gate the value, but then again as DevilsD says, your question is a bit nonsensical 🙂

[ember osprey]

Is there a callback function for something like AllClientsReadyToPlay ?

I want to get all players at the start of the match.

Where should I try to get all players in a multiplayer life cycle?

[meager spade]

no

you need to do that yourself

there is NumTravellingPlayers if your using server travel, but you need to handle all players ready

[uncut atlas]

Quick question: Can RPCs be created in a component class or does it have to be an Actor class? I was seeing if I could create a server RPC in my custom static mesh class.

[ember osprey]

Ok. Thanks.

[fringe dove]

components can have RPCs but they go through their net owner's actor channel

[uncut atlas]

Oh ok thanks @fringe dove

[fringe dove]

they are also a bit less efficient than an RPC on the actor itself, at least that was the release notes comment when they moved character movement component rpcs onto the character itself

so if you always have just one component always on the same type of actor you may favor it being there on the actor, but if you have multiple components or use it with a wide variety of actors you may still need it on the components themselves

[foggy wave]

When i rotate my player to mouse cursor it rotates all other clients

and seriously i cant replicate the rotation correctly

[vocal cloud]

can anyone help me and my friend with a multi user editing problem, as though im unable to find my freinds session

[edgy knot]

Been spending my whole yesterday to implement a name tag on widget components on top of my players but can't replicate that correctly. Anyone's got a guide or something as to what to do ? Each player has their name in a save file, correctly loaded at beginplay. Best I've got is using repnotify which makes it work for all players connecting after, but the player can't retrieve the infos for the already present players.

I've tried accessing the gamestate to foreach on the names and update the according components but the names get all mixed up.

Thought the widget would be the culprit but even with a rendered text I can't make it work

[chrome bay]

Don't replicate it is the answer

All of that can (and should) be handled by clients locally

If you're doing it with widget components instead of regular 2D widgets it gets easier, all you need to do is attach one to your pawn class, assign a player state/pawn variable in the widget, then have the widget read from the player states' name

Everything you need is already client-side

[winged badger]

or attach a widget component to the playerstate, then physically attach PS to Pawn 😄

[chrome bay]

Galaxy Brain 😄

[winged badger]

no need to worry about PS arriving late, which it usually does, then

[fast arrow]

Hellow, does somebody know what does it mean?
LogNetTraffic: Error: UActorChannel::ReadContentBlockHeader: Sub-object not in parent actor
So i try to replicate uobject and call RPC on it. Probably the problem is that i use outer to handle replication, but i try manually define where to call this RPC. So as i result use custom property for CallRemoteFunction and GetFunctionCallspace. The reason i did this, is that the actor that handles replication can not be owned by client - only by the server, but in these uobject i want to determine on what client should i sent RPC.
At least is there other way, to separate replication and callspace of RPC ?👀

[chrome bay]

The UObject's Outer has to be an Actor

No way around that, but assuming you set the UObject up like I did here, you're good to go:
https://jambax.co.uk/replicating-uobjects/

Then you can call RPC's on it, have replicated properties etc.

[open quail]

Hi I started to learn replication but can't figure out how to properly setting variables on server. Am trying to create ready check where client press R to signal that he is ready. When host press R and client is ready, game can be started. Otherwise host will be informed that client is not ready yet. Here is a blueprint which does not work. After setting client ready server still see client as not ready. Can anyone help me?

[fast arrow]

Yea i know it. the problem is that an actor that is responsible for replication can not be owner by the client, but at same time i want to make rpc from its sub object to specific client. If i stay as it is, it will call Client call on every client, not at specific one. As i understand it, it happens because of this realisation in my uobject
GetFunctionCallspace(UFunction* Function, FFrame* Stack)
{
return (GetOwner() ? GetOwner()->GetFunctionCallspace(Function, Stack) : FunctionCallspace::Local);
}
So is it possible to make it work in other way?

[chrome bay]

If you call a 'Client' RPC it will only go to the owner of the Actor? Ownership is determined at the actor level

You need to override CallRemoteFunction as well

But yeah you can't make an RPC go to a specific client without using an object that is owned by that client

That's not even supported at the actor level

[fast arrow]

when you press R it is pressed on client side so this print will never be hit cos has authority will always go to remote

[kindred widget]

@open quail Your issue is that you're not checking the player's character. So your player will set that bool to true in their own character on the server, but then the listenserver player will press R and check it on their own character, but they're not changing it on their own character. You'll need to get all of the player's characters and check them on the Authority side of your switch.

[chrome bay]

The way to do it is remove the switch entirely

Just call the Server function directly

[mortal kernel]

Hey there just an easy question here... how would I need to set this stuff up in order to prevent cheating ?

[chrome bay]

Doesn't appear to be anything related to Multiplayer there?

[mortal kernel]

It's something about replication

so yes

[chrome bay]

There's no replication in that image

[mortal kernel]

That is what the question was :o

[chrome bay]

Needs more explanation

The Server is the only thing that should apply XP

Clients should never send RPC's to request it

[mortal kernel]

I know I have to somehow check on server if the client is legitimate able to level up

[chrome bay]

Otherwise, you can't prevent cheating.

[mortal kernel]

but I'm not sure how to set it up

[chrome bay]

You're thinking about it the wrong way

The Server is what applies XP

Then tells the client what their level is

The client never directly tells the server their level, nor tells it to add XP

[mortal kernel]

so Gain Exp runs on server ? and multicast to the clients ?

[chrome bay]

no

[fast arrow]

And there is no way around it? Basically i've made an action system which contains actions(uobject), action manager is responsible for replication right now. So if i want it to work properly, i should make action manager as a component for player controller, for example, and pass it from certain client as an outor for u object?

[chrome bay]

There is no way around that no

There are two types of RPC for clients, Client and Multicast only.

Client goes to the owner of the actor

Multicast goes to everyone who has the actor relevant at the time

That's all there is

[fast arrow]

i mean not pc but an actor) (messed up)

[chrome bay]

A Client RPC called on a PlayerController will only go to that player yeah, they own their player controller

And it's the only player controller they know about

[fast arrow]

that sucks(

[mortal kernel]

Hey uhm... can I not use the "Has authority" node inside actor components ?

[fast arrow]

this is all what this thing does

so you can do just this

[peak sentinel]

TimeStamp means "GetWorld->Time" ?

[proven grove]

https://youtu.be/JCF1LJYPjSY
It's done! Multiplayer integration of ballistics FX and Easy Ballistics!

[peak sentinel]

Jambax, if you are here, can I ask a question? I was trying to do what you told me about smoothing bReplicateMovement, on PostNetReceiveLocationAndRotation I am logging these, and the error logs are coming from Tick. Seems like Mesh (visual) is already always "0,0,0", how can I smooth it if its already being teleported to root everytime?

[chrome bay]

Well you need to offset the mesh manually

If it's not using an absolute transform then it will just inherit it's transform from the parent

If you still want it to use a relative transform, then you would calculate the offset of the mesh, apply that and over time interp it back

[peak sentinel]

So its like, when new data arrived from PostNetReceiveLocAndRot, i am saving "current" or "old" world position of mesh, and comparing with new arrived datas "new" world location, and lerping it, that way even if engine updates it, I am undoing that update with Lerp and smothly updating it because lerp teleports to "start location" before starting to process lerp operation, right?

Sorry if I am being a headache about it btw. Been trying to solve that for days. I'll try to ask minimum questions about that

[chrome bay]

Well the mesh position isn't replicated, the position is for the capsule alone

the meshes position is inferred from the capsules' position, in the case of characters, as it's attached

[exotic jay]

I've got an event that handles cosmetic stuff only relevant to the local player called on tick. I only want it to run if the actor is owned by the player. What can I use to test for this?

edit: specifically, if I want to test if a given machine owns a player pawn

Is Locally Controlled seems like a winner

[exotic jay]

Er, wait. Would it be better to mark a function as runs on owning client? My gut intuition says this means we're adding an rpc call every tick if that's the case and it'd be better to just handle it all on the client

[chrome bay]

If you mark it as "Runs On Owning client", it is an RPC

[exotic jay]

Right, and that means a message needs to be sent from the server.

If something is 100% local, it'd be better to not send a message at all, and just test "is locally controlled" instead, correct?

[ember osprey]

When and What way is best to get all the active players in the game safely without using a Callback to add a player controller to an array everytime a player is ready. All players start at the same time at the beginning, players cannot join mid game.

[bitter oriole]

Iterating all PlayerState actors (client or server) or all PlayerController actors (server only)

[ember osprey]

Where would be safe to do this 100% to make sure all players are ready to play?

[bitter oriole]

Define "ready to play"

[ember osprey]

Like I would be able to get all of the player controllers in one loop to store in an actor in the map.

instead of using a callback to fill an array everytime a player is ready.

[ember osprey]

basically, where would an actor in the map who exists on the clients be able to get a list of all players in the game at once and be accurate?

[bitter oriole]

My first approach would be to simply always fetch the list of currently connected players any time you need it

[ember osprey]

I agree, but where would be safe to do this for an actor in the map?

[bitter oriole]

What do you mean, where ?

[ember osprey]

lifecycle functions

[bitter oriole]

Well, any time you actually need to use that list of players

[ember osprey]

begin play would not be safe, i don't think

[bitter oriole]

Don't store

Just get the list every time

You'll worry about caching things when you're in optimization

And yeah, BeginPlay won't cut it

[ember osprey]

I agree

Also, I don't think the world is ready on PostLogin in game mode.

So I don't think grabbing actors from the world in gamemode PostLogin is safe either.

[bitter oriole]

The simplest, safest, is to grab it all the time, when you need it

[ember osprey]

I need the Player Array list when the game is ready to be played, but the players become ready at different times because initialization and stuff.

[bitter oriole]

Okay

Your real problem is defining "when the game is ready to be played"

So work on that first

[ember osprey]

That was my original question

When?

and then there was where

[bitter oriole]

That's a game design question

[ember osprey]

no its a multiplayer lifecycle question

[bitter oriole]

No, it really is not

[ember osprey]

ofc it is, different functions are called at different times

[bitter oriole]

Alright, so let me ask you one question

[ember osprey]

I need to know when its safe programmaticlly to obtain the references in a multiplayer paradigm.

[bitter oriole]

How do you know all your players are connected ?

That's not an UE4 question, that's a "how does your server and session system work"

UE4 doesn't know how many players are going to connect

You might

UE4 knows how many players are connected

[ember osprey]

Players cannot join mid round as mentioned.

once the game starts, there number of pc in the game are final

[bitter oriole]

See, this is why I keep telling you this a design problem

How do you know the game can start ?

[ember osprey]

life cycle functions in UE

[bitter oriole]

UE4 does not handle this in any shape or form

[ember osprey]

UE defines when functions are called.

lifecycle functions.

that will determine when it is safe

[bitter oriole]

So let me rephrase my question so that you understand

How are you preventing players from joining mid match ?

[ember osprey]

There is nothing setup rn to decide, I am manually deciding how many clients are connected in the editor.

You can't join programmitcally yet.

its all editor stuff by me.

[bitter oriole]

Do you know how people will be joining a game server ?

In the real game ?

The point I keep trying to make is that UE4 simply does not have a concept of "all players joined"

It just does not

By default anyone can join anytime

[ember osprey]

so callbacks it is

I know there is a better way, theres gotta be

but I guess I will just have to hack together a callback system to fill the array as players become ready to play.

[bitter oriole]

You have a design problem where you haven't decided what the start condition is - maybe when 5 players connected, maybe 30s after the first one, maybe a voting system

This is not a technical issue at all

[ember osprey]

btw, UE knows how many players will join because I'm setting it in the editor before I even play.

[bitter oriole]

But that's 100% an editor thing

You're not even going to test your game that way, it's just a debugging tool

You should be thinking about the actual game and how do you know there are enough players

[ember osprey]

basically, its a lifecylce question I'm trying to asnwer.

[bitter oriole]

And I keep telling you the very concept of "all players have joined" does not exist in the engine

So there is no lifecycle for that

[ember osprey]

I get that.

[bitter oriole]

Players could be joining 10s after anyone else

They could be joining a full minute later

[ember osprey]

I have to figure out when its safest to update an array of players

[bitter oriole]

Right when your game logic has started the match

Based on your game-design decision on what a match need to start

If it's a MOBA, it's probably "10 players joined and all picked a hero"

[ember osprey]

is there OnMatchStart function?

yes its a MOBA

[bitter oriole]

Is there a OnMatchStart - depends if you are using GameMode or GameModeBase

GameMode has a basic workflow for match states

Except you will still need to call that stuff yourself

[ember osprey]

Should I be using gamestate for this?

[bitter oriole]

That's not up to me

It's a game design decision

[ember osprey]

GM only on server, gamestate both

I need an actor that exists on each client to have a reliable array of each actor somehow.

[bitter oriole]

Alright, I give up, sorry, I don't have the patience for that

[ember osprey]

and the actor is in the map when the game starts, it is not spawned.

[bitter oriole]

You keep thinking this is a technical issue, but it's not

Read up on GameMode if you want to implement a match system : https://docs.unrealengine.com/en-US/InteractiveExperiences/Framework/GameMode/index.html

You'll need to implement your custom logic for when a match starts, and you would set your array when you call StartMatch

When you do that, is a game design decision

[ember osprey]

So how would you fill an array for an actor in the level that exists on all clients. Would you do it via a gamestate callback or a gamemode callback?

[bitter oriole]

Depends if you need the info client side or just server side.

[ember osprey]

GM = rules, GS = data storage in a nutshell.

I need it client side.

[bitter oriole]

Then put a replicated array in GameState and fill it as soon as you have called StartMatch from your code on the server

[ember osprey]

Yeah, the replicated array in GameState was something I was considering. Had it in my notes.

just wasn't sure it was the best way.

If ISMs could replicate, I wouldn't even be having this issue.

All this workaround crap is due to Instance Static Meshes.

[bitter oriole]

I mean, you haven't solved your actual issue here

You solved the "how do I get the server to send the array to clients"

You did not solve "when do I set the array on the server"

Which is what you asked, and is a game design decision

[ember osprey]

So this is what I'm gonna try

I'm gonna put a replicated array in the game state and when players join, I'm going to update the game state from game mode PostLogin, when game state receives the updated player count it will obtain the actor on every client containing the ISM and do what I needed it to do there on each client.

@bitter oriole what do you think?

[bitter oriole]

I'm thinking you could simply read the array of all PlayerStates on tick and be done with it

But sure

[errant lance]

You aware, that GameState has Players array by default which has all joined players PlayerStates?

No need to reinvent the wheel.

[ember osprey]

I'm afraid of Tick

[bitter oriole]

Be sure to also update when a player quits

Yeah, that's a common problem

Get the game state, get the player array on tick, you have your safe list of all currently connected players

Not including players currently connecting

[ember osprey]

Is there anyway I we could do a voice chat?

I understand if you don't want to. its completely fine.

[bitter oriole]

Nope, sorry

[ember osprey]

I understand, I would probably be able to explain my issues better, but I understand your solution. I appreciate your help!

[ember osprey]

Yes, I'm aware, but when is it safe to call that?

[meager spade]

@ember osprey you can access it anytime

[ember osprey]

like what part of the gameplay lifecycle is it safely full of all the players, or do I need to keep checking it.

[meager spade]

it might not have everyone

[ember osprey]

@meager spade

[meager spade]

you need to decide that, take fortnite for example, they shove you on a server in a small waiting island

[bitter oriole]

I keep saying it

[meager spade]

once a criteria is met

[bitter oriole]

This is entirely up to you

[meager spade]

they start the match (ie time was too long or 100 players are there)

[bitter oriole]

what part of the gameplay lifecycle is it safely full of all the players
There is no such thing in Unreal

I keep saying it

[meager spade]

normally done by a timer

which checks the starting conditions

[ember osprey]

this is a good suggestion right here.

[bitter oriole]

It's literally the thing that I can't seem to explain well enough - there is no built-in way to decide when to start a match

[ember osprey]

a delayed timer

[meager spade]

i think i mentioned that last night also :D, but either way, check UT4 GameMode, check SHooterGame source code

i am sure they have the concepts there

[bitter oriole]

This is a game design decision and it needs a game specific answer - basically wait until there are 10 players, for example

Plus a timeout to start anyway at 3v5

[ember osprey]

You said I needed to handle it myself.

I'm trying to do just that.

[meager spade]

as @bitter oriole said, the server only knows who is connected and how many max can connect

[bitter oriole]

First step : when do YOU want a game to start ?

5 players ? 10 players ?

10s after server spool up ?

[ember osprey]

I think i'm going to put a timer on begin play on the actor in the world for like 2 seconds and then get the Player Array.

[bitter oriole]

2 seconds is not nearly enough

Think 30s

[ember osprey]

hmmm

[errant lance]

I have bIsReady on my PlayerStates and when all connected players are ready (by clicking ready on UI) then match will start. Override GameMode::ReadyToStartMatch which ever logic you need for your game.

[ember osprey]

that seems like a long time for a game start, is there another lifecycle function, like AfterBeginPlay or something?

[bitter oriole]

Your timer needs to include the difference between the fastest and slowest client to load the map

[ember osprey]

damn you're right

[bitter oriole]

And no, there is nothing in the lifecycle that addresses it, for the 56th time

It's a game des- you know, I'm done

[ember osprey]

If you're ever in the DFW area I'll buy you a coffee.

[meager spade]

if you base from AGameMode, you have the concept of match states,

that you can also dabble into

[bitter oriole]

But then you still need to decide when to call StartMatch

Same discussion

[meager spade]

right, so UT4 for example this when the state changes

https://www.thegames.dev/snaps/devenv_dIH2LMMFGr.png

waiting to start will be doing you start criteria

[chrome bay]

ah the days before gameplay tags

[meager spade]

InProgress will be whilst your game is actively playing, etc

[ember osprey]

but this will different for every player no?

[meager spade]

this is SERVER only

[ember osprey]

ahh

[meager spade]

GameMode <

players should never decide when a game starts 😄

[ember osprey]

lol

@meager spade this is all related to the ISM solution we discussed a while back.

my note:

[meager spade]

does the array have to be replicated?

[ember osprey]

I have been struggling with this since!

[meager spade]

why can't the client have its own array locally?

[ember osprey]

it can

it just has to match every other clients array.

[meager spade]

why would they not?

[ember osprey]

IDK? lol

I haven't been able to get that far.

I need each client to know how many players are in the game and tell an actor ISM manager, to create an ISM component to represent each client.

its frekin' hard

then have each client sends its Player MeshTransorm (on a timer) to each connected client to draw their representation of the ISM on their local instance.

[meager spade]

this is something the clients should handle themselves

every client knows where the player is

and can update the stuff locally

no replication is needed here, all the replication is handled already

[soft shell]

Anyone use steam sockets? I'm seeing throttling to 10Kb/s; however I'm sure I've all the required configuration set-up (given switching in "SteamNetDriver" shows 120Kb/s on a particular game-mode we have).. is there some other option steam sockets use for throttling?

[meager spade]

every client know where the players mesh is

[ember osprey]

hmmm...thats true.

[meager spade]

on a timer you can simply loop through all player states, grab the pawn, grab its mesh loc, or w/e

and update the isms

[rose egret]

wth ! is it UT4 ? why they dont use enum simply

[meager spade]

the name based thing is cause they used the engines default GM as a base

which has MatchState defined as strings

[ember osprey]

@meager spade Ok, I'm gonna try that!

[meager spade]

and can be extended

[bitter oriole]

The GameMode thing comes from UT3 quite very directly, too

So UT4 devs were familiar with it

[ember osprey]

when is the next time you will be in Texas?

[peak sentinel]

Is UT open source?

[bitter oriole]

@ember osprey Probably never

[peak sentinel]

I see its being shared here a lot

[bitter oriole]

Yes it is

[meager spade]

open source in the sense you can look at the code, but you can not copy or use anything out of it

[bitter oriole]

Yeah, "source available" like UE

[ember osprey]

ok, since never, here ya go ☕

you get one also @meager spade ☕

[rose egret]

is there any right way to exclude some components from dedicated server ?
something like bEditorOnly, but without changing source code .
because I see by default UObject has some function for that NeedsLoadForServer, NeedsLoadForClient, but there is no variable for them

[atomic acorn]

does anyone know if it's possible to create a dedicated server buld without building UE4 from source

[meager spade]

i think its in cooker settings

@rose egret

https://www.thegames.dev/snaps/UE4Editor-Win64-DebugGame_MCHOzV3Y5h.png

like this

[rose egret]

yea but its class based unfortunately, so I have to make lots of inheritance 😦

[meager spade]

eh

what is your use case?

[rose egret]

for instance I have items on the ground, on server I just need the root (scene component) but it has lots of static mesh and skeletal mesh component as child

[meager spade]

dedicated server wont render them

[rose egret]

which I want them to be excluded, nearly 10 000 items are on the ground

and it takes memory

[meager spade]

nor will it cost anything apart from a tiny bit of memory

not a lot though

[rose egret]

and spawn cost anyway

[meager spade]

spawn cost will be the same

[rose egret]

I wonder why they have a bool bIsEditorOnly for editor only components but nothing for client server

🤔

btw If I move them on server, lots of redundant children move as well

they calculate world transform and bound

[chrome bay]

If you have other stuff dependent on them then by definition you have to include them

You'll find that 'Editor Only' components can't have children that are non-editor only for example

Also I can't imagine the issues it would cause having relative transforms / attach parents being different between client and server etc... I mean have fun dealing with that mess

In the context of meshes, also need to consider collision etc.

[rose egret]

I considered all those options, I am kind of obsessed with memory.

[chrome bay]

don't be

it's not worth it

[rose egret]

some game engine take 300mb for an open world map

[chrome bay]

On a dedicated server your bottleneck isn't going to be caused by a few extra mesh components

[rose egret]

but UE4 takes 700mb for a normal dedicated server

😁

hopefully we are not using source version, I would also remove all those redundant BP multicast delegates in components

😁

things like OnClick, OnRelease, etc

🤔

this way I guess I could save a lot

[chrome bay]

...but why

they cost almost nothing

if you don't have anything bound, it's an empty array essentially

[rose egret]

🤔

[exotic jay]

Can someone help me get an object pickup working with replication? I've got two problems. My basic flow is

• Walk up to an object with an interactable component
• Play lifting animation
• Anim notify triggers an event to actually trigger the pickup

I have this working so that the anim notify is gated by switch has authority and am fairly sure it's all working up to this point correctly. Then things fall apart. This is the basic chain I'm trying to do

Get Picked Up modifies some collision on the mesh of the object. Reposition Held Item for Holding rotates, attaches, and then offsets the object to look visually correct.

[winged badger]

why? you just need to replicate a pointer in the pickupable to whatever picked it up

then they can attach, offset, and whatnot on each machine individually

[exotic jay]

Which piece of this seems off to you?

[winged badger]

never multicast stateful changes

if i was outside the relevancy range or joined late then came near you while you're holding that itme

i'd see it on the floor

you are essentially overcomplicating it

if item has a Socket name on the CDO and a pointer to whatever it holding it

it just needs to do AttachToComponent and thats it

as for animation - use a montage, rather then animation

its easier to replicate and sync

[exotic jay]

Hold up please, I've got a handful of questions to all that haha

[winged badger]

and its notifies fire on listen server even if the host camera isn't looking at it

[exotic jay]

Ok, one, never multicast stateful changes. What do you mean by that? I get that it probably doesn't make sense to multicast something that Sets a var (which could be set on server and replicated), but isn't your described method multicasting a command to, say, call attach component?

That is, things like changing collisions, and attaching, and whatever feel like they're stateful changes.

[winged badger]

im not suggesting multicasting anything

im suggesting using a pointer to a component with RepNotify

when that replicates, if pointer is not null, attach and do all the other stuff

[exotic jay]

Got it, makes sense

Second q, on montages

You say they're easier to replicate, and I think I agree, but I'm concerned I'm not doing it wisely. This is my setup.

(ignore the remote thread)

Is this stupid

First one is a macro I use to play montages, always called by the server. It then passes that information through to a client.

I tried doing a rep notify setup first, where I just sent a struct with the montage info. But I ran into problems understanding how and when to clear the struct, as well as how to utilize the out pins of Play Montage if I call it in a notify.

[past sonnet]

How can I solve this?

Client does not replicate animation on server

[exotic jay]

@winged badger switching to repnotify's solved it in an instant. Thanks so much. Still curious for your thoughts on the montage setup whenever you have a minute. It does seem to work without any problems though?

[meager spade]

we use a replicated prop

but we do it via c++ @exotic jay

we do additional things like montage catchups, etc

[rich ridge]

I m seeing this montage catchup first time.
Can you explain this please?

[winged badger]

its timestamped, network clocks are synced, client will adjust the playerrate and/or start time if it differs too much from what it should be

[meager spade]

if its a long montage and player becomes relevant, the player seeing it for the first time, will see the montage from the start

we work out the difference and play the montage from the correct time

[winged badger]

so for example, our dead monsters don't get up on their feet to play death montage if you walk into pile of corpses from outside the relevancy

[meager spade]

nor play the spawn montage again

[rich ridge]

interesting, good to know

[meager spade]

though the most usual use case is vaulting

where players see monsters doing vault action no where near vaults 😄

or doing a random attack no where near anything

multicasts don't really cut it for that kinda thing

[rich ridge]

for the time being all my gameplay logics are derived via GAS, does GAS also have this problem?

[meager spade]

if you use the montage node in an ability it has a kinda catch up system

but only if you use the one via Gameplay Tasks

also remember that system is highly limited

one montage only at a time, and only on the main skel mesh

maybe ill get my new montage task finished up

and release it

[rich ridge]

will this be problematic if my character have sub-skel mesh with animation?

[meager spade]

it only plays montage on a single mesh at a time

if you run another node, it will cancel the first one

[rich ridge]

ohh i see

[meager spade]

and you cant select what mesh

[rich ridge]

right

[meager spade]

my new task i was working on solves this

by encapsulating that inside the task itself

not forwarding off to the ASC

[rich ridge]

do you any gist of this task? can I have a look.

[meager spade]

no

[rich ridge]

then I will have to implement it.

I will do that, now I have problem statement and approach.

thanks a lot @meager spade and @winged badger

[devout isle]

Hey guys having some weird behavior

I have an actor component responsible for replicating some values

For whatever reason UE4 seems to be serializing the entire component - any idea why?

Here is a warning that keeps popping up. It clearly takes a while to perform this serialization

[2020.12.21-07.45.34:056][786]LogNetPackageMap: Warning: Long net serialize: 36.619884ms, Serialized Object [OBJECT NAME HERE]

serialization seems intermittent and unpredictable

no clue why it is happening

[bitter oriole]

What do the values look like ?

[exotic jay]

@meager spade is there any decent way to handle this in bp? Sounds like you could hypothetically unnormalize the starting position input and try to start it at the appropriate delta, but that sounds annoying.

[meager spade]

in BP that would be a lot of work

in C++ it was a lot of work

[devout isle]

set of 3 vectors

[tidal crown]

Lets say I have 4 characters, each of them has a light actor attached to their player character. I want to be able to press a button and toggle the light on and off. When I toggle the light on and off, I'd like the other players in the world to see this. Each player should manage their own light visibility state. We've started off by putting the on/off visibility in the player state and we can prove through onRep notify the value for the owning actor is getting flipped on and off and we're seeing the light toggle. However, the 3rd party individuals are not seeing any state change or light actor change on the actor that originates the event...should we be firing multicast RPCs to notify the others to update their version of my pawn? That feels weird... I thought the whole idea w/ PlayerState replication (and the associated pawn) is that this would properly sync...what are we doing wrong?

[loud ridge]

Hi guys, experiencing an issue with making my game multiplayer. I've managed to make a door 'open' correctly for all clients, and all of them have the interact function working. However...Although the door's open animation plays, and the static mesh 'swings open', the collision remains in the same place, making clients unable to step through the door. I've done a good bit of googling and haven't been able to find anybody experiencing this problem.
Note: The collision is a collision set to the static mesh itself, not a box collision or something added onto the blueprint.
As far as I can tell the statich mesh's collision should move with its position, and there's no BP function to move the collision itself. Any ideas?

The only solution I've managed to come up with is disabling the mesh's collision entirely when the door is opened...But that means being able to walk through the actual door, which is obviously not desirable.

[lost inlet]

if you rubberband on it, that means the location is desync'd between client and server

we had a fun time getting doors to work reliably in our game

[loud ridge]

This is my first attempt to wire up multiplayer in UE4 lol. There's no rubberbanding--and not even the 'server' character can walk through the door, oddly enough.

@lost inlet any possibility you could walk me through how you got it working a little?

[lost inlet]

well our door actor is like 2k lines of C++

but we have a bunch of features for it

[loud ridge]

holy fuck lol

it seemed so simple to get running based on the guides i've seen on youtube

like I said it's working other than the collision

and those guides had 0 issues with collision, it "just worked" so to speak

can't figure out why my collision isn't moving with my mesh

[lost inlet]

our doors allow you to shoot the hinges and breach the door

which is not going to be applicable to every type of game

but it's stuff we had to make sure worked over the network

[loud ridge]

ah yeah that's pretty fancy

[peak sentinel]

Best one was kicking the doors in sandstorm

[fossil spoke]

Pretty sure sswires worked on that 😛

Is that right?

[lost inlet]

yes

[fossil spoke]

👍

[lost inlet]

if your door just has an open and closed state without being able to be opened partially, you would just have a state variable with an OnRep

you would have to make sure any rotation or changes in collision are run on both client and server

[loud ridge]

the issue is that as far as I can tell, the collision and mesh are supposed to go "hand-in-hand"

there's no 'set relative collision', for example, as it's supposed to have the same position that the mesh does consistently

as far as I can tell there's no way to update the static mesh's collision at all--i'd have to make a box collision with blocking collision on the blueprint to manipulate it

and in the guides I've watched, they've never had to manipulate the collision themselves, it always seems to update with the door's mesh moving

[twin juniper]

hey quick question, a slider in my widget, when i click and drag it changes the float value but the slider wont move with my mouse, confused

[lost inlet]

yes but if it's desync'd between client and server then you get issues like that, that's why I mentioned rubberbanding

[summer tide]

Do you need to save and load in multiplayer individually? Also do the players have to join the lobby prior loading as well? I have a steam multiplayer project trying to understand and get it to work. THe save and load works in standalone and 1 client currently.

[lost inlet]

what is saving anything to do with steam

[summer tide]

sorry let's say only multiplayer nvm steam

[lost inlet]

well I know nothing about your implementation and there's probably 100s of ways of implementing a system like that

if it's just saving actors and their states and the actors are replicated, wouldn't this only need to be done once by the server?

[summer tide]

So when I start a multiplayer I choose 2 clients, since one client will act as a server, since i'm not gnna use dedicated server

Ok so let's say the server saves and load the game. During game load do the players have to be present in the lobby and connected via session

[lost inlet]

the server should be the authority over this, there is no point loading anything on anything but the server

any state or actors the save game restores should be replicated

[summer tide]

That I have but the second question about players being prsent in lobby

[lost inlet]

well like I said, I know nothing about your implementation. if you're using replication systems, it should be resilient enough to account for late joining

[summer tide]

Currently my client gets kicked out to the main menu

Only the server load

[lost inlet]

well that's definitely not enough information

[summer tide]

Ok 2 clients - 1 host and 1 client

Client joins the host

[lost inlet]

I don't know what your implementation looks like

how is anything saved? how's it loaded? what does the server log look like when the client gets kicked?

[summer tide]

Ok let me try to give you more info

So from the widget I click on load game after 2 clients have joined the lobby

click event connects to an event in my game instance

[lost inlet]

the UI is irrelevant here

[summer tide]

there I unload lobby and load gameplay level

From game instance I call the Load Game event which is in another BP

[loud ridge]

you're not giving us any technical information of how your blueprints actually work so there's 0 way for us to help you lol

[summer tide]

I am gather them

1 sec

Do you have Survival Game Kit?

[loud ridge]

no

[summer tide]

I think my save and load is done on server for individual only

[summer tide]

The save system uses the player name to determine which save to load when a player joins a server.

IS this right in game instance? https://gyazo.com/4019eb7578774f8f47bb805f7518f548

https://gyazo.com/41387b0afc0c0f5d7ce280814fff253d

[lost inlet]

rip it's BP

but the session finding stuff is pretty irrelevant for the saving/loading system

[meager spade]

btw @summer tide i would advise NOT to use the player name

what if there are some weird chars in the name?

always use some kinda ID

[lost inlet]

oh yeah that's bad

[winged badger]

had an incident when he tried to use the steam name for a filename in windows, did not end well

[meager spade]

hence why i mentioned it 😄

[winged badger]

well it was only that nobody with weird chars in steam name could save any progress

[lost inlet]

weird unicode characters in names is pretty common on steam

[winged badger]

having to rewire that mid steam festival demo without nuking everyone's progress was a stress i could had done without

[lost inlet]

also since anyone can change their name to anything, you could also steal someone's else's save

[summer tide]

@meager spade Using Steam ID

https://gyazo.com/4c7e5654e86603e4871cfa5d111d5981

[summer tide]

So with this setup i'm trying to see if the player shows up. I'm running the project in two diff PC. connected to diff steam account.

After host is in lobby and the other client tries to find a game. It doesn't show up but in editor or launching the game from the same pc I see the server list

I only see the host in lan mode

@meager spade @lost inlet Do you know what's wrong? I'm still using the default coe in engine ini file.

[lost inlet]

no

and you still haven't shown enough

[summer tide]

I'm trying to test from 2 diff pc prior saving and loading i'm having issue joining the host in lobby.

[twin juniper]

thanks!

[summer tide]

Anybody knows about Advance Session plugin?

[final rover]

@gleaming vector have you tested the new cmc you linked from the new networking plugin? I tried to use it in 4.26 but it just crashes for me.

[gleaming vector]

i have not

also that is for 4.27

so im not surprised it crashes

[peak sentinel]

New CMC? 👀

[karmic briar]

networkprediction

[peak sentinel]

https://github.com/EpicGames/UnrealEngine/commit/e8ad1938cc1c8e1e2dee4b32b092c163fde580e2 you guys talking about this, right?

[final rover]

Yeah. I figured it wouldn't work yet but still wanted to give it a go

If anyone figures it out though, feel free to let me know :p

[rich ridge]

If you use gas ⛽, don't try it yet.

[rose egret]

how do I serialize a float fixed and compressed ? for instance my range is -3000 to 3000 and I want it to be scaled into 8 bit.
I found WriteFixedCompressedFloat, ReadFixedCompressedFloat but if I use them with low NumBits I get compiles error

[chrome bay]

The easy way is to re-range the float from 0-255 using FMath::GetMappedRangeValueClamped

then static cast to uint8

and vice-versa for unpacking

[rose egret]

I was doing something like that but it did not support sing

looked WriteFixedCompressedFloat source and it seems complicated to me,

[chrome bay]

It's not for ranging floats, it's just for compression for lower accuracy

uint8 Compressed = static_cast<uint8>(FMath::GetMappedRangeValueClamped(FVector(-3000.f, 3000.f), FVector2D(0.f, 255), SomeFloat))

Compression is as easy as that

float Uncompressed = FMath::GetMappedRangeValueClamped(FVector2D(0.f, 255.f), FVector2D(-3000.f, 3000.f), SomeByte);

[rose egret]

got it

going to test

🙏

[frank birch]

I am a bit of a newbie here so maybe this is a silly question.
From reading EXI super-duper-compendium I understand that GameMode only exists in the server and contains the game rules.
However, some of this rules must be known by clients... what is the correct way of doing it? 🤔
Writing it to the player GameState on connection? 🤔

[chrome bay]

yeah that's the way

Game State and Mode are usually both pretty tied together

[frank birch]

thx ❤️

[frank birch]

more silly questions: If I have an event marked as "run on server" (an RPC, right?), should my client code (say, a player input) check that it is indeed a client and not authority before calling the other event? 🤔

[frank birch]

riiiiiiight, has authority is to double check before running a multicast 🤔

[hallow mica]

hi , a beginner question.
i wanna make mobile multiplayer game using listen servers
how can i do it for free ? what should i look for

i think steam subsystem isn't for mobile

[frank birch]

as far as I understand, either you use a network subsystem (like steam, facebook, or something you coded your own) or ask the user to punch in the ip adress of his friend 🤔

[hallow mica]

is there any free subsystem that i can use for mobile

[frank birch]

a quick google search spewed this: https://redpointgames.gitlab.io/eos-online-subsystem/
no idea how good or bad it is 🤣

Here you can find some of the classes that exist, Google, Amazon, Twitch...
https://docs.unrealengine.com/en-US/API/Plugins/OnlineSubsystem/FOnlineSubsystemImpl/index.html

I am changing the player collision response to a layer.... from the client.... and the server doesn't complain

this shouldn't work...

[dark edge]

@frank birch What machine is actually executing the change?

[frank birch]

client 👀

(i use a print string right after and it says client)

but the server doesn't correct my physics object

I am doing a "semisolid" platform, I set the player collision to ignore the semisolid layer depending on his speed and other stuff

it works, playing as client, however.... why?

(I am using unreal's character)

[shut gyro]

Why would I be getting this error sometimes? It's rare

[2020.12.22-17.33.32:447][718]LogNetSerialization: Error: FBitWriter overflowed! (WriteLen: -1, Remaining: 7628, Max: 7628)
[2020.12.22-17.33.32:447][718]LogNet: Warning: Can't send function 'Server_SendMove' on 'CDTurretReplicator /Game/Maps/Deadwood_TestMap.Deadwood_TestMap:PersistentLevel.CDWarhawk_0.ChassisComponent.Turret.TurretReplicator': Reliable buffer overflow. FieldCache->FieldNetIndex: 2 Max 4. Ch MaxPacket: 1024
[2020.12.22-17.33.32:458][719]LogNetSerialization: Error: FBitWriter overflowed! (WriteLen: -1, Remaining: 7628, Max: 7628)
[2020.12.22-17.33.32:458][719]LogNet: Warning: Closing connection. Can't send function 'ServerUpdateState' on 'CDTrackedMovementComponent /Game/Maps/Deadwood_TestMap.Deadwood_TestMap:PersistentLevel.CDWarhawk_0.MovementComponent': Reliable buffer overflow. FieldCache->FieldNetIndex: 3 Max 4. Ch MaxPacket: 1024.

Seems to happen on initial join. Then, the client gets kicked out shortly after

[thin stratus]

Is it possible to stop PIE from calling BeginPlay?

As far as I can see, they more or less enforce it

[sinful tree]

Are you sending RPCs on tick or something?

[sinful tree]

What actor or class are you trying to prevent from running in the editor?

[thin stratus]

Well, logcally, BeginPlay doesn't call before the Game starts

If you delay the start, it shouldn't call BeginPlay

But PIE is like "Hey, lemme call it anyway."

[sinful tree]

But why would you want Begin Play to not be called?

[thin stratus]

Because the game hasn't started yet

void AGameModeBase::StartPlay()
{
    GameState->HandleBeginPlay();
}

void AGameStateBase::HandleBeginPlay()
{
    bReplicatedHasBegunPlay = true;

    GetWorldSettings()->NotifyBeginPlay();
    GetWorldSettings()->NotifyMatchStarted();
}

That usually handles that

But StartPlay isn't called yet, cause Delayed (as wanted)

But PIE is calling BeginPlay through a second code path

...

FGameInstancePIEResult UGameInstance::StartPlayInEditorGameInstance(ULocalPlayer* LocalPlayer, const FGameInstancePIEParameters& Params)

[atomic vale]

Hi. I have a question. I will be working on creating simple 4 players multiplayer game. Only playing with friends, nothing huge. I don't want to host dedicated server online, therefore I want to go with Listen Server, so one of the clients hosting the game. That's not debatable, that's the system I will be going with, I know its pros and cons.

My only question is.. do I need to ask my internet provider to grant me public IP, or should it just work using my public ip right now?
By public IP I mean that normally within your household broadband, you cannot normally host servers until you specifically ask your internet provider for it, and pay extra or have business network.
Is that the case with listen server for UE4 as well, or should it just work(maybe UE does some magic)?
If I need that public IP, then how do other games do it, so that they have listen server or peer-to-peer connections directly between players, without them needing external IP?

[thin stratus]

By public IP I mean that normally within your household broadband, you cannot normally host servers until you specifically ask your internet provider for it, and pay extra or have business network.

Ehm

ListenServer can host without that

Just need a proper NAT PunchThrough + MasterServer

e.g. via Steam

No need for a public IP

You can't get a static one in Germany unless you are a business :D

[dark edge]

@atomic vale you will want some sort of NAT punchthrough. Usually your OnlineSubSystem handles that.

@atomic vale for testing you can just forward the unreal engine ports and direct connect to your IP address.

[sinful tree]

yeah most ISPs won't care if you're running a small server on your network, especially if it's not being accessed frequently. It's only when you start to get into having major traffic into your home would they care that you're hosting something.

[limber gyro]

Does any 1 know if theres a way to detect if steam is active, be it through c++ or BP?

[sinful tree]

Yes, but it requires you to implement Steam's online subsystem.

[limber gyro]

it is already

i just want to know the line of code/BP node if theres any

[sinful tree]

If you create a blueprint function library you can do this:
.h file:

#pragma once

#include "CoreMinimal.h"
#include "Kismet/BlueprintFunctionLibrary.h"
#include "Online.h"
#include "OnlineSubsystem.h"
#include "ThirdParty/Steamworks/Steamv147/sdk/public/steam/steam_api.h"  //This line may need to change based upon what version you have 


class IOnlineSubsystem;
/**
 * 
 */
UCLASS()
class GASDOCUMENTATION_API UGDBlueprintLibrary : public UBlueprintFunctionLibrary
{
    GENERATED_BODY()

public:
    // Retrieves the current Steam session ticket available on the PC.
    UFUNCTION(BlueprintPure, category = "Steam")
    static FString GetSteamSessionTicket();
}```

.cpp

#include "GDBlueprintLibrary.h"

FString UGDBlueprintLibrary::GetSteamSessionTicket()
{
    if (SteamAPI_Init()) 
    {
        IOnlineSubsystem* OnlineInterface = IOnlineSubsystem::Get();
        FString SessionTicket = OnlineInterface->GetIdentityInterface()->GetAuthToken(0);
        return SessionTicket;
    } 
    else
    {
        return FString(TEXT("0"));
    }
}```

If it fails to get the ticket, steam is not open and online and will return "0"

May need to change the class name declarations in the .h to fit your project too.

You will also be able to call "Get Steam Session Ticket" in blueprints as well to get the value.

[limber gyro]

ty

did a bit of diging in google and found a simpler solution with the advanced sessions plugin which i alredy have

if u do "get steam persona name" and it returns 0 then steam if not running

[sinful tree]

Nice, probably does the same kinda call.

[shut gyro]

Yes, I have to send turret data to replicate every tick. One for each client to send up and then there is logic to receive data on the simulated proxies.

[sinful tree]

It floods the network, especially if you're doing reliable calls.

[limber gyro]

the work around is turning out to bee to messy might just have to use ur solution

[dark edge]

Don't send a reliable call every frame. Mark control variables as non reliable.

[shut gyro]

This is my implementation:

        void Server_SendMove(FCDTurretMove Move);```

So it already is unreliable, not sure why I would get Reliable buffer overflow. on that function call then

What do you mean to set control variables as non-reliable? I thought you can only set functions to be reliable/unreliable

[dark edge]

I mean sending over dynamic analog things like aim rotation or input vector or whatever. Anything continuous

[limber gyro]

wont calling init on steam again cause issues?

[sinful tree]

To be honest, I'm not sure. In my use case, I'm only calling it on a client PC and using the session ticket. I don't use any other Steam API functions.

[limber gyro]

i cant even compile ur code lol

its complaining about a bunch of unidentified stuff

guess i will google it some more

[sinful tree]

This tutorial tells you how to set up whats needed to get the session ticket, but in my case I used my blueprint function library instead of creating a C++ character
https://www.youtube.com/watch?v=4CgeAxiS19s

[vocal cargo]

@winged badger @lost inlet
Ended up using in-editor features.
The Switch SDK has a input keybind that you can change the actual physical mapping of those buttons, so they work in the menus as intended without any extra code involved. Just got to map the actual in-game keybindings when the platform is the switch and that's it

[atomic vale]

Thanks. So what I did now, I integrated minipnpc library into UE4 to port forward, and it works, forwards all ports we need just fine, but there is additional issue. Everyone can easily connect to me, but if anyone hosts they can't connect to him. In other words, only I am able to host, nobody else. We tried disabling firewalls, port forwarding manually, nothing seems to work. I have no idea what's different about my network. None of us have business network. None of us applied for public ip, yet only I am able to host properly. Master server is something I'll add later, at the moment we just want to connect by sharing our IP

[dark edge]

The minimum amount of steps necessary should just be to have the project, and forward the ports. Are you sure those ports aren't blocked when your friend hosts?

[atomic vale]

Well, I am never 100% sure about it, but I did set up port forwarding for them myself, and I think it should work just fine

Maybe lack of NAT punch is what's missing?

[dark edge]

Just forwarding has always worked for me. How are they joining?

[atomic vale]

simply by open xx.xx.xx.xx

we always use standard 7777 port

And it works immediately when I am hosting. Although I am in UK and they are in other parts of Europe

But whenever anyone else is hosting, nobody can connect to him, even me

[meager spade]

problem is normal routers use NAT to map incoming stuff to the correct device

you connect using the IP, the router needs to make sure it gets to the correct endpoint, this is the main disadvantage with home networks and a single IP. You will need to use something that sets up a punch through, so it goes direct to that machine. You really don't want people to have to adjust there router settings for your game, which is why things like Steam, setup a nat punchthrough and you can connect in mostly all cases (there are exceptions of course)

[atomic vale]

Yeah, I don't want players to play with any of this stuff, which is why I integrated UPnP NAT-PMP library o port forward all of this automatically. But that doesn't seem to be enough. I need to educate myself on the NAT punchthrough.
But since our game will be 100% deployed on Steam... do you recommend using existing Steam libraries for this?

[meager spade]

we use steam just fine

not for dedicated servers though

ours is Listen Server

[atomic vale]

I am not going to use dedicated, just listen

[meager spade]

yeah we just use steam, not had any major issues or reports of people not being able to connect

[atomic vale]

So steam libraries actually provide API to do the punchthrough as well as the master servers?

[meager spade]

we dont use master servers

we use steam lobbies

and this provides a way to list games, etc players can join

[atomic vale]

That's great. But is it all compatible with UE networking? Or do I have to use some kind of steam networking system to run the game? I am guessing that steam works simply to figure out what port router chose to send packets outside the NAT, and then just populate it through that servers lists?

[meager spade]

steam does it all

you don't connect using IP

this is what a lobby looks like with steam lobbies

[atomic vale]

But it's still using UE networking then?

[hollow eagle]

You have the option to use steam sockets as the netdriver.

[meager spade]

yes we use steam as the netdriver

[atomic vale]

Oh yeah that's true

forgot there is that one

[hollow eagle]

When turning on the steam OSS I believe it turns on steam sockets by default

[atomic vale]

Cool! I'll try educating myself on that steam net stuff tomorrow 🙂 Thanks for clarifying that for me!

[meager spade]

steam is not too bad

this is how you connect to the host when using steam lobbies UKismetSystemLibrary::ExecuteConsoleCommand(this, FString::Printf(TEXT("open steam.%s"), *GetCurrentGameLobby().LobbyOwnerIDString), UGameplayStatics::GetPlayerController(this, 0));

you don't use IP's (you don't know IP's)

[atomic vale]

Nice one! Thanks a lot. Does it provide option to put password in a lobby or something like that? Or is it already something to implement ourselves?

[meager spade]

not sure if there is a password system in steam lobbies

i don't remember ever seeing one

this should be something that is trivial

[atomic vale]

Because I would like to be able to only join session with our friends, not particularly having a whole list of available sessions

[meager spade]

you can store lobby data, which can be a password, upon connecting if that value is non-empty, then you ask them for the password

then compare, if its wrong, don't join

like i would do this in the server browser

before attempting connection

you click on an entry, it checks for password, shows dialog, match password, reject or accept

[atomic vale]

Yeah of course, that just introduces risk of cheaters joining the session, if password is verified locally

[meager spade]

would probably want to store the password encrypted

and only match encrypted versions

[hollow eagle]

you could have the client send the password over to the server/host when they join, server kicks them if it doesn't match

it's not like you lose control over the game when you are using steam lobbies

[atomic vale]

right, that sounds good

[meager spade]

plenty of ways to do it

either prejoin

or whilst joining

i would likely do it prejoin

[atomic vale]

Cool, I need to see how that whole thing is handled, then I will definitely pull something out

You helped me a lot. Thank you

[echo trench]

Hey I'm really stuck with something and I have spent a lot of time looking for workarounds but found nothing suitable.

I'm trying to find out if there is a way to use something similar to Instance Level (by name) to spawn a copy of another level at a specific position in such a way that it is replicated to the clients (Which is not the case for that function). Do you guys know of a way to achieve that/work around it?

[karmic briar]

hey guys i wanna ask is there getping() fucntion equivalent in bp?

[meager spade]

Ping

just that

[karmic briar]

or its this replicated variable one

[round roost]

Is it possible to replicate some actors only to specific clients?

without manual RPCs

[karmic briar]

thats my current setup right now

[meager spade]

@round roost override IsNetRelevantFor in C++

and you can adjust who will get it

GetPing just returns Ping

in BP you just use Ping, C++, you use GetPing

[karmic briar]

ahh okay

thanks

[round roost]

in the character?

[meager spade]

what you mean?

the actor you don't want to replicate to specific players, you have to override its IsNetRelevantFor

[round roost]

Ah its in the replicated actor?

got it, thanks

[heady python]

How can i make smooth replicated movement in BP's? Everything i try to do ends up rubberbanding the client or not updating to the server/ other clients.

[kindred widget]

@heady python What kind of movement?

[heady python]

character movement. WASD and jumping/crouching

[kindred widget]

Should be pretty smooth by default. You're just using AddMovementInput for WASD right?

Jumping should also be replicated fairly well with the Character's Jump/StopJumping functions, and I recall there being a default crouch function as well. If you haven't changed any settings, these should all function fairly decently over network.

[shy osprey]

what's the best way to get network stats and debug?

And also getting variables from a weapon to the HUD? The HUD sees the weapon reference on the client, but the values all read 0, despite being replicated

[winged badger]

weapon can just register with the HUD

on BeginPlay or some such

if its Owner is LocallyControlled

[shy osprey]

The HUD has the weapon reference on the Client.

I've set it up so that when the weapon fires or one of the variables is updated, it calls an event dispatcher.

The HUD has bound an event to those dispatchers, so that when the the weapon fires, I can pull the reference to the weapon and get the variable, then pass it to the ammo counter.

The event dispatcher doesn't fire on the client though. So I have a second event on the character that calls the update on the HUD. This event does fire every time I shoot, but the ammo count reads 0 every time.

the ammo and dispatchers are set to replicate, and the weapon firing and variable updates occur on the server, called by a Gameplay Ability.

[winged badger]

have you verified the client has good ammo counts?

you can access the HUD Actor easily, from anywhere that has world context

GetGameInstance()->GetFirstLocalPlayerController()->GetHUD()

what i am suggesting is trying to inject the weapon dependency into the HUD, and then having the HUD instantiate your weapon panels after receiving it

rather then relying on order of replication for that reference to be good at the time you do the delegate bindings

[shy osprey]

The reference is set when I equip the weapon

And I can verify it's always a good reference

[winged badger]

on start of the game, if weapon is spawned at runtime

[shy osprey]

I am finding that the Client is not getting good values for the weapon, they take a while to sync up