I have created two level sequences, simple roll of an actor object. My goal is to be able to see those objects roll in all clients.
I do replicate the event on server and with multicast. I see that the blueprint goes up to the point to play the sequence but it is only triggered for the server.
Is it possible to trigger a sequence over network or I should use a different approach?
Found the solution, if anyone stumbles upon the same issue. I triggered the sequence through the player character and it worked just fine.
Related
I need a little advice with deploying Triton inference server with explicit model control. From the looks of it, this mode gives the user the most control to which model goes live. But the problem I’m not able to solve is how to load models in case the server goes down in production which triggers a new instance to spawn up.
The only solution I can think of is to have a service poll the server at regular time intervals, constantly check if my live models are actually live and if not, load them. But this seems like quite a complicated process.
I would like to know how others have solved this problem.
Thanks in advance
I'm trying to understand how to call events between client and server. My goal for now is simple. I want to create anything that is interactable for 2 players.
Easiest thing I could think of was cube that is switching color when clicked. So I did create actor based blueprint, checked "Replicates" and AlwaysRelevant to be sure. PlayerController is also replicated and there is no pawn needed.
Color change blueprint:
SM is just static mesh if that is important. As far as I know client have no authority to call multicast events so I wanted to push it through server but it stops there. Called from server works as expected and color itself IS replicated to client, however client cannot change color himself.
What am I missing in this concept? I've watched like 5 videos about replication and I started to think there is something missing which is either obvious for everyone but me or their examples do not need things I do here.
As you've found out, a player's client can not directly call server RPCs on actors which the player does not own. Calls must be routed through that player's PlayerController. The server copy of the player's PlayerController can then call server methods on server-owned actors.
Another issue is that you seem to be using both RPCs and replicated properties for the same purpose. Unclear to me why changed is replicated since you're modifying it in a multicast event which normally runs on all the machines. This is a recipe for hard to find race condition bugs.
Replication in Unreal is definitely one of the harder concepts to get the hang of. The resource that helped me the most is this guide which while quite dated, is both comprehensive and to the point.
You can't have it in PlayerController, it's got to be in a Pawn, or if not, in PlayerState, or it won't get shared to other clients.
What I'm trying to make
Hi, game development newbie here. The game I am trying to make is fairly simple. It's almost exactly like the old FC game "Ballon Fight" except that I'm trying to make it online where players can go through a match making to find opponents.
BalloonFight:
What I Read
I have read some articles, and found most of them lead to two approaches:
Put all game logic on the client, and the client sends player inputs to server on every frame update. The server acts like a dispatcher which only makes sure player A's input is received by both client A and B. My understanding is that if we see the client in this case as a pure function, and if the two players' inputs are received by each other, the game should produce same results on both clients. Thus synchronization is achieved.
Put all game logic on the server, and let the server do the calculations and send back results to both clients. In this case, clients only worry about displaying.
My Fears
Solution 1 sounded like a simpler one to me, but immediately I realized when network problem is put into account, it becomes incredibly complicated. Losing player A's connection for a few seconds means all the input is lost in that period. What I can guess is, to counter that, the server has to detect whether player A is lagged out and accumulate input from player B until player A is back then feed all the accumulated input to player A's client. Player A's client then need to do a fast forward to catch up. This sounds like there's huge amount of infra work on both client side and server side.
Solution 2 on the other hand looks very daunting to me, since for now I have only written some games on the client side.
My questions
in order to make a simple online game like this, what is the most beginner friendly way to synchronize game state?
if I were to use solution 1 stated above, is there any framework that provides such infra so that I don't have to handle network issues all by myself?
In advance, thank you game dev gurus.
Using Axon framework- I was able to replay the entire event store and re-create the view model. But is it possible to replay event for a particular type or for a particular Id.
Let's say, I have a customer event and I want to replay all the event of a customer with Id= 100. Is it make sense to do a replay for a particular customer or it make more sense to replay for the entire event store always?
Thanks in advance
It is OK to do whatever makes sense for you, for this particular ReadModel.
One reason to re-process only one customer is the speed. If it's a lot faster than a complete rebuild (i.e because you have a lot of customers) and the outcome is the same then do it.
As Constantin points out, this request to replay a specific view makes total sense.
The provided replay process in Axon Framework at this point only provides to trigger a replay for a specific Processing Group allowing you to set the point in time from when you want to replay it.
There are ideas to provide a more fine grained solution to replaying, I'd however be hard pressed to tell you when that'll happen.
Thus replaying just a single view model for, for example speed, will require some custom code.
Let me know if you'd be interested in some pointers on how to do that.
Update
I'd like to state that with more recent versions of Axon Framework is is possible to tell a TrackingEventProcessor to reset itself, thus replay a set of events.
The API for this is the TrackingEventProcessor#resetTokens(TrackingToken), which allows you to reset a Tracking Event Processor from a given point in time.
This still doesn't give you the option to replay a given instance of a Read Model. This would still require some handy work from your part.
I´m just trying to wrap my head around CQRS(/ES). I have not done anything serious with CQRS. Probably I´m just missing something very fundamental right now. Currently, I´m reading "Exploring CQRS and Event Sourcing". There is one sentence that somehow puzzles me in regards to commands:
"A single recipient processes a command."
I´ve seen this also in the CQRS sample application from Greg Young (FakeBus.cs) where an exception is thrown when more then one command handler is registered for any command type.
For me, this is an indication that this is a fundamental principle for CQRS (or Commands?). What is the reason? For me, it is somewhat counter-intuitive.
Imagine I have two components that need to perform some action in response to a command (it doesn´t matter if I have two instances of the same component or two independent components). Then I would need to create a handler that delegates the command to these components.
In my opinion, this is introducing an unnecessary dependency. In terms of CQRS, a command is nothing more than a message that is sent. I don´t get the reason why there should be only one handler for this message.
Can someone tell me what I am missing here? There is probably a very good reason for this that I just don´t see right now.
Regards
I am by no means an expert myself with CQRS, but perhaps I can help shed some light.
"A single recipient processes a command.", What is the reason?
One of the fundamental reasons for this is transactional consistency. A command needs to be handled in one discrete (and isolated) part of the application so that it can be committed in a single transaction. As soon as you start to have multiple handlers, distributing the application beyond a single process (and maintaining transactional consistency) is nearly impossible. So, while you could design that way, it is not recommended.
Hope this helps.
Imagine I have two components that need to perform some action in response to a command (it doesn´t matter if I have two instances of the same component or two independent components). Then I would need to create a handler that delegates the command to these components.
That's the responsibility of events.
A command must be handled by one command handler and must change the state for a single aggregate root. The aggregate root then raises one or more events indicating that something happened. These events can have multiple listeners that perform desired actions.
For example, you have a PurchaseGift command. Your command handler loads the Purchase aggregate root and performs the desired operation raising a GiftPurchased event. You can have one or more listeners to the GiftPurchase event, one for sending an email to the buyer confirming the operation and another to send the gift by mail.