Replicating a cpp type on blueprint

Development Programming & Scripting Blueprint
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1

Hi,

I created in c++ a new type for use in blueprints. The type works and it behaves correctly.
Hovever, when I set on the blueprint that variable as replicated, it is not.
I have tested and if I create a variable of a different type with the same setup, it is replicated, so I assume is something wrong with my type definition.

In terms of the class definition (EDITED)

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "Object.h"
#include "Order.h"
#include "UnrealNetwork.h"
#include  "MasterGruntC.h"
#include "Plan.generated.h"


/**
*
*/
UCLASS(BlueprintType, Blueprintable)
class THESIS_API UPlan : public  UObject
{
	GENERATED_BODY()
public:

	UPROPERTY(Replicated)
	bool bcanContinue;
	UPROPERTY(Replicated)
	TArray < UOrder*> orders;
	UPROPERTY(Replicated)
	TArray < AMasterGruntC*> soldiers;
	UPROPERTY(Replicated)
	FString planName;
	UPROPERTY(Replicated)
	int planPhase;


	
	UPlan(FString newPlanName);
	UPlan();

	//Plan Maintenance
	UFUNCTION(BlueprintCallable, Category = "Plan")
	void changeName(FString newName);

	UFUNCTION(BlueprintCallable, Category = "Plan")
	void resetPlan();

	//Orders
	UFUNCTION(BlueprintCallable, Category = "Plan")
	bool executeNextOrder();
	UFUNCTION(BlueprintCallable, Category = "Plan")
	void addOrder(UOrder* newOrder);
	UFUNCTION(BlueprintCallable, Category = "Plan")
	FText showOrders();
	UFUNCTION(BlueprintCallable, Category = "Plan")
	void removeOrder(int index);
	
	//Soldiers
	UFUNCTION(BlueprintCallable, Category = "Plan")
	void addNewSoldier(AMasterGruntC* newSoldier);
	UFUNCTION(BlueprintCallable, Category = "Plan")
	void removeSoldier(int index);
	UFUNCTION(BlueprintCallable, Category = "Plan")
	void listSoldiers();
	UFUNCTION(BlueprintCallable, Category = "Plan")
	bool checkIfSoldiersReady();


	//Replication
	void GetLifetimeReplicatedProps(TArray< FLifetimeProperty > & OutLifetimeProps) const;

};

And the override

void UPlan::GetLifetimeReplicatedProps(TArray< FLifetimeProperty > & OutLifetimeProps) const {
	Super::GetLifetimeReplicatedProps(OutLifetimeProps);

	DOREPLIFETIME(UPlan, bcanContinue);
	DOREPLIFETIME(UPlan, orders);
	DOREPLIFETIME(UPlan, soldiers);
	DOREPLIFETIME(UPlan, planName);
	DOREPLIFETIME(UPlan, planPhase);

}

And the blueprint setup, where repTest is changed but plan is not.

126540-repsetup.png
126540-repsetup.png1587×281 89.4 KB

Finally the var definition on blueprint:

126541-varsetup.png
126541-varsetup.png473×554 23.9 KB

Variables:

126621-notreplicated.png

2

I changed the c++ parent class from UObject to AInfo, as I read that it had replication already implemented. Still no change.

3

This is a good start point for learning the concepts of replication in C++: https://wiki.unrealengine.com/Networking/Replication

https://wiki.unrealengine.com/Replication

In short:

  • Declare the members you wish to replicate as UPROPERTY

  • They must be marked UPROPERTY(Replicated)

  • You must override the function

    virtual void GetLifetimeReplicatedProps(class TArray<class FLifetimeProperty, class FDefaultAllocator>& OutLifetimeProps) const;

4

Thank you for your answer but it still does not work. Edited code in main question.

5

Please derive your UPlan from AActor, not UObject (and name it APlan), because property replication only works on actors (and members/components of actors) out of the box. Sorry, I thought you had already done this, because you mentioned AInfo in your comment above.

6

My problem with doing that is the spawn transform needed when creating the plan reference. This class does not need to spawn in the level.

7

I’m pretty sure you can also get your UObject replicating (I don’t know which implementations are necessary to do that), but I am also pretty sure it will be much easier using an Actor, even if it is not visible in the game. You can use default/empty transform for the spawn.
Another approach would be to make the Plan a UActorComponent of another Actor in your game. Not sure if this fits better into your design.
It is also possible to let the Plan be a component of your GameMode or GameState class (which are both actors, even though they do not spawn in level, btw).