Need help with replicating Yaw.

Development Programming & Scripting C++
1

If this question is in the wrong forum or can be solved with Blueprints, please move it to the proper section.

Heyo UE Community,

I found this Project a couple hours ago for a Top Down Shooter ( GitHub - EdwardCoughlan/TwinStickShooter: Twin stick shooter starting point ) and got it working with the latest UE4 Version (was only some minor stuff to fix).

Sadly I am only learning Blueprints right now and the project is written in C++, where it also has Blueprints.

The thing is:

Moving the mouse lets the Owen Actor look around where the mouse is pointing. If I emulate a 2nd player (Dedicated Server Checkbox checked or not), then the mouse look is not being replicated. Can this only be done in C++, since it is a C++ project or can it also be done using Blueprints?

(Asking this, since I tried to use BP Replication and it somehow did not work, but I bet I just did something wrong)

Either yes or no: Can someone point me in the right direction? That would be nice.

Greetings,

2

Hi, I’m pretty sure your problem can be solved in Blueprints. It may have been an issue if a C++ parent class of your Blueprint would override certain settings after initiliazation, but the C++ classes in your linked project don’t do anything like this. Aside from Yaw, is movement replicated?

I think the issue may be that the Yaw that you see is only set client-side, in a way that the value not replicated. I’m not sure how Yaw is actually set, from the code you linked (haven’t downloaded the project). The best I can find is this in TwinStickShooterPlayer.cpp:

But I don’t see where the value of AimAtAngle is actually used in other cpp files, maybe its used in the level blueprint? You could try out this: In C++, ATwinStickShooterPlayerController::LookAtMouseCursor(), manually set the pawn’s actor rotation using SetActorRotation. If you can find where AimAtAngle is used in the level blueprints or pawn’s event graph, can you post a screenshot of the setup?

3

Thank you for the reply, NisshokuZK.

Aside from the “event tick” (how i would call it now) yaw, everything is replicated. The Character updates properly whenever movement with the keyboard keys is done, only the AimAtAngle with the mouse is not being updated.

I also added a Weapon via Blueprint and picking it up is being replicated as well.

I will check the C++ files and Project right away :slight_smile:

EDIT:

AimAtAngle is not defined in the Level Blueprint and TSS_Hero is the Character’s Blueprint, which is empty as well. Everything is completely C++ based.

AimAtAngle is defined in the following places:

TwinStickShooterCharacter.cpp:


ATwinStickShooterCharacter::ATwinStickShooterCharacter(const class FPostConstructInitializeProperties& PCIP)
	: Super(PCIP)
{
...
AimAtAngle = 0;
}

TwinStickShooterCharacter.h:


class ATwinStickShooterCharacter : public ACharacter
{
...
	//Current Aiming Angle initial is 0;
	/** UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Aimer)  **/
	UPROPERTY(EditAnywhere, Category = Aimer)
	float AimAtAngle;
...
}

TwinStickShooterPlayerController.cpp:


void ATwinStickShooterPlayerController::LookAtMouseCursor()
{
	ATwinStickShooterCharacter* const MyPawn = (ATwinStickShooterCharacter*)GetPawn();
	if (MyPawn)
	{
...
		//The Aim at angle for the character
		MyPawn->AimAtAngle = ((acosf(FVector::DotProduct(PlayerDirection, MouseDirection))) * (180 / 3.1415926));
...
}

TwinStickShooterPlayerController.h:


UCLASS()
class ATwinStickShooterPlayerController : public APlayerController
{
	GENERATED_UCLASS_BODY()

	//Current Aiming Angle initial is 0;
	/** UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Aimer) **/
	UPROPERTY(EditAnywhere, Category = Aimer)
	float AimAtAngle;
...
}

I can’t find any other instances of AimAtAngle nor anywhere within the Project’s Blueprints.

EDIT:

Tried it with C++ and the SetActorRotation, but I’m not a C++ person (so far). Failed with implementing SetActorRotation on the C++ side. ^^’

4

This post by Tom Shannon has provided me some insight on what the problem is. Be sure to check it out.

Ignore AimAtAngle for now, it seems to be a variable that isn’t further used. Also, calling SetActorRotation in C++ isn’t going to help for synchronization unless it happens server-side. So what needs to be done is, you need to request the server to change your pawn’s rotation. Check out the post I linked and the third BP diagram in particular. Hope that helps. :slight_smile:

5

Thanks for the link, but it isn’t working. I added the BP nodes as how it is shown there, but nothing happens, except that now one player sees the other facing in the W Key Direction, instead of the Actor also turning and looking in the other directions :confused:

Still investigating it.

Here’s my current EventGraph from TSS_Hero as attachement.

EDIT:

Oh wait, do you mean the one I followed or the one above that one?

6

Hmm…I “google’d” a lot and found no solution for the problem, except others also having this problem, that extending the Top Down Example to have mouse look causes it to only work for a single player. It can work for more than one player, if both players are clients and connect to a dedicated server, but a peer 2 peer solution…haven’t found one so far.

7

Bump:

I’m highly lost with getting it replicated :confused: I tried several suggestions and examples I found to replicate it with Blueprints, but somehow it won’t work :frowning: