Problem with OnComponentHit

Development Programming & Scripting
1

I have been following the FPS tutorial here When I get to the projectile interacting with the world section it tells me to the following line of code:
CollisionComp->OnComponentHit.AddDynamic(this, &AFPSProjectile::OnHit);
The AddDynamic function isnt there for me I can only call __Internal_AddDynamic which doesnt work.
So how can I call my OnHit function when I collide with an object?

2

Hi Luciuspain,

What happens if you AddDynamic manually without using the autocomplete and compile. Does it throw up an error?

-W

3

Yeah that worked thanks. I have been spoiled by autocomplete so I automatically assume if it doesnt show up in autocomplete its not there. Hopefully I wont make that mistake again.

4

hi, I have the same problem. AddDynamic don’t work.

FPSProjectile.h

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

#pragma once


#include "GameFramework/Actor.h"
#include "FPSProjectile.generated.h"

UCLASS()
class FPSPROJECT_API AFPSProjectile : public AActor
{
	GENERATED_BODY()

public:
	// Sets default values for this actor's properties
	AFPSProjectile();

	// Called when the game starts or when spawned
	virtual void BeginPlay() override;

	// Called every frame
	virtual void Tick(float DeltaSeconds) override;

	// Sphere collision component.
	UPROPERTY(VisibleDefaultsOnly, Category = Projectile)
		USphereComponent* CollisionComponent;

	// Projectile movement component.
	UPROPERTY(VisibleAnywhere, Category = Movement)
		UProjectileMovementComponent* ProjectileMovementComponent;

	// Function that initializes the projectile's velocity in the shoot direction.
	void FireInDirection(const FVector& ShootDirection);

	// Function that is called when the projectile hits something.
	UFUNCTION()
		void OnHit(AActor* OtherActor, UPrimitiveComponent* OtherComp, FVector NormalImpulse, const FHitResult& Hit);
};

FPSProjectile.cpp

// Fill out your copyright notice in the Description page of Project Settings.
#include "FPSProject.h"
#include "FPSProjectile.h"

// Sets default values
AFPSProjectile::AFPSProjectile()
{
	// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
	PrimaryActorTick.bCanEverTick = true;

	// Use a sphere as a simple collision representation.
	CollisionComponent = CreateDefaultSubobject<USphereComponent>(TEXT("SphereComponent"));
	CollisionComponent->BodyInstance.SetCollisionProfileName(TEXT("Projectile"));
	CollisionComponent->OnComponentHit.AddDynamic(this, &AProjectile::OnHit);

	// Set the sphere's collision radius.
	CollisionComponent->InitSphereRadius(15.0f);
	// Set the root component to be the collision component.
	RootComponent = CollisionComponent;

	// Use this component to drive this projectile's movement.
	ProjectileMovementComponent = CreateDefaultSubobject<UProjectileMovementComponent>(TEXT("ProjectileMovementComponent"));
	ProjectileMovementComponent->SetUpdatedComponent(CollisionComponent);
	ProjectileMovementComponent->InitialSpeed = 3000.0f;
	ProjectileMovementComponent->MaxSpeed = 3000.0f;
	ProjectileMovementComponent->bRotationFollowsVelocity = true;
	ProjectileMovementComponent->bShouldBounce = true;
	ProjectileMovementComponent->Bounciness = 0.3f;

	// Die after 3 seconds.
	InitialLifeSpan = 3.0f;
}

// Called when the game starts or when spawned
void AFPSProjectile::BeginPlay()
{
	Super::BeginPlay();

}

// Called every frame
void AFPSProjectile::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);

}

// Function that initializes the projectile's velocity in the shoot direction.
void AFPSProjectile::FireInDirection(const FVector& ShootDirection)
{
	ProjectileMovementComponent->Velocity = ShootDirection * ProjectileMovementComponent->InitialSpeed;
}

// Function that is called when the projectile hits something.
void AFPSProjectile::OnHit(AActor* OtherActor, UPrimitiveComponent* OtherComponent, FVector NormalImpulse, const FHitResult& Hit)
{
	if (OtherActor != this && OtherComponent->IsSimulatingPhysics())
	{
		OtherComponent->AddImpulseAtLocation(ProjectileMovementComponent->Velocity * 100.0f, Hit.ImpactPoint);
	}
}

these are the errors:

Errore C2664 ‘void TBaseDynamicMulticastDelegate<FWeakObjectPtr,void,UPrimitiveComponent *,AActor *,UPrimitiveComponent *,FVector,const FHitResult &>::__Internal_AddDynamic(UserClass ,void (__cdecl AFPSProjectile:: )(UPrimitiveComponent *,AActor *,UPrimitiveComponent ,FVector,const FHitResult &),FName)’: impossibile convertire l’argomento 2 da 'void (__cdecl AFPSProjectile:: )(AActor *,UPrimitiveComponent ,FVector,const FHitResult &)’ a 'void (__cdecl AFPSProjectile:: )(UPrimitiveComponent *,AActor *,UPrimitiveComponent *,FVector,const FHitResult &)’ FPSProject C:\Users\mrcso\Desktop\Marco[IMPORTANTE]–Studio–\UnrealEngine\ProveQuickProgramming\FPSProject\Source\FPSProject\FPSProjectile.cpp

Errore Failed to produce item: C:\Users\mrcso\Desktop\Marco[IMPORTANTE]–Studio–\UnrealEngine\ProveQuickProgramming\FPSProject\Binaries\Win64\UE4Editor-FPSProject-2933.dll FPSProject C:\Users\mrcso\Desktop\Marco[IMPORTANTE]–Studio–\UnrealEngine\ProveQuickProgramming\FPSProject\Intermediate\ProjectFiles\ERROR 1

Errore MSB3075 uscita del comando ““C:\Program Files (x86)\Epic Games\4.13\Engine\Build\BatchFiles\Build.bat” FPSProjectEditor Win64 Development “C:\Users\mrcso\Desktop\Marco[IMPORTANTE]–Studio–\UnrealEngine\ProveQuickProgramming\FPSProject\FPSProject.uproject” -waitmutex” con codice 5. Verificare di disporre di diritti sufficienti per eseguire il comando. FPSProject C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V140\Microsoft.MakeFile.Targets

5

Add a first argument UPrimitiveComponent* in your OnHit function

In .h

UFUNCTION()
void OnHit(UPrimitiveComponent* HitComponent, AActor* OtherActor, UPrimitiveComponent* OtherComponent, FVector NormalImpulse, const FHitResult& Hit);

In .cpp:

void AFPSProjectile::OnHit(UPrimitiveComponent* HitComponent, AActor* OtherActor, UPrimitiveComponent* OtherComponent, FVector NormalImpulse, const FHitResult& Hit)
{
	if (OtherActor != this && OtherComponent->IsSimulatingPhysics())
	{
		OtherComponent->AddImpulseAtLocation(ProjectileMovementComponent->Velocity * 100.0f, Hit.ImpactPoint);
	}
}