I am up to section 3.2 of the fps tutorial on unreal engine 4. In this section I’m supposed to implement shooting into the code via the fire function so that i can shoot projectiles in-game. However, after typing the code the tutorial provided, I got one error when compiling it. The error is as follows
/Users/apple/Documents/Unreal Projects/FPSProject/Source/FPSProject/FPSCharacter.cpp:120:38: ‘Instigator’ is a private member of ‘AActor’
When I remove this line and compile the code it does so successfully, but when I test it out on unreal, I can’t shoot projectiles at all.
Here is the code
FPSCharacter.cpp
#include “FPSCharacter.h”
#include “FPSProject.h”
#include “FPSCharacter.generated.h”
#include “FPSProjectile.h”
#include “GameFramework/Actor.h”
// Sets default values
AFPSCharacter::AFPSCharacter()
{
// Set this character to call Tick() every frame. You can turn this off to improve performance if you don’t need it.
PrimaryActorTick.bCanEverTick = true;
// Create a first person camera component.
FPSCameraComponent = CreateDefaultSubobject<UCameraComponent>(TEXT("FirstPersonCamera"));
// Attach the camera component to our capsule component.
FPSCameraComponent->SetupAttachment(GetCapsuleComponent());
// Position the camera slightly above the eyes.
FPSCameraComponent->SetRelativeLocation(FVector(0.0f, 0.0f, 50.0f + BaseEyeHeight));
// Allow the pawn to control camera rotation.
FPSCameraComponent->bUsePawnControlRotation = true;
// Create a first person mesh component for the owning player.
FPSMesh = CreateDefaultSubobject<USkeletalMeshComponent>(TEXT("FirstPersonMesh"));
// Only the owning player sees this mesh.
FPSMesh->SetOnlyOwnerSee(true);
// Attach the FPS mesh to the FPS camera.
FPSMesh->SetupAttachment(FPSCameraComponent);
// Disable some environmental shadowing to preserve the illusion of having a single mesh.
FPSMesh->bCastDynamicShadow = false;
FPSMesh->CastShadow = false;
// The owning player doesn't see the regular (third-person) body mesh.
GetMesh()->SetOwnerNoSee(true);
}
// Called when the game starts or when spawned
void AFPSCharacter::BeginPlay()
{
Super::BeginPlay();
if (GEngine)
{
// Put up a debug message for five seconds. The -1 "Key" value (first argument) indicates that we will never need to update or refresh this message.
GEngine->AddOnScreenDebugMessage(-1, 5.0f, FColor::Red, TEXT("We are using FPSCharacter."));
}
}
// Called every frame
void AFPSCharacter::Tick( float DeltaTime )
{
Super::Tick( DeltaTime );
}
// Called to bind functionality to input
void AFPSCharacter::SetupPlayerInputComponent(class UInputComponent* PlayerInputComponent)
{
Super::SetupPlayerInputComponent(PlayerInputComponent);
// Set up "movement" bindings.
PlayerInputComponent->BindAxis("MoveForward", this, &AFPSCharacter::MoveForward);
PlayerInputComponent->BindAxis("MoveRight", this, &AFPSCharacter::MoveRight);
// Set up "look" bindings.
PlayerInputComponent->BindAxis("Turn", this, &AFPSCharacter::AddControllerYawInput);
PlayerInputComponent->BindAxis("LookUp", this, &AFPSCharacter::AddControllerPitchInput);
// Set up "action" bindings.
PlayerInputComponent->BindAction("Jump", IE_Pressed, this, &AFPSCharacter::StartJump);
PlayerInputComponent->BindAction("Jump", IE_Released, this, &AFPSCharacter::StopJump);
PlayerInputComponent->BindAction("Fire", IE_Pressed, this, &AFPSCharacter::Fire);
}
void AFPSCharacter::MoveForward(float Value)
{
// Find out which way is “forward” and record that the player wants to move that way.
FVector Direction = FRotationMatrix(Controller->GetControlRotation()).GetScaledAxis(EAxis::X);
AddMovementInput(Direction, Value);
}
void AFPSCharacter::MoveRight(float Value)
{
// Find out which way is “right” and record that the player wants to move that way.
FVector Direction = FRotationMatrix(Controller->GetControlRotation()).GetScaledAxis(EAxis::Y);
AddMovementInput(Direction, Value);
}
void AFPSCharacter::StartJump()
{
bPressedJump = true;
}
void AFPSCharacter::StopJump()
{
bPressedJump = false;
}
void AFPSCharacter::Fire()
{
// Attempt to fire a projectile.
if (ProjectileClass)
{
// Get the camera transform.
FVector CameraLocation;
FRotator CameraRotation;
GetActorEyesViewPoint(CameraLocation, CameraRotation);
// Transform MuzzleOffset from camera space to world space.
FVector MuzzleLocation = CameraLocation + FTransform(CameraRotation).TransformVector(MuzzleOffset);
FRotator MuzzleRotation = CameraRotation;
// Skew the aim to be slightly upwards.
MuzzleRotation.Pitch += 10.0f;
UWorld* World = GetWorld();
if (World)
{
FActorSpawnParameters SpawnParams;
SpawnParams.Owner = this;
SpawnParams.Instigator = Instigator;
// Spawn the projectile at the muzzle.
AFPSProjectile* Projectile = World->SpawnActor<AFPSProjectile>(ProjectileClass, MuzzleLocation, MuzzleRotation, SpawnParams);
if (Projectile)
{
// Set the projectile's initial trajectory.
FVector LaunchDirection = MuzzleRotation.Vector();
Projectile->FireInDirection(LaunchDirection);
}
}
}
}