GetLookVectorHitLocation() only returning 1.0, 1.0, 1.0

[ktonegawa]

I am officially stuck as I have honestly no idea what any of these lines are supposed to do (the explanation that Ben gives I find are too vague and without much context or repetitive use where I can’t really follow each line’s purpose).

I followed upto Lecture 139 and i only get the message LogTemp: Warning: Hit direction: X=1.000 Y=1.000 Z=1.000 in the Output Log (Please note that i am following the Archived course). Here are my files:

TankPlayerController.h:

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

#pragma once

#include "Tank.h"
#include "CoreMinimal.h"
#include "GameFramework/PlayerController.h"
#include "TankPlayerController.generated.h" // must be the last include

/**
 * 
 */
UCLASS()
class BATTLETANK_API ATankPlayerController : public APlayerController
{
	GENERATED_BODY()
	
private:
	ATank* GetControlledTank() const;

	virtual void Tick(float DeltaTime) override;

	virtual void BeginPlay() override;

	// Start the tank moving the barrel so that a shot would hit where
	// the crosshair intersects the world
	void AimTowardsCrosshair();
	
	// Return an OUT parameter, true if hits landscape
	bool GetSightRayHitLocation(FVector& OutHitLocation) const;

	UPROPERTY(EditAnywhere)
	float CrosshairXLocation = 0.5;

	UPROPERTY(EditAnywhere)
	float CrosshairYLocation = 0.33333;

	UPROPERTY(EditAnywhere)
	float LineTraceRange = 1000000;

	bool GetLookDirection(FVector2D ScreenLocation, FVector& LookDirection) const;

	bool GetLookVectorHitLocation(FVector LookDirection, FVector& HitLocation) const;
};

TankPlayerController.cpp:

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

#include "TankPlayerController.h"

void ATankPlayerController::BeginPlay()
{
	Super::BeginPlay();

	auto ControlledTank = GetControlledTank();
	if (!ControlledTank)
	{
		UE_LOG(LogTemp, Warning, TEXT("PlayerController not possesing a tank"));
	}
	else
	{
		UE_LOG(LogTemp, Warning, TEXT("PlayerController possessing: %s"), *(ControlledTank->GetName()));
	}

	UE_LOG(LogTemp, Warning, TEXT("PlayerController BeginPlay"));
}

void ATankPlayerController::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);
	AimTowardsCrosshair();
	// UE_LOG(LogTemp, Warning, TEXT("Player controller ticking"));
}

ATank* ATankPlayerController::GetControlledTank() const
{
	return Cast<ATank>(GetPawn());
}

void ATankPlayerController::AimTowardsCrosshair()
{
	if (!GetControlledTank()) { return; }

	FVector OutHitLocation; // Out Parameter
	if (GetSightRayHitLocation(OutHitLocation)) // Has "side-effect", is going to line trace
	{
		UE_LOG(LogTemp, Warning, TEXT("Hit direction: %s"), *(OutHitLocation.ToString()));
		// Tell controlled tank to aim at this point
	}
}

// Get world location if linetrace through crosshair, true if hits location
bool ATankPlayerController::GetSightRayHitLocation(FVector& OutHitLocation) const
{
	OutHitLocation = FVector(1.0);
	// Find crosshair position
	int32 ViewPortSizeX, ViewPortSizeY;
	GetViewportSize(ViewPortSizeX, ViewPortSizeY);
	auto ScreenLocation = FVector2D(ViewPortSizeX * CrosshairXLocation, ViewPortSizeY * CrosshairYLocation);
	// UE_LOG(LogTemp, Warning, TEXT("ScreenLocation: %s"), *(ScreenLocation.ToString()));
	
	// de-project screen position of the crosshair to world direction
	FVector LookDirection;
	if (GetLookDirection(ScreenLocation, LookDirection))
	{
		// Line-trace along that LookDirection and see what we hit
		//UE_LOG(LogTemp, Warning, TEXT("Look direction: %s"), *(LookDirection.ToString()));
		GetLookVectorHitLocation(LookDirection, OutHitLocation);
	}
		
	return true;
}

bool ATankPlayerController::GetLookVectorHitLocation(FVector LookDirection, FVector& HitLocation) const
{
	FHitResult HitResult;
	auto StartLocation = PlayerCameraManager->GetCameraLocation();
	auto EndLocation = StartLocation = (LookDirection * LineTraceRange);
	if (GetWorld()->LineTraceSingleByChannel(HitResult, StartLocation, EndLocation, ECollisionChannel::ECC_Visibility))
	{
		HitLocation = HitResult.Location;
		return true;
	}
	return false; // line trace didn't succeed
}

bool ATankPlayerController::GetLookDirection(FVector2D ScreenLocation, FVector& LookDirection) const
{
	FVector CameraWorldLocation; // To be discarded
	return DeprojectScreenPositionToWorld(ScreenLocation.X, ScreenLocation.Y, CameraWorldLocation, LookDirection);
}

The results were working upto the end result of Lecture 139 so now I have no clue of what broke here, as it compiles without errors, and from what it looks like I have written almost exactly what Ben wrote

Could I get some assistance to get this to a working result (where it registers basically 0 when pointing at the sky)?

[ktonegawa]

I realized after looking at Ben’s code on github that one of my lines was not adding values and instead was incorrectly reassigning variables:

auto EndLocation = StartLocation = (LookDirection * LineTraceRange);

should have been adding (instead of whatever was going on here):

auto EndLocation = StartLocation + (LookDirection * LineTraceRange);