Does anyone else have this? Even when I turn on the debug trace line when it is not appearing my boolean check still ticks that it has the solution, for example when I aim at the sky, there is no debug trace, but it is still ticking and showing as if it found the solution. Weird.
Yes, this happens for me. It just always returns true. Did you end up finding the cause?
I think because when we aim at the sky sphere, we are actually aiming at 0,0,0. If you remember, we made HitLocation equal FVector(0) in GetLookVectorHitLocation. And because 0,0,0 is close by, we can technically hit it. This thread shows how you can fix that: Aim solution found problem
However, it’s still annoying, because apparently the other logs that say you can find an aiming solution are actually just the AI tanks that are aiming at you. Why wasn’t this the case with Ben’s AI tanks? Your guess is as good as mine. It sucks to have inconsistencies like this, but it’s good for learning I suppose!
I noticed the same problem. Here is how I solved it.
The problem isn’t really that we aim at (0, 0, 0). The problem is that we are trying to aim when we shouldn’t be trying to!
In the TankPlayerController.cpp, I noticed that the GetSightRayHitLocation method ALWAYS returns true, which shouldn’t be the case. Returning true means that the ray hitted something to aim at, but the ray will never hit the sky!
To fix that, I did this:
// Get the look direction from the screen position of the crosshair
FVector LookDirection;
if (GetLookDirection(ScreenLocation, LookDirection))
{
// Line-trace along that look direction, and see what we hit (up to max range)
return GetLookVectorHitLocation(LookDirection, OutHitLocation);
}
return false;
With this, I actually return the result of the GetLookVectorHitLocation method insteed of always returning true 
1 Like
Nicely spotted! This problem was driving me crazy!
Thank you!
so i tried all the methods listed by @jinhyui and @Kevin_Duguay and i still get the sky to return as “Aim solution found”.
heres my TankAimingComponent.cpp:
// Fill out your copyright notice in the Description page of Project Settings.
#include "TankBarrel.h"
#include "TankAimingComponent.h"
// Sets default values for this component's properties
UTankAimingComponent::UTankAimingComponent()
{
// Set this component to be initialized when the game starts, and to be ticked every frame. You can turn these features
// off to improve performance if you don't need them.
PrimaryComponentTick.bCanEverTick = true;
// ...
}
void UTankAimingComponent::SetBarrelReference(UTankBarrel* BarrelToSet)
{
Barrel = BarrelToSet;
}
void UTankAimingComponent::AimAt(FVector HitLocation, float LaunchSpeed)
{
auto OurTankName = GetOwner()->GetName();
auto BarrelLocation = Barrel->GetComponentLocation().ToString();
// UE_LOG(LogTemp, Warning, TEXT("%s aiming at direction: %s from: %s"), *(OurTankName), *(HitLocation.ToString()), *(BarrelLocation));
// UE_LOG(LogTemp, Warning, TEXT("Firing at speed: %f"), LaunchSpeed);
FVector OutLaunchVelocity(0);
FVector StartLocation = Barrel->GetSocketLocation(FName("Projectile"));
// Calculate the OutLaunchVelocity
const TArray<AActor*> ActorsToIgnore;
bool bHaveAimSolution = UGameplayStatics::SuggestProjectileVelocity(this,
OutLaunchVelocity,
StartLocation,
HitLocation,
LaunchSpeed,
false, 0, 0,
ESuggestProjVelocityTraceOption::DoNotTrace,
FCollisionResponseParams::DefaultResponseParam,
ActorsToIgnore,
true);
if(bHaveAimSolution&&(HitLocation!=FVector(0)))
{
auto AimDirection = OutLaunchVelocity.GetSafeNormal();
// UE_LOG(LogTemp, Warning, TEXT("Aiming at : %s"), *(AimDirection.ToString()));
MoveBarrelTowards(AimDirection);
auto Time = GetWorld()->GetTimeSeconds();
UE_LOG(LogTemp, Warning, TEXT("%f: Aim solution found"), Time);
}
else
{
auto Time = GetWorld()->GetTimeSeconds();
UE_LOG(LogTemp, Warning, TEXT("%f: No aim solution found"), Time);
}
}
void UTankAimingComponent::MoveBarrelTowards(FVector AimDirection)
{
// Work out difference between current barrel rotation and AimDirecdtion
auto BarrelRotator = Barrel->GetForwardVector().Rotation();
auto AimAsRotator = AimDirection.Rotation();
auto DeltaRotator = AimAsRotator - BarrelRotator;
// UE_LOG(LogTemp, Warning, TEXT("AimAsARotator at : %s"), *(AimAsRotator.ToString()));
Barrel->Elevate(5); // TODO remove magic number
}
As you can see I also added some parameters suggested by @wilf, but that just to me looks like it lists a “history” of where it was aiming previously.
Some clarification as to why it keeps returning true for me would be greatly appreciated…
EDIT: I was messing around, and turns out for my specific case only the solution provided by @jinhyui and @Darren_Gresch was needed, and that by setting return false; in ATankPlayerController::GetSightRayHitLocation() actually prevented ATankPlayerController::AimTowardsCrosshair() from running since it would come back as false, so basically not going all the way to UTankAimingComponent::AimAt. here is my code for reference (theres a lot of log lines because i like keeping them around for future testing)
TankAimingComponent.cpp
// Fill out your copyright notice in the Description page of Project Settings.
#include "TankBarrel.h"
#include "TankAimingComponent.h"
// Sets default values for this component's properties
UTankAimingComponent::UTankAimingComponent()
{
// Set this component to be initialized when the game starts, and to be ticked every frame. You can turn these features
// off to improve performance if you don't need them.
PrimaryComponentTick.bCanEverTick = true;
// ...
}
void UTankAimingComponent::SetBarrelReference(UTankBarrel* BarrelToSet)
{
Barrel = BarrelToSet;
}
void UTankAimingComponent::AimAt(FVector HitLocation, float LaunchSpeed)
{
auto OurTankName = GetOwner()->GetName();
auto BarrelLocation = Barrel->GetComponentLocation().ToString();
// UE_LOG(LogTemp, Warning, TEXT("%s aiming at direction: %s from: %s"), *(OurTankName), *(HitLocation.ToString()), *(BarrelLocation));
// UE_LOG(LogTemp, Warning, TEXT("Firing at speed: %f"), LaunchSpeed);
FVector OutLaunchVelocity(0);
FVector StartLocation = Barrel->GetSocketLocation(FName("Projectile"));
// Calculate the OutLaunchVelocity
bool bHaveAimSolution = UGameplayStatics::SuggestProjectileVelocity(this,
OutLaunchVelocity,
StartLocation,
HitLocation,
LaunchSpeed,
false, 0, 0,
ESuggestProjVelocityTraceOption::DoNotTrace);
/* debug version:
const TArray<AActor*> ActorsToIgnore;
bool bHaveAimSolution = UGameplayStatics::SuggestProjectileVelocity(this,
OutLaunchVelocity,
StartLocation,
HitLocation,
LaunchSpeed,
false, 0, 0,
ESuggestProjVelocityTraceOption::DoNotTrace,
FCollisionResponseParams::DefaultResponseParam,
ActorsToIgnore,
true);
*/
if(bHaveAimSolution&&(HitLocation!=FVector(0)))
{
auto AimDirection = OutLaunchVelocity.GetSafeNormal();
// UE_LOG(LogTemp, Warning, TEXT("Aiming at : %s"), *(AimDirection.ToString()));
MoveBarrelTowards(AimDirection);
auto Time = GetWorld()->GetTimeSeconds();
// UE_LOG(LogTemp, Warning, TEXT("%f: Aim solution found"), Time);
UE_LOG(LogTemp, Warning, TEXT("%f: %s Aiming at : %s"), Time, *(OurTankName), *(AimDirection.ToString()));
}
else
{
auto Time = GetWorld()->GetTimeSeconds();
UE_LOG(LogTemp, Warning, TEXT("%f: No aim solution found for %s"), Time, *(OurTankName));
}
}
void UTankAimingComponent::MoveBarrelTowards(FVector AimDirection)
{
// Work out difference between current barrel rotation and AimDirecdtion
auto BarrelRotator = Barrel->GetForwardVector().Rotation();
auto AimAsRotator = AimDirection.Rotation();
auto DeltaRotator = AimAsRotator - BarrelRotator;
// UE_LOG(LogTemp, Warning, TEXT("AimAsARotator at : %s"), *(AimAsRotator.ToString()));
Barrel->Elevate(5); // TODO remove magic number
}
TankPlayerController.cpp
// Fill out your copyright notice in the Description page of Project Settings.
#include "Tank.h"
#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; }
// UE_LOG(LogTemp, Warning, TEXT("AimTowardsCrosshair still running for %s"), *(GetControlledTank()->GetName()));
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()));
GetControlledTank()->AimAt(OutHitLocation);
}
}
// 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;
}
HitLocation = FVector(0);
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);
}
it would be interesting to see why for @Kevin_Duguay the first solution did not work and that his solution of setting false worked for him…