UE4 射线检测

1.获得射线起点

FVector StartLocation;
	FRotator PlayerRotation;

	this->GetWorld()->GetFirstPlayerController()
		->GetPlayerViewPoint(StartLocation, PlayerRotation);

2.获得射线终点

FVector EndLocation = PlayerRotation.Vector() * RayLength;

3.获得射线路径

FVector LineTrace = StartLocation + EndLocation;

4.画出射线

	DrawDebugLine(GetWorld(), StartLocation, LineTrace, FColor(255, 0, 0),
		false, 0.0f, 0.0f, 10.0f);

5.发出射线，并返回被击中物体

FHitResult HitResult;	
	FCollisionQueryParams QueryParams = FCollisionQueryParams("", false, GetOwner());
	GetWorld()->LineTraceSingleByObjectType(HitResult, StartLocation,
			LineTrace,
		FCollisionObjectQueryParams(ECollisionChannel::ECC_PhysicsBody), 
		QueryParams );

6.打印目标名字

AActor *HitObject = HitResult.GetActor();
	if (HitObject != nullptr)
	{
		UE_LOG(LogTemp, Warning, TEXT("Name: %s"), *(HitObject->GetName()));
	}