多人射击有点难，发现这个更加基础，先学习这个

显示日志

可以在代码中插入这样一行来打印日志，蓝图里的printstring会在屏幕和日志里都显示。可以使用%f，d等来获取后边的输入值。对于打映字符串变量，传入需要*

UE_LOG(LogTemp,Warning,TEXT("time:%f"), DeltaTime);
if (GEngine)
{	
	FString Name = GetName();
	FString Message = FString::Printf(TEXT("name:%s"), *Name);
	//显示位置，时间，颜色，文本
	GEngine->AddOnScreenDebugMessage(-1, 5, FColor::Red,Message);
}

 Draw a debug sphere

可以将画球的代码封装成宏，放到一个新的头文件里那么在别的代码里也能直接调用，同时引入头文件

 Draw a debug Line

if (World)
{	//获取向前的单位向量
	FVector Forward = GetActorForwardVector();
	//地图，起始点，终止点，颜色，时间
	DrawDebugLine(World,Location,Location+Forward*100.f,FColor::Red,false,60.f);
}

 Draw a debug point

if (World)
{
	DrawDebugPoint(World, Location + Forward * 100.f,15.f,FColor::Blue,true);
}

 将它们都定义成宏来调用

#define DRAW_SPHERE(Location) if(GetWorld()) DrawDebugSphere(GetWorld(), Location,25.f,24,FColor::Red,false,30.f);
#define DRAW_LINE(StartLocation,EndLocation) if(GetWorld()) DrawDebugLine(GetWorld(),StartLocation,EndLocation,FColor::Red,true,-1.f,0,1.f);
#define DRAW_POINT(Location) if(GetWorld()) DrawDebugPoint(GetWorld(),Location,15.f,FColor::Blue,true);
#define DRAW_VECTOR(StartLocation,EndLocation) if(GetWorld())\
	{\
		DrawDebugLine(GetWorld(),StartLocation,EndLocation,FColor::Red,true,-1.f,0,1.f);\
		DrawDebugPoint(GetWorld(), EndLocation, 15.f, FColor::Blue, true);}

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

	UE_LOG(LogTemp,Warning,TEXT("BeginPLay"));
	if (GEngine)
	{
		//显示位置，时间，颜色，文本
		GEngine->AddOnScreenDebugMessage(-1,5,FColor::Red,TEXT("hello"));
	}

	//得到所在世界
	UWorld* World = GetWorld();
	//获取组件的位置
	FVector Location = GetActorLocation();
	//获取向前的单位向量
	FVector Forward = GetActorForwardVector();
	
	DRAW_SPHERE(Location);
	/*DRAW_LINE(Location,Location+Forward*100.f);
	DRAW_POINT(Location + Forward * 100.f);*/
	DRAW_VECTOR(Location, Location + Forward * 100.f);
}