学习虚幻C++开发日志——基础案例（持续更新中）

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1.物体上下起伏并旋转 

1.1第一种写法

创建一个继承于Actor的类，并为新的Actor命名为FloatingActor，然后点击Create Class

重新加载代码文件

在Games->(用户自定义工程文件名)->Source->FloatingActor.h

在头文件添加代码

public:	// 设置构造默认函数AFloatingActor();UPROPERTY(VisibleAnywhere)
//使用继承于UObject的指针UStaticMeshComponent*UStaticMeshComponent* VisualMesh;

在源文件：

//设置默认值
AFloatingActor::AFloatingActor()
{//将设置为每帧调用Tick（）。如果你不需要它，你可以关闭它来提高性能。PrimaryActorTick.bCanEverTick = true;//创建Object，可在蓝图details查看VisualMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("Mesh"));VisualMesh->SetupAttachment(RootComponent);//根组件//根组件另一种写法：RootComponent = VisualMesh;//不推荐此写法//静态网格体Copy Reference：/Script/Engine.StaticMesh'/Game/StarterContent/Shapes/Shape_Cone.Shape_Cone'static ConstructorHelpers::FObjectFinder<UStaticMesh> CubeVisualAsset(TEXT("/Game/StarterContent/Shapes/Shape_Cone.Shape_Cone"));//判断是否初始化成功if (CubeVisualAsset.Succeeded()){VisualMesh->SetStaticMesh(CubeVisualAsset.Object);VisualMesh->SetRelativeLocation(FVector(0.0f, 0.0f, 0.0f));}
}void AFloatingActor::BeginPlay()
{Super::BeginPlay();//注意BeginPlay一定要调用Super::BeginPlay()
}//调用每一帧
void AFloatingActor::Tick(float DeltaTime)
{Super::Tick(DeltaTime);//初始化FVector NewLocation = GetActorLocation();FRotator NewRotation = GetActorRotation();float RunningTime = GetGameTimeSinceCreation();//得到在世界的时间从创建开始float DeltaHeight = (FMath::Sin(RunningTime + DeltaTime) - FMath::Sin(RunningTime));  //设置高度变化呈现正弦曲线变化float DeltaRotation = DeltaTime * 20.0f;	//Rotate by 20 degrees per second旋转变化	NewLocation.Z += DeltaHeight * 20.0f;       //高度变化，系数放大20倍NewRotation.Yaw += DeltaRotation;SetActorLocationAndRotation(NewLocation, NewRotation);
}

思路：在默认构造函数初始化网格体，运用引擎内置函数SetStaticMesh和SetRelativeLocation。在Tick时间函数内先初始化状态信息，并运用数学函数改变状态数值，最后用SetActorLocationAndRotation函数实现Actor位置变化。

1.2第二种写法（初始化网格体）

在上述头文件添加新的代码 ：

public:UPROPERTY(BlueprintReadWrite, EditAnywhere, Category = "Name")UStaticMesh* NewMesh;UPROPERTY(BlueprintReadWrite, EditAnywhere, Category = "FloatingActor")float FloatSpeed = 20.0f;UPROPERTY(BlueprintReadWrite, EditAnywhere, Category = "FloatingActor")float RotationSpeed = 20.0f;	

此写法是运用宏从而在蓝图进行快速修改 

从而不需要前一种方法默认构造函数的指定网格体的写法：

	//静态网格体Copy Reference：/Script/Engine.StaticMesh'/Game/StarterContent/Shapes/Shape_Cone.Shape_Cone'static ConstructorHelpers::FObjectFinder<UStaticMesh> CubeVisualAsset(TEXT("/Game/StarterContent/Shapes/Shape_Cone.Shape_Cone"));

在源文件的BeginPlay()函数处代码：

void AFloatingActor::BeginPlay()
{Super::BeginPlay();//注意BeginPlay一定要调用Super::BeginPlay()//将原默认构造函数的判断放在这里if (NewMesh){VisualMesh->SetStaticMesh(NewMesh);VisualMesh->SetRelativeLocation(FVector(0.0f, 0.0f, 0.0f));}
}