02UEc++【打飞艇：无人机运动】

项目设置里创建三个动作：上下，前后，旋转

2.在头文件里，添加两个public的变量

	//向上加速度
	UPROPERTY(EditAnywhere , BlueprintReadWrite , Category = "init")
	float LiftAcc = 100.0f;
	//最大向上推力
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "init")
	float LiftThrustMax = 2000.0f;

 3.三个输入相关的函数

private:
	UFUNCTION()
	void Lift( float val);
 
	UFUNCTION()
	void Forward(float val);
 
	UFUNCTION()
	void Turn(float val);

4.进入无人机的源文件

引入头文件

#include "Kismet/KismetMathLibrary.h"
#include "Kismet/KismetSystemLibrary.h"

5.在void ADrone::SetupPlayerInputComponent(UInputComponent* PlayerInputComponent)函数中进行绑定，输入函数

PlayerInputComponent->BindAxis(TEXT("Lift"), this, &ADrone::Lift);
PlayerInputComponent->BindAxis(TEXT("Forward"), this, &ADrone::Forward);
PlayerInputComponent->BindAxis(TEXT("Turn"), this, &ADrone::Turn);

6.定义list函数

void ADrone:: Lift(float val)
{
	//推进力变化
	UpThruster->ThrustStrength += val * LiftAcc * GetWorld()->DeltaTimeSeconds;
	//限制推进力变化
	UpThruster->ThrustStrength = FMath::Clamp(UpThruster->ThrustStrength, -LiftThrustMax, LiftThrustMax);
	//打印推进力
	FString::SanitizeFloat(UpThruster->ThrustStrength);
	UKismetSystemLibrary::PrintString(this,FString::SanitizeFloat(UpThruster->ThrustStrength));
}

7.添加向前的加速度，和最大力量

//向前加速度
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "init")
	float ForwardAcc = 1000.0f;
 
	//最大向前推力
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "init")
	float ForwardThrustMax = 2000.0f;

 8.在源文件中定义向前函数

void ADrone::Forward(float val)
{
	//推进力变化
	ForwardThruster->ThrustStrength += val * LiftAcc * GetWorld()->DeltaTimeSeconds;
	//限制推进力变化
	ForwardThruster->ThrustStrength = FMath::Clamp(ForwardThruster->ThrustStrength, -ForwardThrustMax, ForwardThrustMax);
 
}

9.头文件添加一个转向力

	//转向力
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "init")
	float TurnThrust = 5000.0f;

10.定义转向函数

void ADrone::Turn(float val)
{
	OutCollision->AddTorqueInDegrees(this->GetActorUpVector() * val * TurnThrust);
}

 11.当我们松开键盘，推进力应该恢复初始状态，这个功能在每帧函数里实现

	if (InputComponent->GetAxisValue(TEXT("Lift")) == 0.0f)
	{
		UpThruster->ThrustStrength = 980.0f;
	}
	if (InputComponent->GetAxisValue(TEXT("Forward")) == 0.0f)
	{
		ForwardThruster->ThrustStrength = 0.0f;
	}

12.点击场景中的无人机，进行设置操作权限

13.添加弹簧臂和相机 ，更容易观察

14.设置臂长

15.再添加两个输入

16.接下来用蓝图实现弹簧臂的摇动

   17.设置弹簧臂

 18.测试成功。

 ==========================================

让螺旋桨动起来

1.添加一个数组容器和一个函数，权限是private

private:
	//TArray 是虚幻引擎中最常用的容器类。
	TArray paddles;
 
	void RotatePaddle(float Delta);

2.在构造函数中将四个螺旋桨的指针存入容器

	//将螺旋桨放入容器
	paddles.Add(Paddle1);
	paddles.Add(Paddle2);
	paddles.Add(Paddle3);
	paddles.Add(Paddle4);

3.添加一个螺旋桨旋转速度变量，public权限

	//螺旋桨旋转速度
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "init")
	float PaddleRotateSpeed  = 1500.0f;

4.定义RotatePaddle函数

void ADrone::RotatePaddle(float Delta)
{
	for (auto Paddle : paddles)
	{
		Paddle->AddRelativeRotation(FRotator(.0f, Delta*PaddleRotateSpeed, .0f));
	}
} 

5.在每帧函数里调用这个函数

RotatePaddle(DeltaTime);

==================================

前进和后退时，设置机身倾斜

1.在Forward函数里面，得到机身实时的前倾角度值，如果倾斜度小于30，就允许倾斜

	//获得机身实时前倾角度
	float pitch = Mesh->GetRelativeRotation().Pitch;
 
	//如果倾斜度小于30，就允许倾斜
	if (FMath::Abs(pitch) < 30.0f)
	{
		Mesh->AddRelativeRotation(FRotator(100.0f * GetWorld()->DeltaTimeSeconds * val, .0f, .0f));
	}

2.在每帧函数里，当不向前（向后）的时候，从倾斜状态恢复水平状态

void ADrone::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);
	if (InputComponent->GetAxisValue(TEXT("Lift")) == 0.0f)
	{
		UpThruster->ThrustStrength = 980.0f;
	}
	if (InputComponent->GetAxisValue(TEXT("Forward")) == 0.0f)
	{
		//推力清零
		ForwardThruster->ThrustStrength = 0.0f;
 
 
		//检测倾斜状态
		if (Mesh->GetRelativeRotation().Pitch != 0.0f)
		{
			//此时的倾斜量
			float CurrentPitch = Mesh->GetRelativeRotation().Pitch;
			FString::SanitizeFloat(CurrentPitch);
			UKismetSystemLibrary::PrintString(this, FString::SanitizeFloat(CurrentPitch));
 
			//向反方向进行倾斜
			Mesh->AddRelativeRotation(FRotator(-CurrentPitch * DeltaTime, .0f, .0f));
			//避免机身抖动
			if (FMath::Abs(Mesh->GetRelativeRotation().Pitch) <= KINDA_SMALL_NUMBER)
			{
				Mesh->SetRelativeRotation(FRotator(.0f, .0f, .0f));
			}
		}
	}
	//旋转螺旋桨
	RotatePaddle(DeltaTime);
	
}