Challenge Create a Launch Pad

在头文件中定义网格体组件和重叠组件

    UPROPERTY(VisibleAnywhere,Category="Components")
    UStaticMeshComponent* MeshComp;

    UPROPERTY(VisibleAnywhere, Category = "Components")
    UBoxComponent* OverlapComp;

导入头文件

#include "Components/BoxComponent.h"
#include "Components/StaticMeshComponent.h"
#include "Components/ArrowComponent.h"
#include "GameFramework/Character.h"
#include "Kismet/GameplayStatics.h"

创建OverlapLaunchPad函数，重叠时发生弹射角色

UFUNCTION()
    void OverlapLaunchPad(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);

定义弹射力度和弹射角度

    UPROPERTY(EditInstanceOnly, Category = "LaunchPad")
    float LaunchStrength;

    UPROPERTY(EditInstanceOnly, Category = "LaunchPad")
    float LaunchPitchAngle;

定义一个粒子系统

    UPROPERTY(EditDefaultsOnly, Category = "LaunchPad")
    UParticleSystem* ActivateLaunchPadEffect;

设置重叠组件及其尺寸，设置网格体组件作为基底

    OverlapComp = CreateDefaultSubobject<UBoxComponent>(TEXT("OverlapComp"));
    OverlapComp->SetBoxExtent(FVector(, , ));
    RootComponent = OverlapComp;

    MeshComp = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("MeshComp"));
    MeshComp->SetupAttachment(RootComponent);

将OverlapLaunchPad函数和OverlapComp绑定在一起

    OverlapComp->OnComponentBeginOverlap.AddDynamic(this, &AFPSLaunchPad::OverlapLaunchPad);

初始化弹射力度和弹射角度

    LaunchStrength = ;
    LaunchPitchAngle = 35.0f;

实现OverlapLaunchPad函数

void AFPSLaunchPad::OverlapLaunchPad(UPrimitiveComponent * OverlappedComponent, AActor * OtherActor, UPrimitiveComponent * OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult & SweepResult)
{
    FRotator LaunchDirection = GetActorRotation();//获取Actor旋转度
    LaunchDirection.Pitch += LaunchPitchAngle;//俯仰角，可以让Actor不直接按旋转量旋转，而是朝着某一角度进行旋转
    FVector LaunchVelocity = LaunchDirection.Vector() * LaunchStrength;//弹射速率，将旋转量变为矢量再乘以弹射力度

    ACharacter* OtherCharacter = Cast<ACharacter>(OtherActor);//强制转换为Character
    if (OtherCharacter)
    {
        OtherCharacter->LaunchCharacter(LaunchVelocity, true, true);//调用游戏内置的发射函数，后面两个参数可用于重写当前速率，无论从哪个方向走入发射平台都能确保弹射速率的一致性

        UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), ActivateLaunchPadEffect, GetActorLocation());//原地创建发射器
    }
    else if (OtherComp && OtherComp->IsSimulatingPhysics())//检测角色是否转换失败
    {
        OtherComp->AddImpulse(LaunchVelocity, NAME_None, true);//施加相同速率的推力

        UGameplayStatics::SpawnEmitterAtLocation(GetWorld(), ActivateLaunchPadEffect, GetActorLocation());
    }
}