UE 黑洞效果制作

注意：所吸取的物体必须开启 模拟物理 和 生成重叠事件 两个选项

创建一个Actor的C++类，名称为BlackHole。

为类头文件添加两个SphereComponent和一个StaticMesh

UPROPERTY(EditDefaultsOnly, Category = "BlackHole")
USphereComponent* DestroySphere;

UPROPERTY(EditDefaultsOnly, Category = "BlackHole")
USphereComponent* RangeSphere;

UPROPERTY(EditDefaultsOnly, Category = "BlackHole")
UStaticMeshComponent* BlackHoleMesh;

在构造函数中初始化成员

//初始化成员
DestroySphere = CreateDefaultSubobject<USphereComponent>(TEXT("BlackHole"));
//设置DestroySphere碰撞为仅查询
DestroySphere->SetCollisionEnabled(ECollisionEnabled::QueryOnly);
//设置球体半径为32.0f
DestroySphere->SetSphereRadius(32.0f);

RangeSphere = CreateDefaultSubobject<USphereComponent>(TEXT("RangeBlackHole"));
RangeSphere->SetCollisionEnabled(ECollisionEnabled::QueryOnly);
RangeSphere->SetSphereRadius(3000.0f);

BlackHoleMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("BlackHoleMesh"));
//设置BlackHoleMesh碰撞为无碰撞
BlackHoleMesh->SetCollisionEnabled(ECollisionEnabled::NoCollision);

//设置根组件为BlackHoleMesh
RootComponent = BlackHoleMesh;
//将DestroySphere、RangeSphere添加到BlackHoleMesh下
DestroySphere->SetupAttachment(BlackHoleMesh);
RangeSphere->SetupAttachment(BlackHoleMesh);

//==============添加DestroySphere重叠的触发方法==============
DestroySphere->OnComponentBeginOverlap.AddDynamic(this, &ABlackHole::DestroyOnOverlapBegin);

添加DestroySphere重叠的触发方法

声明：

//重叠方法的参数列表必须一致，且必须添加UFUNCTION()
UFUNCTION()
void DestroyOnOverlapBegin(class UPrimitiveComponent* HitComp,
    class AActor* OtherActor, class UPrimitiveComponent* OtherComp,
    int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);

实现：

void ABlackHole::DestroyOnOverlapBegin(UPrimitiveComponent* HitComp, 
	AActor* OtherActor, UPrimitiveComponent* OtherComp, 
	int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult)
{
	OtherActor->Destroy();
}

将函数添加至DestroySphere中

//将函数添加至DestroySphere的重叠触发方法
DestroySphere->OnComponentBeginOverlap.AddDynamic(this, &ABlackHole::DestroyOnOverlapBegin);

为RangeSphere范围内的所有物体添加力

void ABlackHole::Tick(float DeltaTime)
{
        Super::Tick(DeltaTime);
	TSet<UPrimitiveComponent*> OverlapObjects;
        //获取组件重叠范围内的所有对象，将信息保存至TSet中
	GetOverlappingComponents(OverlapObjects);
	for (UPrimitiveComponent* overlapObject : OverlapObjects)
	{
		//此处bAccelChange属性为true则该力为加速力忽略物理力，即质量将不产生作用
		overlapObject->AddRadialForce(GetActorLocation(),RangeSphere->GetScaledSphereRadius(),
			-1500.0f,ERadialImpulseFalloff::RIF_MAX,true);

	}
}

AddRadialForce属性信息

完成后你的代码应该如下：

BlackHole.h

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "BlackHole.generated.h"

class USphereComponent;

UCLASS()
class MULTIPLAYERGAMES_API ABlackHole : public AActor
{
	GENERATED_BODY()
	
public:	
	// Sets default values for this actor's properties
	ABlackHole();

protected:
	// Called when the game starts or when spawned
	virtual void BeginPlay() override;

	UPROPERTY(EditDefaultsOnly, Category = "BlackHole")
	USphereComponent* DestroySphere;
	UPROPERTY(EditDefaultsOnly, Category = "BlackHole")
	USphereComponent* RangeSphere;
	UPROPERTY(EditDefaultsOnly, Category = "BlackHole")
	UStaticMeshComponent* BlackHoleMesh;
	
	UFUNCTION()
	void DestroyOnOverlapBegin(class UPrimitiveComponent* HitComp,
		class AActor* OtherActor, class UPrimitiveComponent* OtherComp,
		int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);
public:	
	// Called every frame
	virtual void Tick(float DeltaTime) override;
};

BlackHole.cpp

// Fill out your copyright notice in the Description page of Project Settings.

#include "BlackHole.h"
#include <Components/SphereComponent.h>

// Sets default values
ABlackHole::ABlackHole()
{
 	// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
	PrimaryActorTick.bCanEverTick = true;

	//初始化成员
	DestroySphere = CreateDefaultSubobject<USphereComponent>(TEXT("BlackHole"));
	//设置DestroySphere碰撞为仅查询
	DestroySphere->SetCollisionEnabled(ECollisionEnabled::QueryOnly);
	//设置球体半径为32.0f
	DestroySphere->SetSphereRadius(32.0f);

	RangeSphere = CreateDefaultSubobject<USphereComponent>(TEXT("RangeBlackHole"));
	RangeSphere->SetCollisionEnabled(ECollisionEnabled::QueryOnly);
	RangeSphere->SetSphereRadius(3000.0f);

	BlackHoleMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("BlackHoleMesh"));
    //设置BlackHoleMesh碰撞为无碰撞
	BlackHoleMesh->SetCollisionEnabled(ECollisionEnabled::NoCollision);
    
	//设置根组件为BlackHoleMesh
	RootComponent = BlackHoleMesh;
	//将DestroySphere、RangeSphere添加到BlackHoleMesh下
	DestroySphere->SetupAttachment(BlackHoleMesh);
	RangeSphere->SetupAttachment(BlackHoleMesh);

	//==============添加DestroySphere重叠的触发方法==============
	DestroySphere->OnComponentBeginOverlap.AddDynamic(this, &ABlackHole::DestroyOnOverlapBegin);
}

// Called when the game starts or when spawned
void ABlackHole::BeginPlay()
{
	Super::BeginPlay();
	
}

void ABlackHole::DestroyOnOverlapBegin(UPrimitiveComponent* HitComp,
	AActor* OtherActor, UPrimitiveComponent* OtherComp,
	int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult)
{
	OtherActor->Destroy();
}

// Called every frame
void ABlackHole::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);
	TSet<UPrimitiveComponent*> OverlapObjects;
	//获取组件重叠范围内的所有对象，将信息保存至TSet中
	GetOverlappingComponents(OverlapObjects);
	for (UPrimitiveComponent* overlapObject : OverlapObjects)
	{
		//此处bAccelChange属性为true则该力为加速力忽略物理力，即质量将不产生作用
		overlapObject->AddRadialForce(GetActorLocation(), RangeSphere->GetScaledSphereRadius(),
			-1500.0f, ERadialImpulseFalloff::RIF_MAX, true);

	}
}