5.在编辑器中运行
在 虚幻编辑器 中,按下 Compile 按钮即可加载代码修改。
需要将 CollidingPawn 的一个实例放入世界场景。类保存在 内容浏览器“C++ Classes/HowTo_Components/CollidingPawn”路径下。
按下 Play 按钮后,使用 WASD 键移动球体,使用鼠标转向,与场景中的对象(如此例中的桌子或椅子,或放置在场景中的其他物理对象)发生碰撞和滑动。按下空格键还可以在球体上生成火焰(或消除已生成的火焰)!
虚幻引擎 4 中有各种类型的 组件 - 我们此处对常见组件的仅仅是停留在表面而已。尝试探索内置的组件或自行编写吧!它们灵活且功能强大,有助于使项目代码整洁有序,便于重复使用。
CollidingPawn.h
// 版权所有 1998-2017 Epic Games, Inc. 保留所有权利。
#pragma once
#include "GameFramework/Pawn.h"
#include "CollidingPawn.generated.h"
UCLASS()
class HOWTO_COMPONENTS_API ACollidingPawn : public APawn
{
GENERATED_BODY()
public:
// 设置该 pawn 属性的默认值
ACollidingPawn();
// 游戏开始时或生成时调用
virtual void BeginPlay() override;
// 每帧调用
virtual void Tick( float DeltaSeconds ) override;
// 调用后将功能绑定到输入
virtual void SetupPlayerInputComponent(class UInputComponent* InputComponent) override;
UParticleSystemComponent* OurParticleSystem;
class UCollidingPawnMovementComponent* OurMovementComponent;
virtual UPawnMovementComponent* GetMovementComponent() const override;
void MoveForward(float AxisValue);
void MoveRight(float AxisValue);
void Turn(float AxisValue);
void ParticleToggle();
};
CollidingPawn.cpp
// 版权所有 1998-2017 Epic Games, Inc. 保留所有权利。
#include "HowTo_Components.h"
#include "CollidingPawn.h"
#include "CollidingPawnMovementComponent.h"
// 设置默认值
ACollidingPawn::ACollidingPawn()
{
// 将此 pawn 设为每帧调用 Tick()。不需要时可将此关闭,以提高性能。
PrimaryActorTick.bCanEverTick = true;
// 我们的根组件是对物理作出反应的球体
USphereComponent* SphereComponent = CreateDefaultSubobject<USphereComponent>(TEXT("RootComponent"));
RootComponent = SphereComponent;
SphereComponent->InitSphereRadius(40.0f);
SphereComponent->SetCollisionProfileName(TEXT("Pawn"));
// 创建并放置一个网格体组件,以便了解球体的所在位置
UStaticMeshComponent* SphereVisual = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("VisualRepresentation"));
SphereVisual->AttachTo(RootComponent);
static ConstructorHelpers::FObjectFinder<UStaticMesh> SphereVisualAsset(TEXT("/Game/StarterContent/Shapes/Shape_Sphere.Shape_Sphere"));
if (SphereVisualAsset.Succeeded())
{
SphereVisual->SetStaticMesh(SphereVisualAsset.Object);
SphereVisual->SetRelativeLocation(FVector(0.0f, 0.0f, -40.0f));
SphereVisual->SetWorldScale3D(FVector(0.8f));
}
// 创建一个可启用或停用的粒子系统
OurParticleSystem = CreateDefaultSubobject<UParticleSystemComponent>(TEXT("MovementParticles"));
OurParticleSystem->AttachTo(SphereVisual);
OurParticleSystem->bAutoActivate = false;
OurParticleSystem->SetRelativeLocation(FVector(-20.0f, 0.0f, 20.0f));
static ConstructorHelpers::FObjectFinder<UParticleSystem> ParticleAsset(TEXT("/Game/StarterContent/Particles/P_Fire.P_Fire"));
if (ParticleAsset.Succeeded())
{
OurParticleSystem->SetTemplate(ParticleAsset.Object);
}
// 使用弹簧臂让摄像机运动平稳而自然。
USpringArmComponent* SpringArm = CreateDefaultSubobject<USpringArmComponent>(TEXT("CameraAttachmentArm"));
SpringArm->AttachTo(RootComponent);
SpringArm->RelativeRotation = FRotator(-45.f, 0.f, 0.f);
SpringArm->TargetArmLength = 400.0f;
SpringArm->bEnableCameraLag = true;
SpringArm->CameraLagSpeed = 3.0f;
// 创建一个摄像机,将其附着到弹簧臂
UCameraComponent* Camera = CreateDefaultSubobject<UCameraComponent>(TEXT("ActualCamera"));
Camera->AttachTo(SpringArm, USpringArmComponent::SocketName);
// 掌控默认玩家
AutoPossessPlayer = EAutoReceiveInput::Player0;
// 创建移动组件的一个实例,并告知其更新根组件。
OurMovementComponent = CreateDefaultSubobject<UCollidingPawnMovementComponent>(TEXT("CustomMovementComponent"));
OurMovementComponent->UpdatedComponent = RootComponent;
}
// 游戏开始时或生成时调用
void ACollidingPawn::BeginPlay()
{
Super::BeginPlay();
}
// 每帧调用
void ACollidingPawn::Tick( float DeltaTime )
{
Super::Tick( DeltaTime );
}
// 调用后将功能绑定到输入
void ACollidingPawn::SetupPlayerInputComponent(class UInputComponent* InputComponent)
{
Super::SetupPlayerInputComponent(InputComponent);
InputComponent->BindAction("ParticleToggle", IE_Pressed, this, &ACollidingPawn::ParticleToggle);
InputComponent->BindAxis("MoveForward", this, &ACollidingPawn::MoveForward);
InputComponent->BindAxis("MoveRight", this, &ACollidingPawn::MoveRight);
InputComponent->BindAxis("Turn", this, &ACollidingPawn::Turn);
}
UPawnMovementComponent* ACollidingPawn::GetMovementComponent() const
{
return OurMovementComponent;
}
void ACollidingPawn::MoveForward(float AxisValue)
{
if (OurMovementComponent && (OurMovementComponent->UpdatedComponent == RootComponent))
{
OurMovementComponent->AddInputVector(GetActorForwardVector() * AxisValue);
}
}
void ACollidingPawn::MoveRight(float AxisValue)
{
if (OurMovementComponent && (OurMovementComponent->UpdatedComponent == RootComponent))
{
OurMovementComponent->AddInputVector(GetActorRightVector() * AxisValue);
}
}
void ACollidingPawn::Turn(float AxisValue)
{
FRotator NewRotation = GetActorRotation();
NewRotation.Yaw += AxisValue;
SetActorRotation(NewRotation);
}
void ACollidingPawn::ParticleToggle()
{
if (OurParticleSystem && OurParticleSystem->Template)
{
OurParticleSystem->ToggleActive();
}
}
CollidingPawnMovementComponent.h
// 版权所有 1998-2017 Epic Games, Inc. 保留所有权利。
#pragma once
#include "GameFramework/PawnMovementComponent.h"
#include "CollidingPawnMovementComponent.generated.h"
/**
*
*/
UCLASS()
class HOWTO_COMPONENTS_API UCollidingPawnMovementComponent : public UPawnMovementComponent
{
GENERATED_BODY()
public:
virtual void TickComponent(float DeltaTime, enum ELevelTick TickType, FActorComponentTickFunction *ThisTickFunction) override;
};
CollidingPawnMovementComponent.cpp
// 版权所有 1998-2017 Epic Games, Inc. 保留所有权利。
#include "HowTo_Components.h"
#include "CollidingPawnMovementComponent.h"
void UCollidingPawnMovementComponent::TickComponent(float DeltaTime, enum ELevelTick TickType, FActorComponentTickFunction *ThisTickFunction)
{
Super::TickComponent(DeltaTime, TickType, ThisTickFunction);
// 确保所有内容仍然有效,并允许移动。
if (!PawnOwner || !UpdatedComponent || ShouldSkipUpdate(DeltaTime))
{
return;
}
// 获取(然后清除)在 ACollidingPawn::Tick 设置的移动矢量。
FVector DesiredMovementThisFrame = ConsumeInputVector().GetClampedToMaxSize(1.0f) * DeltaTime * 150.0f;
if (!DesiredMovementThisFrame.IsNearlyZero())
{
FHitResult Hit;
SafeMoveUpdatedComponent(DesiredMovementThisFrame, UpdatedComponent->GetComponentRotation(), true, Hit);
// 如碰到物体,尝试沿其滑动
if (Hit.IsValidBlockingHit())
{
SlideAlongSurface(DesiredMovementThisFrame, 1.f - Hit.Time, Hit.Normal, Hit);
}
}
};