【UE4 C++】實現旋轉小球的第三人稱自由視角

原創 ColorGalaxy 2020-06-02 12:53

本文將介紹用C++實現一個簡單的玩家可通過WASD控制移動，Shift進行加速，鼠標控制視角旋轉和縮放的小球。

本人也只是一個UE4初學者，大佬勿噴。

一、技術難點

  • 小球通過角速度控制旋轉，因此想實現自由視角相機，它就不能作爲小球的子物體。
  • 小球的移動方向始終要保持與視野前方相同。

二、最終效果圖

 

三、核心代碼模塊

在此先將模塊分類，使結構清晰明瞭，最後有完整代碼，可具體查看。

1、首先創建組件

  • SphereBase.h（自己創建的C++類）下
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "RootComp")
	    class USceneComponent * RootComp;//聲明根節點組件

    UPROPERTY(EditAnywhere, BlueprintReadWrite,Category = "SphereMeshComp")
	    class UStaticMeshComponent * SphereMeshComp;//小球Mesh組件

    UPROPERTY(EditAnywhere, BlueprintReadWrite,Category = "CameraArmComp")
    	class USpringArmComponent * CameraArmComp;//相機臂組件

    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "CameraComp")
    	class UCameraComponent * CameraComp;//相機組件
  •  SphereBase.cpp
    //創建組件
    RootComp = CreateDefaultSubobject<USceneComponent>(TEXT("RootComp"));
    SphereMeshComp = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("SphereBaseComp"));
    CameraArmComp = CreateDefaultSubobject<USpringArmComponent>(TEXT("CameraArmComp"));
    CameraComp = CreateDefaultSubobject<UCameraComponent>(TEXT("CameraComp"));

    //添加組件父子關係
    SphereMeshComp->SetupAttachment(RootComp);
    CameraArmComp->SetupAttachment(RootComp);
    CameraComp->SetupAttachment(CameraArmComp);

    //設置小球物理效果爲真
    SphereMeshComp->SetSimulatePhysics(true);
  • 創建藍圖類繼承該C++類後，組件已創建 

2、綁定按鍵輸入

 

    //綁定前後左右移動
    PlayerInputComponent->BindAxis("MoveForward", this, &ASphereBase::MoveForward);
    PlayerInputComponent->BindAxis("MoveRight", this, &ASphereBase::MoveRight);
    //Shift按下與擡起
    PlayerInputComponent->BindAction("MoveQuick", IE_Pressed, this, &ASphereBase::MoveQuick);
PlayerInputComponent->BindAction("MoveQuick", IE_Released, this, &ASphereBase::MoveNormal);
    //相機上下左右旋轉
    PlayerInputComponent->BindAxis("CameraYaw", this, &ASphereBase::YawCamera);
    PlayerInputComponent->BindAxis("CameraPitch", this, &ASphereBase::PitchCamera);
    //相機縮放
    PlayerInputComponent->BindAction("ZoomIn", IE_Pressed, this, &ASphereBase::ZoomIn);
    PlayerInputComponent->BindAction("ZoomIn", IE_Released, this, &ASphereBase::ZoomStop);
    PlayerInputComponent->BindAction("ZoomOut", IE_Pressed, this, &ASphereBase::ZoomOut);
    PlayerInputComponent->BindAction("ZoomIn", IE_Released, this, &ASphereBase::ZoomStop);

具體函數請查看完整代碼 

3、相機自由視角

建議採用世界座標系函數修改值，不要使用相對座標系Relative函數，否則會遇到很多問題。

  • 小球移動控制
    if (!AngularVector.IsZero())
    {
        FVector NewVector = FVector(0, 0, 0);
        NewVector += AngularVector.X  * CameraArmComp->GetForwardVector() * SphereSpeed;
        NewVector += AngularVector.Y  * CameraArmComp->GetRight	Vector() * SphereSpeed;
        SphereMeshComp->SetPhysicsAngularVelocity(NewVector);//給小球施加角速度向量
    }
  • 相機臂左右旋轉
    FRotator LRRotation = CameraArmComp->GetComponentRotation();
    LRRotation.Yaw += CameraInput.X;
    CameraArmComp->SetWorldRotation(LRRotation);
  • 相機臂上下旋轉 
    FRotator UDRotation = CameraArmComp->GetComponentRotation();
    UDRotation.Pitch = FMath::Clamp(UDRotation.Pitch + CameraInput.Y, -80.0f, -15.0f);//控制上下視野範圍
    CameraArmComp->SetWorldRotation(UDRotation);
  • 相機臂跟隨小球
    FVector NewLocation = SphereMeshComp->GetComponentLocation();
    CameraArmComp->SetWorldLocation(NewLocation);

4、相機縮放 

    ZoomValue = FMath::Clamp<float>(ZoomValue, 0.0f, 1.0f);
    //基於ZoomFActor來混合控制相機的視域和彈簧臂的長度 0.0f對應90.0f 1500.0f
    CameraComp->FieldOfView = FMath::Lerp<float>(90.0f, 60.0f, ZoomValue);
    CameraArmComp->TargetArmLength = FMath::Lerp<float>(1500.0f, 500.0f, ZoomValue);

滾輪控制ZoomValue值的變化

四、完整代碼

  •  Sphere.h
#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Pawn.h"
#include "SphereBase.generated.h"//必須放在頭文件最後

UCLASS()
class BILICODE_API ASphereBase : public APawn//APawn 繼承 Actor
{
    GENERATED_BODY()

public:
    // Sets default values for this pawn's properties
    ASphereBase();

    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "RootComp")
        class USceneComponent * RootComp;

    UPROPERTY(EditAnywhere, BlueprintReadWrite,Category = "SphereMeshComp")
        class UStaticMeshComponent * SphereMeshComp;//class聲明

    UPROPERTY(EditAnywhere, BlueprintReadWrite,Category = "CameraArmComp")
        class USpringArmComponent * CameraArmComp;

    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "CameraComp")
        class UCameraComponent * CameraComp;

public:
    FVector AngularVector;
    float SphereSpeed;
    float SpeedMin;
    float SpeedMax;

    FVector CameraInput;
    float ZoomValue;
    UPROPERTY(EditAnyWhere, BlueprintReadWrite)
        bool IsInput;//控制是否能輸入按鍵

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

public:	
    // Called every frame
    virtual void Tick(float DeltaTime) override;

    // Called to bind functionality to input
    virtual void SetupPlayerInputComponent(class UInputComponent* PlayerInputComponent) override;

    UFUNCTION(BlueprintCallable)
        void MoveForward(float AxisValue);
    UFUNCTION(BlueprintCallable)
        void MoveRight(float AxisValue);
    UFUNCTION(BlueprintCallable)
        void MoveQuick();
    UFUNCTION(BlueprintCallable)
        void MoveNormal();

    void PitchCamera(float AxisValue);
    void YawCamera(float AxisValue);

    void StartJump();
    void StopJump();

    void ZoomIn();
    void ZoomStop();
    void ZoomOut();
};
  • Sphere.cpp
// Fill out your copyright notice in the Description page of Project Settings.

#include "SphereBase.h"
#include "Components/StaticMeshComponent.h"//Mesh頭文件
#include "GameFramework/SpringArmComponent.h"//攝像機手臂頭文件
#include "Camera/CameraComponent.h"
#include "Components/SceneComponent.h"
#include "Components/InputComponent.h"//輸入按鍵綁定頭文件
#include "Engine.h"

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

    IsInput = true;
    SphereSpeed = 300.0f;
    SpeedMin = SphereSpeed;
    SpeedMax = 500.0f;
    ZoomValue = 0.5f;

    //創建組件
    RootComp = CreateDefaultSubobject<USceneComponent>(TEXT("RootComp"));
    SphereMeshComp = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("SphereBaseComp"));
    CameraArmComp = CreateDefaultSubobject<USpringArmComponent>(TEXT("CameraArmComp"));
    CameraComp = CreateDefaultSubobject<UCameraComponent>(TEXT("CameraComp"));

    //組件關係
    SphereMeshComp->SetupAttachment(RootComp);
    CameraArmComp->SetupAttachment(RootComp);
    CameraComp->SetupAttachment(CameraArmComp);
	
    //設置物理效果爲真
    SphereMeshComp->SetSimulatePhysics(true);
}

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


// Called every frame
void ASphereBase::Tick(float DeltaTime)
{
    Super::Tick(DeltaTime);

    if (!AngularVector.IsZero())
    {
        FVector NewVector = FVector(0, 0, 0);
        NewVector += AngularVector.X  * CameraArmComp->GetForwardVector() * SphereSpeed;
        NewVector += AngularVector.Y  * CameraArmComp->GetRightVector() * SphereSpeed;
        SphereMeshComp->SetPhysicsAngularVelocity(NewVector);//小球向一個向量方向旋轉移動
    }

    {//相機臂左右旋轉（相機臂與小球是兄弟關係
        FRotator LRRotation = CameraArmComp->GetComponentRotation();
        LRRotation.Yaw += CameraInput.X;
        CameraArmComp->SetWorldRotation(LRRotation);
    }

    {//相機臂跟隨小球
        FVector NewLocation = SphereMeshComp->GetComponentLocation();
        CameraArmComp->SetWorldLocation(NewLocation);
        //兩種方便的調試方法
        //GEngine->AddOnScreenDebugMessage(-1, 3.f, FColor::Purple, NewLocation.ToString());
        /*DrawDebugLine(
            GetWorld(),
            SphereBeginLocation,
            SphereMeshComp->GetComponentLocation(),
            FColor::Red,
            false, -1, 0,
            3.
        );*/
    }
    {//相機臂上下旋轉
        FRotator UDRotation = CameraArmComp->GetComponentRotation();
        UDRotation.Pitch = FMath::Clamp(UDRotation.Pitch + CameraInput.Y, -80.0f, -15.0f);//控制旋轉範圍
        CameraArmComp->SetWorldRotation(UDRotation);
    }

    {//相機縮放
        ZoomValue = FMath::Clamp<float>(ZoomValue, 0.0f, 1.0f);
        //基於ZoomFActor來混合相機的視域和彈簧臂的長度
        CameraComp->FieldOfView = FMath::Lerp<float>(90.0f, 60.0f, ZoomValue);
        CameraArmComp->TargetArmLength = FMath::Lerp<float>(1500.0f, 500.0f, ZoomValue);
    }
}

// Called to bind functionality to input
void ASphereBase::SetupPlayerInputComponent(UInputComponent* PlayerInputComponent)//pawn不同於actor的地方,用於綁定按鍵
{
    Super::SetupPlayerInputComponent(PlayerInputComponent);

    PlayerInputComponent->BindAxis("MoveForward", this, &ASphereBase::MoveForward);//綁定 前後移動映射 的函數
    PlayerInputComponent->BindAxis("MoveRight", this, &ASphereBase::MoveRight);//綁定左右
    PlayerInputComponent->BindAction("MoveQuick", IE_Pressed, this, &ASphereBase::MoveQuick);
    PlayerInputComponent->BindAction("MoveQuick", IE_Released, this, &ASphereBase::MoveNormal);
    PlayerInputComponent->BindAxis("CameraYaw", this, &ASphereBase::YawCamera);
    PlayerInputComponent->BindAxis("CameraPitch", this, &ASphereBase::PitchCamera);
    PlayerInputComponent->BindAction("ZoomIn", IE_Pressed, this, &ASphereBase::ZoomIn);
    PlayerInputComponent->BindAction("ZoomIn", IE_Released, this, &ASphereBase::ZoomStop);
    PlayerInputComponent->BindAction("ZoomOut", IE_Pressed, this, &ASphereBase::ZoomOut);
    PlayerInputComponent->BindAction("ZoomIn", IE_Released, this, &ASphereBase::ZoomStop);
}

//前後左右輸入控制
void ASphereBase::MoveForward(float AxisValue)
{
    if (IsInput)
    {
        AngularVector.Y = FMath::Clamp<float>(AxisValue, -1.0f, 1.0f);
    }
}

void ASphereBase::MoveRight(float AxisValue)
{
    if (IsInput)
    {
        AngularVector.X = FMath::Clamp<float>(AxisValue, -1.0f, 1.0f);
    }
}
//shift輸入控制
void ASphereBase::MoveQuick()
{
    SphereSpeed = SpeedMax;
}

void ASphereBase::MoveNormal()
{
    SphereSpeed = SpeedMin;
}
//相機旋轉輸入控制
void ASphereBase::PitchCamera(float AxisValue)
{
    CameraInput.Y = AxisValue;
}

void ASphereBase::YawCamera(float AxisValue)
{
    CameraInput.X = AxisValue;
}

void ASphereBase::ZoomIn()
{
    ZoomValue += 0.1f;
}
//相機縮放輸入控制
void ASphereBase::ZoomStop()
{
}

void ASphereBase::ZoomOut()
{
    ZoomValue -= 0.1f;
}

 

發表評論
所有評論
還沒有人評論，想成為第一個評論的人麼? 請在上方評論欄輸入並且點擊發布.
相關文章

【UE4 C++】大規模人羣繞行避讓的最優解DetourCrowdAIController如何開啓

目錄 問題闡述與解決效果 RVO Avoidance與Detour Crowd AI Controller的區別 如何使用Detour Crowd AI Controller 藍圖  C++ 棄用的寫法 新版寫法（也很簡便） 問題闡述與解

ColorGalaxy 2020-06-24 04:00:44

【UE4 C++】構建多輸出執行引腳藍圖節點（同步節點與異步節點）

ColorGalaxy 2020-02-27 19:56:27

【UE4 C++】由點面數據，批量繪製ProceduralMesh並轉化爲StaticMesh資產

ColorGalaxy 2020-02-24 12:02:07

【UE4 C++】RawMesh.h引用報錯

ColorGalaxy 2020-02-21 00:31:55

【UE4 C++】無法打開源文件"ProceduralMeshComponent.h"的解決辦法

ColorGalaxy 2020-02-21 00:31:54

【UE4 C++】大規模人羣繞行避讓的最優解DetourCrowdAIController如何開啓

目錄 問題闡述與解決效果 RVO Avoidance與Detour Crowd AI Controller的區別 如何使用Detour Crowd AI Controller 藍圖  C++ 棄用的寫法 新版寫法（也很簡便） 問題闡述與解

ColorGalaxy 2020-06-24 04:00:44

UE4C++中如何申明“TSubclassOf”型數組

之前查了查居然沒人回答過，不廢話，直接看代碼：  UPROPERTY(EditDefaultsOnly) TArray<TSubclassOf<AActor>> ArrayOfActor;  

冗谈 2020-06-24 02:14:59

UE4C++如何讓Actor啓用Input響應

沒記錯的話Pawn有自帶響應，而Actor需要在類宏UCLASS聲明時啓用：

冗谈 2020-06-24 02:14:59

UE4服務端

原文作者：@玄冬Wong轉載請註明原文出處：http://aigo.iteye.com/blog/2268777這是論壇上對UE服務端功能的回答，意思是UE4提供了主流MMO網遊服務端所具備的特性，包括位移修正、物理碰撞檢測。這些特性不是

七月墨晴 2020-06-11 15:22:25

【UE4 C++】構建多輸出執行引腳藍圖節點（同步節點與異步節點）

ColorGalaxy 2020-02-27 19:56:27

【UE4 C++】由點面數據，批量繪製ProceduralMesh並轉化爲StaticMesh資產

ColorGalaxy 2020-02-24 12:02:07

如何在UE4 C++中進行按鍵綁定

冗谈 2020-02-21 09:31:21

爲什麼UE4動態物體在哪裏都會反射陽光？

冗谈 2020-02-21 09:31:21

【UE4 C++】RawMesh.h引用報錯

ColorGalaxy 2020-02-21 00:31:55

【UE4 C++】無法打開源文件"ProceduralMeshComponent.h"的解決辦法

ColorGalaxy 2020-02-21 00:31:54