UE4_自定义相机碰撞组件

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UE4_自定义相机碰撞组件

相比较UE4自带的SpringArm中的碰撞，主要特点在于前后推进速度不一样
在碰撞时向前推进的速度较快，在离开碰撞时向后退的速度较慢

SpringArm自带的碰撞检测

SpringArm的碰撞检测，在墙角的位置，由于频繁的碰撞和离开，导致来回的闪动

我的碰撞检测组件

推进，后退使用不同的差值速度，避免相机频繁推拉，视觉感受上更舒适

C++ 代码部分
h

// TAZORN.COM 2017 ALL RIGHTS RESERVED
#pragma once
#include "CoreMinimal.h"
#include "Components/ActorComponent.h"
#include "GameFramework/SpringArmComponent.h"
#include "CameraCollisionComponentBase.generated.h"

/*
相机碰撞组件，可以被Bp继承，继续修改或复写
*/

UCLASS(Blueprintable, BlueprintType, ClassGroup = (Custom), meta = (BlueprintSpawnableComponent))
class XLABORATORY_API UCameraCollisionComponentBase : public UActorComponent
{
    GENERATED_BODY()public:
    UCameraCollisionComponentBase();
    // SpringArm组件的引用
    USpringArmComponent* SpringComponent;
    float DesiredDistance;
    float CamSpringCurrLength;
    float HitLength;
    float CameraLerpSpeed;
    float Delta;
    virtual void BeginPlay() override;
    virtual void TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction) override;

    UPROPERTY(BlueprintReadWrite, Category = "CameraCollision")
    bool bEnable;

    UPROPERTY(BlueprintReadWrite, Category = "CameraCollision")
    float CameraTraceRadius;
    // 推进的差值速度
    UPROPERTY(BlueprintReadWrite, Category = "CameraCollision")
    float PushSpeed;
    // 拉远的差值速度
    UPROPERTY(BlueprintReadWrite, Category = "CameraCollision")
    float PullSpeed;

    UFUNCTION(BlueprintCallable, Category = "CameraCollision")
    void Init(USpringArmComponent* InSpringComponent);

    UFUNCTION(BlueprintCallable, Category = "CameraCollision")
    void CalcCameraCollision(USpringArmComponent* SpringArm, float InDesiredDistance, float InPushSpeed, float InPullSpeed);

    UFUNCTION(BlueprintCallable, Category = "CameraCollision")
    void SetDesiredDistance(float InDesiredDistance);

    UFUNCTION(BlueprintCallable, BlueprintPure, Category = "CameraCollision")
    float GetDesiredDistance();
    // 需要在Bp中，指定碰撞的通道
    UPROPERTY(EditAnywhere, BlueprintReadWrite, meta = (Bitmask, BitmaskEnum = "ECollisionChannel"), Category = "CameraCollision")
        int32 ObjectType;
        
    // 简化的球面检测
    bool SphereTrace(AActor* ActorToIgnore, const FVector& Start, const FVector& End, const float Radius,
        FHitResult& HitOut, FCollisionObjectQueryParams& TraceChannels);
};

cpp

// TAZORN.COM 2017 ALL RIGHTS RESERVED#include "CameraCollisionComponentBase.h"
// 构造函数UCameraCollisionComponentBase::UCameraCollisionComponentBase()
{
    PrimaryComponentTick.bCanEverTick = true;
    // 属性默认值
    DesiredDistance = 400.f;
    CameraTraceRadius = 30.f;
    PushSpeed = 12.f;
    PullSpeed = 0.8f;
    bEnable = true;
}
void UCameraCollisionComponentBase::BeginPlay()
{
    Super::BeginPlay();
}
void UCameraCollisionComponentBase::TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction)
{
    Super::TickComponent(DeltaTime, TickType, ThisTickFunction);
    Delta = DeltaTime;
    if (SpringComponent && bEnable)
    {
        CalcCameraCollision(SpringComponent, DesiredDistance, PushSpeed, PullSpeed);
    }
}
// 初始化，需要在Bp中指定 SpringArm组件引用
void UCameraCollisionComponentBase::Init(USpringArmComponent* InSpringComponent)
{
    SpringComponent = InSpringComponent;
}
// 计算碰撞void UCameraCollisionComponentBase::CalcCameraCollision
(
    USpringArmComponent* SpringArm, float InDesiredDistance, float InPushSpeed, float InPullSpeed
)
{
   // 开始结束点，获得SprintArm的位置，以及反向*希望的距离作为结束点
    FVector start = SpringArm->GetComponentToWorld().GetLocation();
    FVector end = (SpringArm->GetForwardVector() * -1.f * DesiredDistance) + start;
    // 碰撞通道
    FCollisionObjectQueryParams Channels(ObjectType);
    // 使用简化的球面检测函数
    FHitResult HitOut = FHitResult(ForceInit);
    bool hit = SphereTrace(SpringArm->GetOwner(), start, end, CameraTraceRadius, HitOut, Channels);
    if (hit)
    {
        HitLength = (HitOut.Location - start).Size();
    }
    else
    {
        HitLength = InDesiredDistance;
    }
    // 差值
    CamSpringCurrLength = FMath::FInterpTo(CamSpringCurrLength, HitLength, Delta, CameraLerpSpeed);
    CameraLerpSpeed = (CamSpringCurrLength - HitLength > 0.f) ? PushSpeed : PullSpeed;
    // 设置到SprintArm
    SpringArm->TargetArmLength = CamSpringCurrLength;

}

// 设置DesiredDistancevoid UCameraCollisionComponentBase::SetDesiredDistance(float InDesiredDistance)
{
    DesiredDistance = InDesiredDistance;
}

float UCameraCollisionComponentBase::GetDesiredDistance()
{
    return DesiredDistance;
}

// 简化的球面检测函数bool UCameraCollisionComponentBase::SphereTrace
(
    AActor* ActorToIgnore,
    const FVector& Start,
    const FVector& End,
    const float Radius,
    FHitResult& HitOut,
    FCollisionObjectQueryParams& TraceChannels
)

{
    FCollisionQueryParams TraceParams(true);
    //TraceParams.bTraceComplex = true;
    //TraceParams.bTraceAsyncScene = true;
    TraceParams.bReturnPhysicalMaterial = false;
    //Ignore Actors
    TraceParams.AddIgnoredActor(ActorToIgnore);
    //Re-initialize hit info
    HitOut = FHitResult(ForceInit);
    return GetWorld()->SweepSingleByObjectType
    (
        HitOut,
        Start,
        End,
        FQuat(),
        TraceChannels,
        FCollisionShape::MakeSphere(Radius),
        TraceParams
    );
}