前进时改变 FOV（视野）

Question

我有情况。我想在前进的同时平稳地改变 FOV。在父 class 的相机设置中，我设置默认值：

FollowCamera->FieldOfView = 90.0f;

然后在MoveForward函数中我这样设置

void AStarMotoVehicle::MoveForward(float Axis)
{
    if ((Controller != NULL) && (Axis != 0.0f) && (bDead != true))
    { 
        //Angle of direction of camera on Yaw
    const FRotator Rotation = Controller->GetControlRotation();
    const FRotator YawRotation(0, Rotation.Yaw, 0);

    const FVector Direction = FRotationMatrix(YawRotation).GetUnitAxis(EAxis::X);
    AddMovementInput(Direction, Axis);

    FollowCamera->FieldOfView = 140.0f;
    }

实际上它可以工作，所以当我向前移动时，FOV 变为 140，但它工作得非常粗略并且立即发生。我想从90到140顺利完成。你能帮我吗？

Answer 1

FInterpTo 会为您做这个： https://docs.unrealengine.com/en-US/API/Runtime/Core/Math/FMath/FInterpTo/index.html

每次调用“MoveForward”，fov都会增加到140。到slow/speed过渡，decrease/increaseInterpSpeed值

使用您的代码：

void AStarMotoVehicle::MoveForward(float Axis)
{
    if ((Controller != NULL) && (Axis != 0.0f) && (bDead != true))
    { 
        //Angle of direction of camera on Yaw
    const FRotator Rotation = Controller->GetControlRotation();
    const FRotator YawRotation(0, Rotation.Yaw, 0);

    const FVector Direction = FRotationMatrix(YawRotation).GetUnitAxis(EAxis::X);
    AddMovementInput(Direction, Axis);

    // could check if World is valid
    UWorld *World = GetWorld();
    

    const float CurrentFOV = FollowCamera->FieldOfView;
    const float InterpSpeed = 2.0f
    FollowCamera->FieldOfView = FMath::FInterpTo(CurrentFOV, 
     140.0f, 
     World->GetTimeSeconds(),
     InterpSpeed);
    }

前进时改变 FOV（视野）

Changing FOV(Field of view) while moving forward

c++

unreal-development-kit

unreal-engine4