keywords: [Math]Parabola movement

keywords：抛物运动、Parabola、重力加速度、Gravitational Speed 、UE4 implement.

header

AStaticMeshActor* TestCube = nullptr;

//throw speed
UPROPERTY(EditDefaultsOnly)
FVector StartForce = FVector(100.f, 100.f, 2000.f);

//gravitational acceleration
float GravityAcclerator = -980.f;

//accumulated movtion time
float AccumulateTime = 0.f;

cpp

void ATestTPGameMode::StartPlay()
{
    Super::StartPlay();

    //finding the Actor in scene.
    for (TActorIterator<AStaticMeshActor> Iter(GetWorld()); Iter; ++Iter)
    {
        if (Iter->GetName() == TEXT("Cube_2"))
        {
            TestCube = *Iter;
            break;
        }
    }
}

void ATestTPGameMode::Tick(float DeltaSeconds)
{
    Super::Tick(DeltaSeconds);

    AccumulateTime += DeltaSeconds;

    //calculate gravitational speed in real time.
    float ZSpeed = GravityAcclerator * AccumulateTime;

    //calculate summation speed of gravitational speed and throw speed.
    FVector CurrSpeed = StartForce + FVector(0.f, 0.f, ZSpeed) ;

    //calculate movement distance in real time.
    FVector MoveDist = CurrSpeed * DeltaSeconds;

    //set relative location.
    TestCube->AddActorWorldOffset(MoveDist, true);
}