首先 Actor是没有Position的，读写它的位置是引用于RootComponent。

ProjectileMovement 抛射位移

用来抛掷其它的Component。

AMyActor::AMyActor()
{
    RootComponment = CreateDefaultSubObject<USphereComponment>(TEXT("SPComp"));
    UProjectileMovementComponment* PMC;
    PMC = CreateDefaultSubObject<UProjectileMovementComponment>(TEXT("PMComp"));
    PMC->UpdatedComponment = RootComponment;
    PMC->InitalSpeed = 3000.0f;
    PMC->MaxSpeed = 3500.0f;
    PMC->bRotationFollowsVelocity = true;
    PMC->bShouldBounce = true;
}