// Called every frame
void AMovingPlatform3::Tick( float DeltaTime )
{
     Super::Tick( DeltaTime );
     FVector PlatformLocation = GetActorLocation();
     FVector Start = PlatformLocation;
     FVector End = ???;
     float Duration = 3.0f; // seconds
     
     FVector Delta = (End - Start)/2;
     FVector Origin = Start + Delta/2;

     phase = sin(PlatformTime / Duration * 2*pi);

     PlatformLocation = Origin + Delta * phase;

     PlatformTime += DeltaTime; 

     SetActorLocation(PlatformLocation);
}