// 点投影到直线，或过点作直线的垂线与直线的交点.
// 注意：当点在直线上时，函数获取的就是该点
FVector UKismetMathLibrary::FindClosestPointOnLine(FVector Point, FVector LineOrigin, FVector LineDirection)
{
	const FVector SafeDir = LineDirection.GetSafeNormal();
	const FVector ClosestPoint = LineOrigin + (SafeDir * ((Point-LineOrigin) | SafeDir));
	return ClosestPoint;
}