public void AddPoint(Point3D point)
 {
     Paths.Add(point);
 }
 public static double CalcDistance3D(Point3D first, Point3D second)
 {
     return Math.Sqrt((second.X - first.X) * (second.X - first.X) +
         (second.Y - first.Y) * (second.Y - first.Y) +
         (second.Z - first.Z) * (second.Z - first.Z));
 }