/// <summary>
        /// Projects the specified 3D point to a 2D screen point.
        /// </summary>
        /// <param name="viewport">The viewport.</param>
        /// <param name="point">The 3D point.</param>
        /// <returns>The point.</returns>
        public static Point Project(this Viewport3DX viewport, Point3D point)
        {
            var p = viewport.Project(point.ToVector3());

            return(new Point(p.X, p.Y));
        }