/// <summary>
        /// Add an array of 3-D points to the document
        /// </summary>
        public object AddPoints(object pointsObj)
        {
            var points = new List <Point3d>();

            if (SampleCsRhinoHelpers.ConvertToPoint3dList(pointsObj, ref points))
            {
                var doc = RhinoDoc.ActiveDoc;
                if (null != doc)
                {
                    var object_ids = new ArrayList();
                    for (var i = 0; i < points.Count(); i++)
                    {
                        var object_id = doc.Objects.AddPoint(points[i]);
                        if (!object_id.Equals(System.Guid.Empty))
                        {
                            object_ids.Add(object_id.ToString());
                        }
                    }
                    if (object_ids.Count > 0)
                    {
                        doc.Views.Redraw();
                        return(object_ids.ToArray());
                    }
                }
            }
            return(null);
        }
        /// <summary>
        /// Add a 3-D point to the document
        /// </summary>
        public object AddPoint(object pointObj)
        {
            var point = new Point3d();

            if (SampleCsRhinoHelpers.ConvertToPoint3d(pointObj, ref point))
            {
                var doc = RhinoDoc.ActiveDoc;
                if (null != doc)
                {
                    var object_id = doc.Objects.AddPoint(point);
                    if (!object_id.Equals(System.Guid.Empty))
                    {
                        doc.Views.Redraw();
                        return(object_id.ToString());
                    }
                }
            }
            return(null);
        }