/// <summary>
        /// Annotates drawn area. Could be computational inefficient
        /// </summary>
        public static void Annotate(AnnotationType t)
        {
            // Get Bounding Box of _currentPointSet
            BBox box = Util.ComputeBoundingBox(_currentPointSet.ToArray());

            // Determine all Points which fit into the boundings of the box
            HashSet <Point3D> annotated = new HashSet <Point3D>();

            // Add all points to annotationGroup
            _annotatedPointsList.AddLast(new AnnotationGroup(annotated, t));
        }
 public Node()
 {
     _objects = new HashSet <Point3D>();
     _box     = BBox.Empty();
 }