UnityEditor.EditorUtility.SetDirty C# (CSharp) Method

        public static extern void SetDirty(Object target);
        /// <summary>

        private static void AddWaypointToGroupOnClick(WaypointGroup group, int afterIndex, Vector3 worldPosition)
        {
            if (Event.current.alt)
            {
                // when using alt the user is likely panning around an object, ignore the add method.
                return;
            }

            Handles.Label(worldPosition, "Inserted waypoint at: " + worldPosition);
            Handles.color = Color.green;
            Handles.SphereCap(-1, worldPosition, Quaternion.identity, 0.5f);

            var afterIndexClamped = Mathf.Max(0, afterIndex - 1);

            if (afterIndexClamped > 0 && afterIndexClamped < group.waypoints.Length)
            {
                Handles.DrawAAPolyLine(LineWidth, group.waypoints[afterIndexClamped].transform.position, worldPosition);
            }

            Handles.color = Color.white;

            // Connect from the last to a new waypoint
            if (Event.current.type == EventType.MouseDown && Event.current.button == 0)
            {
                Undo.RecordObject(group, "Added waypoint");
                group.InsertWaypointAfter(group.transform.worldToLocalMatrix * (worldPosition - group.transform.localPosition), afterIndex);

                _selectedWaypointGroup = group;
                _selectedWaypointIndex = afterIndex;

                EditorUtility.SetDirty(group);
            }
        }