+ inline SGBucket get_tile_bucket() const { return tile_bucket; }
+
+ /**
+ * Add terrain mesh and ground lighting to scene graph.
+ */
+ void add_ssg_nodes( ssgBranch* terrain_branch,
+ ssgBranch* gnd_lights_branch,
+ ssgBranch* rwy_lights_branch );
+
+ /**
+ * disconnect terrain mesh and ground lighting nodes from scene
+ * graph for this tile.
+ */
+ void disconnect_ssg_nodes();
+
+
+ /**
+ * return the SSG Transform node for the terrain
+ */
+ inline ssgTransform *get_terra_transform() { return terra_transform; }
+
+ void set_timestamp(double time_ms) { timestamp = time_ms; }
+
+ inline double get_timestamp() const { return timestamp; }
+