private IEnumerator AddMap(Place place)
        {
            // Store current place
            this._place = place;

            // Convert lat/long to Google/Bing/AGOL tile.
            var tile = this._place.Location.ToTile(this._place.Level);

            // Get children.
            //var children = tile.GetChildren(CHILDREN_LEVEL);

            var children = tile.GetNeighbor(CHILDREN_LEVEL);

            // Elevation and texture variables.
            Texture2D[] textures = new Texture2D[children.Length];

            yield return(null);

            // Retrieve imagery.
            foreach (var child in children)
            {
                this.StartCoroutine(Imagery.GetTexture(child, currentStyle, texture =>
                {
                    textures[Array.IndexOf(children, child)] = texture;

                    if (textures.All(t => t != null))
                    {
                        this.StartCoroutine(this.BuildMap(textures, children));
                    }
                }));
            }
        }
        private IEnumerator AddTerrain(Place place)
        {
            // Store current place
            this._place = place;

            // Convert lat/long to Google/Bing/AGOL tile.
            var tile = this._place.Location.ToTile(this._place.Level);

            // Get children.
            var children = tile.GetChildren(CHILDREN_LEVEL);

            // Elevation and texture variables.
            ElevationData el = null;

            Texture2D[] textures = new Texture2D[children.Length];
            yield return(null);

            // Retrieve elevation.
            this.StartCoroutine(Elevation.GetHeights(tile, elevation =>
            {
                el = elevation;
                // Construct terrain if both elevation and textures downloaded.
                if (textures.All(t => t != null))
                {
                    this.StartCoroutine(this.BuildTerrain(el, textures));
                }
            }));
            yield return(null);

            // Retrieve imagery.
            foreach (var child in children)
            {
                this.StartCoroutine(Imagery.GetTexture(child, texture =>
                {
                    textures[Array.IndexOf(children, child)] = texture;
                    // Construct terrain if both elevation and textures downloaded.
                    if (el != null && textures.All(t => t != null))
                    {
                        this.StartCoroutine(this.BuildTerrain(el, textures));
                    }
                }));
            }
        }
        private IEnumerator AddTerrain(Place place)
        {
            // Store current place
            this._place = place;

            // Convert lat/long to Google/Bing/AGOL tile.
            var tile = this._place.Location.ToTile(this._place.Level);

            // Get children.
            //var children = tile.GetChildren(CHILDREN_LEVEL);

            var children = tile.GetNeighbor(CHILDREN_LEVEL);

            // Elevation and texture variables.
            ElevationData el = null;

            Texture2D[] textures = new Texture2D[children.Length];
            yield return(null);

            // Retrieve elevation.

            if (currentDimension == "3D")
            {
                this.StartCoroutine(Elevation.GetHeights(tile, elevation =>
                {
                    el = elevation;
                    // Construct terrain if both elevation and textures downloaded.
                    if (textures.All(t => t != null))
                    {
                        this.StartCoroutine(this.BuildTerrain(el, textures));
                    }
                }));
                yield return(null);
            }

            // Retrieve imagery.
            foreach (var child in children)
            {
                this.StartCoroutine(Imagery.GetTexture(child, currentStyle, texture =>
                {
                    textures[Array.IndexOf(children, child)] = texture;
                    // Construct terrain if both elevation and textures downloaded.
                    //if (el != null && textures.All(t => t != null))
                    if (textures.All(t => t != null))
                    {
                        this.StartCoroutine(this.BuildTerrain(el, textures));
                    }
                }));
            }
            //add 2

            /*
             * if (needupdate)
             * {
             *  this.StartCoroutine(this.Updatemap(updateURL));
             *  //destroy all exist buildingļ¼Œerase the items form
             *  GameObject[] gameObjects = GameObject.FindGameObjectsWithTag("Rotate");
             *  for (var i = 0; i < gameObjects.Length; i++)
             *  {
             *      Destroy(gameObjects[i]);
             *  }
             *  //StartCoroutine(Eraseitems(queryURL));
             * }
             */
        }