: 1,
                            "far": 200
                        },
                    }]
                };

                var viewshed = earth.sceneTree.$refs.viewshed.czmObject;
                this._viewshed = viewshed;
                var tileset1 = earth.sceneTree.root.children[0].czmObject;

                // only for Debug
                window.earth = earth;
                window.tileset1 = tileset1;
                window.viewshed = viewshed;

                // 1.1.5 数据绑定
       