添加覆盖物对鼠标移动事件的支持

src/core/event/EventType.js

   CLICK: Cesium.ScreenSpaceEventType.LEFT_CLICK,
   RIGHT_CLICK: Cesium.ScreenSpaceEventType.RIGHT_CLICK,
   DB_CLICK: Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK,
+  MOUSE_MOVE: Cesium.ScreenSpaceEventType.MOUSE_MOVE,
   MOUSE_OVER: 'mouseover',
   MOUSE_OUT: 'mouseout'
 }

src/core/overlay/model/Tileset.js

    *
    * @private
    */
-  _initVisibleEvent() {
-    if (!this._tileVisibleCallback) {
-      this._tileVisibleCallback = this._delegate.tileVisible.addEventListener(
-        this._updateTile,
-        this
-      )
-    }
+  _bindVisibleEvent() {
+    this._tileVisibleCallback && this._tileVisibleCallback()
+    this._tileVisibleCallback = this._delegate.tileVisible.addEventListener(
+      this._updateTile,
+      this
+    )
   }
 
   /**
   /**
    * Sets height
    * @param height
+   * @param isAbsolute
    * @returns {Tileset}
    */
-  setHeight(height) {
+  setHeight(height, isAbsolute = false) {
     this.readyPromise.then(tileset => {
       let center = Cesium.Cartographic.fromCartesian(
         tileset.boundingSphere.center
       let offset = Cesium.Cartesian3.fromRadians(
         center.longitude,
         center.latitude,
-        center.height + height
+        isAbsolute ? height : center.height + height
       )
       let translation = Cesium.Cartesian3.subtract(
         offset,
    */
   setProperties(properties) {
     this._properties = properties
-    this._initVisibleEvent()
+    this._bindVisibleEvent()
     return this
   }
 
    */
   setCustomShader(customShader) {
     this._customShader = customShader
-    this._initVisibleEvent()
+    this._bindVisibleEvent()
     return this
   }