Fix eastwards drift while adjusting height

src/index.js

@@ -5,6 +5,7 @@ import { name, version, mapVersion } from '../package.json';
 import BIMOptions, { bimOptionsId } from './upload.vue';
 import objectList, { objectListId } from './objectList.vue';
 import scaleControl, { scaleControlId } from './scaleControl.vue';
+import * as Cesium from "@vcmap-cesium/engine";
 
 
 let model;
@@ -204,8 +205,10 @@ class HeightInteraction extends AbstractInteraction {
       }
       heightDif = heightDif - (dif / 50);
       let pos = model.position.getValue();
+      let cart = Cesium.Cartographic.fromCartesian(pos);
+      cart.height -= (dif/50);
+      pos = Cesium.Cartesian3.fromRadians(cart.longitude, cart.latitude, cart.height);
       currentMousePosition = [event.windowPosition.x, event.windowPosition.y];
-      pos.z = pos.z - (dif / 50);
       model.position.setValue(pos);
     }
     return event;