function createModel() {
    var params = {
      tx: 94.94663004042711, //模型中心X轴坐标(经度，单位：十进制度)
      ty: 29.74529725388329,//模型中心Y轴坐标(纬度，单位：十进制度)
      tz: 3400.0, //模型中心Z轴坐标(高程，单位：米)
      rx: 0, //X轴(经度)方向旋转角度(单位：度)
      ry: 0, //Y轴(纬度)方向旋转角度(单位：度)
      rz: -90 //Z轴(高程)方向旋转角度(单位：度)
    };
    var point = viewer.entities.add({
      position: Cesium.Cartesian3.fromDegrees(params.tx, params.ty, 30),
      point: {
        pixelSize: 8,
        color: Cesium.Color.TRANSPARENT,
        outlineColor: Cesium.Color.RED,
        outlineWidth: 3,
      },
    });
    var model = viewer.scene.primitives.add(
      Cesium.Model.fromGltf({
        url: "./static/ceshi/hp3/滑坡原始位置/ys.gltf", //如果为bgltf则为.bgltf static\ceshi\滑坡原始位置(1)\滑坡原始位置\ys.gltf
        show: true,                     // default
        scale: 3.0,
        maximumScale: 1
      })
    );
    model.type = "model";
    model.tx = params.tx;
    model.ty = params.ty;
    model.tz = params.tz;
    model.rx = 0;
    model.ry = 0;
    model.rz = 0;

    update3dtilesMaxtrix(model, params)
    model.readyPromise.then(function (model) {
      viewer.camera.setView({
        destination: Cesium.Cartesian3.fromDegrees(params.tx,
          params.ty,
          60000.0),
        orientation: {
          heading: Cesium.Math.toRadians(0),
          pitch: Cesium.Math.toRadians(-90),
          roll: Cesium.Math.toRadians(0)
        }
      });
    }).otherwise(function (error) {
      window.alert(error);
    });
    let leftDownFlag = false;
    var handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);
    // 旋转的关键代码
    handler.setInputAction(function (movement) {
      pickedObject = viewer.scene.pick(movement.position);
      if (Cesium.defined(pickedObject)) {
        if (pickedObject.primitive.isCesium3DTileset == undefined) {
          leftDownFlag = true;
          document.body.style.cursor = 'pointer';
          viewer.scene.screenSpaceCameraController.enableRotate = false;//锁定相机
          pickedObject.primitive.color = new Cesium.Color(0, 1, 0, 1); //选中模型后高亮
          pickedObject.primitive.silhouetteSize = 3.0;//选中模型后高亮
        }
      }
    }, Cesium.ScreenSpaceEventType.LEFT_DOWN);
    handler.setInputAction(function () {
      if(Cesium.defined(pickedObject)){
        pickedObject.primitive.color = new Cesium.Color(1, 1, 1, 1);
        pickedObject.primitive.silhouetteSize = 0;
        leftDownFlag = false;
        pickedObject = null;
        viewer.scene.screenSpaceCameraController.enableRotate = true;//解除锁定相机
        document.body.style.cursor = 'default';
      }
    }, Cesium.ScreenSpaceEventType.LEFT_UP);
    handler.setInputAction((movement) => {
      if (leftDownFlag && pickedObject.primitive.modelMatrix) {
        // ************g关键代码：cartesian的值************
        // let ray = viewer.camera.getPickRay(movement.endPosition);
        // let cartesian = viewer.scene.globe.pick(ray, viewer.scene);
        
        // 屏幕转世界坐标
        let cartesian = viewer.scene.globe.pick(viewer.camera.getPickRay(movement.endPosition),viewer.scene);
        // 世界坐标转经纬度
        let ellipsoid = viewer.scene.globe.ellipsoid;
        let cartesian3=new Cesium.Cartesian3(cartesian.x,cartesian.y,cartesian.z);
        let cartographic=ellipsoid.cartesianToCartographic(cartesian3);
        let lat=Cesium.Math.toDegrees(cartographic.latitude);
        let lng=Cesium.Math.toDegrees(cartographic.longitude);
        params.tx = lng
        params.ty = lat
        console.log(lat,lng)
        update3dtilesMaxtrix(pickedObject,params)
      }
    }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);
  }
  function update3dtilesMaxtrix(model, params) {
    //旋转
    let mx = Cesium.Matrix3.fromRotationX(Cesium.Math.toRadians(params.rx));
    let my = Cesium.Matrix3.fromRotationY(Cesium.Math.toRadians(params.ry));
    let mz = Cesium.Matrix3.fromRotationZ(Cesium.Math.toRadians(params.rz));
    let rotationX = Cesium.Matrix4.fromRotationTranslation(mx);
    let rotationY = Cesium.Matrix4.fromRotationTranslation(my);
    let rotationZ = Cesium.Matrix4.fromRotationTranslation(mz);
    //平移
    let position = Cesium.Cartesian3.fromDegrees(params.tx, params.ty, params.tz);
    let m = Cesium.Transforms.eastNorthUpToFixedFrame(position);
    //旋转、平移矩阵相乘
    Cesium.Matrix4.multiply(m, rotationX, m);
    Cesium.Matrix4.multiply(m, rotationY, m);
    Cesium.Matrix4.multiply(m, rotationZ, m);
    //赋值给model
    if (Cesium.defined(model.primitive)) {
    model.primitive.modelMatrix = m;
    }
    model.modelMatrix = m;
    model.color = Cesium.Color.WHITE.withAlpha(1);
  }