没有开发修改模型位置的功能，所以就用笨办法，根据两个点取中心点，最后调节模型角度就行了 

忘了当时怎么取的模型的右上角、左下角，好像是根据做模型的地形

// 模型的右上角、左下角2个点（忘了是怎么取得2个点了），根据turf分析，取中间点当模型的中心点  
viewer.entities.add({
      position: Cesium.Cartesian3.fromDegrees(94.885058999, 29.841307998, 2000),
      point: {
        pixelSize: 8,
        color: Cesium.Color.TRANSPARENT,
        outlineColor: Cesium.Color.RED,
        outlineWidth: 3
      }
    });
    viewer.entities.add({
      position: Cesium.Cartesian3.fromDegrees(94.995276332, 29.6946277879, 2000),
      point: {
        pixelSize: 8,
        color: Cesium.Color.TRANSPARENT,
        outlineColor: Cesium.Color.RED,
        outlineWidth: 3
      }
    });
    console.log(turf)
    var point1 = turf.point([94.885058999, 29.841307998]);
    var point2 = turf.point([94.995276332, 29.6946277879]);
    var midpoint = turf.midpoint(point1, point2);
    viewer.entities.add({
      position: Cesium.Cartesian3.fromDegrees(midpoint.geometry.coordinates[0],midpoint.geometry.coordinates[1], 4000),
      point: {
        pixelSize: 8,
        color: Cesium.Color.TRANSPARENT,
        outlineColor: Cesium.Color.RED,
        outlineWidth: 3
      }
    });
    console.log(midpoint)