cesium 叠加影像切片

$vc.creatingPromise.then((readyObj) => {
    if(tileLayer){
      readyObj.viewer.imageryLayers.remove(tileLayer)
       tileLayer = null
    }
    let provider = new Cesium.WebMapTileServiceImageryProvider({
        url : `http://192.168.8.28:8080/geoserver/gwc/service/wmts?layer=cite:dom_${d.value}&style=&tilematrixset=EPSG:3857&Service=WMTS&Request=GetTile&Version=1.0.0&Format=image/png&TileMatrix=EPSG:3857:{TileMatrix}&TileCol={TileCol}&TileRow={TileRow}`,
        layer : 'USGSShadedReliefOnly',
        style : 'default',
        format : 'image/png',
        tileMatrixSetID : 'EPSG',
        maximumLevel: 19,
        credit : new Cesium.Credit('U. S. Geological Survey'),
        rectangle: rectangle
    });
    tileLayer = readyObj.viewer.imageryLayers.addImageryProvider(provider);
    provider.readyPromise.then((state)=>{
        if(state){
          loading.close()
          readyObj.viewer.camera.flyTo({
            destination: rectangle
          });
          // emit('loaded')
        }
    })

 })