参考dynamic-render-data实现动态加载VcCollectionBillboard，导致多个VcCollectionBillboard时候，第二个图层以后的图片出现缩放重影

[flywin8]

import { randomPoint } from '@turf/turf';
const createBillboards = (url, zIndex) =>
randomPoint(1000, { bbox: [95, 41, 118, 25] }).features.map(({ geometry }, i) => ({
id: 'billboards-' + zIndex + '-' + i,
name: '桥梁-' + i,
image: url,
width: 60,
height: 60,
verticalOrigin: 1,
heightReference: 2,
eyeOffset: { x: 0, y: 0, z: zIndex }, // 控制层级
disableDepthTestDistance: Number.POSITIVE_INFINITY,
scaleByDistance: new Cesium.NearFarScalar(4.0e2, 1, 2.0e6, 0.1),
position: { lng: geometry.coordinates[0], lat: geometry.coordinates[1] },
}));
const dataLayer = { id:'id1', page: 'page1', datasets: [] };
let billboards = createBillboards('./resource/images/a.png',0)
dataLayer.datasets.push({ component: 'VcCollectionBillboard', props: { billboards }});
mapStore.addDataLayer(dataLayer);

const dataLayer2 = { id:'id1', page: 'page1', datasets: [] };
billboards = createBillboards('./resource/images/b.png',100)
dataLayer2.datasets.push({ component: 'VcCollectionBillboard', props: { billboards }});
mapStore.addDataLayer(dataLayer2);

[flywin8]

const layers: any[] = [];
layers.push(createBillboards('./resource/images/a.svg', 0));
layers.push(createBillboards('./resource/images/b.svg', 100));
billboardLayers.value = layers;
使用这种方式渲染就没有缩放重影的问题