Cesium 问题：加载 geojson 数据量大浏览器会崩，使用primitive方式加载

问题

之前加载geojson数据都是使用dataSource和entity的方式，但是当数据量大时，浏览器就会崩掉：提示浏览器内存不足，已暂停渲染

分析

使用primitive方式加载数据，可以提高加载渲染效率。实现方法如下：

getServePyApi(tempData).then((res)=>{if(res){var contents = res.data.result;console.log(res);const instances = [];let features = contents.features;for (let i = 0; i < features.length; i++) {for (let j = 0; j < features[i].geometry.coordinates.length; j++) {const polygonArray = features[i].geometry.coordinates[j].toString().split(',');const polygon = new Cesium.PolygonGeometry({polygonHierarchy: new Cesium.PolygonHierarchy(Cesium.Cartesian3.fromDegreesArray(polygonArray)),// 设置面的拉伸高度extrudedHeight: 35,});var count = features[i].properties.index_coun;const color = null; // 根据 count 值设置不同的颜色if (count >= 0 && count < 10) {color = Cesium.Color.fromCssColorString('#FF0000');  // 设置红色} else if (count >= 10 && count < 20) {color = Cesium.Color.fromCssColorString('#00FF00');  // 设置绿色} else {color = Cesium.Color.fromCssColorString('#0000FF');  // 设置蓝色}const geometry = Cesium.PolygonGeometry.createGeometry(polygon);instances.push(new Cesium.GeometryInstance({geometry: geometry,attributes: {color: Cesium.ColorGeometryInstanceAttribute.fromColor(color),},}));}}// 合并单个geometry,提高渲染效率this.od5 = new Cesium.Primitive({geometryInstances: instances,appearance: new Cesium.PerInstanceColorAppearance(),});window.viewer.scene.primitives.add(this.od5);});