1、安装cesiumJS、heatmap、webpack插件依赖包:
yarn install/npm install
"dependencies": { ... "cesium": "^1.90.0", "heatmap.js": "^2.0.5" ... }, "devDependencies": { ... "copy-webpack-plugin": "^5.0", "html-webpack-plugin": "3.2.0", ... }
2、cesium目录配置
项目是用vue-cli生成的,在vue.config.js中配置CesiumJS目录:
'use strict' const path = require('path') ... function resolve(dir) { return path.join(__dirname, dir) } ... const CopyWebpackPlugin = require('copy-webpack-plugin') const webpack = require('webpack') const cesiumSource = 'node_modules/cesium/Source'; const cesiumWorkers = '../Build/Cesium/Workers'; // console.log('cesiumSource->',cesiumSource) // console.log('cesiumWorkers->',cesiumWorkers) // console.log('__dirName->', __dirname) // console.log('cesium', path.resolve(__dirname, cesiumSource)) module.exports = { publicPath: process.env.NODE_ENV === 'development' ? '/xxx' : './', outputDir: 'dist', assetsDir: 'static', lintOnSave: process.env.NODE_ENV === 'development', productionSourceMap: false, devServer: { port: 8888, open: false, overlay: { warnings: false, errors: true }, proxy: { ... } }, configureWebpack: { ... resolve: { alias: { '@': resolve('src'),'cesium': path.resolve(__dirname, cesiumSource) //CesiumSource绝对路径别名 } }, plugins: [ new CopyWebpackPlugin([{ from: path.join(cesiumSource, cesiumWorkers), to: 'Workers' }]), new CopyWebpackPlugin([{ from: path.join(cesiumSource, 'Assets'), to: 'Assets' }]), new CopyWebpackPlugin([{ from: path.join(cesiumSource, 'Widgets'), to: 'Widgets' }]), new CopyWebpackPlugin([ { from: path.join(cesiumSource, 'ThirdParty/Workers'), to: 'ThirdParty/Workers'}]), new webpack.DefinePlugin({ CESIUM_BASE_URL: JSON.stringify('') }) ], }, ... }
项目页面JS中这样导包:
import * as Cesium from 'cesium/Cesium' import 'cesium/Widgets/widgets.css'
3、开发热力图
直接参考https://github.com/manuelnas/CesiumHeatmap
由于此插件不支持es6导入,需要改源码(找了github上的其它支持es6 import方式导入的cesium热力图插件,存在一些未知的bug反而影响了开发效率,故还是自己整靠谱)
移除CesiumHeatmap.js中的h337源码,直接在文件头引入cesium和heatmap.js,如下:
import * as Cesium from 'cesium/Cesium' import h337 from 'heatmap.js'
删掉IIEF及相关匿名函数包裹代码,直接暴露出CesiumHeatmap对象并导出,大致如下:
/**
* 修改自https://github.com/manuelnas/CesiumHeatmap
*/
import * as Cesium from 'cesium/Cesium' import h337 from 'heatmap.js' /* * CesiumHeatmap.js v0.1 | Cesium Heatmap Library * * Works with heatmap.js v2.0.0: http://www.patrick-wied.at/static/heatmapjs/ */ const CesiumHeatmap = { defaults: { ... CesiumHeatmap.rad2deg = function(r) { var d = r / (Math.PI / 180.0) return d } /* Initiate a CesiumHeatmap instance * c: CesiumWidget instance * bb: a WGS84 bounding box like {north, east, south, west} * o: a heatmap.js options object (see http://www.patrick-wied.at/static/heatmapjs/docs.html#h337-create) */ function CHInstance(c, bb, o) { ... export default CesiumHeatmap
4、页面中引入CesiumHeatmap并使用
把修改的cesiumHeatmap.js放入某个公共目录下,如src/utils/gis下面。
vue中引入使用:
... import CesiumHeatmap from '@/utils/gis/cesiumHeatmap.js' ... addHeatmap() { const geojson = this.geojson const points = [] let west = 1000; let east = -1000; let south = 1000; let north = -1000 geojson.features.forEach(function(feature) { const lon = feature.geometry.coordinates[0] const lat = feature.geometry.coordinates[1] west = Math.min(west, lon) east = Math.max(east, lon) south = Math.min(south, lat) north = Math.max(north, lat) points.push({ x: lon, y: lat, value: 1 }) }) const bounds = { west, east, south, north } // init heatmap const heatMap = CesiumHeatmap.create( this.viewer, bounds, { minOpacity: 0.15, maxOpacity: 0.8, radius: 15, blur: 0.9, gradient: { '.7': '#546AA4', '.9': '#0DB212', '.95': '#D6CE3B', '.96': '#CC9C1B', '.998': '#DC0F2A' } } ) const valueMin = 0 const valueMax = 10 heatMap.setWGS84Data(valueMin, valueMax, points) this.heatmap = heatMap },
...