渐变地图echarts 配置项内容和展示

      var map

      function initMap(options) {
        //合并属性参数，可覆盖config.json中的对应配置
        var mapOptions = mars3d.Util.merge(options, {
          scene: {
            center: { lat: 26.339073, lng: 118.495643, alt: 937783, heading: 355, pitch: -58 },
          },
        })

        //创建三维地球场景
        map = new mars3d.Map('mars3dContainer', mapOptions)

        map.basemap = 2017 //蓝色底图

        let geoJsonLayer = new mars3d.layer.GeoJsonLayer({
          name: '安徽各市',
          url: '//data.mars3d.cn/file/geojson/areas/340000_full.json',
          symbol: {
            type: 'polygon',
            styleOptions: {
              materialType: mars3d.MaterialType.PolyGradient, //重要参数，指定材质
              color: '#3388cc',
              opacity: 0.7,
              alphaPower: 1.3,
              //面中心点，显示文字的配置
              label: {
                text: '{name}', //对应的属性名称
                opacity: 1,
                font_size: 25,
                color: '#fff',
                font_family: '楷体',
                outline: false,
                scaleByDistance: true,
                scaleByDistance_far: 20000000,
                scaleByDistance_farValue: 0.1,
                scaleByDistance_near: 1000,
                scaleByDistance_nearValue: 1,
              },
            },
            callback: function (attr, styleOpt) {
              let randomHeight = attr.gdp * 5 //测试的高度
              return {
                color: getColor(),
                diffHeight: randomHeight,
              }
            },
          },
          popup: '{name} : {gdp}亿元  ',
        })
        map.addLayer(geoJsonLayer)

        //绑定事件
        geoJsonLayer.on(mars3d.EventType.load, function (event) {
          console.log('数据加载完成', event)
        })
        geoJsonLayer.on(mars3d.EventType.click, function (event) {
          console.log('单击了图层', event)
        })
      }

      let arrColor = ['rgb(15,176,255)', 'rgb(18,76,154)', '#40C4E4', '#42B2BE', 'rgb(51,176,204)', '#8CB7E5', 'rgb(0,244,188)', '#139FF0']

      let index = 0
      function getColor() {
        return arrColor[++index % arrColor.length]
      }