echarts中Scatter3D使用问题echarts scatter3D配置项内容和展示

在echarts中使用geo3D绘制的地图上面叠加散列图(scatter3D),图标会被埋在地图中，如何让图标紧靠在地图表面，不让其埋在地图里面？

      var uploadedDataURL = "/asset/get/s/data-1527220135675-Hkehv-HJ7.json";

$.getJSON(uploadedDataURL,function(data){
			echarts.registerMap("chengdu",data);
			//chart=echarts.init(ele);
			var option={
				geo3D: {
			       map: "chengdu",
			       roam: true,
			       center:[103.9526,30.7617],
			       itemStyle: {
			           opacity: 1,
			           borderWidth: 0.4,
			           areaColor:  '#99ff99',
			           color: '#99ff99',
					   borderColor: '#111'
			       },
			       label: {
			           show: true,
			           textStyle:{
	                        color:'#000',
	                        fontWeight : 'normal',
	                        fontFamily:'sans-serif',
	                        fontSize : 12,
	                        backgroundColor: 'rgba(0,23,11,0)'
	                    },
			        },
			        emphasis: { //当鼠标放上去  地区区域是否显示名称
			            itemStyle:{
	                   		color: '#00CED1',
	                   		areaColor:'#00CED1',
	                   }
			        },
			        viewControl: {
		                autoRotate: false,
		                minDistance:0
		            },
			        regions:regionsJsonData(data)
			    },
			    series:[
			    	{
			    		name: 'spotName',
				        type: 'scatter3D',
				        coordinateSystem: "geo3D",
						symbol:"circle",
				        symbolSize: 12,
				        silent:false,
				        hoverAnimation:false,
				    	data:[
				        	{
				        		"name":"都江堰",
								"value":[103.62,31.00]
				        	},
				        	{
				        		"name":"郫县",
								"value":[103.88,30.82]
				        	},
				        	{
				        		"name":"温江",
								"value":[103.83,30.70]
				        	},
				        	{
				        		"name":"成华",
								"value":[104.10,30.67]
				        	},
				        	{
				        		"name":"青羊",
								"value":[104.05 ,30.70]
				        	},
				        	{
				        		"name":"浦江",
								"value":[103.50,30.20]
				        	},
				        	{
				        		"name":"新津",
								"value":[103.82,30.42]
				        	}
				        ]
			    	}
			    ]
			};
			myChart.setOption(option);
			console.log(myChart.getOption());
			
			function regionsJsonData(geoJson){
        		var data=[];
        		for(var i=0;i<geoJson.features.length;++i){
        			data.push({
        				"id":geoJson.features[i].properties.id,
        				"name":geoJson.features[i].properties.name,
        				"center":geoJson.features[i].properties.cp
        			}); 
        		}
        		return data;
        	}
		})