本文适合对vue，arcgis4.x，threejs，ES6较熟悉的人群食用。

(资料图片)

效果图：

素材：

主要思路：

先用arcgisexternalRenderers封装了一个ExternalRendererLayer，在里面把arcgis和threejs的context关联，然后再写个子类继承它，这部分类容在上一个帖子里面有讲过。

子类AreaLayer继承它，并在里面实现绘制流光边界线的方法，我这里其实就是绘制城市区域的边界线。尝试过直线LineCurve3，三维二次贝塞尔曲线QuadraticBezierCurve3，三维三次贝塞尔曲线CubicBezierCurve3，结果感觉差不多=_=，所以最后还是用CatmullRomCurve3这个来构建管道，这个类使用也比其他的方便。

1：创建一个基于图片的材质

1 const lineImg = require("../../../../public/static/img/line.png") 2         let lineTexture = new THREE.TextureLoader().load(lineImg) 3         lineTexture.wrapS = lineTexture.wrapT = THREE.RepeatWrapping; //每个都重复 4         lineTexture.repeat.set(1, 1) 5         lineTexture.needsUpdate = true 6          7         let lineMaterial = new THREE.MeshBasicMaterial({ 8             map: lineTexture, 9             side: THREE.DoubleSide,10             transparent: true11         })

2：处理坐标转换数据

1 let linePoints = []2         for(let i = 0; i < pointList.length; i++) {3             var item = pointList[i];4             var renderLinePoints = this.lngLatToXY(this.view, [item[0], item[1], 10]);5             var vector3List = renderLinePoints.vector3List;6             7             linePoints.push(new THREE.Vector3(vector3List.x, vector3List.y, vector3List.z));8         }

3：构建TubeGeometry，创建Mesh

1 const curvePath = new THREE.CatmullRomCurve3(linePoints) // 曲线路径2         3         let geometry = new THREE.TubeGeometry(curvePath, 64, 30, 8, true )4         let lineMesh = new THREE.Mesh(geometry, lineMaterial);

4：最后再updateModels里面更新贴图的位置（其实就是render事件）。

1 updateModels(context) {2         super.updateModels(context);3         4         if (this.textures.length > 0) {5             this.textures.forEach(texture => {6                 if (texture) texture.offset.x -= 0.01;7             })8         }9     }

ExternalRendererLayer：

1 import * as THREE from "three"  2 import Stats from "three/examples/jsm/libs/stats.module.js"  3 import * as webMercatorUtils from "@arcgis/core/geometry/support/webMercatorUtils"  4 import * as externalRenderers from "@arcgis/core/views/3d/externalRenderers"  5   6 export default class ExternalRendererLayer {  7     constructor({  8         view,  9         options 10     }) { 11         this.view = view 12         this.options = options 13  14         this.objects = [] 15         this.scene = null 16         this.camera = null 17         this.renderer = null 18          19         this.setup(); 20     } 21      22     setup() { 23         if (process.env.NODE_ENV !== "production") { 24             const sid = setTimeout(() => { 25                 clearTimeout(sid) 26                 //构建帧率查看器 27                 let stats = new Stats() 28                 stats.setMode(0) 29                 stats.domElement.style.position = "absolute" 30                 stats.domElement.style.left = "0px" 31                 stats.domElement.style.top = "0px" 32                 document.body.appendChild(stats.domElement) 33                 function render() { 34                   stats.update() 35                   requestAnimationFrame(render) 36                 } 37                 render() 38             }, 5000) 39         } 40     } 41  42     apply() { 43         let myExternalRenderer = { 44             setup: context => { 45                 this.createSetup(context) 46             }, 47             render: context => { 48                 this.createRender(context) 49             } 50         } 51          52         externalRenderers.add(this.view, myExternalRenderer); 53     } 54  55     createSetup(context) { 56         this.scene = new THREE.Scene(); // 场景 57         this.camera = new THREE.PerspectiveCamera(); // 相机 58  59         this.setLight(); 60  61         // 添加坐标轴辅助工具 62         const axesHelper = new THREE.AxesHelper(10000000); 63         this.scene.Helpers = axesHelper; 64         this.scene.add(axesHelper); 65  66         this.renderer = new THREE.WebGLRenderer({ 67             context: context.gl, // 可用于将渲染器附加到已有的渲染环境(RenderingContext)中 68             premultipliedAlpha: false, // renderer是否假设颜色有 premultiplied alpha. 默认为true 69             // antialias: true 70             // logarithmicDepthBuffer: false 71             // logarithmicDepthBuffer: true  72         }); 73         this.renderer.setPixelRatio(window.devicePixelRatio); // 设置设备像素比。通常用于避免HiDPI设备上绘图模糊 74         this.renderer.setViewport(0, 0, this.view.width, this.view.height); // 视口大小设置 75          76         // 防止Three.js清除ArcGIS JS API提供的缓冲区。 77         this.renderer.autoClearDepth = false; // 定义renderer是否清除深度缓存 78         this.renderer.autoClearStencil = false; // 定义renderer是否清除模板缓存 79         this.renderer.autoClearColor = false; // 定义renderer是否清除颜色缓存 80         // this.renderer.autoClear = false; 81          82         // ArcGIS JS API渲染自定义离屏缓冲区，而不是默认的帧缓冲区。 83         // 我们必须将这段代码注入到three.js运行时中，以便绑定这些缓冲区而不是默认的缓冲区。 84         const originalSetRenderTarget = this.renderer.setRenderTarget.bind( 85             this.renderer 86         ); 87         this.renderer.setRenderTarget = target => { 88             originalSetRenderTarget(target); 89             if (target == null) { 90                 // 绑定外部渲染器应该渲染到的颜色和深度缓冲区 91                 context.bindRenderTarget(); 92             } 93         }; 94          95         this.addModels(context); 96  97         context.resetWebGLState(); 98     } 99 100     createRender(context) {101         const cam = context.camera;102         this.camera.position.set(cam.eye[0], cam.eye[1], cam.eye[2]);103         this.camera.up.set(cam.up[0], cam.up[1], cam.up[2]);104         this.camera.lookAt(105             new THREE.Vector3(cam.center[0], cam.center[1], cam.center[2])106         );107         // this.camera.near = 1;108         // this.camera.far = 100;109 110         // 投影矩阵可以直接复制111         this.camera.projectionMatrix.fromArray(cam.projectionMatrix);112         113         this.updateModels(context);114 115         this.renderer.state.reset();116 117         context.bindRenderTarget();118 119         this.renderer.render(this.scene, this.camera);120 121         // 请求重绘视图。122         externalRenderers.requestRender(this.view);123 124         // cleanup125         context.resetWebGLState();126     }127     128     //经纬度坐标转成三维空间坐标129     lngLatToXY(view, points) {130     131         let vector3List; // 顶点数组132     133         let pointXYs;134     135     136         // 计算顶点137         let transform = new THREE.Matrix4(); // 变换矩阵138         let transformation = new Array(16);139     140         // 将经纬度坐标转换为xy值\141         let pointXY = webMercatorUtils.lngLatToXY(points[0], points[1]);142     143         // 先转换高度为0的点144         transform.fromArray(145             externalRenderers.renderCoordinateTransformAt(146                 view,147                 [pointXY[0], pointXY[1], points[148                     2]], // 坐标在地面上的点[x值, y值, 高度值]149                 view.spatialReference,150                 transformation151             )152         );153     154         pointXYs = pointXY;155     156         vector3List =157             new THREE.Vector3(158                 transform.elements[12],159                 transform.elements[13],160                 transform.elements[14]161             )162     163         return {164             vector3List: vector3List,165             pointXYs: pointXYs166         };167     }168     169     setLight() {170         console.log("setLight")171         let ambient = new THREE.AmbientLight(0xffffff, 0.7);172         this.scene.add(ambient);173         let directionalLight = new THREE.DirectionalLight(0xffffff, 0.7);174         directionalLight.position.set(100, 300, 200);175         this.scene.add(directionalLight);176     }177     178     addModels(context) {179         console.log("addModels")180     }181     182     updateModels(context) {183         // console.log("updateModels")184     }185     186 }

AreaLayer：源码中mapx.queryTask是封装了arcgis的query查询，这个可以替换掉，我只是要接收返回的rings数组，自行构建静态数据也行

1 import * as THREE from "three"  2 import ExternalRendererLayer from "./ExternalRendererLayer.js"  3 import Graphic from "@arcgis/core/Graphic";  4 import SpatialReference from "@arcgis/core/geometry/SpatialReference"  5 import * as externalRenderers from "@arcgis/core/views/3d/externalRenderers"  6   7 import mapx from "@/utils/mapUtils.js";  8   9 export default class AreaLayer extends ExternalRendererLayer { 10     constructor({ 11         view, 12         options 13     }) { 14         super({ 15             view, 16             options 17         }) 18     } 19      20     setup() { 21         super.setup() 22          23         this.textures = [] 24     } 25  26     addModels(context) { 27         // super.addModels(context) 28         // =====================mesh加载=================================// 29         const url = config.mapservice[1].base_url + config.mapservice[1].jd_url; 30         // const url = "http://10.100.0.132:6080/arcgis/rest/services/wuchang_gim/gim_region/MapServer/2"; 31         mapx.queryTask(url, { 32             where: "1=1", 33             returnGeometry: true 34         }).then(featureSet => { 35             if (featureSet.length > 0) { 36                 featureSet.forEach(feature => { 37                     const polygon = feature.geometry; 38                     const rings = polygon.rings; 39                     rings.forEach(ring => { 40                         this._addModel(ring); 41                     }) 42                 }) 43             } 44         }).catch(error => { 45             console.log(error) 46         }) 47     } 48      49     _addModel(pointList) { 50         const lineImg = require("../../../../public/static/img/line.png") 51         let lineTexture = new THREE.TextureLoader().load(lineImg) 52         lineTexture.wrapS = lineTexture.wrapT = THREE.RepeatWrapping; //每个都重复 53         lineTexture.repeat.set(1, 1) 54         lineTexture.needsUpdate = true 55          56         let lineMaterial = new THREE.MeshBasicMaterial({ 57             map: lineTexture, 58             side: THREE.DoubleSide, 59             transparent: true 60         }) 61          62         //确定几何体位置 63         let linePoints = [] 64         // let curvePath = new THREE.CurvePath(); 65         for(let i = 0; i < pointList.length; i++) { 66             var item = pointList[i]; 67             var renderLinePoints = this.lngLatToXY(this.view, [item[0], item[1], 10]); 68             var vector3List = renderLinePoints.vector3List; 69              70             linePoints.push(new THREE.Vector3(vector3List.x, vector3List.y, vector3List.z)); 71              72             // if(i < pointList.length - 1) { 73             //     var item1 = pointList[i + 1]; 74             //     var renderLinePoints1 = this.lngLatToXY(this.view, [item1[0], item1[1], 10]); 75             //     var vector3List1 = renderLinePoints1.vector3List; 76                  77             //     // var item2 = pointList[i + 1]; 78             //     // var renderLinePoints2 = this.lngLatToXY(this.view, [item2[0], item2[1], 10]); 79             //     // var vector3List2 = renderLinePoints2.vector3List; 80                  81             //     const line = new THREE.LineCurve3(vector3List, vector3List1); 82             //     // const line = new THREE.QuadraticBezierCurve3(vector3List, vector3List1, vector3List2); 83             //     curvePath.curves.push(line) 84             // } 85         } 86          87         // console.log(curvePath) 88          89         // CatmullRomCurve3创建一条平滑的三维样条曲线 90         const curvePath = new THREE.CatmullRomCurve3(linePoints) // 曲线路径 91          92         let geometry = new THREE.TubeGeometry(curvePath, 64, 30, 8, true ) 93         let lineMesh = new THREE.Mesh(geometry, lineMaterial); 94          95         this.scene.add(lineMesh); 96          97         this.textures.push(lineTexture); 98         this.objects.push(lineMesh); 99     }100 101 102     updateModels(context) {103         super.updateModels(context);104         105         if (this.textures.length > 0) {106             this.textures.forEach(texture => {107                 if (texture) texture.offset.x -= 0.01;108             })109         }110     }111 112 }