ArcGIS For JavaScript结合ThreeJS功能
- 概述
- three.js中功能实现
- externalRenderers(4.28及以下版本)
- RenderNode(4.29版本)
概述
ArcGIS For Javacript提供了一些对象可以支持加载webgl上下文信息,这里包括webgl编程的代码及webgl封装的threejs的代码。并且4.29版本之前,ArcGIS For Javacript提供了externalRenderers去实现这些功能,4.29版本则摒弃了externalRenderers对象,新增了RenderNode的对象去加载第三方的渲染平台。
RenderNode相对于externalRenderers,功能上有了很大的提升。它不仅可以去加载第三方的三维渲染平台(ThreeJS)的功能,还可以对当前SceneView场景中的渲染内容进行后处理操作。
今天这里只介绍一下externalRenderers和RenderNode如何加载ThreeJS的功能操作。
three.js中功能实现
对于ThreeJS而言,一般基础的元素包含了Scene、Camera、Renderer以及三维对象。
一般步骤如下:
- 引入three.js
<script src="three.min.js">
- 创建一个场景(Scene),用于放置3D元素。
const scene = new THREE.Scene();
- 创建相机(Camera),通过相机将渲染的结果呈现给观察者。
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
- 创建渲染器(Renderer),渲染器将3D场景呈现为二维的图像,使得屏幕显示3D更真实。
//定义一个渲染器Renderconst renderer = new THREE.WebGLRenderer();//设置render的渲染范围renderer.setSize(window.innerWidth, window.innerHeight);//将场景元素添加到body中document.body.appendChild(renderer.domElement);
- 创建3D对象,这个时候就可以创建一些球、立方体等。
//定义一个geometry,geometry定义了物体的形状,three有很多种geometryconst geometry = new THREE.BoxGeometry();const material= new THREE.MeshBasicMaterial({color: 0x00ffff});let mesh = new THREE.Mesh(geometry, material);scene.add(mesh);
- 渲染场景,主要是将视图渲染到屏幕,这步主要为了调用我们前面创建的渲染器。
//定义渲染的动画函数function animate() {//将animate函数添加到requestAnimationFrame,进行循环调用requestAnimationFrame(animate);cube.rotation.x += 0.01;cube.rotation.y += 0.01;//执行渲染器的渲染函数renderer.render(scene, camera);}//执行渲染函数animate();
完整代码如下:
<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>ThreeJs基础知识_Scene</title><!-- <script src="./js/three.js"></script> --><script type="text/javascript" src="../js/threejs/r141/three.min.js"></script><style>body {margin: 0;}</style><!--three的场景主要包括了三个对象,场景Scene,相机Camera和渲染器Render,同时在正常应用的时候还需要包括物体 Object和控制器Contro以及灯光Light。--></head><body><script>const scene = new THREE.Scene();//创建一个场景Scene//定义一个相机Camera( 透视摄像机 )const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);scene.rotation.x = THREE.MathUtils.degToRad(-60);// camera.rotateZ(THREE.MathUtils.degToRad(30));//定义一个渲染器Renderconst renderer = new THREE.WebGLRenderer();//设置render的渲染范围renderer.setSize(window.innerWidth, window.innerHeight);//将场景元素添加到body中document.body.appendChild(renderer.domElement);let geometry = new THREE.CylinderBufferGeometry(1, 0, 2, 4);geometry.rotateX(Math.PI / 2);geometry.computeBoundingSphere();const material = new THREE.MeshBasicMaterial({color: 0x00ff00,transparent: true,opacity: 0.5,});//material定义了物体的材质,简单说就是外观// 长方体作为EdgesGeometry参数创建一个新的几何体const edges = new THREE.EdgesGeometry(geometry);const edgesMaterial = new THREE.LineBasicMaterial({color: 0x00ffff,})const line = new THREE.LineSegments(edges, edgesMaterial);let object3D = new THREE.Object3D();let mesh = new THREE.Mesh(geometry, material);mesh.add(line);object3D.add(mesh);scene.add(object3D);//然后将物体添加到场景中去//定义相机的z坐标,就是相机看的位置,此时要注意一下three中相机坐标系的概念,x横向,z纵向,y是竖直的,后期有兴趣可以慢慢研究three的坐标系camera.position.z = 4;let ambient = new THREE.AmbientLight(0xffffff, 0.5);scene.add(ambient);//定义渲染的动画函数function animate() {//将animate函数添加到requestAnimationFrame,进行循环调用requestAnimationFrame(animate);// cube.rotation.x += 0.01;// cube.rotation.y += 0.01;if (object3D) {let vec = new THREE.Vector3(0, 0, 1);object3D.rotateOnAxis(vec, Math.PI / 300);}//执行渲染器的渲染函数renderer.render(scene, camera);}//执行渲染函数animate();</script>
</body></html>
效果:
externalRenderers(4.28及以下版本)
externalRenderer提供了add方法,该方法支持将外部渲染器添加到当前的视图中。外部渲染器由包含一些方法和属性的对象定义的。这样就可以将其他渲染器和ArcGIS的平台融合在一起使用。
renderer的内容,可以按照ExternalRenderer的对象去定义,ExternalRenderer定义如下:
我们实例化的时候,就可以按照上面的结构去定义ExternalRenderer对象:
完成代码如下:
externalRenderClass.js
<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>ThreeJS+ArcGIS</title><!-- <script type="text/javascript" src="./js/threejs/r109/three.min.js"></script><script type="text/javascript" src="./js/threejs/r109/GLTFLoader.js"></script> --><script type="text/javascript" src="./js/threejs/r141/three.min.js"></script><script src="./externalRenderClass.js"></script><link rel="stylesheet" href="https://js.arcgis.com/4.28/esri/themes/light/main.css" /><script src="https://js.arcgis.com/4.28/"></script><style>html,body,#viewDiv {height: 100%;width: 100%;margin: 0;padding: 0;}</style><script async src="https://unpkg.com/es-module-shims@1.8.0/dist/es-module-shims.js"></script><script>window.THREE = THREE;window.GLTFLoader = THREE.GLTFLoader;require(["esri/views/SceneView","esri/Map","esri/layers/TileLayer","esri/views/3d/externalRenderers"], (SceneView, Map, TileLayer, externalRenderers) => {// const baselayer = new TileLayer({// url: "http://map.geoq.cn/ArcGIS/rest/services/ChinaOnlineStreetPurplishBlue/MapServer",// });let map = new Map({// layers:[scenelayer]basemap:"satellite"})// map.add(baselayer);let view = new SceneView({map: map,container: 'viewDiv',viewingMode: "local"});// let position = [13529536.50333642, 3626588.0048437016, 1000]view.when(function () {view.goTo({fov: 55,heading: 55.99495193816657,position: {x: 13513809.919879783,y: 3616346.75042186,z: 8574.5211164545,spatialReference: {wkid: 102100}},tilt: 69.0179407311609});})view.on("click",function(){console.log(view.camera);})let dynamicGLTFRender = new externalRenderClass({view,externalRenderers})externalRenderers.add(view, dynamicGLTFRender);window.view = view;// let myExternalRenderer = {// setup: function (context) {// // 在外部渲染器添加到视图后执行一次。// // 你可以使用这个函数来分配所有的静态WebGL资源(着色器,缓冲区等)。// },// render: function (context) {// // 在每一帧执行,绘制几何图形到画布。在这个函数中完成的任务:// // *更新动态资源的状态// // *根据需要设置WebGL状态// // *发出WebGL绘制调用// }// }})</script>
</head><body><div id="viewDiv"></div>
</body></html>
index.html
class externalRenderClass {constructor(options) {this.opts = {externalRenderers: null,}this.opts.externalRenderers = options.externalRenderers;this.view = options.view;this.cube = null;this.mesh = null;}setParams() {this.isStop = !this.isStop;}setup(context) {let THREE = window.THREE;// this.mixer = new THREE.AnimationMixer();this.horseMixer = THREE.AnimationMixer;this.clock = new THREE.Clock();this.horseClock = new THREE.Clock();this.mixer = THREE.AnimationMixer;this.renderer = new THREE.WebGLRenderer({context: context.gl, // 可用于将渲染器附加到已有的渲染环境(RenderingContext)中premultipliedAlpha: false, // renderer是否假设颜色有 premultiplied alpha. 默认为true});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this.renderer.setViewport(0, 0, this.view.width, this.view.height); // 视口大小设置this.renderer.autoClear = false;this.renderer.autoClearDepth = false;this.renderer.autoClearColor = false;// this.renderer.autoClearStencil = false;let originalSetRenderTarget = this.renderer.setRenderTarget.bind(this.renderer);this.renderer.setRenderTarget = function (target) {originalSetRenderTarget(target);if (target == null) {context.bindRenderTarget();}};this.scene = new THREE.Scene();// setup the cameralet cam = context.camera;this.camera = new THREE.PerspectiveCamera(cam.fovY, cam.aspect, cam.near, cam.far);// 添加坐标轴辅助工具const axesHelper = new THREE.AxesHelper(1);axesHelper.position.copy(1000000, 100000, 100000);this.scene.add(axesHelper);let grid = new THREE.GridHelper(30, 10, 0xf0f0f0, 0xffffff);this.scene.add(grid);// setup scene lightingthis.ambient = new THREE.AmbientLight(0xffffff, 0.5);this.scene.add(this.ambient);let geometry = new THREE.CylinderBufferGeometry(1500, 0, 2000, 4);geometry.rotateX(Math.PI / 2);geometry.computeBoundingSphere();const material = new THREE.MeshBasicMaterial({color: 0x00ff00,transparent: true,opacity: 0.5,});//material定义了物体的材质,简单说就是外观// 长方体作为EdgesGeometry参数创建一个新的几何体const edges = new THREE.EdgesGeometry(geometry);const edgesMaterial = new THREE.LineBasicMaterial({color: 0x00ffff,})const line = new THREE.LineSegments(edges, edgesMaterial);let object3D = new THREE.Object3D();let mesh = new THREE.Mesh(geometry, material);mesh.add(line);object3D.add(mesh);// object3D.position.set(cenP[0], cenP[1], cenP[2] + 2000 / 2);let position = [13529536.50333642, 3626588.0048437016, 1000];let cenP = [];this.opts.externalRenderers.toRenderCoordinates(this.view, [position[0], position[1], position[2]], 0, this.view.spatialReference, cenP, 0, 1);object3D.position.set(cenP[0], cenP[1], cenP[2] + 2000 / 2);this.scene.add(object3D);//然后将物体添加到场景中去this.mesh = object3D;// this.getCoords(context);context.resetWebGLState();}/*** 渲染器更新渲染* @memberof BuildingEffect* @method render* @param {Object} context 已有渲染器信息,无需传值*/render(context) {let THREE = window.THREE;let cam = context.camera;//需要调整相机的视角this.camera.position.set(cam.eye[0], cam.eye[1], cam.eye[2]);this.camera.up.set(cam.up[0], cam.up[1], cam.up[2]);this.camera.lookAt(new THREE.Vector3(cam.center[0], cam.center[1], cam.center[2]));// Projection matrix can be copied directlythis.camera.projectionMatrix.fromArray(cam.projectionMatrix);if (this.mesh) {let vec = new THREE.Vector3(0, 0, 1);this.mesh.rotateOnAxis(vec, Math.PI / 300);}// draw the scene/// this.renderer.resetGLState();this.renderer.state.reset();//Three.js r127版本重构了WebGLState,//this.renderer.state.reset(); 之后需要加一行 context.bindRenderTarget(); 否则渲染不出来context.bindRenderTarget();// this.renderer.setRenderTarget();this.renderer.render(this.scene, this.camera);// as we want to smoothly animate the ISS movement, immediately request a re-renderthis.opts.externalRenderers.requestRender(this.view);// cleanupcontext.resetWebGLState();}}
效果:
RenderNode(4.29版本)
RenderNode在加载ThreeJS模块的时候和externalRenderer有些不一样。
- 调用的对象类型发生了变化。externalRenderer以class的形式调用,RenderNode必须以返回的对象类型调用。
- 内部方法名发生了变化。externalRenderer初始化的方法名为setup,RenderNode初始化的方法名为initialize。
- 调用方式不同。externalRenderer直接通过add的方式去添加并传参。RenderNode需要先通过RenderNode.createSubclass去创建子类,然后通过new一个子类对象,去传参数。
具体代码如下:
let RenderNodeClass = {constructor(options) {this.webgl = options.webgl;this.view = options.view;this.cube = null;this.mesh = null;this._camera = null;},setParams() {this.isStop = !this.isStop;},initialize() {let THREE = window.THREE;// this.mixer = new THREE.AnimationMixer();this.horseMixer = THREE.AnimationMixer;this.clock = new THREE.Clock();this.horseClock = new THREE.Clock();this.mixer = THREE.AnimationMixer;this.renderer = new THREE.WebGLRenderer({context: this.gl, // 可用于将渲染器附加到已有的渲染环境(RenderingContext)中premultipliedAlpha: false, // renderer是否假设颜色有 premultiplied alpha. 默认为true});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this.renderer.setViewport(0, 0, this.view.width, this.view.height); // 视口大小设置this.renderer.autoClear = false;this.renderer.autoClearDepth = false;this.renderer.autoClearColor = false;// this.renderer.autoClearStencil = false;let originalSetRenderTarget = this.renderer.setRenderTarget.bind(this.renderer);this.renderer.setRenderTarget = function (target) {originalSetRenderTarget(target);if (target == null) {context.bindRenderTarget();}};this.scene = new THREE.Scene();// setup the cameralet cam = this.camera;this._camera = new THREE.PerspectiveCamera(cam.fovY, cam.aspect, cam.near, cam.far);// 添加坐标轴辅助工具const axesHelper = new THREE.AxesHelper(1);axesHelper.position.copy(1000000, 100000, 100000);this.scene.add(axesHelper);let grid = new THREE.GridHelper(30, 10, 0xf0f0f0, 0xffffff);this.scene.add(grid);// setup scene lightingthis.ambient = new THREE.AmbientLight(0xffffff, 0.5);this.scene.add(this.ambient);let geometry = new THREE.CylinderBufferGeometry(1500, 0, 2000, 4);geometry.rotateX(Math.PI / 2);geometry.computeBoundingSphere();const material = new THREE.MeshBasicMaterial({color: 0x00ff00,transparent: true,opacity: 0.5,});//material定义了物体的材质,简单说就是外观// 长方体作为EdgesGeometry参数创建一个新的几何体const edges = new THREE.EdgesGeometry(geometry);const edgesMaterial = new THREE.LineBasicMaterial({color: 0x00ffff,})const line = new THREE.LineSegments(edges, edgesMaterial);let object3D = new THREE.Object3D();let mesh = new THREE.Mesh(geometry, material);mesh.add(line);object3D.add(mesh);// object3D.position.set(cenP[0], cenP[1], cenP[2] + 2000 / 2);let position = [13529536.50333642, 3626588.0048437016, 1000];let cenP = [];this.webgl.toRenderCoordinates(this.view, [position[0], position[1], position[2]], 0, this.view.spatialReference, cenP, 0, 1);object3D.position.set(cenP[0], cenP[1], cenP[2] + 2000 / 2);this.scene.add(object3D);//然后将物体添加到场景中去this.mesh = object3D;// this.getCoords(context);this.resetWebGLState();},/*** 渲染器更新渲染* @memberof BuildingEffect* @method render* @param {Object} context 已有渲染器信息,无需传值*/render(context) {let THREE = window.THREE;let cam = this.camera;//需要调整相机的视角this._camera.position.set(cam.eye[0], cam.eye[1], cam.eye[2]);this._camera.up.set(cam.up[0], cam.up[1], cam.up[2]);this._camera.lookAt(new THREE.Vector3(cam.center[0], cam.center[1], cam.center[2]));// Projection matrix can be copied directlythis._camera.projectionMatrix.fromArray(cam.projectionMatrix);if (this.mesh) {let vec = new THREE.Vector3(0, 0, 1);this.mesh.rotateOnAxis(vec, Math.PI / 300);}this.renderer.state.reset();this.bindRenderTarget();this.renderer.render(this.scene, this._camera);// as we want to smoothly animate the ISS movement, immediately request a re-renderthis.requestRender();// cleanupthis.resetWebGLState();}}
index.html
<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>ThreeJS+ArcGIS</title><!-- <script type="text/javascript" src="./js/threejs/r109/three.min.js"></script><script type="text/javascript" src="./js/threejs/r109/GLTFLoader.js"></script> --><script type="text/javascript" src="./js/threejs/r141/three.min.js"></script><script src="./RenderNodeClass.js"></script><link rel="stylesheet" href="https://js.arcgis.com/4.29/esri/themes/light/main.css" /><script src="https://js.arcgis.com/4.29/"></script><style>html,body,#viewDiv {height: 100%;width: 100%;margin: 0;padding: 0;}</style><script async src="https://unpkg.com/es-module-shims@1.8.0/dist/es-module-shims.js"></script><script>window.THREE = THREE;window.GLTFLoader = THREE.GLTFLoader;require(["esri/views/SceneView","esri/Map","esri/layers/TileLayer","esri/views/3d/webgl/RenderNode","esri/views/3d/webgl"], (SceneView, Map, TileLayer, RenderNode, webgl) => {let map = new Map({basemap:"satellite"})let view = new SceneView({map: map,container: 'viewDiv',viewingMode: "local"});view.when(function () {view.goTo({fov: 55,heading: 55.99495193816657,position: {x: 13513809.919879783,y: 3616346.75042186,z: 8574.5211164545,spatialReference: {wkid: 102100}},tilt: 69.0179407311609});})view.on("click",function(){console.log(view.camera);})let subRenderClass = RenderNode.createSubclass(RenderNodeClass);view.when(function(){new subRenderClass({view,webgl})})// let myExternalRenderer = {// initialize: function (context) {// // 在外部渲染器添加到视图后执行一次。// // 你可以使用这个函数来分配所有的静态WebGL资源(着色器,缓冲区等)。// },// render: function (context) {// // 在每一帧执行,绘制几何图形到画布。在这个函数中完成的任务:// // *更新动态资源的状态// // *根据需要设置WebGL状态// // *发出WebGL绘制调用// }// }})</script>
</head><body><div id="viewDiv"></div>
</body></html>
结果: