一.前言
由于最近在学习three.js,所以观摩了一下掘金,csdn等网站上的有关这部分的内容,刚好看到一个带你入门three.js——从0到1实现一个3d可视化地图 - 掘金 (juejin.cn),再加上我的专业属性是地理相关,可以说是专业对口,但文章已经是三年以前写的,而且没有在框架底下完成,有关three的很多API也发生了更改,所以我的思路是来自该篇文章,我进行了模仿和相应的修改,但是大致没有发生改变,可以说是站在前人的肩膀上。
二.预览
三.实现
首先就是开启一个vue项目,再npm install --save three,再引入一下d3就可以了,配置方面没有什么好配置的,这方面大家应该是没问题的。将代码写在子组件里,再引入到App.vue中展示就可以了。需要注意用到的全国的json数据来自DataV.GeoAtlas地理小工具系列 (aliyun.com)
子组件xx.vue对应代码
<template><div id="container" ref="canvasContainer"></div><div id="tooltip" ref="tooltip"></div>
</template><script setup>import * as THREE from 'three';//OrbitControls 是一个附加组件,必须显式导入import { OrbitControls } from 'three/addons/controls/OrbitControls.js';//墨卡托投影转换可以把我们经纬度坐标转换成我们对应平面的2d坐标,d3里面自带墨卡托投影转换//该引入方式是查阅官网得到的import * as d3 from "https://cdn.jsdelivr.net/npm/d3@7/+esm";import { onMounted, onUnmounted,ref } from 'vue';let canvasContainer = ref(null);let tooltip = ref(null)let scene,camera,renderer,ambientLight,raycaster,mouse;let lastPick = null;//初始化摄像机function initCamera(){camera = new THREE.PerspectiveCamera(75,canvasContainer.value.offsetWidth / canvasContainer.value.offsetHeight, 0.1, 1000);camera.position.set(0,0,120);camera.lookAt(scene.position);}//初始化rendererfunction initRenderer(){renderer = new THREE.WebGLRenderer();renderer.setSize(canvasContainer.value.offsetWidth,canvasContainer.value.offsetHeight)}//初始化灯光function initLight(){ambientLight = new THREE.AmbientLight(0xffffff,20);}//加载json数据function loadJson(){const loader = new THREE.FileLoader();loader.load('src/assets/中华人民共和国.json',(data)=>{const jsondata = JSON.parse(data);generateGeometry(jsondata)console.log(jsondata);})}// 根据JSON数据生成地图几何体function generateGeometry(jsondata){let map = new THREE.Object3D();// 使用d3的地图投影const projection = d3.geoMercator().center([104.0,37.5]).translate([0,0]);// 遍历每个省份,创建几何体jsondata.features.forEach((element)=>{let province = new THREE.Object3D();const coordinates = element.geometry.coordinates;if(Array.isArray(coordinates[0][0][0])){coordinates.forEach((multiPolygon)=>{multiPolygon.forEach((polygon)=>{const shape = new THREE.Shape();const points = [];polygon.forEach((coord,i)=>{const [x,y] = projection(coord);if(i===0) shape.moveTo(x,-y);else shape.lineTo(x,-y);points.push(new THREE.Vector3(x,-y,5));})const lineGeometry = new THREE.BufferGeometry().setFromPoints(points);const lineMaterial = new THREE.LineBasicMaterial({ color: 'white' });const line = new THREE.Line(lineGeometry, lineMaterial);const extrudeSettings = { depth: 10, bevelEnabled: false };const geometry = new THREE.ExtrudeGeometry(shape, extrudeSettings);const material = new THREE.MeshBasicMaterial({ color: '#2defff', transparent: true, opacity: 0.6 });const material1 = new THREE.MeshBasicMaterial({color: '#3480C4',transparent: true,opacity: 0.5,})const mesh = new THREE.Mesh(geometry, [material,material1]);province.properties = element.properties;province.add(mesh);province.add(line);})})}else if(Array.isArray(coordinates[0][0])){coordinates.forEach((polygon)=>{const shape = new THREE.Shape();const points = [];polygon.forEach((coord,i)=>{const [x,y] = projection(coord);if(i===0) shape.moveTo(x,-y);else shape.lineTo(x,-y);points.push(new THREE.Vector3(x,-y,5));})const lineGeometry = new THREE.BufferGeometry().setFromPoints(points);const lineMaterial = new THREE.LineBasicMaterial({ color: 'white' });const line = new THREE.Line(lineGeometry, lineMaterial);const extrudeSettings = { depth: 10, bevelEnabled: false };const geometry = new THREE.ExtrudeGeometry(shape, extrudeSettings);const material = new THREE.MeshBasicMaterial({ color: '#2defff', transparent: true, opacity: 0.6 });const material1 = new THREE.MeshBasicMaterial({color: '#3480C4',transparent: true,opacity: 0.5,})const mesh = new THREE.Mesh(geometry, [material,material1]);province.properties = element.properties;province.add(mesh);province.add(line);})}map.add(province);})scene.add(map);}// 设置光线投射器和鼠标位置,用于检测鼠标悬停对象function setRaycaster(){raycaster = new THREE.Raycaster();mouse = new THREE.Vector2();const onMouseMove = (event) => {mouse.x = (event.clientX / canvasContainer.value.offsetWidth) * 2 - 1mouse.y = -(event.clientY / canvasContainer.value.offsetHeight) * 2 + 1tooltip.value.style.left = event.clientX + 2 + 'px'tooltip.value.style.top = event.clientY + 2 + 'px'}window.addEventListener('mousemove', onMouseMove, false)}// 显示或隐藏工具提示function showTip(){if(lastPick){const properties = lastPick.object.parent.properties;tooltip.value.textContent = properties.name;tooltip.value.style.visibility = 'visible';console.log(tooltip.value.textContent);}else{tooltip.value.style.visibility = 'hidden';}}// 动画循环,用于渲染场景和更新状态function animate() {requestAnimationFrame(animate);raycaster.setFromCamera(mouse,camera);const intersects = raycaster.intersectObjects(scene.children,true);if (lastPick) {lastPick.object.material[0].color.set('#2defff')lastPick.object.material[1].color.set('#3480C4')}lastPick = nulllastPick = intersects.find((item) => item.object.material && item.object.material.length === 2)if (lastPick) {lastPick.object.material[0].color.set(0xff0000)lastPick.object.material[1].color.set(0xff0000)}showTip();renderer.render(scene, camera);}//窗口大小改变时,更新摄像机的宽高比和渲染器的大小function handleResize(){if(camera && renderer && canvasContainer.value){camera.aspect = canvasContainer.value.offsetWidth / canvasContainer.value.offsetHeight;camera.updateProjectionMatrix();renderer.setSize(canvasContainer.value.offsetWidth, canvasContainer.value.offsetHeight);}}// 组件挂载时的初始化逻辑onMounted(()=>{scene = new THREE.Scene();setRaycaster();initLight();scene.add(ambientLight);initCamera();loadJson();initRenderer();canvasContainer.value.appendChild(renderer.domElement);new OrbitControls(camera,canvasContainer.value)animate();window.addEventListener('resize',handleResize)})onUnmounted(()=>{window.removeEventListener('resize',handleResize)})
</script><style>body{margin: 0;padding: 0;overflow: hidden;}#container{/* border: 1px solid black; */width: 100vw;height: 100vh;}#tooltip {position: absolute;z-index: 2;background: white;padding: 10px;border-radius: 5px;visibility: hidden;}
</style>
注意在用JSON数据生成地图集合体时分两种情况是因为:
不同省份数据数组嵌套的层数不一样,类似于下面这两地
四.总结
共勉,如果对于实现的步骤还有疑惑,可以转至我在前言分享的那篇文章 ,它对于实现步骤更详细,可以结合着看。