原理：利用 CSS2DObject 將二維物體轉(zhuǎn)為 threejs 可以識(shí)別的 3d 物品，然后利用 CSS2DRenderer 將其渲染到頁(yè)面心傀，以下注釋中步驟 4 和 步驟 6 最為重要
使用場(chǎng)景：常常用來(lái)標(biāo)志 3d 物體或者制作信息展示面板
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
<title>three.js css2d - label</title>
<link type="text/css" rel="stylesheet" href="main.css">
<style>
.label {
color: #FFF;
font-family: sans-serif;
padding: 2px;
background: rgba(0, 0, 0, .6);
}
</style>
</head>
<body>
<div id="info"><a target="_blank" rel="noopener">three.js</a> css2d - label</div>
<script type="module">
import * as THREE from '../build/three.module.js';
import { OrbitControls } from './jsm/controls/OrbitControls.js';
import { CSS2DRenderer, CSS2DObject } from './jsm/renderers/CSS2DRenderer.js';
var camera, scene, renderer, labelRenderer;
var clock = new THREE.Clock();
var textureLoader = new THREE.TextureLoader();
var earth, moon;
init();
animate();
function init() {
// 1兔甘、創(chuàng)建場(chǎng)景舆绎，相機(jī)星立，光源
var EARTH_RADIUS = 1;
camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 1000 );
camera.position.set( 10, 5, 20 );
scene = new THREE.Scene();
var dirLight = new THREE.DirectionalLight( 0xffffff );
dirLight.position.set( 0, 0, 1 );
scene.add( dirLight );
// 2、創(chuàng)建地球 Mesh
var earthGeometry = new THREE.SphereBufferGeometry( EARTH_RADIUS, 16, 16 );
var earthMaterial = new THREE.MeshPhongMaterial( {
specular: 0x333333,
shininess: 5,
map: textureLoader.load( 'textures/planets/earth_atmos_2048.jpg' ),
specularMap: textureLoader.load( 'textures/planets/earth_specular_2048.jpg' ),
normalMap: textureLoader.load( 'textures/planets/earth_normal_2048.jpg' ),
normalScale: new THREE.Vector2( 0.85, 0.85 )
} );
earth = new THREE.Mesh( earthGeometry, earthMaterial );
scene.add( earth );
// 3灾锯、創(chuàng)建地球Label(二維物品)
var earthDiv = document.createElement( 'div' );
earthDiv.className = 'label';
earthDiv.textContent = 'Earth';
earthDiv.style.marginTop = '-1em';
var earthLabel = new CSS2DObject( earthDiv );
earthLabel.position.set( 0, EARTH_RADIUS, 0 );
// 4兢榨、將 label 掛載到 3d 物品上
earth.add( earthLabel );
// 5、分別創(chuàng)建 WebGLRenderer 和 CSS2DRenderer
renderer = new THREE.WebGLRenderer();
renderer.setPixelRatio( window.devicePixelRatio );
renderer.setSize( window.innerWidth, window.innerHeight );
document.body.appendChild( renderer.domElement );
labelRenderer = new CSS2DRenderer();
labelRenderer.setSize( window.innerWidth, window.innerHeight );
labelRenderer.domElement.style.position = 'absolute';
labelRenderer.domElement.style.top = 0;
document.body.appendChild( labelRenderer.domElement );
var controls = new OrbitControls( camera, labelRenderer.domElement );
}
function animate() {
requestAnimationFrame( animate );
// 6顺饮、每幀執(zhí)行兩個(gè)渲染器
renderer.render( scene, camera );
labelRenderer.render( scene, camera );
}
</script>
</body>
</html>
效果：
