79 Three.js 使用导入的模型生成粒子

时间：2021-10-06 05:28:21

简介

前几节我已经将现在一些经常使用的模型导入的方法。之前也接触粒子的创建。这个案例是把两者结合起来，通过导入模型获得几何体的数据，然后创建粒子。

实现案例

案例查看地址：http://www.wjceo.com/blog/threejs/2018-03-25/139.html

  • 首先，引入script加载器，这里的案例是使用的STL格式的文件生成，所以，引入STL文件加载器
<script src="/lib/js/loaders/STLLoader.js"></script>
  • 然后，获取到模型的几何体，然后创建点云。
var loader = new THREE.STLLoader();
loader.load("/lib/assets/models/SolidHead_2_lowPoly_42k.stl", function (geometry) {
    //创建纹理
    var material = new THREE.PointsMaterial({
        color: 0xffffff,
        size: 0.4,
        opacity: 0.6,
        transparent: true,
        blending: THREE.AdditiveBlending,
        depthTest: false,
        map: generateSprite()
    });

    var mesh = new THREE.Points(geometry, material);
    mesh.rotation.x = -0.5 * Math.PI; //将模型摆正
    mesh.scale.set(0.1, 0.1, 0.1); //缩放
    geometry.center(); //居中显示
    scene.add(mesh);
});

案例代码

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css"> html, body { margin: 0; height: 100%; } canvas { display: block; } </style>
</head>
<body onload="draw();">

</body>
<script src="/lib/three.js"></script>
<script src="/lib/js/loaders/STLLoader.js"></script>
<script src="/lib/js/controls/OrbitControls.js"></script>
<script src="/lib/js/libs/stats.min.js"></script>
<script src="/lib/js/libs/dat.gui.min.js"></script>

<script> var renderer; function initRender() { renderer = new THREE.WebGLRenderer({antialias:true}); renderer.setSize(window.innerWidth, window.innerHeight); //告诉渲染器需要阴影效果 renderer.setClearColor(0x000000); document.body.appendChild(renderer.domElement); } var camera; function initCamera() { camera = new THREE.PerspectiveCamera(45, window.innerWidth/window.innerHeight, 0.1, 1000); camera.position.set(0, 20, 25); camera.lookAt(new THREE.Vector3(0,0,0)); } var scene; function initScene() { scene = new THREE.Scene(); } //初始化dat.GUI简化试验流程 var gui; function initGui() { //声明一个保存需求修改的相关数据的对象 gui = { }; var datGui = new dat.GUI(); //将设置属性添加到gui当中，gui.add(对象，属性，最小值，最大值） } var light; function initLight() { scene.add(new THREE.AmbientLight(0x444444)); light = new THREE.PointLight(0xffffff); light.position.set(0,50,50); //告诉平行光需要开启阴影投射 light.castShadow = true; scene.add(light); } function initModel() { //辅助工具 var helper = new THREE.AxesHelper(50); scene.add(helper); var loader = new THREE.STLLoader(); loader.load("/lib/assets/models/SolidHead_2_lowPoly_42k.stl", function (geometry) { //创建纹理 var material = new THREE.PointsMaterial({ color: 0xffffff, size: 0.4, opacity: 0.6, transparent: true, blending: THREE.AdditiveBlending, depthTest: false, map: generateSprite() }); var mesh = new THREE.Points(geometry, material); mesh.rotation.x = -0.5 * Math.PI; //将模型摆正 mesh.scale.set(0.1, 0.1, 0.1); //缩放 geometry.center(); //居中显示 scene.add(mesh); }); } //使用canvas生成粒子的纹理 function generateSprite() { var canvas = document.createElement('canvas'); canvas.width = 16; canvas.height = 16; var context = canvas.getContext('2d'); var gradient = context.createRadialGradient(canvas.width / 2, canvas.height / 2, 0, canvas.width / 2, canvas.height / 2, canvas.width / 2); gradient.addColorStop(0, 'rgba(255,255,255,1)'); gradient.addColorStop(0.2, 'rgba(0,255,255,1)'); gradient.addColorStop(0.4, 'rgba(0,0,64,1)'); gradient.addColorStop(1, 'rgba(0,0,0,1)'); context.fillStyle = gradient; context.fillRect(0, 0, canvas.width, canvas.height); var texture = new THREE.Texture(canvas); texture.needsUpdate = true; return texture; } //初始化性能插件 var stats; function initStats() { stats = new Stats(); document.body.appendChild(stats.dom); } //用户交互插件 鼠标左键按住旋转，右键按住平移，滚轮缩放 var controls; function initControls() { controls = new THREE.OrbitControls( camera, renderer.domElement ); // 如果使用animate方法时，将此函数删除 //controls.addEventListener( 'change', render ); // 使动画循环使用时阻尼或自转 意思是否有惯性 controls.enableDamping = true; //动态阻尼系数 就是鼠标拖拽旋转灵敏度 //controls.dampingFactor = 0.25; //是否可以缩放 controls.enableZoom = true; //是否自动旋转 controls.autoRotate = true; controls.autoRotateSpeed = 0.5; //设置相机距离原点的最远距离 controls.minDistance = 1; //设置相机距离原点的最远距离 controls.maxDistance = 200; //是否开启右键拖拽 controls.enablePan = true; } function render() { renderer.render( scene, camera ); } //窗口变动触发的函数 function onWindowResize() { camera.aspect = window.innerWidth / window.innerHeight; camera.updateProjectionMatrix(); render(); renderer.setSize( window.innerWidth, window.innerHeight ); } function animate() { //更新控制器 render(); //更新性能插件 stats.update(); controls.update(); requestAnimationFrame(animate); } function draw() { initGui(); initRender(); initScene(); initCamera(); initLight(); initModel(); initControls(); initStats(); animate(); window.onresize = onWindowResize; } </script>
</html>
标签：

相关文章