简介
CTM是由openCTM创建的一种文件格式，可以用来以压缩格式存储三维网格的三角形面片。
实现案例
- 首先，引入script加载器
<script src="/lib/js/loaders/ctm/lzma.js"></script>
<script src="/lib/js/loaders/ctm/ctm.js"></script>
<script src="/lib/js/loaders/ctm/CTMLoader.js"></script>
- 然后，实例化加载器对象，然后加载模型，
CTM模型里面只保存了几何体，所以我们实例化了一个纹理，添加到场景当中。
var loader = new THREE.CTMLoader();
loader.load("/lib/assets/models/auditt_wheel.ctm", function (geometry) {
//创建纹理
var mat = new THREE.MeshLambertMaterial({color: 0x00ffff});
group = new THREE.Mesh(geometry, mat); //生成模型
group.rotation.x = - Math.PI/2;
group.scale.set(20, 20, 20); //放大二十倍
scene.add(group);
});
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/ctm/lzma.js"></script>
<script src="/lib/js/loaders/ctm/ctm.js"></script>
<script src="/lib/js/loaders/ctm/CTMLoader.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(0xffffff);
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, 40, 50);
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);
}
var loaded = false,group;
function initModel() {
//辅助工具
var helper = new THREE.AxesHelper(50);
scene.add(helper);
var loader = new THREE.CTMLoader();
loader.load("/lib/assets/models/auditt_wheel.ctm", function (geometry) {
//创建纹理
var mat = new THREE.MeshLambertMaterial({color: 0x00ffff});
group = new THREE.Mesh(geometry, mat); //生成模型
group.rotation.x = - Math.PI/2;
group.scale.set(20, 20, 20); //放大二十倍
scene.add(group);
//修改loaded值，可以选择模型
loaded = true;
});
}
//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;
}
var step = 0.1; // 轮子每帧的滚动角度
function render() {
if(loaded){
group.rotation.y +=step;
}
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>
