three.js模型贴图压缩详细代码

以下是使用three.js进行模型贴图压缩的详细代码：

1. 导入必要的three.js库和压缩库

<script src="https://cdn.bootcdn.net/ajax/libs/three.js/r128/three.min.js"></script>
<script src="https://cdn.bootcdn.net/ajax/libs/three.js/r128/DDSLoader.min.js"></script>
<script src="https://cdn.bootcdn.net/ajax/libs/three.js/r128/MTLLoader.min.js"></script>
<script src="https://cdn.bootcdn.net/ajax/libs/three.js/r128/OBJLoader.min.js"></script>
<script src="https://cdn.bootcdn.net/ajax/libs/three.js/r128/OrbitControls.min.js"></script>
<script src="https://cdn.bootcdn.net/ajax/libs/three.js/r128/DRACOLoader.min.js"></script>

2. 加载模型和纹理

var loader = new THREE.OBJLoader();
var mtlLoader = new THREE.MTLLoader();
var ddsLoader = new THREE.DDSLoader();
var dracoLoader = new THREE.DRACOLoader();

mtlLoader.setPath('models/');
mtlLoader.load('model.mtl', function(materials) {
    materials.preload();
    loader.setMaterials(materials);
    loader.setPath('models/');
    loader.load('model.obj', function(object) {
        object.traverse(function(child) {
            if (child instanceof THREE.Mesh) {
                child.material.map = ddsLoader.load('textures/texture.dds');
                child.material.map.minFilter = THREE.LinearFilter;
                child.material.map.magFilter = THREE.LinearFilter;
                child.material.map.anisotropy = 16;
                child.material.map.encoding = THREE.sRGBEncoding;
            }
        });
        scene.add(object);
    }, function(xhr) {
        console.log((xhr.loaded / xhr.total * 100) + '% loaded');
    }, function(error) {
        console.log('An error happened');
    });
}, function(xhr) {
    console.log((xhr.loaded / xhr.total * 100) + '% loaded');
}, function(error) {
    console.log('An error happened');
});

3. 使用DRACO压缩模型

dracoLoader.setDecoderPath('js/libs/draco/');
loader.setDRACOLoader(dracoLoader);
loader.load('model.drc', function(object) {
    object.traverse(function(child) {
        if (child instanceof THREE.Mesh) {
            child.material.map = ddsLoader.load('textures/texture.dds');
            child.material.map.minFilter = THREE.LinearFilter;
            child.material.map.magFilter = THREE.LinearFilter;
            child.material.map.anisotropy = 16;
            child.material.map.encoding = THREE.sRGBEncoding;
        }
    });
    scene.add(object);
}, function(xhr) {
    console.log((xhr.loaded / xhr.total * 100) + '% loaded');
}, function(error) {
    console.log('An error happened');
});

注意：使用DRACO压缩需要下载DRACO解码器并设置路径。

4. 渲染场景

var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);

var controls = new THREE.OrbitControls(camera, renderer.domElement);
controls.enableDamping = true;
controls.dampingFactor = 0.25;
controls.enableZoom = true;

camera.position.set(0, 0, 5);

var animate = function() {
    requestAnimationFrame(animate);

    controls.update();

    renderer.render(scene, camera);
};

animate();

示例代码中使用了DDS和DRACO格式进行压缩。DDS是一种常用的压缩纹理格式，可以提高加载速度和减少内存占用。DRACO是一种压缩模型格式，可以有效减小模型文件大小。