22three.js粒子系統（二）

three.js版本不同，效果會有些差異，我的這個版本中粒子貼圖有問題，邊緣沒有透明，會互相遮擋。也許可以通過修改代碼來彌補吧。
在材質中添加一個屬性即可： depthTest:false
depthTesh深度測試，該參數可以打開或關閉GL_DEPTH_TEST參數。該參數決定像素深度是否用來計算新的像素值。

    var renderer;
    var scene;
    var camera, cubeCamera;
    var orbit;
    var sceneCube;
    var cameraCube;
    function init() {
        scene = new THREE.Scene();
        sceneCube = new THREE.Scene();
        cameraCube = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 1000);
        camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 10000);
        camera.position.x = 0;
        camera.position.y = 5;
        camera.position.z = 33;
        camera.lookAt(scene.position);
        orbit = new THREE.OrbitControls(camera);
        renderer = new THREE.WebGLRenderer();
        renderer.setClearColor(0x000000, 1.0);
        renderer.setSize(window.innerWidth, window.innerHeight);
        var textureCube = createCubeMap();
        textureCube.format = THREE.RGBFormat;
        var shader = THREE.ShaderLib["cube"];
        shader.uniforms["tCube"].value = textureCube;
        var material = new THREE.ShaderMaterial({
            fragmentShader: shader.fragmentShader,
            vertexShader: shader.vertexShader,
            uniforms: shader.uniforms,
            depthWrite: false,
            side: THREE.DoubleSide
        });
        cubeMesh1 = new THREE.Mesh(new THREE.BoxGeometry(10, 10, 10), material);
        cubeMesh1.position.set(10,0,0);
        scene.add(cubeMesh1);
        var spotlight = new THREE.SpotLight(0xffffff);
        spotlight.position.set(-40,60,40);
        scene.add(spotlight);
        var spotlight1 = new THREE.SpotLight(0xffffff);
        spotlight1.position.set(40,-60,-40);
        scene.add(spotlight1);
        var cube1 = creatcube(0,0,0,6);
        var skybox = new THREE.Mesh(new THREE.BoxGeometry(10000, 10000, 10000), material);
        scene.add(skybox);
        cubeCamera = new THREE.CubeCamera(0.1, 20000, 256);
        scene.add(cubeCamera);
        document.body.appendChild(renderer.domElement);
        render();
    }
    function createCubeMap() {
        var path = "textures/parliament/";
        var format = '.jpg';
        var urls = [
            path + 'posx' + format, path + 'negx' + format,
            path + 'posy' + format, path + 'negy' + format,
            path + 'posz' + format, path + 'negz' + format
        ];
        var textureCube = THREE.ImageUtils.loadTextureCube( urls );
        //var textureCube = THREE.ImageUtils.loadTextureCube(urls, new THREE.CubeReflectionMapping());
        return textureCube;
    }
    function creatcube(x,y,z,len) {
        var cubeme = new THREE.BoxGeometry(len,len,len);
        var cubemer = new THREE.MeshPhongMaterial();
        var texture = new THREE.ImageUtils.loadTexture("textures/223.jpg");
        cubemer.map = texture;  //紋理貼圖
        cubemer.bumpMap = texture; //凹凸貼圖
        cubemer.bumpScale = 0.2;
        var cube = new THREE.Mesh(cubeme,cubemer);
        cube.position.set(x,y,z);
        scene.add(cube);
        return cube;
    }
    function render() {
        orbit.update();
        cubeCamera.updateCubeMap(renderer, scene);
        renderer.render(scene, camera);
        //renderer.render(sceneCube,cameraCube);
        requestAnimationFrame(render);
    }
    window.onload = init;