l2.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<style>
    body { margin: 0; }
    canvas { width: 100%; height: 100% }
</style>
<body>

<script src="js/three.js"></script>
<script>
    var scene = new THREE.Scene();

    var VIEW_ANGLE = window.innerWidth / -2,
            NEAR = 0.1,
            FAR = 1000;

    var camera = new THREE.OrthographicCamera(  VIEW_ANGLE,
            window.innerWidth / 2,
            window.innerHeight / 2,
            window.innerHeight / -2,
            NEAR,
            FAR);

    // pull the camera position back
    camera.position.z = 300;

    var renderer = new THREE.WebGLRenderer();
    renderer.setSize( window.innerWidth, window.innerHeight );
    document.body.appendChild( renderer.domElement );

    // Create the particle variables
    var particleCount = 1000;
    var particles = new THREE.Geometry();
    var particle_Material = new THREE.PointsMaterial({
        color: 'red',
        size: 1
    });

    var min = -10,
            max = 10;

    // Create the individual particles
    for (var i = 0; i < particleCount; i++) {

        var radius = 200;

        var random = Math.random();
        var variance = Math.random();

        var max = 10,
                min = -10;

        radius += (Math.floor(variance * (max - min + 1)) + min);

        var pX = radius * Math.cos(random * (2 * Math.PI)),
                pY = radius * Math.sin(random * (2 * Math.PI)),
                pZ = Math.random() * 100;


        var particle = new THREE.Vector3(
                pX,pY,pZ
        );

        particle.velocity = new THREE.Vector3(
                0,
                -Math.random(),
                0
        );

// Add the particle to the geometry
        particles.vertices.push(particle);
    }

    // Create the particle system
    var particleSystem = new THREE.Points(
            particles,particle_Material
    );

    particleSystem.sortParticles = true;

    // Add the particle system to the scene
    scene.add(particleSystem);

    var lastTime = 0;
    function animate() {
        var timeNow = new Date().getTime();
        if (lastTime != 0) {
            var elapsed = timeNow - lastTime;
            var pCount = particleCount;
            while(pCount--) {
                // Get particle
                var particle = particles.vertices[pCount];
                //console.log(particle);
                particle.y -= Math.random() * elapsed * 10.0 / 1000.0;
                //console.log(particle);
            }
        }
        lastTime = timeNow;
    }

    // Animation Loop
    function render() {
        requestAnimationFrame(render);
        animate();
        renderer.render(scene,camera);
    }
    render();
</script>

</body>
</html>