HTML5 画布上的 Three.js 环境灯光（HTML5 Canvas Three.js Ambient Lighting）
太阳火神的美丽人生 (http://blog.csdn.net/opengl_es)
本文遵循“署名-非商业用途-保持一致”创作公用协议
HTML5 画布上的 Three.js 环境灯光
HTML5 Canvas Three.js Ambient Lighting
<!DOCTYPE HTML>
<html>
<head>
<style>
body {
margin: 0px;
padding: 0px;
}
</style>
</head>
<body>
<div id="container"></div>
<script src="http://www.html5canvastutorials.com/libraries/three.min.js"></script>
<script defer="defer">
// revolutions per second
var angularSpeed = 0.2;
var lastTime = 0;
// this function is executed on each animation frame
function animate(){
// update
var time = (new Date()).getTime();
var timeDiff = time - lastTime;
var angleChange = angularSpeed * timeDiff * 2 * Math.PI / 1000;
cube.rotation.y += angleChange;
lastTime = time;
// render
renderer.render(scene, camera);
// request new frame
requestAnimationFrame(function(){
animate();
});
}
// renderer
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// camera
var camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 1000);
camera.position.z = 500;
// scene
var scene = new THREE.Scene();
// cube
var cube = new THREE.Mesh(new THREE.CubeGeometry(200, 200, 200), new THREE.MeshLambertMaterial({
color: 'blue'
}));
cube.overdraw = true;
cube.rotation.x = Math.PI * 0.1;
scene.add(cube);
// add subtle blue ambient lighting
var ambientLight = new THREE.AmbientLight(0x000044);
scene.add(ambientLight);
// directional lighting
var directionalLight = new THREE.DirectionalLight(0xffffff);
directionalLight.position.set(1, 1, 1).normalize();
scene.add(directionalLight);
// start animation
animate();
</script>
</body>
</html>
讨论
Discussion
要使用 Three.js 创建环境灯光，我们可以实例化一个 AmbientLight 对象，然后把它添加到场景中。环境灯光需要一个颜色来定义。环境灯光照亮整个场景，可用于柔化位置灯光，诸如 directional 灯光。
To create ambient lighting with Three.js, we can instantiate an AmbientLight object and then add it to the scene. AmbientLight requires is defined with a color. Ambient lights illuminate the entire scene and can be used to soften positional lights such as directional lights.
