简介
这种光在整个面上均匀地发射出一个矩形平面。这可以用来模拟像明亮的窗户或带状照明的东西。
案例查看地址：http://www.wjceo.com/blog/threejs/2018-02-12/31.html
简单创建
由于是特殊光源，而且比较复杂，所以此灯光需要额外引入插件来创建
<script src="examples/js/lights/RectAreaLightUniformsLib.js"></script>
然后就可以实例化了
var rectLight =
new THREE.RectAreaLight(颜色, 光的强度, 宽度, 高度);
最后添加到场景当中即可
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="build/three.js"></script>
<script src="examples/js/lights/RectAreaLightUniformsLib.js"></script>
<script src="examples/js/controls/OrbitControls.js"></script>
<script src="examples/js/libs/stats.min.js"></script>
<script src="examples/js/libs/dat.gui.min.js"></script>
<script>
var renderer;
function initRender() {
renderer = new THREE.WebGLRenderer({antialias: true});
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.shadowMap.enabled = true;
renderer.shadowMap.type = THREE.PCFSoftShadowMap;
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, 100);
camera.lookAt(new THREE.Vector3(0, 0, 0));
}
var scene;
function initScene() {
scene = new THREE.Scene();
}
var rectLight,rectLightHelper;
function initLight() {
var ambientLight = new THREE.AmbientLight(0x111111);
scene.add(ambientLight);
rectLight = new THREE.RectAreaLight(0xffffff, 500, 10, 10);
rectLight.position.set(5, 10, -20);
scene.add(rectLight);
rectLightHelper = new THREE.RectAreaLightHelper(rectLight);
scene.add(rectLightHelper);
}
var cube,plane;
function initModel() {
var helper = new THREE.AxisHelper(10);
scene.add(helper);
var sphereGeometry = new THREE.SphereGeometry(10,30,30);
var sphereMaterial = new THREE.MeshStandardMaterial({color:0xff00ff});
var sphere = new THREE.Mesh(sphereGeometry,sphereMaterial);
sphere.position.set(-20,20,0);
sphere.castShadow = true;
scene.add(sphere);
var cubeGeometry = new THREE.CubeGeometry(10,10,10);
var cubeMaterial = new THREE.MeshLambertMaterial({color: 0x00ffff});
cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
cube.position.x = 30;
cube.position.y = 5;
cube.position.z = -5;
cube.castShadow = true;
scene.add(cube);
var planeGeometry = new THREE.PlaneGeometry(5000, 5000, 20, 20);
var planeMaterial = new THREE.MeshStandardMaterial({color: 0xaaaaaa});
plane = new THREE.Mesh(planeGeometry, planeMaterial);
plane.rotation.x = -0.5 * Math.PI;
plane.position.y = -0;
plane.receiveShadow = true;
scene.add(plane);
}
var stats;
function initStats() {
stats = new Stats();
document.body.appendChild(stats.dom);
}
var controls;
function initControls() {
controls = new THREE.OrbitControls(camera, renderer.domElement);
controls.enableDamping = true;
controls.enableZoom = true;
controls.autoRotate = false;
controls.minDistance = 50;
controls.maxDistance = 200;
controls.enablePan = true;
controls.maxPolarAngle = Math.PI*4.5/10;
}
var param;
function initGui() {
param = {
motion: true,
width: rectLight.width,
height: rectLight.height,
color: rectLight.color.getHex(),
intensity: rectLight.intensity
};
var datGui = new dat.GUI();
datGui.add(param, 'width', 0.1, 100).onChange(function (val) {
rectLight.width = val;
});
datGui.add(param, 'height', 0.1, 100).onChange(function (val) {
rectLight.height = val;
});
datGui.addColor(param, 'color').onChange(function (val) {
rectLight.color.setHex(val);
});
datGui.add(param, 'intensity', 0.0, 1000).onChange(function (val) {
rectLight.intensity = val;
});
datGui.open();
}
function render() {
rectLightHelper.update();
renderer.render(scene, camera);
}
function onWindowResize() {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
render();
renderer.setSize(window.innerWidth, window.innerHeight);
}
function animate() {
render();
stats.update();
controls.update();
requestAnimationFrame(animate);
}
function draw() {
initRender();
initScene();
initCamera();
initLight();
initModel();
initControls();
initStats();
initGui();
animate();
window.onresize = onWindowResize;
}
</script>
</html>
