让生命充满爱演讲three.js06-03之ExtrudeGeometry⾼级⼏何体
本篇介绍 three.js 中的 ExtrudeGeometry 拉伸⼏何体。它是从⼀个⼆维图形创建出⼀个三维图形。譬如，我们可以先通过
THREE.Shap 对象，先创建⼀个⼆维的图形，然后通过 ExtrudeGeometry 将它拉伸为⼀个三维图形。也可以先通过
THREE.PlaneGeometry 对象创建⼀个⼆维平⾯，然后再利⽤ ExtrudeGeometry 进⾏拉伸。关于 ExtrudeGeometry 的⼏个常⽤属性，如下表所⽰：
属性描述
amount（数量）可选。此属性定义图形可以拉多⾼。默认值是 100
bevelThinkness（斜⾓厚度）可选。此属性定义图形斜⾓的厚度。斜⾓是指前后⾯和拉伸体之间的倒⾓。默认值是 6
bevelSize（斜⾓尺⼨）可选。此属性定义图形斜⾓的⾼度。默认值是 bevelThickness - 2
bevelSegments（斜⾓分段数）可选。此属性定义图形斜⾓的分段数。默认值是 3
bevelEnabled（是否启⽤斜⾓）可选。此属性定义图形是否启⽤斜⾓。默认值是 true
curveSegments（曲线分段数）可选。此属性定义图形拉伸时曲线分成多少份。默认值是 12
steps（拉伸体段数）可选。此属性定义图形拉伸体被分成多少段
extrudePath（拉伸路径）可选。此属性定义图形沿着什么路径拉伸。如果未指定，默认就会沿着 z 轴拉伸
frames可选。此属性定义⼀种沿着 extrudePath 路径的每⼀步包含有 tangents, normals, binormals 数组的对象UVGenerator（UV⽣成器）可选。此属性定义⼀种提供UV⽣成器功能的对象
光看这些属性似乎不太好理解，下⾯我们给出⼀个具体⽰例以便帮助读者进⾏理解，代码如下所⽰：
<!DOCTYPE html>
<html>
<head>
<title>⽰例 06.03 - ExtrudeGeometry</title>
<script src="../build/three.js"></script>
<script src="../build/js/controls/OrbitControls.js"></script>
<script src="../build/js/libs/stats.min.js"></script>
<script src="../build/js/libs/dat.gui.min.js"></script>
<script src="../jquery/jquery-3.2.1.min.js"></script>
<style>
body {
/* 设置 margin 为 0，并且 overflow 为 hidden，来完成页⾯样式 */
margin: 0;
overflow: hidden;
}
/
郑州英语培训* 统计对象的样式 */
#Stats-output {
position: absolute;
left: 0px;
top: 0px;
}
</style>
</head>
<body>
<!-- ⽤于 WebGL 输出的 Div -->上海学西班牙语
<div id="webgl-output"></div>
<!-- ⽤于统计 FPS 输出的 Div -->
<div id="stats-output"></div>
<!-- 运⾏ Three.js ⽰例的 Javascript 代码 -->
<script type="text/javascript">
var scene;
var camera;
var render;
var webglRender;
//var canvasRender;
var controls;
var stats;
duster
var guiParams;
var ground;
var extrude;
var meshMaterial;
var ambientLight;
var spotLight;
var axesHelper;
//var cameraHelper;
$(function() {
stats = initStats();
scene = new THREE.Scene();
webglRender = new THREE.WebGLRenderer( {antialias: true, alpha: true} ); // antialias 抗锯齿
webglRender.tSize(window.innerWidth, window.innerHeight);
webglRender.tClearColor(0xeeeeee, 1.0);
abled = true; // 允许阴影投射
render = webglRender;
camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.01, 1000); // 2147483647 camera.position.t(-45.5, 68.2, 90.9);
var target = new THREE.Vector3(10, 0 , 0);
controls = new THREE.OrbitControls(camera, render.domElement);
controls.target = target;
camera.lookAt(target);
$('#webgl-output')[0].appendChild(render.domElement);
window.addEventListener('resize', onWindowResize, fal);
// 加⼊⼀个坐标轴：X（橙⾊）、Y（绿⾊）、Z（蓝⾊）
axesHelper = new THREE.AxesHelper(60);
scene.add(axesHelper);
ambientLight = new THREE.AmbientLight(0x0c0c0c);
lotnoscene.add(ambientLight);
spotLight = new THREE.SpotLight(0xffffff);
spotLight.position.t(0, 60, 30);
spotLight.shadow.mapSize.width = 5120; // 必须是 2的幂，默认值为 512
spotLight.shadow.mapSize.height = 5120; // 必须是 2的幂，默认值为 512
spotLight.castShadow = true;
scene.add(spotLight);
//cameraHelper = new THREE.CameraHelper(spotLight.shadow.camera);
//scene.add(cameraHelper);
trayvon martin// 加⼊⼀个地⾯
var groundGeometry = new THREE.PlaneGeometry(100, 100, 4, 4);
var groundMaterial = new THREE.MeshLambertMaterial({color: 0x777777}); // MeshBasicMaterial 材质不能接收阴影 ground = new THREE.Mesh(groundGeometry, groundMaterial);besides的用法
scene.add(ground);
// 材质
meshMaterial = [
new THREE.MeshNormalMaterial({side: THREE.DoubleSide}),
iasnew THREE.MeshBasicMaterial({wireframe: true})
];
/** ⽤来保存那些需要修改的变量 */
guiParams = new function() {
this.options = {
amount: 10,
bevelThinkness: 2,
bevelSize: 1,
bevelSegments: 3,
bevelEnabled: true,
curveSegments: 12,
steps: 1
};
}
/** 定义 dat.GUI 对象，并绑定 guiParams 的⼏个属性 */
var gui = new dat.GUI();
gui.add(guiParams.options, "amount", 0, 20).onChange(function(e){updateMesh()});
gui.add(guiParams.options, "bevelThinkness", 0, 10).onChange(function(e){updateMesh()}); gui.add(guiParams.options, "bevelSize", 0, 10).onChange(function(e){updateMesh()});
gui.add(guiParams.options, "bevelSegments", 0, 30, 1).onChange(function(e){updateMesh()}); gui.add(guiParams.options, "bevelEnabled").onChange(function(e){updateMesh()});
gui.add(guiParams.options, "curveSegments", 1, 30, 1).onChange(function(e){updateMesh()}); gui.add(guiParams.options, "steps", 1, 5, 1).onChange(function(e){updateMesh()});
updateMesh();
renderScene();
});
/** 渲染场景 */
function renderScene() {
stats.update();wupload
rotateMesh(); // 旋转物体
requestAnimationFrame(renderScene);
}
/** 初始化 stats 统计对象 */
function initStats() {
stats = new Stats();
stats.tMode(0); // 0 为监测 FPS；1 为监测渲染时间
$('#stats-output').append(stats.domElement);
return stats;
}
/** 当浏览器窗⼝⼤⼩变化时触发 */
function onWindowResize() {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
render.tSize(window.innerWidth, window.innerHeight);
}
/** 旋转物体 */
var step = 0;
function rotateMesh() {
step += ationSpeed;
if (mesh === extrude) {
//ation.x = step;
//ation.z = step;
}
});
}
function updateMesh() {
// 定义 extrude
var extrudeGeometry = new THREE.ExtrudeGeometry(drawShape(), guiParams.options);
extrude = new ateMultiMaterialObject(extrudeGeometry, meshMaterial);
extrude.children[1].castShadow = true; // extrude.children[0] 的材质是 MeshNormalMaterial，不能投射阴影 //extrude.position.t(0, guiParams.radius * 2 + 3, 0);
scene.add(extrude);
}
/** 绘制⼆维图形 */
function drawShape() {
var shape = new THREE.Shape();
shape.lineTo(10, 40); // lineTo( x, y ) - 线
shape.bezierCurveTo(15, 25, 25, 25, 30, 40); // bezierCurveTo( cp1X, cp1Y, cp2X, cp2Y, x, y ) - 贝塞尔曲线 shape.splineThru([
new THREE.Vector2(32, 30),
new THREE.Vector2(28, 20),
new THREE.Vector2(30, 10)
]); // splineThru ( vector2Array ) - 样条线
shape.quadraticCurveTo(20, 15, 10, 10); // quadraticCurveTo( cpX, cpY, x, y ) - ⼆次曲线
var hole = new THREE.Path(); // 添加“眼睛”孔洞1
hole.abllip(16, 24, 2, 3, 0, Math.PI * 2, fal);
shape.holes.push(hole);
hole = new THREE.Path(); // 添加“眼睛”孔洞2
hole.abllip(23, 24, 2, 3, 0, Math.PI * 2, fal);
shape.holes.push(hole);estc
hole = new THREE.Path(); // 添加“嘴巴”孔洞
hole.absarc(20, 16, 2, 0, Math.PI, fal);
shape.holes.push(hole);
return shape;
}
</script>
</body>
</html>
未完待续···
