Three.js拉伸几何体THREE.TubeGeometry代码详解

17-12-20 来源：[db:作者]

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简介

THREE.TubeGeometry可以沿着一条三维的样式曲线（THREE.CatmullRomCurve3对象）拉伸出一根管。

最简单实现

var tubeGeometry = new THREE.TubeGeometry(path,segments,radius,radiusSegments,closed);

属性	是否必需	描述
path	是	该属性用一个THREE.CatmullRomCurve3对象来指定THREE.TubeGeometry对象应当遵循的路径
segments	否	该属性指定构建这个THREE.TubeGeometry对象所用的分段数。默认值为64。路径越长，指定的分段数应该越多
radius	否	该属性指定THREE.TubeGeometry对象的半径。默认值为1
radiusSegments	否	该属性指定THREE.TubeGeometry对象圆周的分段数。默认值为8。分段数越多，越圆滑
colosed	否	如果该属性设为true，THREE.TubeGeometry头和尾部会连接起来。默认值为false。

案例代码

这里写图片描述

<!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="https://johnson2heng.github.io/three.js-demo/lib/three.js"></script>
<script src="https://johnson2heng.github.io/three.js-demo/lib/js/QuickHull.js"></script>
<script src="https://johnson2heng.github.io/three.js-demo/lib/js/geometries/ConvexGeometry.js"></script>
<script src="https://johnson2heng.github.io/three.js-demo/lib/js/controls/OrbitControls.js"></script>
<script src="https://johnson2heng.github.io/three.js-demo/lib/js/libs/stats.min.js"></script>
<script src="https://johnson2heng.github.io/three.js-demo/lib/js/libs/dat.gui.min.js"></script>
<script>
    var renderer;
    function initRender() {
        renderer = new THREE.WebGLRenderer({antialias:true});
        renderer.setSize(window.innerWidth, window.innerHeight);
        document.body.appendChild(renderer.domElement);
    }

    var camera;
    function initCamera() {
        camera = new THREE.PerspectiveCamera(45, window.innerWidth/window.innerHeight, 1, 10000);
        camera.position.set(0, 0, 100);
    }

    var scene;
    function initScene() {
        scene = new THREE.Scene();
    }

    var light;
    function initLight() {
        scene.add(new THREE.AmbientLight(0x404040));

        light = new THREE.DirectionalLight(0xffffff);
        light.position.set(1,1,1);
        scene.add(light);
    }

    function initModel() {
        var shape = new THREE.ShapeGeometry(drawShape());
        var material = new THREE.MeshPhongMaterial({color:0xff00ff});
        material.side = THREE.DoubleSide;//设置成两面都可见
        var mesh = new THREE.Mesh(shape,material);
        scene.add(mesh);
        /*此方法是创建两种纹理的方法
        * var shape = new THREE.ShapeGeometry(drawShape());
        var mesh = createMesh(shape);
        scene.add(mesh);
        * */
    }

    //初始化性能插件
    var stats;
    function initStats() {
        stats = new Stats();
        document.body.appendChild(stats.dom);
    }

    //用户交互插件 鼠标左键按住旋转，右键按住平移，滚轮缩放
    var controls;
    function initControls() {

        controls = new THREE.OrbitControls( camera, renderer.domElement );

        // 如果使用animate方法时，将此函数删除
        //controls.addEventListener( 'change', render );
        // 使动画循环使用时阻尼或自转 意思是否有惯性
        controls.enableDamping = true;
        //动态阻尼系数 就是鼠标拖拽旋转灵敏度
        //controls.dampingFactor = 0.25;
        //是否可以缩放
        controls.enableZoom = true;
        //是否自动旋转
        controls.autoRotate = false;
        //设置相机距离原点的最远距离
        controls.minDistance  = 20;
        //设置相机距离原点的最远距离
        controls.maxDistance  = 160;
        //是否开启右键拖拽
        controls.enablePan = true;
    }

    //生成gui设置配置项
    var gui,spGroup,tubeMesh;
    function initGui() {
        //声明一个保存需求修改的相关数据的对象
        gui = {
            numberOfPoints:5,
            segments:64,
            radius:1,
            radiusSegments:8,
            closed:false,
            points: [],
            newPoints:function () {
                //生成一些随机点放置到数组当中
                var points = [];
                for (var i = 0; i < gui.numberOfPoints; i++) {
                    var randomX = -20 + Math.round(Math.random() * 50);
                    var randomY = -15 + Math.round(Math.random() * 40);
                    var randomZ = -20 + Math.round(Math.random() * 40);

                    points.push(new THREE.Vector3(randomX, randomY, randomZ));
                }
                gui.points = points;
                gui.redraw();
            },
            redraw:function () {
                //清楚掉场景中原来的模型对象
                scene.remove(spGroup);
                scene.remove(tubeMesh);
                //重新绘制模型
                generatePoints(gui.points, gui.segments, gui.radius, gui.radiusSegments, gui.closed);
            }
        };
        var datGui = new dat.GUI();
        //将设置属性添加到gui当中，gui.add(对象，属性，最小值，最大值）
        datGui.add(gui, 'newPoints');
        datGui.add(gui, 'numberOfPoints', 2, 15).step(1).onChange(gui.newPoints);
        datGui.add(gui, 'segments', 0, 200).step(1).onChange(gui.redraw);
        datGui.add(gui, 'radius', 0, 10).onChange(gui.redraw);
        datGui.add(gui, 'radiusSegments', 0, 100).step(1).onChange(gui.redraw);
        datGui.add(gui, 'closed').onChange(gui.redraw);


        gui.newPoints();
    }

    //通过配置项绘制出几何体
    function generatePoints(points, segments, radius, radiusSegments, closed) {
        spGroup = new THREE.Object3D(); //赋值spGroup存储模型点的3d对象
        var material = new THREE.MeshBasicMaterial({color: 0xff0000, transparent: false}); //声明一个红色普通纹理
        //将所有的顶点创建出球形存储到spGroup内
        points.forEach(function (point) {

            var spGeom = new THREE.SphereGeometry(0.2);
            var spMesh = new THREE.Mesh(spGeom, material);
            spMesh.position.copy(point);
            spGroup.add(spMesh);
        });
        // 将spGroup对象添加到场景当中
        scene.add(spGroup);

        // THREE.CatmullRomCurve3方法可以将一组顶点生成一条平滑的曲线
        var tubeGeometry = new THREE.TubeGeometry(new THREE.CatmullRomCurve3(points), segments, radius, radiusSegments, closed);
        //将模型对象赋值给tubeMesh并添加到场景当中
        tubeMesh = createMesh(tubeGeometry);
        scene.add(tubeMesh);
    }

    function createMesh(geom) {

        // 创建两个纹理
        //创建一个透明纹理
        var meshMaterial = new THREE.MeshBasicMaterial({color: 0x00ff00, transparent: true, opacity: 0.3});

        //创建一个线框纹理
        var wireFrameMat = new THREE.MeshBasicMaterial();
        wireFrameMat.wireframe = true;

        // 使用纹理和几何体创建模型
        var mesh = THREE.SceneUtils.createMultiMaterialObject(geom, [meshMaterial, wireFrameMat]);

        return mesh;
    }

    function render() {
        renderer.render( scene, camera );
    }

    //窗口变动触发的函数
    function onWindowResize() {
        camera.aspect = window.innerWidth / window.innerHeight;
        camera.updateProjectionMatrix();
        render();
        renderer.setSize( window.innerWidth, window.innerHeight );

    }

    function animate() {
        //更新控制器
        controls.update();
        render();

        //更新性能插件
        stats.update();
        requestAnimationFrame(animate);
    }

    function draw() {
        initRender();
        initScene();
        initCamera();
        initLight();
        //initModel();
        initControls();
        initStats();
        initGui();

        animate();
        window.onresize = onWindowResize;
    }
</script>
</html>

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Three.js拉伸几何体THREE.TubeGeometry代码详解

简介

最简单实现

相关参数说明

案例代码