7 Three.js内置几何

时间:2022-06-02 00:27:08

7 Three.js内置几何

这个案例是官方案例,个人通过一个一个测试备注,感受模型如何配置参数,来生成理想的形状。three.js内置的这些几何确实够平常使用,还可以通过顶点实现效果。

案例查看地址:http://www.wjceo.com/blog/threejs/2018-02-09/9.html

案例代码:

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Three框架</title>
    <script src="build/three.js"></script>
    <style type="text/css">
        html, body {
            margin: 0;
            height: 100%;
        }

        canvas {
            display: block;
        }

    </style>
    <script>
        //渲染器
        var renderer;
        function initRender() {
            width = window.innerWidth;
            height = window.innerHeight;
            renderer = new THREE.WebGLRenderer({
                antialias: true
            });
            //设置canvas尺寸
            renderer.setSize(width, height);
            //设置背景
            renderer.setClearColor(0x000000, 1.0);
            //设置设备像素比
            renderer.setPixelRatio( window.devicePixelRatio );
            //添加到dom
            document.body.appendChild(renderer.domElement);
        }

        //相机
        var camera;
        function initCamera() {
            camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 2000 );
            camera.position.y = 400;
        }

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

        //光源
        var light;
        function initLight() {
            //添加环境光
            scene.add(new THREE.AmbientLight( 0x404040));

            //添加平衡光
            light = new THREE.DirectionalLight( 0xffffff );
            light.position.set(0,1,0);
            scene.add(light);
        }

        //模型
        function initModel() {
            //通过加载图片生成一个纹理
            var map = new THREE.TextureLoader().load("examples/textures/UV_Grid_Sm.jpg");
            //定义纹理在水平和垂直方向简单的重复到无穷大。
            map.wrapS = map.wrapT = THREE.RepeatWrapping;
            //定义纹理的各向异性
            map.anisotropy = 16;

            //定义兰伯特网孔材质
            var material = new THREE.MeshLambertMaterial({map:map,side:THREE.DoubleSide});

            //球形网格 (半径长度,水平块的密度,垂直块的密度)
            object = new THREE.Mesh( new THREE.SphereGeometry(75,20,10), material);
            object.position.set( -400, 0, 200 );
            scene.add(object);

            //二十面体 (图形大小半径,大于零将不是二十面体,越大越圆滑)
            object = new THREE.Mesh( new THREE.IcosahedronGeometry( 75, 0 ), material );
            object.position.set( -200, 0, 200 );
            scene.add( object );

            //八面体(图形大小半径,大于零将不是八面体,越大越圆滑)
            object = new THREE.Mesh( new THREE.OctahedronGeometry( 75, 0 ), material );
            object.position.set( 0, 0, 200 );
            scene.add( object );

            //四面体(图形大小半径,大于零将不是四面体,越大越圆滑)
            object = new THREE.Mesh( new THREE.TetrahedronGeometry( 75, 0 ), material );
            object.position.set( 200, 0, 200 );
            scene.add( object );

            //长方形平面 (x轴宽度,y轴高度,x方向分段数,y方向分段数)
            object = new THREE.Mesh( new THREE.PlaneGeometry( 100, 100, 1, 1 ), material );
            object.position.set( -400, 0, 0 );
            scene.add( object );

            //立方体 (x轴宽度,y轴高度,z轴深度,沿宽面分段数,沿高度面分段数,沿深度面分段数)
            object = new THREE.Mesh( new THREE.BoxGeometry( 100, 100, 100, 1, 1, 1 ), material );
            object.position.set( -200, 0, 0 );
            scene.add( object );

            //圆形平面 (半径,顶点密度,绘制起点弧度,绘制弧度)
            object = new THREE.Mesh( new THREE.CircleGeometry( 50, 20, 0, Math.PI * 2 ), material );
            object.position.set( 0, 0, 0 );
            scene.add( object );

            //空心圆平面 (内圆半径,外圆半径,分割面越大越圆滑,垂直外边分割面,开始绘制弧度,绘制弧度)
            object = new THREE.Mesh( new THREE.RingGeometry( 10, 50, 10, 5, 0, Math.PI * 2 ), material );
            object.position.set( 200, 0, 0 );
            scene.add( object );

            //圆柱体 (头部圆的半径,底部圆半径,高度,上下圆顶点个数,上下面切割线条数,上下面是否显示,开始弧度,绘制弧度)
            object = new THREE.Mesh( new THREE.CylinderGeometry( 25, 75, 100, 40, 5 ), material );
            object.position.set( 400, 0, 0 );
            scene.add( object );

            //车床模型
            var points = [];

            for ( var i = 0; i < 50; i ++ ) {

                points.push( new THREE.Vector2( Math.sin( i * 0.2 ) * Math.sin( i * 0.1 ) * 15 + 50, ( i - 5 ) * 2 ) );

            }

            //(一个vector2的数组分别代表xy轴,生成圆周段的数目,开始弧度,绘制弧度)
            object = new THREE.Mesh( new THREE.LatheGeometry( points, 20 ), material );
            object.position.set( -400, 0, -200 );
            scene.add( object );

            //救生圈 (救生圈半径,管道直径,基于管道横切顶点数,救生圈横切顶点个数)
            object = new THREE.Mesh( new THREE.TorusGeometry( 50, 20, 20, 20 ), material );
            object.position.set( -200, 0, -200 );
            scene.add( object );

            //环面扭结模型 (图形半径,管道直径,基于管道横切定点数,根据图形半径横切顶点数,绕旋转对称轴的圈数,绕环面的圆的圈数)
            object = new THREE.Mesh( new THREE.TorusKnotGeometry( 50, 10, 50, 20 ), material );
            object.position.set( 0, 0, -200 );
            scene.add( object );

            //轴辅助 (每一个轴的长度)
            object = new THREE.AxisHelper( 50 );
            object.position.set( 200, 0, -200 );
            scene.add( object );

            //箭头辅助(箭头头的方向必须是vecteor3,箭头起点必须是vector3,箭头长度,颜色)
            object = new THREE.ArrowHelper( new THREE.Vector3( 0, 1, 0 ), new THREE.Vector3( 0, 0, 0 ), 50 ,0x00ffff);
            object.position.set( 400, 0, -200 );
            scene.add( object );


        }

        function animate() {

            requestAnimationFrame( animate );

            render();
            //stats.update();

        }

        function render() {

            var timer = Date.now() * 0.0001;

            camera.position.x = Math.cos( timer ) * 800;
            camera.position.z = Math.sin( timer ) * 800;

            camera.lookAt( scene.position );

            for ( var i = 0, l = scene.children.length; i < l; i ++ ) {

                var object = scene.children[ i ];

                object.rotation.x = timer * 5;
                object.rotation.y = timer * 2.5;

            }

            renderer.render( scene, camera );

        }

        //窗口变动触发的函数
        function onWindowResize() {

            camera.aspect = window.innerWidth / window.innerHeight;
            camera.updateProjectionMatrix();

            renderer.setSize( window.innerWidth, window.innerHeight );

        }

        //绘制
        function draw() {
            initRender();
            initCamera();
            initScene();
            initLight();
            initModel();

            animate();

            window.addEventListener( 'resize', onWindowResize, false );
        }



    </script>
</head>

<body onload="draw();">
</body>
</html>