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Three.js的基础动画实现案例

程序员文章站 2024-02-18 00:01:34
简介 模型导入到上一节也就先告一段落了，接下来，我将学习动画方面的知识。在这之前，我先复习了一下基础变化的相关知识。 基础动画就是缩放、位置和旋转，也就是配置模型的scale、position和ro...

简介

模型导入到上一节也就先告一段落了，接下来，我将学习动画方面的知识。在这之前，我先复习了一下基础变化的相关知识。

基础动画就是缩放、位置和旋转，也就是配置模型的scale、position和rotation。我直接写了一个案例，来实现三种动画。

实现案例

- 首先，我们创建了三个添加动画的模型：立方体、球和圆柱。

sphere = new three.mesh(spheregeometry, spherematerial);
cube = new three.mesh(cubegeometry, cubematerial);
cylinder = new three.mesh(cylindergeometry, cylindermaterial);

然后在render里面分别修改它们的scale、position和rotation。 

//处理位置变化的球的移动
positionstep += gui.positionstep;
sphere.position.x = 10*math.cos(positionstep) - 10;
sphere.position.y = 5 + math.abs(math.sin(positionstep))*10;

//处理立方体的旋转
cube.rotation.x += gui.rotationstep;
cube.rotation.y += gui.rotationstep;
cube.rotation.z += gui.rotationstep;

//处理圆柱体的缩放
scalestep += gui.scalestep;
cylinder.scale.x = math.abs(math.sin(scalestep));
cylinder.scale.y = math.abs(math.cos(scalestep));
cylinder.scale.z = math.abs(math.sin(scalestep));

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="/lib/three.js"></script>
<script src="/lib/js/controls/orbitcontrols.js"></script>
<script src="/lib/js/libs/stats.min.js"></script>
<script src="/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);
        //告诉渲染器需要阴影效果
        renderer.shadowmap.enabled = true;
        renderer.shadowmap.type = three.pcfsoftshadowmap; // 默认的是，没有设置的这个清晰 three.pcfshadowmap
        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, 50);
        camera.lookat(new three.vector3(0,0,0));
    }

    var scene;
    function initscene() {
        scene = new three.scene();
    }

    //初始化dat.gui简化试验流程
    var gui;
    function initgui() {
        //声明一个保存需求修改的相关数据的对象
        gui = {
            scalestep:0.01,
            rotationstep:0.03,
            positionstep:0.05
        };
        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, "scalestep", 0, 1);
        datgui.add(gui, "rotationstep", 0, 1);
        datgui.add(gui, "positionstep", 0, 1);
    }

    var light;
    function initlight() {
        scene.add(new three.ambientlight(0x444444));

        light = new three.pointlight(0xffffff);
        light.position.set(15,50,10);

        //告诉平行光需要开启阴影投射
        light.castshadow = true;

        scene.add(light);
    }

    var sphere,cube,cylinder;
    function initmodel() {

        //球
        var spheregeometry = new three.spheregeometry(5,200,200);
        var spherematerial = new three.meshlambertmaterial({color:0xaaaaaa});

        sphere = new three.mesh(spheregeometry, spherematerial);
        sphere.position.x = -10;
        sphere.position.y = 5;
        sphere.position.z = 10;

        //告诉球需要投射阴影
        sphere.castshadow = true;

        scene.add(sphere);

        //辅助工具
        var helper = new three.axeshelper(50);
        scene.add(helper);

        //立方体
        var cubegeometry = new three.cubegeometry(10,10,8);
        var cubematerial = new three.meshlambertmaterial({color:0x00ffff});

        cube = new three.mesh(cubegeometry, cubematerial);
        cube.position.x = 15;
        cube.position.y = 5;
        cube.position.z = -5;

        //告诉立方体需要投射阴影
        cube.castshadow = true;

        scene.add(cube);

        //创建圆柱体
        var cylindergeometry = new three.cylindergeometry(5, 5, 10, 40, 20);
        var cylindermaterial = new three.meshphongmaterial({color:0xff5f4d});
        cylinder = new three.mesh(cylindergeometry, cylindermaterial);
        cylinder.position.set(-15, 5, -10);
        cylinder.castshadow = true;

        scene.add(cylinder);

        //底部平面
        var planegeometry = new three.planegeometry(100,100);
        var planematerial = new three.meshstandardmaterial({color:0xaaaaaa});

        var plane = new three.mesh(planegeometry, planematerial);
        plane.rotation.x = - 0.5 * math.pi;
        plane.position.y = 0;

        //告诉底部平面需要接收阴影
        plane.receiveshadow = true;

        scene.add(plane);

    }

    //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  = 100;
        //设置相机距离原点的最远距离
        controls.maxdistance  = 200;
        //是否开启右键拖拽
        controls.enablepan = true;
    }

    var positionstep = 0,scalestep = 0; //模型旋转的速度
    function render() {

        //处理简单动画

        //处理位置变化的球的移动
        positionstep += gui.positionstep;
        sphere.position.x = 10*math.cos(positionstep) - 10;
        sphere.position.y = 5 + math.abs(math.sin(positionstep))*10;

        //处理立方体的旋转
        cube.rotation.x += gui.rotationstep;
        cube.rotation.y += gui.rotationstep;
        cube.rotation.z += gui.rotationstep;

        //处理圆柱体的缩放
        scalestep += gui.scalestep;
        cylinder.scale.x = math.abs(math.sin(scalestep));
        cylinder.scale.y = math.abs(math.cos(scalestep));
        cylinder.scale.z = math.abs(math.sin(scalestep));

    }

    //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
        render();

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

        controls.update();

        renderer.render( scene, camera );

        requestanimationframe(animate);
    }

    function draw() {
        initgui();
        initrender();
        initscene();
        initcamera();
        initlight();
        initmodel();
        initcontrols();
        initstats();

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

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