3D圆形加载器（circle loader）

示例

HTML

<canvas></canvas>

<!-- twitter / dribbble -->
<a href="https://greensock.com" target="_blank"><img class="gsap-3-logo" src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/gsap-3-logo.svg"></a>
<a class="dribbble" href="https://dribbble.com/shots/8206266-3D-Circle-Loader" target="_blank"><img src="https://dribbble.com/assets/logo-small-2x-9fe74d2ad7b25fba0f50168523c15fda4c35534f9ea0b1011179275383035439.png" alt=""></a>
<a class="twitter" target="_blank" href="https://twitter.com/aaroniker_me"><svg xmlns="http://www.w3.org/2000/svg" width="72" height="72" viewBox="0 0 72 72"><path d="M67.812 16.141a26.246 26.246 0 0 1-7.519 2.06 13.134 13.134 0 0 0 5.756-7.244 26.127 26.127 0 0 1-8.313 3.176A13.075 13.075 0 0 0 48.182 10c-7.229 0-13.092 5.861-13.092 13.093 0 1.026.118 2.021.338 2.981-10.885-.548-20.528-5.757-26.987-13.679a13.048 13.048 0 0 0-1.771 6.581c0 4.542 2.312 8.551 5.824 10.898a13.048 13.048 0 0 1-5.93-1.638c-.002.055-.002.11-.002.162 0 6.345 4.513 11.638 10.504 12.84a13.177 13.177 0 0 1-3.449.457c-.846 0-1.667-.078-2.465-.231 1.667 5.2 6.499 8.986 12.23 9.09a26.276 26.276 0 0 1-16.26 5.606A26.21 26.21 0 0 1 4 55.976a37.036 37.036 0 0 0 20.067 5.882c24.083 0 37.251-19.949 37.251-37.249 0-.566-.014-1.134-.039-1.694a26.597 26.597 0 0 0 6.533-6.774z"></path></svg></a>

CSS

body {
    background: #275EFE;
}

canvas {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}

// dribbble & twitter
body {
    min-height: 100vh;
    overflow: hidden;
    .gsap-3-logo {
        width: 88px;
        position: fixed;
        bottom: 12px;
        right: 152px;
    }
    .dribbble {
        position: fixed;
        display: block;
        right: 20px;
        bottom: 20px;
        img {
            display: block;
            width: 76px;
        }
    }
    .twitter {
        position: fixed;
        display: block;
        right: 112px;
        bottom: 14px;
        svg {
            width: 24px;
            height: 24px;
            fill: white;
        }
    }
}

JS

const $ = (s, o = document) => o.querySelector(s);

let width = 440,
    height = 440,
    canvas = $('canvas'),
    renderer = new THREE.WebGLRenderer({
        canvas: canvas,
        context: canvas.getContext('webgl2'),
        antialias: true,
        alpha: true
    }),
    shape = (inner = 13, outer = 20, height = 6, segments = 60) => {

        let arc = new THREE.Shape(),
            hole = new THREE.Path();

        arc.moveTo(outer, 0);
        arc.absarc(0, 0, outer, 0, Math.PI * 2, false);

        hole.moveTo(inner, 0);
        hole.absarc(0, 0, inner, 0, Math.PI * 2, true);
        arc.holes.push(hole);

        let geometry = new THREE.ExtrudeGeometry(arc, {
                depth: height,
                bevelEnabled: false,
                curveSegments: segments
            }),
            material = new THREE.MeshLambertMaterial({
                color: 0xD3D4EC
            }),
            object = new THREE.Mesh(geometry, material),
            proxy = new Proxy({
                z: null,
                s: null
            }, {
                set(target, key, value) {
                    target[key] = value;
                    if(target.z !== null) {
                        object.position.z = target.z;
                    }
                    if(target.s !== null) {
                        object.scale.x = target.s;
                        object.scale.y = target.s;
                    }
                    return true;
                },
                get(target, key) {
                    return target[key];
                }
            });

        object.castShadow = true;
        object.receiveShadow = true;

        return {
            geometry: geometry,
            object: object,
            proxy: proxy
        }

    };

renderer.setSize(width, height);
renderer.setPixelRatio(2);

renderer.shadowMap.enabled = true;
renderer.shadowMap.type = THREE.PCFSoftShadowMap;

let scene = new THREE.Scene();
    camera = new THREE.PerspectiveCamera(45, width / height, .1, 1000);

camera.position.z = 100;
camera.position.y = -160;
camera.rotation.x = THREE.Math.degToRad(60);

let planeGeometry = new THREE.PlaneGeometry(200, 200),
    planeMaterial = new THREE.ShadowMaterial();

planeMaterial.opacity = .1;

let plane = new THREE.Mesh(planeGeometry, planeMaterial);
plane.position.y = 6;
plane.receiveShadow = true;

scene.add(plane);

let lightTop = new THREE.DirectionalLight(0xFFFFFF, .4);
lightTop.position.set(100, 100, 200);
lightTop.castShadow = true;

let d = 40;
lightTop.shadow.camera.left = -d;
lightTop.shadow.camera.right = d;
lightTop.shadow.camera.top = d;
lightTop.shadow.camera.bottom = -d;

lightTop.shadow.radius = 8;

scene.add(lightTop);

scene.add(new THREE.AmbientLight(0xE8EBFB));

// Setup

let first = shape(),
    second = shape(),
    third = shape();

scene.add(first.object);
scene.add(second.object);
scene.add(third.object);

first.proxy.s = .8;

second.proxy.z = 9;
second.proxy.s = .55;

third.proxy.z = 18;
third.proxy.s = .35;

// Animate

gsap.to(first.proxy, {
    repeat: -1,
    duration: 1,
    keyframes: [{
        z: 9,
        s: .95
    }, {
        z: 18,
        s: .35
    }, {
        z: 0,
        s: .3
    }, {
        z: 0,
        s: .8,
        delay: -.1
    }]
});

gsap.to(second.proxy, {
    repeat: -1,
    duration: 1,
    keyframes: [{
        z: 10,
        s: .5
    }, {
        z: 0,
        s: .5
    }, {
        z: 4,
        s: .65
    }, {
        z: 8,
        s: .55
    }]
});

gsap.to(third.proxy, {
    repeat: -1,
    duration: 1,
    keyframes: [{
        z: 0,
        s: .3
    }, {
        z: 0,
        s: .8,
        delay: -.1
    }, {
        z: 9,
        s: .95
    }, {
        z: 18,
        s: .35
    }]
});

let render = () => {

    requestAnimationFrame(render);

    renderer.render(scene, camera);

};

render();

更多有趣示例 尽在 小红砖社区https://xhz.bos.xyz