预览效果如图所示：
代码如下：
<!DOCTYPE html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>html5背景</title> <style type="text/css"> *{margin:0;padding:0;list-style-type:none;} a,img{border:0;} </style> <script type="text/javascript" src="http://code.jquery.com/jquery-1.8.3.min.js"></script> </head> <body> <div id="container" style="100%;height:700px;"> <div id="anitOut"></div> </div> <script type="text/javascript"> $(function () { if (!window.ActiveXObject && !!document.createElement("canvas").getContext) { $.getScript("http://im-img.qq.com/pcqq/js/200/cav.js?_=1428576021379", function () { var t = { 1.5, height: 1.5, depth: 10, segments: 12, slices: 6, xRange: 0.8, yRange: 0.1, zRange: 1, ambient: "#525252", diffuse: "#FFFFFF", speed: 0.0002 }; var G = { count: 2, xyScalar: 1, zOffset: 100, ambient: "#002c4a", diffuse: "#005584", speed: 0.001, gravity: 1200, dampening: 0.95, minLimit: 10, maxLimit: null, minDistance: 20, maxDistance: 400, autopilot: false, draw: false, bounds: CAV.Vector3.create(), step: CAV.Vector3.create(Math.randomInRange(0.2, 1), Math.randomInRange(0.2, 1), Math.randomInRange(0.2, 1)) }; var m = "canvas"; var E = "svg"; var x = { renderer: m }; var i, n = Date.now(); var L = CAV.Vector3.create(); var k = CAV.Vector3.create(); var z = document.getElementById("container"); var w = document.getElementById("anitOut"); var D, I, h, q, y; var g; var r; function C() { F(); p(); s(); B(); v(); K(z.offsetWidth, z.offsetHeight); o() } function F() { g = new CAV.CanvasRenderer(); H(x.renderer) } function H(N) { if (D) { w.removeChild(D.element) } switch (N) { case m: D = g; break } D.setSize(z.offsetWidth, z.offsetHeight); w.appendChild(D.element) } function p() { I = new CAV.Scene() } function s() { I.remove(h); D.clear(); q = new CAV.Plane(t.width * D.width, t.height * D.height, t.segments, t.slices); y = new CAV.Material(t.ambient, t.diffuse); h = new CAV.Mesh(q, y); I.add(h); var N, O; for (N = q.vertices.length - 1; N >= 0; N--) { O = q.vertices[N]; O.anchor = CAV.Vector3.clone(O.position); O.step = CAV.Vector3.create(Math.randomInRange(0.2, 1), Math.randomInRange(0.2, 1), Math.randomInRange(0.2, 1)); O.time = Math.randomInRange(0, Math.PIM2) } } function B() { var O, N; for (O = I.lights.length - 1; O >= 0; O--) { N = I.lights[O]; I.remove(N) } D.clear(); for (O = 0; O < G.count; O++) { N = new CAV.Light(G.ambient, G.diffuse); N.ambientHex = N.ambient.format(); N.diffuseHex = N.diffuse.format(); I.add(N); N.mass = Math.randomInRange(0.5, 1); N.velocity = CAV.Vector3.create(); N.acceleration = CAV.Vector3.create(); N.force = CAV.Vector3.create() } } function K(O, N) { D.setSize(O, N); CAV.Vector3.set(L, D.halfWidth, D.halfHeight); s() } function o() { i = Date.now() - n; u(); M(); requestAnimationFrame(o) } function u() { var Q, P, O, R, T, V, U, S = t.depth / 2; CAV.Vector3.copy(G.bounds, L); CAV.Vector3.multiplyScalar(G.bounds, G.xyScalar); CAV.Vector3.setZ(k, G.zOffset); for (R = I.lights.length - 1; R >= 0; R--) { T = I.lights[R]; CAV.Vector3.setZ(T.position, G.zOffset); var N = Math.clamp(CAV.Vector3.distanceSquared(T.position, k), G.minDistance, G.maxDistance); var W = G.gravity * T.mass / N; CAV.Vector3.subtractVectors(T.force, k, T.position); CAV.Vector3.normalise(T.force); CAV.Vector3.multiplyScalar(T.force, W); CAV.Vector3.set(T.acceleration); CAV.Vector3.add(T.acceleration, T.force); CAV.Vector3.add(T.velocity, T.acceleration); CAV.Vector3.multiplyScalar(T.velocity, G.dampening); CAV.Vector3.limit(T.velocity, G.minLimit, G.maxLimit); CAV.Vector3.add(T.position, T.velocity) } for (V = q.vertices.length - 1; V >= 0; V--) { U = q.vertices[V]; Q = Math.sin(U.time + U.step[0] * i * t.speed); P = Math.cos(U.time + U.step[1] * i * t.speed); O = Math.sin(U.time + U.step[2] * i * t.speed); CAV.Vector3.set(U.position, t.xRange * q.segmentWidth * Q, t.yRange * q.sliceHeight * P, t.zRange * S * O - S); CAV.Vector3.add(U.position, U.anchor) } q.dirty = true } function M() { D.render(I) } function J(O) { var Q, N, S = O; var P = function (T) { for (Q = 0, l = I.lights.length; Q < l; Q++) { N = I.lights[Q]; N.ambient.set(T); N.ambientHex = N.ambient.format() } }; var R = function (T) { for (Q = 0, l = I.lights.length; Q < l; Q++) { N = I.lights[Q]; N.diffuse.set(T); N.diffuseHex = N.diffuse.format() } }; return { set: function () { P(S[0]); R(S[1]) } } } function v() { window.addEventListener("resize", j) } function A(N) { CAV.Vector3.set(k, N.x, D.height - N.y); CAV.Vector3.subtract(k, L) } function j(N) { K(z.offsetWidth, z.offsetHeight); M() } C(); }) } else { alert('调用cav.js失败'); } }); </script> </body> </html>