本篇文章给大家介绍通过js+css3的transforms属性和keyframes属性来实现烟花绽放的动画效果的方法。有一定的参考价值，有需要的朋友可以参考一下，希望对你们有所帮助。

首先我们来看看效果：

动画的实现原理：

动画使用了两个关键帧(keyframes)：

一个是烟花筒上升的轨迹，另一个是烟花绽放中的火星碎片。在这里你可以看到正在进行的基本草图：

每个烟花筒沿着场地底部的线分配一个随机的起始位置。它还在标记的区域内分配了一个随机目标。当烟花筒接近其目标点时，它会缩小为不可见(0x0像素)。

此时，耀斑变得可见。这些实际上是一系列以径向方式向外指向的DIV，在向外的尖端有一种颜色 - 就像火柴棍一样。为了模拟爆炸，他们只是增加了长度，使灯光向外移动。

JavaScript用于：

1、将所有必需的元素添加到页面(DOM);

2、为每个烟花筒创建和分配关键帧 ; 和

3、指定颜色并将每个光斑旋转到正确的位置。

代码示例：

html代码：

烟花绽放

css代码(css-fireworks.css)@-webkit-keyframes explosion {

from {

width: 0;

opacity: 0;

}

33% {

width: 0;

opacity: 0;

}

34% {

width: 10px;

opacity: 1.0;

}

40% {

width: 80px;

opacity: 1.0;

}

to {

width: 90px;

opacity: 0;

}

}

@-moz-keyframes explosion {

from {

width: 0;

opacity: 0;

}

33% {

width: 0;

opacity: 0;

}

34% {

width: 10px;

opacity: 1.0;

}

40% {

width: 80px;

opacity: 1.0;

}

to {

width: 90px;

opacity: 0;

}

}

#stage {

position: relative;

width: 600px;

height: 400px;

margin: 100px auto;

background: #000 url(img/outerspace.jpg);

}

.launcher {

position: absolute;

-webkit-animation-duration: 4s;

-webkit-animation-iteration-count: infinite;

-moz-animation-duration: 4s;

-moz-animation-iteration-count: infinite;

background: red;

border-bottom: 3px solid yellow;

}

.launcher div {

position: absolute;

opacity: 0;

-webkit-animation-name: explosion;

-webkit-animation-duration: 4s;

-webkit-animation-iteration-count: infinite;

-moz-animation-name: explosion;

-moz-animation-duration: 4s;

-moz-animation-iteration-count: infinite;

left: 3px;

top: 3px;

width: 10px;

height: 4px;

border-right: 4px solid yellow;

border-radius: 2px;

-webkit-transform-origin: 0 0;

-moz-transform-origin: 0 0;

}

js代码(css-fireworks.js)document.addEventListener("DOMContentLoaded", function() {

var num_launchers = 12;

var num_flares = 20;

var flare_colours = ['red', 'aqua', 'violet', 'yellow', 'lightgreen', 'white', 'blue'];

var cssIdx = document.styleSheets.length - 1;

function myRandom(from, to)

{

return from + Math.floor(Math.random() * (to-from));

}

var keyframes_template = "from { left: LEFTFROM%; top: 380px; width: 6px; height: 12px; }\n"

+ "33% { left: LEFTTOP%; top: TOPTOPpx; width: 0; height: 0; }\n"

+ " to { left: LEFTEND%; top: BOTBOTpx; width: 0; height: 0; }";

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

leftfrom = myRandom(15, 85);

lefttop = myRandom(30, 70);

toptop = myRandom(20, 200);

leftend = lefttop + (lefttop-leftfrom)/2;

botbot = toptop + 100;

csscode = keyframes_template;

csscode = csscode.replace(/LEFTFROM/, leftfrom);

csscode = csscode.replace(/LEFTTOP/, lefttop);

csscode = csscode.replace(/TOPTOP/, toptop);

csscode = csscode.replace(/LEFTEND/, leftend);

csscode = csscode.replace(/BOTBOT/, botbot);

try { // WebKit browsers

csscode2 = "@-webkit-keyframes flight_" + i + " {\n" + csscode + "\n}";

document.styleSheets[cssIdx].insertRule(csscode2, 0);

} catch(e) { }

try { // Mozilla browsers

csscode2 = "@-moz-keyframes flight_" + i + " {\n" + csscode + "\n}";

document.styleSheets[cssIdx].insertRule(csscode2, 0);

} catch(e) { }

}

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

var rand = myRandom(0, flare_colours.length - 1);

var rand_colour = flare_colours[rand];

var launch_delay = myRandom(0,100) / 10;

csscode = ".launcher:nth-child(" + num_launchers + "n+" + i + ") {\n"

+ " -webkit-animation-name: flight_" + i + ";\n"

+ " -webkit-animation-delay: " + launch_delay + "s;\n"

+ " -moz-animation-name: flight_" + i + ";\n"

+ " -moz-animation-delay: " + launch_delay + "s;\n"

+ "}";

document.styleSheets[cssIdx].insertRule(csscode, 0);

csscode = ".launcher:nth-child(" + num_launchers + "n+" + i + ") div {"

+ " border-color: " + rand_colour + ";\n"

+ " -webkit-animation-delay: " + launch_delay + "s;\n"

+ " -moz-animation-delay: " + launch_delay + "s;\n"

+ "}";

document.styleSheets[cssIdx].insertRule(csscode, 0);

}

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

csscode = ".launcher div:nth-child(" + num_flares + "n+" + i + ") {\n"

+ " -webkit-transform: rotate(" + (i * 360/num_flares) + "deg);\n"

+ " -moz-transform: rotate(" + (i * 360/num_flares) + "deg);\n"

+ "}";

document.styleSheets[cssIdx].insertRule(csscode, 0);

}

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

var newdiv = document.createElement("div");

newdiv.className = "launcher";

for(var j=0; j < num_flares; j++) {

newdiv.appendChild(document.createElement("div"));

}

document.getElementById("stage").appendChild(newdiv);

}

}, false);

总结：以上就是本篇文的全部内容，大家可以自己动手试试，加深理解。希望能对大家的学习有所帮助，推荐视频学习：css3教程！