3D云标签滚动，是个很酷的东西，当然我不会写，之前找过各式各样的，除了flash版的比较完美，其他JS版本的我还真没看到过比较好的，今天在这里分享一下这个纯js写的，我个人认为已经算是很好的了，也是刚在一个博客那看到的(wanql.sinaapp.com)，顺手转过来了，嘿嘿。

效果图：

js代码：

var radius = 120;
var dtr = Math.PI/180;
var d=300;
var mcList = [];
var active = false;
var lasta = 1;
var lastb = 1;
var distr = true;
var tspeed=10;
var size=250;
var mouseX=0;
var mouseY=0;
var howElliptical=1;
var aA=null;
var oDiv=null;
window.onload=function ()
{
 var i=0;
 var oTag=null;
  
 oDiv=document.getElementById('div1');
  
 aA=oDiv.getElementsByTagName('a');
  
 for(i=0;i<aA.length;i++)
 {
  oTag={};
   
  oTag.offsetWidth=aA[i].offsetWidth;
  oTag.offsetHeight=aA[i].offsetHeight;
   
  mcList.push(oTag);
 }
  
 sineCosine( 0,0,0 );
  
 positionAll();
  
 oDiv.onmouseover=function ()
 {
  active=true;
 };
  
 oDiv.onmouseout=function ()
 {
  active=false;
 };
  
 oDiv.onmousemove=function (ev)
 {
  var oEvent=window.event || ev;
   
  mouseX=oEvent.clientX-(oDiv.offsetLeft+oDiv.offsetWidth/2);
  mouseY=oEvent.clientY-(oDiv.offsetTop+oDiv.offsetHeight/2);
   
  mouseX/=5;
  mouseY/=5;
 };
  
 setInterval(update, 30);
};
function update()
{
 var a;
 var b;
  
 if(active)
 {
  a = (-Math.min( Math.max( -mouseY, -size ), size ) / radius ) * tspeed;
  b = (Math.min( Math.max( -mouseX, -size ), size ) / radius ) * tspeed;
 }
 else
 {
  a = lasta * 0.98;
  b = lastb * 0.98;
 }
  
 lasta=a;
 lastb=b;
  
 if(Math.abs(a)<=0.01 && Math.abs(b)<=0.01)
 {
  return;
 }
  
 var c=0;
 sineCosine(a,b,c);
 for(var j=0;j<mcList.length;j++)
 {
  var rx1=mcList[j].cx;
  var ry1=mcList[j].cy*ca+mcList[j].cz*(-sa);
  var rz1=mcList[j].cy*sa+mcList[j].cz*ca;
   
  var rx2=rx1*cb+rz1*sb;
  var ry2=ry1;
  var rz2=rx1*(-sb)+rz1*cb;
   
  var rx3=rx2*cc+ry2*(-sc);
  var ry3=rx2*sc+ry2*cc;
  var rz3=rz2;
   
  mcList[j].cx=rx3;
  mcList[j].cy=ry3;
  mcList[j].cz=rz3;
   
  per=d/(d+rz3);
   
  mcList[j].x=(howElliptical*rx3*per)-(howElliptical*2);
  mcList[j].y=ry3*per;
  mcList[j].scale=per;
  mcList[j].alpha=per;
   
  mcList[j].alpha=(mcList[j].alpha-0.6)*(10/6);
 }
  
 doPosition();
 depthSort();
}
function depthSort()
{
 var i=0;
 var aTmp=[];
  
 for(i=0;ivItem2.cz)
   {
    return -1;
   }
   else if(vItem1.cz<vItem2.cz)
   {
    return 1;
   }
   else
   {
    return 0;
   }
  }
 );
  
 for(i=0;i<aTmp.length;i++)
 {
  aTmp[i].style.zIndex=i;
 }
}
function positionAll()
{
 var phi=0;
 var theta=0;
 var max=mcList.length;
 var i=0;
  
 var aTmp=[];
 var oFragment=document.createDocumentFragment();
  
 //随机排序
 for(i=0;i<aA.length;i++)
 {
  aTmp.push(aA[i]);
 }
  
 aTmp.sort
 (
  function ()
  {
   return Math.random()<0.5?1:-1;
  }
 );
  
 for(i=0;i<aTmp.length;i++)
 {
  oFragment.appendChild(aTmp[i]);
 }
  
 oDiv.appendChild(oFragment);
  
 for( var i=1; i<max+1; i++){
  if( distr )
  {
   phi = Math.acos(-1+(2*i-1)/max);
   theta = Math.sqrt(max*Math.PI)*phi;
  }
  else
  {
   phi = Math.random()*(Math.PI);
   theta = Math.random()*(2*Math.PI);
  }
  //坐标变换
  mcList[i-1].cx = radius * Math.cos(theta)*Math.sin(phi);
  mcList[i-1].cy = radius * Math.sin(theta)*Math.sin(phi);
  mcList[i-1].cz = radius * Math.cos(phi);
   
  aA[i-1].style.left=mcList[i-1].cx+oDiv.offsetWidth/2-mcList[i-1].offsetWidth/2+'px';
  aA[i-1].style.top=mcList[i-1].cy+oDiv.offsetHeight/2-mcList[i-1].offsetHeight/2+'px';
 }
}
function doPosition()
{
 var l=oDiv.offsetWidth/2;
 var t=oDiv.offsetHeight/2;
 for(var i=0;i<mcList.length;i++)
 {
  aA[i].style.left=mcList[i].cx+l-mcList[i].offsetWidth/2+'px';
  aA[i].style.top=mcList[i].cy+t-mcList[i].offsetHeight/2+'px';
   
  aA[i].style.fontSize=Math.ceil(12*mcList[i].scale/2)+8+'px';
   
  aA[i].style.filter="alpha(opacity="+100*mcList[i].alpha+")";
  aA[i].style.opacity=mcList[i].alpha;
 }
}
function sineCosine( a, b, c)
{
 sa = Math.sin(a * dtr);
 ca = Math.cos(a * dtr);
 sb = Math.sin(b * dtr);
 cb = Math.cos(b * dtr);
 sc = Math.sin(c * dtr);
 cc = Math.cos(c * dtr);
}

html代码：

标签1标签2标签3

css代码：

body {background: #000 url(index.png) no-repeat center 230px;}
 
#div1 {position:relative; width:450px; height:450px; margin: 20px auto 0; }
 
#div1 a {position:absolute; top:0px; left:0px; font-family: Microsoft YaHei; color:#fff; font-weight:bold; text-decoration:none; padding: 3px 6px; }
 
#div1 a:hover {border: 1px solid #eee; background: #000; }
 
#div1 .blue {color:blue;}
 
#div1 .red {color:red;}
 
#div1 .yellow {color:yellow;}