Two.js做出物体环绕动画

var elem = document.getElementById('draw-animation');
var two = new Two({ width: 700, height: 700 }).appendTo(elem);
//外层大运行轨迹
var track = two.makeCircle(0, 0, 200);
track.fill='transparent';
track.stroke='#3366FF';
track.linewidth=3;
//sun
var sun = two.makeCircle(0,0,80);
sun.fill='#FF8000';
sun.stroke='#FF0000';
sun.linewidth=5;
//earth
var earth = two.makeCircle(0,0,50);
earth.fill='#9ACD32';
//moon
var moon = two.makeCircle(100,0,30);
moon.fill='#1C75BC';
//inline 小的运行轨迹
var inline = two.makeCircle(0,0,100);
inline.stroke='#3366FF';
inline.fill='transparent';
inline.linewidth=3;
//group 分组 一类型为一组
var group = two.makeGroup(inline,earth,moon);
console.dir(group);
var group1 = two.makeGroup(sun,track,group);
 
group1.translation.set(two.width / 2, two.height / 2); //平移(x,y)父元素的一半
group.translation.set(200, 0); 
group.scale = 0.8; //比例
two.bind('update', function(frameCount) {//执行动画
  group1.rotation += 0.01 *2* Math.PI;
  group.rotation += 0.01 * Math.PI;
}).play();