//球面随机分布
var u = Math.random()
var v = Math.random()
var theta = 2 * Math.PI * u
var phi = Math.acos(2 * v - 1)
var x = Math.sin(theta) * Math.sin(phi);
var y = Math.cos(theta) * Math.sin(phi)
var z = Math.cos(phi);
//球面环形分布
 for (var i = 0, l = objects.length; i < l; i++) {

    var phi = Math.acos(-1 + (2 * i) / l);
    var theta = Math.sqrt(l * Math.PI) * phi;

    var x = 800 * Math.cos(theta) * Math.sin(phi);
    var y = 800 * Math.sin(theta) * Math.sin(phi);
    var z = 800 * Math.cos(phi);


 }