var RandomXYZ = function (vec3, radius){ 
if (radius === undefined) { 
radius = 1; 
} 
var r = Math.random() * 2 * Math.PI; 
var z = (Math.random() * 2) - 1; 
var zScale = Math.sqrt(1 - z * z) * radius; 
vec3.x = Math.cos(r) * zScale; 
vec3.y = Math.sin(r) * zScale; 
vec3.z = z * radius; 
return vec3; 
} 
; 
module.exports = RandomXYZ;