3D Particles Ball - actionscript-3

Question

If I'd like to make a circle with particles, I'd define random coordinates for particles like this:
for(var i:int = 0; i != 100; i++)
{
var angle:Number = Math.random() * 360;
var r:Number = 600;
var nX:Number = r * Math.cos(angle / 180 * Math.PI);
var nY:Number = r * Math.sin(angle / 180 * Math.PI);
}
But I want to make a ball with particles on 3d space but I don't know how to define random coordinates for particles. Radius is fixed again but there should be a "nZ" value. Can you help me to define these coordinates?
for(var i:int = 0; i != 100; i++)
{
var angle:Number = Math.random() * 360;
var r:Number = 600;
var nX:Number = ???
var nY:Number = ???
var nZ:Number = ???
}
Thanks in advance...

Answer 1

Spherical coordinates are what you want.
You need two angles:
for(var i:int = 0; i != 100; i++)
{
var azimuthAngle:Number = Math.random() * 360;
var elevationAngle:Number = (Math.random() * 180) - 90;
var r:Number = 600;
var nX:Number =
r * Math.cos(azimuthAngle / 180 * Math.PI) * Math.sin(elevationAngle / 180 * Math.PI);
var nY:Number =
r * Math.sin(azimuthAngle / 180 * Math.PI) * Math.sin(elevationAngle / 180 * Math.PI);
var nZ:Number =
r * Math.cos(elevationAngle / 180 * Math.PI);
}