Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!apple!dvb
From: dvb@Apple.COM (David Van Brink)
Newsgroups: comp.graphics
Subject: Re: random points on surface of sphere
Summary: Easy way to get random points on sphere surface
Keywords: uniform spherical distribution, random walk
Message-ID: <40768@apple.Apple.COM>
Date: 6 May 90 19:53:59 GMT
References: <1523@ryn.esg.dec.com>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 16


A mathemetician friend of mine worked out an absurdly
simple means of finding a random point on the surface
of a unit radius sphere. 

1. Pick a random angle, 0 <= theta < 360. This is in
the x-y plane.

2. Pick a random z-value from -1 to 1 ( "<=" or "<" ?
I'm not sure).

Turns out the distribution of area is linear along an
axis. I was somewhat skeptical of this, but at least
one non-disproof is that the surface area of the sphere
is the same as the surface area of the curved part of
a bounding cylinder. (4*pi*r^2).