Re: Random Distribution of Points on a Sphere



 In response to Dongchul's question,
 > Hi fellow chemists,
 > This may fit better in comp.graphics, but someone in this group
 > may have experienced it already. So here it goes.
 > I want to generate points on the surface of a sphere as randomly
 > as possible. These points may be used for drawing van der Waals
 > surface of an atom. I tried with symmetrically distributed points
 > (generated by varying phi and theta, etc), but due to symmetry,
 > the points looked like marching ants at certain angles.
 > Since many of symmetrically distributed points are likely to be
 > overlapped when they are placed in 2-D screen, increasing the
 > density of VDW points would require unnecessarily large number
 > of sphere points. Random distribution of points would help
 > minimizing the number of points required and will give a better
 > appearance.
 > Any ideas?
 > -DCL
 > lim #*at*# rani.chem.yale.edu
 Check Appendix G.4 of Allen and Tildesley's wonderful book
 "Computer Simulation of Liquids" (Clarendon Press, Oxford, 1987)
 for an algorithm for uniformly sampling the surface of a sphere.
 -RQT
             ********************************
             *  Robert Q. Topper            *
             *  Department of Chemistry     *
             *  University of Rhode Island  *
             *  Kingston, RI 02881          *
             ********************************
             *  rtopper #*at*# chm.uri.edu OR      *
             *  topper #*at*# haydn.chm.uri.edu    *
             *  (401) 792-2597 [office]     *
             *  (401) 792-5072 [FAX]        *
             ********************************