Needed -- an algorithm for depth sorting atoms and bonds

[user name unknown]

I am writing a program that displays a ball-and-stick model of a molecule.  
I need an *efficient *algorithm which depth sorts the atoms and bonds 
of a molecule.  I have all the necessary positional and connectivity 
information.

References, code fragments, rought outlines will be appreciated.

Thanks in advance,
-- 
Noel Menezes                            Internet: noel at hermes.chpc.utexas.edu
Research Assistant                      BITNET:   noel at uthermes
Center for High Performance Computing   Phone:    (512) 471-2447
Balcones Resarch Center & UT-Austin     Fax:      (512) 471-2445