Resetting lighting and retaining viewpoint

[Scott "Lord of Sith" Kajihara]

We have programs that switch between the orthogonal projection mode and the
perspective projection mode to view objects.  When using ortho or window, the
viewpoint is reset to looking down the z-axis.  We have the following problems
to solve:  retaining the same viewpoint when switching from ortho to
perspective to ortho projections as one case and resetting the lighting behind
the viewpoint when the viewpoint is changed as a second case.  Is there any
simple way using the defined Model/View and Projection matrices to do this?

     Thank you,

     Scott Kajihara

-- 
     Scott Akira Kajihara "Insanity is a prerequisite for physics techie-types"
mcnc!kajihara  kajihara at mcnc.org  mcnc!{pyvax|pymvjb|pysgjb}!kajihara
kajihara@{pyvax|pymvjb|pysgjb}.nscu.edu kajihara at ncsuphys.BITNET
_et al._ of which I am not aware.