[Radiance-general] Radiance Vs Radiosity

[Mark de la Fuente]

I read through the pab-opto comparisons (thanks Peter!).  Looked pretty
good.  Too bad Viz had not incorporated Lightscape at the time.  Not
sure what AutoDesk's plans are, but I think Viz is already more powerful
than Lightscape in all but a couple of areas.  Had a couple of questions
though that came up after reading the comparison...  They are kind of
general radiance questions. 
Are ambient files really independent of the viewfile?  Somewhere in
Rendering with Radiance (where it talks about ambient files) I had the
impression different views required different ambient files, and thus I
stopped using ambient files the way other people seem to and started
using view dependent ambient files.  Meaning I would use one ambient
file per view regardless of the fact that scene was the same.  If this
is not right, and one file will work for any view, someone please let me
know.  I noticed Rob Guglielmetti also "generates multiple fisheye views
for ambient cache, prior to running calcs".  (Sounds like ambient files
are not view dependent).
 
Another question that came up was regarding ambient bounces.  On pages
29-31, "Typical" ambient bounces are 3-7, and then various calculation
times are shown for ab=0 (.135 hours), ab=1 (.431 hours), ab=7 (24
hours).  How in the world does one accomplish ab=7 in only 24 hours on a
~400MHz computer?  Wow!..  I was blown away considering I've been
running some ab=2 simulations on a 2.66GHz computer and taking 24 hours
each.  Were all the other values minimized (except for ad=16,000?). 
Well it's got me thinking about being more careful about how parameters
are assigned.
 
Then, something I always thought was a hole missing from Radiance, and
perhaps is really just a limitation in my own radiance knowledge is
this.  All other lighting programs that I am aware of allow you to place
calculation grids, run calcs, and then display the grid point results in
relation to the calculation model (though most can't do false color
images).  Most programs will even export the results to DXF for
incorporation into CAD programs.  It seems rshow can do some of this?
 
And last but not least, what is the trick on page 55?  Replicating
image maps in a way that their pattern does not become repetitive.  Are
we talking about making sure the edges match-up and that the image is
generally uniform?
 
Well thanks for responding to my original post.
 
Mark
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