[Radiance-general] Overture calculation

[Randolph M. Fritz]

I've been tracing a relatively small number of rays through a model, 
and when I added more rays, one of the previous illuminance values 
changed by 9%.  Apparently, the ambient file had been inadequately 
populated.

OK.

So, I need an overture calculation.  I think the easiest way to ensure 
a fairly complete ambient file is to generate small images.  I could do 
six orthographics at maybe 200 pixels long-ways, or a trace a more 
comprehensive grid, or ...  Any suggestions?
-- 
Randolph