[Radiance-general]ies photometry+geometry?

[Rob Guglielmetti]

steve michel wrote:
> I am trying to include in a scene file, lamp fixture photometry with a 
> object geometry (dxf model supplied by the manufacturer for that same 
> fixture. Is there a straighforward way  of combining both such that 
> the fixture model doesn't compromise the photometry??
>  
You need to use a procedure where you wrap your geometry with an illum 
sphere or box and you apply the luminous distribution to that illum 
enclosure. Then you also have to generally create some glow polygons 
within the fixture geometry to make the geometry appear correct (the 
glow will not be evaluated beyond the illum boundary so you won't affect 
the distribution of the fixture on the scene).  I would say it's not 
straightforward, but the procedure is outlined in Charles Ehrlich's 
chapter of Rendering with Radiance. The process is very much streamlined 
when you use Georg Mischler's Rayfront interface.  Personally, I am 
usually interested in the calculation result from electric light 
sources, so I tend to just use the simple geometry that ies2rad creates 
for me.  But the visual result of going the distance and actually 
setting up the whole illum enclosure can be fantastic.  I have very 
limited experience with this, but I hope others will chime in here with 
some tips.

- Rob Guglielmetti