[Radiance-general] Re: ies2rad

[Greg Ward]

Hi Rob,

You must have missed the caveat in the Radiance reference manual 
relating to instances, which specifically states that light sources do 
not work within instances.  There are a couple of reasons for this, the 
main one being to discourage people from creating thousands of light 
sources in their scenes, which is a disaster for the calculation times. 
  If you need to do this, use the -x option of replmarks instead of -i 
and just create copies of the geometry.  If the geometry itself is too 
complicated, instance all the geometry except for the actual emitting 
surfaces, and put them in with replmarks -x.

-Greg

> From: Rob Guglielmetti <rpg@rumblestrip.org>
> Date: Mon Aug 25, 2003  2:48:13  PM US/Pacific
>
> Some of you may remember about a week ago I tuned with news of a 
> broken Radiance installation, broken because I was trying to upgrade 
> to 3.5 so I could begin experimenting with ies2rad.  Well, my machine 
> is fixed (the HEAD release compiled just fine, thanks for the advice 
> Francesco), so I am playing around with this ies2rad business, and 
> naturally, I'm showing up here once again scratching my head.  I'd 
> like to be able to use ies2rad to build a luminaire library of frozen 
> octrees, and then use replmarks to rapidly get CAD layouts into my 
> Radiance models.
>
> I did this:
>
> $ ies2rad -di -t default -u white -m (various) -o dl Dla216.ies
>
> $ oconv -f  dl.rad > dl.oct
>
> $ replmarks -i dl.oct room_llights room_llights.tmp > lights.rad
>
> $ oconv mats.rad *.rad > room.oct
>
> Then I looked at the octree in rview.  There are glowing discs where 
> the fixtures are, and the intensity of them changes accordingly when 
> you try different multipliers (-m) in ies2rad.  Problem is, the room 
> is totally dark.  A quick look at the scene files in objview reveals 
> everything to be in order, but when lit with my new lights, I got me 
> one black room. All points in the room are 0L, except for the 
> fixture's luminous aperture. The ies file is just your basic 
> run-of-the-mill Edison Price 6" downlight, fresh off the internet.  
> Ian Ashdown's IES file parser doesn't have any beefs with the file, 
> and indeed it looks fine upon visual inspection.
>
> What the heck am I missing?
>
>      Rob Guglielmetti