[Radiance-general] Can't get gensky to work without sun...

[Guglielmetti, Robert]

Hi George,

The "no light sources found" error is because there is no sun in your sky
model. The celestial hemisphere's sky glow is indeed just that, it's
modeled as a "glow" source in Radiance. Glows are only picked up in the
ambient calculation, so you need to have -ab set to at least 1. You have
-ab 5, so you should be good. As the message states, it's not an error,
merely a warning. You're good.

 
Rob Guglielmetti  IESNA, LEED AP
Commercial Buildings Research Group
National Renewable Energy Laboratory
1617 Cole Blvd MS:RSF202
Golden, CO 80401
T. 303.275.4319
F. 303.630.2055
E. robert.guglielmetti at nrel.gov





On 7/27/11 6:32 AM, "P George Lovell" <p.g.lovell at st-andrews.ac.uk> wrote:

>Hi Everyone,
>
>I'm trying to render some images for a perceptual experiment. When I
>render with a sunlit sky (+s) I have no problems, but the variations in
>illumination are too great - I need more uniformity. But when I change
>the options to no sun (i.e. overcast "-c", or sunny without sun "-s") I
>get an error from rpict:
>
>rpict: warning - no light sources found.
>
>Some key parameters:-
>
>gensky 01 01 13 +s -a 56.3400 -o  0 -m 0.00 -B 27.93 <-- substitute "+s"
>with "-c" or "-s"
>skyfunc glow skyglow 0 0 4 1 1 1 0
>skyglow source sky   0 0 4 0 0 1 180
>
>rpict" -vf j:\radiancefiles\27_07_2011_13_10_893074_#0\view.vf  -x 1800
>-y 1800 -vh 15.30 -vv 15.30 -st 0.01 -ar 512 -aa 0.10 -ab 5 -lw 0.01000
>-lr -10 j:\radiancefiles\27_07_2011_13_10_893074_#0\wholeScene.oct >
>j:\radiancefiles\27_07_2011_13_10_893074_#0\wholeScene.rpict
>
>This is all running on mingw radiance on a windows PC. Anyone have any
>suggestions?
>
>Thanks,
>
>George
>
>
>-- 
>Department of Psychology, University of St Andrews
>
>     RM 1.05 (The white room).
>     Phone      (01334) 462090
>
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