[Radiance-general] Sky illumination vs. mkillum

[John Mardaljevic]

Chris,

> I am trying to visualise the DIRECT sky factor on the floor of a room
> before and after a new building is put in.  The green area is the area
> that is above 0.2% sky factor before the building and the red area is
> the area that is above 0.2% sky factor after the new building is put 
> in.

This looks like a Rights to Light study, yes?  In any case, for the 
direct sky
factor, whack up ad to whatever gives you a converged value - try a few
in steps of two starting -ad 1024.  Turn interpolation off (-aa 0) and, 
of course,
use -ab 1.  If it's RTL, then a uniform sky is used rather than the CIE 
ovc and
I seem to recall that the window is an aperture without any glazing.

I really wouldn't bother with a source window for something like this.

If the grid was orthogonal, I'd be tempted to supply a grid of points to
rtrace and process the results in my preferred crunching/display 
software.

-John

-----------------------------------------------
Dr. John Mardaljevic
Senior Research Fellow
Institute of Energy and Sustainable Development
De Montfort University
The Gateway
Leicester
LE1 9BH, UK
+44 (0) 116 257 7972
+44 (0) 116 257 7981 (fax)

jm at dmu.ac.uk
http://www.iesd.dmu.ac.uk/~jm