[Radiance-general] subtended sun angle in gensky and gendaylit

[pisuke at blueyonder.co.uk]

Hi Jan

> So I assume you changed the value in the source code, or? But as long as
> you are not adapting the radiance value of the light source (which you
> don't do), you'll loose more than 10% of the flux of the sun by reducing
> the value from 0.533 to 0.5 !!

I've just noticed that the cygwin and mingw versions of gendaylit
produce different outputs. I think that I might have used a different
and older source package when I compiled the first cygwin version,
which also doesn't include the -G option.
At least I've understood that I didn't change the gendaylit code :P

I also agree with John about the weather data measurement accuracy,
and usually totally discard the direct normal solar component if lower
than 120 W/m2, as recommended by the WMO. I think S at tel-Light uses
a similar threshold to decide whether there is direct sun or not.

Ciao,

Francesco