[Radiance-general] Questions about uniform sky

[Christopher Kings-Lynne]

> 1. Christopher, the theoretical factor between radiance and irradiance at a
> point in that case is pi, you only have to integrate a uniform radiance over
> a hemisphere to obtain it. Radiance can give some lite error due to the
> randomless of indirect calculation.

Ah, I think I've got it...

Execute "gensky 3 21 14:00 -a 51.3 -o 0.1 -m 0.0 -u" to see:

# Ground ambient level: 23.8

Now, take the 23.8 and multiply by 179PI:

horiz_illum = 23.8 * 179 * PI = 13383.813

Which is very close to my empirical values, so must be correct, right? :D

Thanks,

Chris