[Radiance-general] Re: Cumulative calculations of irradiance

[Rob Guglielmetti]

On Jun 9, 2008, at 1:57 AM, Iván Pajares Sánchez wrote:
>
> I have tried creating a let's call it 'accumulated' sky (rendering  
> multiple skies as a big cube, adding them with pcomb and then re- 
> rendering with them as a light probe). However as I'm trying to  
> include the direct component I generate the skies seperately  
> without sun and the the suns on another file to render. This is  
> leading to extraordinarily big numbers so I guess I have to, and  
> please correct my mathematical language if wrong, normalize the  
> numbers to get a manageable figure to work with, is this right?
>
> I know I might be repeating what F. Anselmo and R. Compagnon have  
> done with radmap and other scripts but I confess I enjoy learning  
> this things 'the hard way'...
>
> So, to sum up:
>
> Is it better to render the direct sun component on separate file to  
> get all the sun's dayli/montly or yearly positions and render with  
> all those direct sources plus the accumulated skies or to  
> accumulate the skies with the sun and render?

Francesco's radmap has worked well for us (that would be Zack &  
myself), creating a single annual sky file (or monthly, or seasonal,  
depending on how much TMY2 data you feed the script) that contains a  
single, summed hemispherical sky describing the total radiance for  
the period, plus all the suns . Your lightprobe idea sounds  
interesting, too.  I would like to update radmap to use gendaylit to  
create the sky descriptions for greater accuracy, but the current  
version works well for us for now.