[Radiance-general] Specular Reflections with the Daylight Coefficient Method

[Greg Ward]

Hi Rob,

Genskyvec always picks the three closest patches, regardless of the  
sky resolution.  It would be difficult to use a sky resolution high  
enough that one patch would be the better choice.  I only mentioned  
the 1-4 range because that's what people have done, not as a  
recommendation per se.

The important thing is to distribute energy according to which patches  
are closest, so if the sun really is in the middle of a particular  
patch, very little energy would be given to neighboring patches.  That  
"very little" should probably be zero in some cases, but I don't think  
it ever quite is in genskyvec with the weighting function I use.

-Greg

> From: "Guglielmetti, Robert" <Robert.Guglielmetti at nrel.gov>
> Date: June 2, 2010 7:37:00 AM PDT
>
> Greg, all:
>
> So what is the protocol for determining the number of patches the  
> sun's energy is distributed across? In Axel Jacob's (excellent)  
> tutorial on rtcontrib three patches are used to represent the sun  
> regardless of whether the Tregenza or the finer Reinhart patch  
> density/distributions are used, but you mention one to four patches  
> being used, Greg. How or when would this number change? Does  
> genskyvec actually make a choice?
>
> - Rob