[Radiance-general] Re: Illum rules of thumb

[Rob Guglielmetti]

Mark de la Fuente wrote:
> Lars,
>  
> I wish I could attach images, as perhaps there is another way to do 
> this.  But the reason for the exterior illums is that the interior 
> architecture follows the windows, forcing me to use triangular illums at 
> some point if I am to seal each opening.  (window panes are not 
> rectangular either)  Or each opening can be sealed from the outside.

Hi Mark,

Yeah, triangular polygons are not a good fit with mkillum, because of 
the way source sampling works.  The triangular polygons are usually the 
source of the "aiming failure" errors seen when running mkillum.   The 
best explanation is of course in the Rendering with Radiance text.  Do 
you have a copy?  If so, this problem is addressed on pg 577.

Your building seems a challenge for mkillum.  Are you trying to create 
pretty pictures, or get some illuminance data at points?  If the former, 
it may still be worth the effort to try and seal your opening -- from 
the inside -- with a combination of polygons less likely to generate 
failures.  If the latter, it's probably best to simply crank up the 
ambient calculation parameters, and wait it out.  (This method could 
also be used for pretty picture generation, but now you're talking about 
*really* waiting...

----

      Rob Guglielmetti

e. rpg at rumblestrip.org
w. www.rumblestrip.org