[Radiance-general] clear sky-calculated indoor illuminance is too lower than that of cloudy sky???

[Thomas Bleicher]

On 15 Jul 2008, at 09:03, ZZ wrote:
> I'm trying to use ESP-r coupling Radiance to perform thermal  
> integrating
> daylight use simulation.


> That1 day is a very clear sky because that day has a highest
> direct and diffuse radiation of those 7days, but the simulated  
> illuminance
> with radiance is
> much lower than other six days. Anybody can tell why? and how to  
> modifiy?

How does ESP-r model the sky and how did you create the sky
for your Radiance scene? A clear sky has a different distribution
than an overcast sky and this could influence the illuminance
in your scene, especially if you're parameters for the ambient
calculation are too low (-ab option as mentioned by Lars).

Thomas