Why is one side of the window more bright when we use sky with a certain illuminance level?

Hi everyone,

I have measured field data with lux meter under an overcast sky with 11000 lux illuminance level. I modeled the building in Honeybee and HB+ and one side of the window is brighter than the other side (I am using sky with certain illuminance). It is interesting that in my field measurements, one side is also brighter (having higher lux level) but my question is, if the sun is affecting this type of sky (either in reality or simulation) then why isn’t rotating the geometry having an effect on results? and why is one side brighter?

It is noteworthy to mention that in reality 263 lux and 356 lux cube positions are reversed.

Thx in advance!

Try to use the medium or high option for Radiance parameters.

Hi, @mostapha thank you for your help; I am actually using the highest possible (as recommended by Radiance website). I even took a step further and set -ab to 12.

Try the visualize sky component to see the generated sky. It should look the same all over the place. We do not have the component to do that but you can render a fish-eye image for a view looking upwards (0, 0, 1)

Also it is not only about ab. It looks like you have some small geometries in front of the window. For a quick test. Try to set aa=0.001 and ab=4 and see how does that affect the results.

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Hi @mostapha, I ran it with the parameters that you said but the results are still the same. How can I visualize the sky component; I don’t know how to do that

Can you share your script?

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@mostapha here it is: It’s a bit messy though sorry! :smiley:
I am working with the lower one which is in Honeybee+ | the upper one is in legacy version
My_Room_Energy.3dm (373.8 KB) MyHome.gh (602.8 KB)