Hi everyone
I am trying to calculate the depth of shadings for each hour of the year to achieve 300 to 500 lux illuminance. The problem i have encountered is that each time i run the daylight analysis for the same situation (same time, percentage of window and depth and number of shadings), it gives a different level of light with a huge difference (more than 100 lux). i have attached the file and two pictures from the same situation and time.
Any help would be greatly appreciated!
Zahraa
Recovered model - final-shading (394100) RhinoAutosave.gh (643.0 KB)
@zahraa.foroughi I downloaded and opened your grasshooper definition. I found the geometry missed. So I can not debug it. Please upload it.

@zahraa.foroughi After ran you model, I eccounted same quesiton.I tried to use small grid size and large ab value. But the result is still different. It is so wizard.
I am wondering if this problem is about grasshopper or it might work better on another computer.
@zahraa.foroughi I re-checked your model and found the question. You should connect teshMesh for calculation.
It still has about 150 lux difference in results. 
@zahraa.foroughi You can use smaller grid size and higher ab value to achieve higher resolution.
The result for grid size =0.5m, ab =4:
It became much better now! thank you very much! 
unfortunately it still has 112 lux difference with higher ab value and smaller grid size. Do you have any other idea?