Daylight factor recipe

hi there,

First time user here, so this question may be pretty basic. When I run the daylight factor recipe by itself, there’s no button to upload a weather file (EPW). Isn’t an EPW file needed for daylighting recipes? I swore it was shown in the tutorial video, but maybe I’m confused.

Also, is true North within Rhino considered 0 or 90? (the Pollination default is set to 0 but Rhino’s sun settings show north as 90)

Last thing, a bit unrelated: is there a way to set the properties for all the apertures at once, instead of one-by-one?

Thanks for the help!! This plugin is really amazing… thank you to the Pollination team for all your efforts in creating this.

Hi @martin8smith! Welcome to the Pollination community. :wave:

Daylight factor is not a climate-based metric and the results don’t depend on the location of the building or orientation of the window. Under the hood it uses an overcast sky which will be the same for any location or orientation.

If you are interested you can study the recipe on Pollination. You’ll see that there is a step for generating the sky but it doesn’t take any inputs for location.


In Pollination world which uses Ladybug Tools under the hood the north is set to +Y vector (0, 1, 0).

You should create a new topic for this with more information. Which CAD plugins are you using for your work? Is it Rhino, Grasshopper or Revit? The answer will be different for each CAD plugin.

Thank you for the kind words! And welcome to the forum. :slightly_smiling_face:

Thanks for the detailed response Mostapha! I guess I need to read up on the daylight factor metric and how it works.