The difference between genCumulativeSkyMtx and genCumSky


I am having trouble understanding the difference between the engines behind these two components.

The logic behind genCumSky is laid out here

http://www.radiance-online.org/learning/documentation/manual-pages/…

While there is very little documentation on genCumulativeSkyMtx I did manage to find this, http://alexandria.tue.nl/openaccess/635611/p1153final.pdf.

I understand that they are both calculating the cumulative solar irradiation over the year and that they are both doing this by producing Radiance scenes however I can’t fathom the difference between the two.

Mostapha in your mind what is the difference between the two? Why did you use gendaymtx for the ladybug solar analysis but genCumSky for the Honeybee irradiance studies?

Is it possible to use gendaymtx for interior irradiance studies (with windows)? I assume that you can since it is actually producing a Radiance scene.

Thank you for any insights!

Hi Anton. I can’t see the image but I think I know which two components are you talking about.

Mostapha in your mind what is the difference between the two? Why did you use gendaymtx for the ladybug solar analysis but genCumSky for the Honeybee irradiance studies?

Gendaymtx is a newer development and is part of radiance. GenCumSky is developed for Daysim and is older. We will remove genCumSky eventually and will use gendaymtx for both ladybug and honeybee.

Is it possible to use gendaymtx for interior irradiance studies (with windows)? I assume that you can since it is actually producing a Radiance scene.

Yes. You can use both of them to generate the sky for radiance’s scene. Using gendaymtx needs a little bit more work. Check Andy’s presentation Page 62 for 2-phase example.