Use Honeybee Gen Custom Sky component as a direct radiation source

Hi all,

I would like to conduct a radiation study using Honeybee for a given solar position and given direct / diffuse radiation values.

I am currently using the GenCustomSky Honeybee component (see file below).

I am having trouble figuring out how to use the generated sky file as a direct radiation source in a Honeybee radiation study.

Here is the gh file.

I would like to use this (below) sky to determine the radiation that falls on an input geometry.

Thank you for the help!


If it is only for a single point of time, you should create a custom sky:…


I did use that component. (See image and .gh file above). But I am unable to figure out how to use the skyFilePath that it outputs. I was hoping to use it directly with Ladybug radiation analysis but that does not seem to be the case. How can I actually use that skyPathFile in a radiation study? What other components are needed?

Thank you for the reply!

You have to use honeybee grid-based recipe. (498 KB)

Mostapha, sorry for the delayed response. This is incredibly helpful, thank you very much for putting this together. I just tested it, and all works well!


I was playing around with this a bit, and noticed that the bottom face (even when clearly not exposed to the sun) still receives radiation according to the study.

The normals of the faces are all correct, so that isn’t the issue. I was wondering if maybe the simulation assumes a default material? Perhaps radiation is being transmitted?

How can I avoid these skewed results?

Thank you,


Add a ground geometry to the scene.

Ok, I was doing that but my problem was my ground was on the same plane as my bottom face and not below the offset. Thank you.

Also in order to not consider reflections I set changed all the RAD Materials to be 0 reflecting mirrors using the radMirrorMaterial and setRADMaterials components. I did this so I can neglect all reflections in this study. Heres my results below:

What you see in this picture is a large floor, and an inclined cube with a shielding cap on it. All surfaces are supposed to be non reflecting. I get 0 W/m^2 on the top and bottom faces (as expected) However, I get ~2 W/m^2 just above the red patch (expected to be 0) and also ~20 W/m^2 on the two sides opposite of the red patches (expected to be 0). Any ideas what is causing this? There must be some sort of reflection going on - perhaps it is the sky model that is generated? Even though I specified 0 diffuse radiation, maybe reflections from the sun are occuring? This is ok if it is the case, but I would like to read about the sky model being used so I know what assumptions are being made. Thank you Mostapha. This is truly an amazing tool you are developing!