HB Custom ModifierSet for room_How to assign radiance modifier for both Interior Face and Exterior Face of an Elements?!

Hi @chris , @mostapha
I am running an Annual Daylight study for a Honeybee model of a single room in my project.
I have an issue about face attributes. When I have a single HB room, all the faces (wall, aperture,roof,floor) are considered as “Outdoor” Boundry Condition. So I should use " HB Exterior Modifier Subset" componant to define reflection for walls, Glazings, floor and Roof. But Could you tell me if this value that I set, is for interior face of wall or exterior face or both? and if there is a way to distinguish radiance modifier of 2 sides of an element?

Thanks for your consideration.

Hi @FatemehMohseni ,

This is a good question. I’ll start with this part:

It is “both” since there’s no easy way to specify modifiers for different sides of the same planar geometry object in Radiance. We have plans to implement some methods that automate the creation of interior and exterior geometry objects from room-based models so that you effectively have two different modifiers on different sides of the same starting geometry. But, for now, you should assume that each Honeybee geometry is getting only one modifier for both sides.

This means that the distinguishing between exterior vs. interior subsets only relates to the Boundary Condition that is assigned to a given Honeybee Face. Honeybee Faces and Apertures with an Outdoors boundary condition get the modifiers of the exterior subset. Those with Surface or Adiabatic boundary conditions get the modifiers of the interior subset.

So you’ll likely want to use different ModifierSets depending on whether your SensorGrids are on the interior or the exterior of your Rooms. If they’re on the interior of your Rooms, you should set the modifier of the exterior_wall to be that of the interior side of your exterior walls. If your sensor grids are on the outside of your Rooms, the modifier of the exterior_wall should be that of the exterior side of the exterior wall.

I hope that helps and feel free to :+1: on that GitHub issue if you think you might make regular use of that automated method.


Hi @chris
Thank you very much for your consideration and great explanation. It is clear now. and it was a big help.

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