HB Shade, plane without thickness or with thickness?

Hi all,

I was wondering if HB add shade components should be done using a planar surface without any thickness (where the thickness use construction material thickness, not from the geometry) or can I add thickness to the shading geometry?

It is for energy analysis (not radiance).

Some people said that I should only use a surface without thickness. But I thought energyplus and radiance allows a shading with whatever geometry we want with any thickness go the geometry?

If I am using only a surface without thickness (in 3d view) for a shading, it is a bit hard to see the result (since visually, different material thickness have the same planar surface).

I hope you can clarify

Thank you


As I know, HB shade only can set the annual transparency schedule, not set construction or materials. So if the thickness is less than 0.1m, you can use zero thickness HB shade.Meanwhite it can accelerate the simulation speed.

1 Like

Hm I use “create hb object” component from a brep and connect it to the shading in “hb room”
Weirdly the simulation works without error even though I am not using planar surface for that shading.

Hi @ricardo Honeybee can automaticly convert shade brep tp tri-mesh for energyplus simulation.

Wow this is new information for me. Do you think if they automatically convert brep to tri-mesh, we can do a 3d shading with thickness instead of just one surface?

May I know where I can find the resource saying that honeybee auto converts the brep shape? I think it is really important info for me to find out whether I can do geometry with thickness as shading.

Perhaps @chris can shed some light on this too

Thank you

Hi @ricardo ,

It sounds like there are two separate questions here:

  1. How does Honeybee convert non-planar Breps into planar geometries that can be sent to the simulation engines?

Without getting into too much detail, we generally do this using Rhino’s built-in meshing and curved subdivision methods. If the geometry is planar but with just a curved edge, we translate it to a single planar geometry in the simulation engines (just turning the curved edge into a polygon. Otherwise, if the shape has single or double curvature, we turn it into a bunch of quads or triangles using Rhino’s meshing and each quad/triangle becomes a separate geometry in the engine. More information on the exact RhinoCommon methods used van be found in the ladybug_rhino.planarize module.

  1. Do Shade geometries have thickness in EnergyPlus and should you explicitly plug thickened solid geometries for shades?

No, EnergyPlus Shade geometries do not have any thickness but this usually does not matter because the only thing that Shade does in EnergyPlus is block the sun. If you think that the thickness of the material is going to make a substantial difference on the amount of sun that your building and windows receive, then you can plug in explicitly thickened solid geometries for the shade. But most materials aren’t that thick to the point that this would have a meaningful impact on things like overall building energy use. So the answer is just “use your judgement.”

Hi @chris , thank you for clarifying.
May I ask if I understood it correctly:

So, it is still acceptable to use the top image for the shading geometry?

It might or might not affect the sun significantly compared to the non-thickened one. I am going to test it if it does for my case. But I just want to make sure that the thickened solid geometry can also be done. For example, if you said “thickened solid geometry will mess up the energy plus simulation”, then I would not do that.

For example, if the shading is thick like this

For me, it is easier to visualise the thickened solid geometry in rhino compared to converting all shading that I have in rhino models to a single planar surface

Thank you


You can definitely use the thickened geometry if you want. It’s not going to mess up your simulation results or anything. It will just possibly make your simulation take longer. So you may not want to include it if the thickness isn’t going to impact the sun falling on your windows.

1 Like

Thank you, Chris
Really appreciate it