Honeybee EP context shading surface -

Hi all,

I’m trying to model various types of shading surfaces infront of a glazed facade, making use of the EP context surface component in Honeybee. However, it seems as though when the shading surface has a irregular boundary (?), that the EP simulation engine is not able to read the geometry from the EP Context Surfaces correctly.

In the attached file (see red groups in th .gh file), there are 2 hypothetical shading surfaces, both planar. Shading geometry 1 is part of what I want to model and shading geomtery 2 is just a random shape to compare the ouputs. Geometry 2 works but Geometry 1 doesn’t, and gives an “severe error” due to non-planar shading surfaces. Is there a limit as to how many surfaces the HBContext_ input in EP simulation can handle? Or is there any other known explanation for the EP engine reading a planar surface as non-planar?

Kind regards,


20160104_IndoorComfort_Baked_Point0_simplified.gh (653 KB)


The geometry in the “planar shading surface” red gropu is faulty. I get “Null Brep” when i open it.

The shading geometry 2 is empty.

Can you check this?


Hey Abraham,

Sorry for that! Here is an updated .gh file, should work. Added the .3dm just incase.


20160104_IndoorComfort_Baked_Point0_simplified.gh (653 KB)
Geometry_simplified.3dm (187 KB)


I also got a null brep in your new files. I think you get a “null brep” because it is not included in your Rhino file. I tired to infer what you meant from your description and the context surface is written into the IDF correctly:

Hope this helps and, if we are far from understanding your error, please give us more information.


20160104_IndoorComfort_Baked_Point0_simplified CWM.gh (571 KB)

I also tested a couple of single and double curvature surfaces and it works fine.

Amanda, Can you send the exact error message? I wonder if there is a different issue with your file. There is limitation for maximum number of shading surfaces in EnergyPlus which you can set using shadowPar > energySimPar.

Hey Chris and Mostapha,

Thanks for taking a look at this! I attached an image of the error message. I noticed that the version which gives me the error is VER 0.0.58 NOV_7_2015, whilst the one Chris uses is NOV_20_2015. The difference seems to be the way the EPContext component interprets the surface. The newer version doesn’t seem to triangulate. Great news! Thanks again!