Is there any way to add an electronic light source to LBT1.4.0?

Hello community,
I know this is probably the only difference from Legacy in HB Radiance, but I would like to know if there are any special ways to load electronic light sources in the current LBT1.4.0 development release. I found the relevant solution here, but when I open it it says the problem is closed.plug Radiance Model folders into the LBT Honeybee Radiance recipes
I’ve already found the multidirectional sensor in the development version, and it’s awesome! It helps me calculate half cylinder illuminance very quickly (although I’ve had a lot of hands-on experience with Legacy versions, I have to say that almost all of my workflows are now based on LBT), but unfortunately I can’t incorporate this workflow into the LBT version right now. To do this I had to create a new virtual machine and spend a lot of time rebuilding the operating environment.
I was hoping for an answer that would allow me to avoid returning to the complexities of the past.
Thank you so much to anyone who can help me or say, "This isn’t working yet.


Hey @ZhengrongTao ,

Sorry for the late response and you clearly did your homework with searching previous forum posts and testing the latest LBT plugin version. You are right that we have added the ability to plug Radiance folders into all of the Radiance recipes. You can see a sample over here on the pollination forum about how to take advantage of this new capability to run large Radiance models:

However, I should have realized when I made that older comment that this support for Radiance folders doesn’t quite enable to you run simulations with electric lights yet. I still have to make some tweaks to the recipes themselves in order to make sure the electric lights are included. So I’m sorry to say that there still isn’t support in any of the recipes for running simulations with electric lights.

Am I correct that the main recipe that you need support for electric light is the Point-In-Time Grid-Based? If so, I might be able to make the necessary tweaks to this recipe with just a little effort. You might still need to use this radiance folder pathway but at least it could work without needing to use Legacy.

Thanks Chris
What I want to say to you is: it’s not too late! Because I can already see the dawn.

Yes, Point-In-Time Grid-Based can solve the problems related to lamps encountered In most of my projects .In my experience with Lecacy, it’s already pretty good.
This example is so interesting that I will take a moment to study it and then share it with some of my students who need the answer to make something that looks great right now!
Thank you very much for your work and reply!


I just wanted to say that I was able to include lights from IES files in a LBT Radiance simulation but it involves a huge amount of manual work such that I really don’t think that it’s worth it to leave Legacy for this right now. I really just need to sit down for a couple of days and write out a couple of classes and components to automate this. I don’t think I’ll get the opportunity to do so for another week or two so I would recommend sticking to Legacy if you really need this right now.

However, if you are feeling particularly motivated, here is the very manual workflow that I used to include IES files in the LBT simulation:

  1. Use the “HB Model To Rad Folder” component to write out a Radiance folder of a Honeybee model.
  2. Use the Legacy IES components to convert the IES file into appropriate Radiance files and copy them into the scene folder of the Radiance Model folder.
  3. Open all 3 of the Radiance files generated by the Legacy components in a text editor and change all file paths in the files to be relative to the root of the model folder.
  4. Plug the Radiance folder into the recipe.

I will post back here if I manage to get parts of this automated. The toughest part of the manual workflow right now is generating the Radiance files from the IES file and editing the file paths to be relative to the root of the model folder so I’ll see if I can tackle that first in a week or so.