How to simulate a lamp with IES data in Honeybee 1.9.15 (no IES Luminaire component?)

Hi everyone!

I am an absolute beginner with Ladybug Tools for Grasshopper and as my first exercise I wanted to simulate the effect a light-emitting bulb has on the surrounding walls/surfaces - in a closed interior space - and measure how the pattern I designed for my lamp (surrounding the bulb) affects the environmental perception of the room.
I saw some tutorials in which - at least the lighting setup - was achieved by using HB IES Luminaries (I am using the Version 1.9.15 and this component is not present anymore) but I can’t think of any Workaround (better said: I have no clue).
Any hints, examples, rough workflows would be extremely appreciated.
Thanks and have a good one! :slight_smile:

It is doable with the new components also, but you are better off just working with the legacy ones if all that you intend to study is lighting from the luminaires.

2025-10-30 12_57_37-Grasshopper - viewbased_
2025-10-30 12_55_19-Grasshopper - viewbased_

You can choose an illuminance based sky and set the value of illuminance to 0 to create darkness. Then you need to bring in the light fixture definition and any other shapes into the radiance folder. I wrote a script to do that (which is the Python component in the screenshot below: customLBToolsIAddIESComponent.py · GitHub).

The example file I modified to do this was lbt-grasshopper-samples/samples/honeybee-radiance/viewbased.gh at master · ladybug-tools/lbt-grasshopper-samples · GitHub . I forgot to save my modified gh file, or else I would have put that in here too :neutral_face:

5 Likes