Hi Marc,
Thank you for the suggestion. What I was aiming to do was model the light environment of an agricultural building (we’ve collected a spatial grid of light intensity data) that incorporates natural light as well as electric light.
I see how the suggested topic would be useful in studying the luminaries
themselves, however, it might not be what I’m looking for.
What I have ended up doing is creating the environment in grasshopper, modeling the natural light portion of the light environment, exporting the geometry to .rad files. Then creating a light.rad file that contains the luminaries and their locations for use with the base Radiance package. I then use Radiance to model only the electric component of the light environment. I then take the light intensity values that are produced and add them to the location specific light intensity values created from grasshopper. This gives me a pretty good result when comparing the predicted values to the values we observed in the building.
Please advise if there is anything wrong with the logic behind adding the two light environments light values to get the combined behavior of the light components. I believe that light is purely additive, so the steps I’ve described make sense to me. Thanks again for the suggestion Marc!
Hi Joshua,
That sounds correct
If you’d want to stay within Grasshopper entirely without having to use Radiance directly, you could use the method linked above, and instead of a dark sky, model the sky of your choice.
Kind regards,
Marc
Your working assumption is correct (enough!). Standard Radiance does not have the level of granularity to handle spectral additions of wavelength bands.
If you are processing results outside of Grasshopper you can run the Electric Lighting calculation once and reuse those results as the only transient variable is daylight.
how exactly are you doing the electric lighting calculation ?
im currently trying to prove how sunlight can be beneficial in a big building not only light wise.
So having comparable and intercalculateable values to visualize the outcome would be great!
In the future im also planning to use it for agriculture/greenhouse calculations.
Would be curious to see how its being done!
Can I assume that the LBT Tools release of the version after 1.9 will not be until July 2026, given the last release was July 2025?
I ask because our major teaching trimesters are March - June and July to October. Our tech staff are building our in-house computer images and we need to be sure what version is to be installed for Trimester 1 in the next couple of weeks.
