Is it possible to simulate luminance level for a certain hour?

Hi All,

I am trying to run a design optimization that is centered on luminance level of a certain hour in a year. I know I can run the annual simulation through Radiance and use Honeybee Read Hourly Results to load hourly data, but since I have more than 80,000 design options to run through this might take too long. Would it be possible just to get data of a certain hour without running the annual simulation?

Or, if Ladybug radiation analysis doesn’t consider reflection, is there some open academic source that can help me understand how reflection works and how to add up the values? I have done works mapping where bouncing light would reach in a room with a grid system out of Grasshopper and VB before, but I don’t know how it works in terms of energy.

Thank you!


It sounds like you want to run just a standard grid-based analysis rather than an annual daylight simulation. See an example file of this here:…;

You may also want to substitute the “Climate-Based Sky” component for a “CIE Sky” component depending on whether you want the cloud conditions for the hour to be dictated by the weather file or to be manually set by yourself.


Hi Chris,

Thank you very much for your fast reply! It works and I am waiting for my 1 week long optimization to stop.