Discrepancy between HB sDA and LB Mesh Threshold Selector


I’m conducting a Daylight Autonomy simulation with HB-Radiance 1.6.0. I used both HB sDA and LB Mesh Threshold Selector to derive the percentage of area compliance but found that they produce very different result.

For the analysis plane with most of the area reaching about 100% target time, sDA regarded only 42% as compliant whereas the Threshold Selector showed 96% as compliant. Did I use the sDA component incorrectly or is it bugged?

Hi @Felicity,

Can you try to flatten the input meshes in the sDA component as shown below?


I get the same sDA when using the sDA component compared to the Ladybug Mesh Threshold Selector Component, then flatten. However, it seems if you run it through Daylight Metrics Component and use the same OCC sch and threshold the results change.