Large differences between radiation analysis in LB 1.3 and LB 0.0.68

[chris]

The LBT one is more accurate and it’s primarily because it includes the contribution of ground-reflected radiation using an emissive “ground hemisphere”. See here for a longer explanation:

Difference Between "LB Incident Radiation" and "Ladybug Solar Radiation" Components

Good question and this is directly linked to what I said here: In LBT, we do the ray tracing for a full sphere around each point so that we can account for the radiation that’s “reflected” off the ground (technically, we’re doing this by assuming an emissive ground hemisphere that has 0.2 the intensity of the sky hemisphere, much in the same way Radiance does). In legacy, we only looked at the radiation coming from the sky dome, which was ok for some purposes but could be 20% less than expect…