Differences in shade maps from SOLWEIG and Shadow Generator

[land333land]

I found in UMEP that both models can output shade maps, my question is whether the principle of outputting shade maps is the same for both models?

[biglimp]

They work the same but one important difference is that the ShadowGenerator calculates sun position at the actual time step given whereas SOLWEIG relates sun position in-between time steps as given in the meteorological forcing data.

[land333land]

Thank you! I have another question about the output from the Shadow Generator. The shading results typically include three values: 0, 0.03（when using the default transmissivity, and 1. These values correspond to the shading from buildings, vegetation, and areas with no shade, respectively, correct?

[biglimp]

yes

[land333land]

My further question is how does the model handle locations that may be shaded by both buildings and trees providing shade. Does the output result in shade from the building (0) or from the vegetation (0.03) at that location? In other words how does the model handle the overlap of shade provided by buildings and trees? This is confusing me.

[biglimp]

0 as building has zero transmission.