CIE Overcast Sky Type 1 or Type 16 for the Daylight Factor recipe into LBT

LaFleur · January 5, 2021, 3:03pm

Hallo dear @chris,

I’m sorry if I disturb you, but I kindly need one information, that I can’t extrapolate.

I would need to document and also find out wich “Overcast sky” is used in the Daylight Factor recipe in the new LBT.

Is used the formula of the CIE Standard Overcast Sky (Type 1) or the Traditional CIE Overcast Sky (Type 16)?

Into the Radiance Gensky Sky https://www.radiance-online.org//learning/documentation/manual-pages/pdfs/gensky.pdf, the Cloudy sky correspond to the standard CIE overcast day.
Is the same used for the HB_DaylightFactor component(LBT 1.1.0) or is different (for example) from the cloudy sky that I can find in the CIESky component?

Thanks in advance

mostapha · January 7, 2021, 4:06pm

Here is the command that we use to generate the sky for Daylight factor simulation:

github.com

ladybug-tools/honeybee-radiance-recipe/blob/193bd3f1bb008a3d81a8d5ac7fc8540041ec202a/honeybee_radiance_recipe/daylight_factor/daylight_factor_flow/main.py#L395


@property
def initiation_folder(self):
    return self._input_params['simulation_folder'].replace('\\', '/')
@property
def params_folder(self):
    return os.path.join(self.execution_folder, self._input_params['params_folder']).replace('\\', '/')
def command(self):
    return 'honeybee-radiance sky illuminance 100000'
def output(self):
    return {
        'sky': luigi.LocalTarget(
            os.path.join(self.execution_folder, 'resources/100000_lux.sky')
        )
    }
@property
def output_artifacts(self):

It translates to !gensky -ang 45 0 -c -B 558.659218 -g 0.200. Here is the sky definition:

!gensky -ang 45 0 -c -B 558.659218 -g 0.200

skyfunc glow sky_glow
0
0
4 1.000 1.000 1.000 0
sky_glow source sky
0
0
4 0 0 1 180

skyfunc glow ground_glow
0
0
4 1.000 1.000 1.000 0
ground_glow source ground
0
0
4 0 0 -1 180

Tokarzewski · July 20, 2022, 8:42am

−c Cloudy sky. The sky distribution will correspond to a standard CIE overcast day.