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Hi,

My question relates to the relationship in Radiance between sky conditions and irradiance. I understand that the packages Gendaymtx,Gendaylit and GenCumulativeSky generate a Radiance scene with sky conditions and they also use both direct and diffuse irradiance data from epw files.

What I don't understand is the relationship between the sky conditions (the R,G,B) values of the sky scene the irradiance data and how irradiance in W/Sr/m2 is calculated for each patch of the sky.

For example the default sky color of Gendaymtx according to the documentation - http://www.radiance-online.org/learning/documentation/manual-pages/pdfs/gendaymtx.pdf is:

0.960 1.004 1.118

So what is the relationship between the sky color above and the epw irradiance values how are they combined to calculate the irradiance or luminance falling on a surface?

Perhaps I am just missing something but the radiance documentation is very sparse on this particularly GenCumulativeSky. Any insights would be greatly appreciated I am trying my best to understand the code behind Radiance. Thank you!

Hi,

My question relates to the relationship in Radiance between sky conditions and irradiance. I understand that the packages Gendaymtx,Gendaylit and GenCumulativeSky generate a Radiance scene with sky conditions and they also use both direct and diffuse irradiance data from epw files.

What I don't understand is the relationship between the sky conditions (the R,G,B) values of the sky scene the irradiance data and how irradiance in W/Sr/m2 is calculated for each patch of the sky.

For example the default sky color of Gendaymtx according to the documentation - http://www.radiance-online.org/learning/documentation/manual-pages/pdfs/gendaymtx.pdf is:

0.960 1.004 1.118

So what is the relationship between the sky color above and the epw irradiance values how are they combined to calculate the irradiance or luminance falling on a surface?

Perhaps I am just missing something but the radiance documentation is very sparse on this particularly GenCumulativeSky. Any insights would be greatly appreciated I am trying my best to understand the code behind Radiance. Thank you!

Hi,

My question relates to the relationship in Radiance between sky conditions and irradiance. I understand that the packages Gendaymtx,Gendaylit and GenCumulativeSky generate a Radiance scene with sky conditions and they also use both direct and diffuse irradiance data from epw files.

What I don't understand is the relationship between the sky conditions (the R,G,B) values of the sky scene the irradiance data and how irradiance in W/Sr/m2 is calculated for each patch of the sky.

For example the default sky color of Gendaymtx according to the documentation - http://www.radiance-online.org/learning/documentation/manual-pages/pdfs/gendaymtx.pdf is:

0.960 1.004 1.118

So what is the relationship between the sky color above and the epw irradiance values how are they combined to calculate the irradiance or luminance falling on a surface?

Perhaps I am just missing something but the radiance documentation is very sparse on this particularly GenCumulativeSky. Any insights would be greatly appreciated I am trying my best to understand the code behind Radiance. Thank you!

Hi,

My question relates to the relationship in Radiance between sky conditions and irradiance. I understand that the packages Gendaymtx,Gendaylit and GenCumulativeSky generate a Radiance scene with sky conditions and they also use both direct and diffuse irradiance data from epw files.

What I don't understand is the relationship between the sky conditions (the R,G,B) values of the sky scene the irradiance data and how irradiance in W/Sr/m2 is calculated for each patch of the sky.

For example the default sky color of Gendaymtx according to the documentation - http://www.radiance-online.org/learning/documentation/manual-pages/pdfs/gendaymtx.pdf is:

0.960 1.004 1.118

So what is the relationship between the sky color above and the epw irradiance values how are they combined to calculate the irradiance or luminance falling on a surface?

Perhaps I am just missing something but the radiance documentation is very sparse on this particularly GenCumulativeSky. Any insights would be greatly appreciated I am trying my best to understand the code behind Radiance. Thank you!

Hi,

My question relates to the relationship in Radiance between sky conditions and irradiance. I understand that the packages Gendaymtx,Gendaylit and GenCumulativeSky generate a Radiance scene with sky conditions and they also use both direct and diffuse irradiance data from epw files.

What I don't understand is the relationship between the sky conditions (the R,G,B) values of the sky scene the irradiance data and how irradiance in W/Sr/m2 is calculated for each patch of the sky.

For example the default sky color of Gendaymtx according to the documentation - http://www.radiance-online.org/learning/documentation/manual-pages/pdfs/gendaymtx.pdf is:

0.960 1.004 1.118

So what is the relationship between the sky color above and the epw irradiance values how are they combined to calculate the irradiance or luminance falling on a surface?

Perhaps I am just missing something but the radiance documentation is very sparse on this particularly GenCumulativeSky. Any insights would be greatly appreciated I am trying my best to understand the code behind Radiance. Thank you!