Percentage of Visible Sky

I am just wondering if there is a way to do daylight condition analysis using Waldram Diagram.

I have checked the old forum regarding this topic, and the post is as follows:

Can anyone suggest an example file to calculate the percentage of sky exposure that a building’s profile allows through to the street below? What is the methodology behind to create a projection of the building on a graph?

Thank you in advance.



Hi @johnchun,
Are you looking for something other than Mostapha provided in the example file in the Grasshopper thread you posted? I see a GH file that Mostapha provided in the thread.

Thanks for the reply.

I have checked Mostapha’s definition showing Waldram diagram, which looks promising. But, how can we calculate/read the percentage of sky exposure from the graph in the output?

Maybe I am lack of understanding this graph. Any explanation is really appreciated.



Does this help?

Shading (411.9 KB)


This would be another way to get the percentage of sky visible from a geometry. (401.7 KB)

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For future reference the definition is also posted here: Cartesian solar path Waldram Diagram

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Great. Thank you very much.

For those visiting this post in the future, there will always be up-to-date example files of the sky mask here:,0

And of the sky view study here:,0