Error on the Run Daylight Simulation component for the sky view workflow

Dear Chris,

I got the following error using your sky view workflow on Hydya by replacing the geometry with mine:…


1. Solution exception:Value cannot be null.
Parameter name: source

Appreciate if you can kindly help to take a look when you have time! (511 KB)


Your file is practically working for me. In any case i updated it to last GH version. Probably the reason it wasn’t working is becouse the hydra file used “old” components and your version installed is newer … and probably (#2) you had other files opened …

In any case the hydra file is not correct in its description and goal. The file is not giving you SVF (as you want) but VSC (vertical sky component). For more info on this see this discussion.

For SVF Chris re-wrote the LB_viewAnalysis component.


And now the file … (527 KB)

Hi Abraham, thanks for your clarification!

However, using the updated GH file, I still got the same error, and I’m not sure what is causing this …

Appreciate if you can kindly advise!

I also tried the viewAnalysis component you suggested, and it seems that the sky view on unobstructed vertical surface is larger than 50% even if I increase the simulation resolution up to 4 (50.98%). Does this mean that this component tents to over-estimate sky view for points on vertical surfaces? (538 KB)

Well … well … well …

First of all, i can’t recreate your error. At first i thought that maybe it is related to RHino tolerance. Changed mine to different options but nothing. Try also changing it at your end and recalculating the GH.

Saying that, then i started to test the HB_ViewAnalysis and found some bugs that i will report on the github. Increasing the resolution gives weird/crazy results (for instance, 100 on vertical surfaces). Something is going on there that i can’t catch fully.

Please look at this issue in github.


Thanks, Abraham!

I really don’t know why this single geometry is causing problem because I have several other geometries which are fine with the workflow. Mayby I’ll try to re-model it.

As the to strange value display, I found that the flatten the inputs to the Tag 3D component can help to correct the error, see below. Please kindly verify.

Nevertheless, waiting for the this component to be debugged…



In the simple cube example i linked in the github flattening “solves” some but not all. It is still unclear for me. I “ffel” there is a problem but can’t point exactly where.

Let’s wait for the debug, if needed, as you said.


Hi Grasshope,

The issue is solved now. See the github link above for Chris’s explanation.

It turned to be a set of bugs, one of them severe.

Attached an updated version of your file.

-A. (540 KB)

Abraham and Grasshope,

Thank you, as always for getting to the heart of these bugs!

There were a few issues that came up in you discussion here and all of them should be addressed with the post I just made on the github issue:

I had made that misleading example file before I had understood the difference between SkyView Factor (SVF) and Vertical Sky Component (VSC). The difference is apparently very significant.……

I had been meaning to update it to be fully in Ladybug and work with the new view analysis for a couple of weeks and this was a good excuse to do so:…

Thank you again!


Thank you very much, Abraham and Chris!

I opened a new post to discuss Sky View Factor:…