Hard time understanding the daylight viz. results

[usernamesam]

Hi,
I’m having a very hard time understanding the logic behind the Daylighting vizualisation feature in Sefaira and I hope someone has a part of the answer. Here’s what happens :

Let’s say I take the results for the 20th, 21st, 22nd and 23rd of April at 8:00 am, as in the picture below. The results of the 20th and 23rd are fairly similar, as they should be since they’re only 3 days apart. But the 21st and 22nd graphics are almost pitch black. I get similar results for the other months.

Does anyone have an explanation for that? I thought these results where calculated under a sunny day, but i’m starting to think that Sefaira makes an average of the local weather conditions for each and every date?

Thanks, any input would be appreciated!

[ktruesd]

Hello,

We at Sefaira would love to help with this! Since we’ll need some additional project information to help assess the issue, please email support@sefaira.com so we can launch a support ticket and get to the heart of the matter with you.

Thank you,

Kerger Truesdell

[HNatarajan]

You can find our assumptions for the type of sky and the other things here - https://sefaira.zendesk.com/hc/en-us/articles/205392365-Material-Assumptions-and-Radiance-Settings

We’ll need to look at your model and the location to understand if the weather file plays any role in this, but that’s where I would look first.

[alyson]

Thanks for posting those example pics. I realize this reply is a bit late, but I hope it helps!

Currently, when running the Date/Time analysis, Sefaira pulls the weather conditions from the weather file for exactly the weather conditions of that day. So, if it was stormy on April 20 at 8 am and completely clear on April 21st at 8 am, the results may be different.

Sefaira is strongly considering moving to a sunny-sky model for the date/time analysis.