Annual Daylight and DGP for CFS

Dear Ladybug experts,

I am using aBSDF type materials on Rhino and HB-Radiance to simulate the effects of the CFS on indoor light environments.

Now, I have two problems:

  1. I noticed that an enhanced 2-phase method used to calculate the annual daylight in HB-Radiance. The recipe is described as " This recipe uses an enhanced 2-phase method for daylight simulation which accurately models direct sun by tracing rays from each sensor to the solar position at each hour of the calculation."
    The enhanced 2-phase method can be used to simulate the model applied aBSDF type materials? I would like to know more about the enhanced 2-phase method and is there any reference or information about it?

  2. Similarly, the imageless method can be used to simulate the model applied aBSDF type materials? I found an article by Nathaniel L. Jones about the imageless method (The Imageless Method for Spatial and Annual Glare Analysis · nljones/Accelerad Wiki · GitHub ), but this article on calculating annual DGP using BSDFs does not seem to be updated.

Thank you for your time and patience!

Best,
Xuran

Dear Chris @chris and Sarith @sarith

I noticed you discussion about “enhanced 2-phase” before, can you help me?

Thank you for your time and patience!

Best,
Xuran

Hi @Xuran , I haven’t been keeping up with the current state of libraries to know what functionality exists. I believe @mikkel would be the right person to answer this. Since BSDFs in the two-phase method (enhanced or not) rely on “in-scene” polygons, you can use any type of BSDFs with them. However, you would (in my opinion) only derive any real benefit if you are using Tensor Tree BSDFs.
aBSDFs do much better “peak extraction” than standard BDSFs. If you are using the Klems-basis BDSFs then the solid-angle of the fenestration will be too large and likely negate any benefit.

Regards,
Sarith

Hi @sarith ,

Thanks for your reply. It was very helpful. In addition, I noticed your PhD thesis discussed this topic and I am studying it.

Again, really appreciate your help!

Best wishes,
Xuran