Available components for computing DGP

Dear all,

I wonder whether we have 3-Phase or 5-Phase image-based components for DGP calculations.

I found 2 components for computing DGP:
(please correct me if I am wrong with my interpolations of the following methods :grinning:)

  • DC image-based in Honeybee[+]: 2 phase (DDS version for more accurate direct sun calculations)

  • Imageless DGP in Honeybee Radiance: 2 phase + discretized sky patches


Hi @SichenLu,

Image-based 3/5-phase recipes are not available. Anyway, it is probably best to stay away from 3-phase if the intention is to do a glare analysis.

You are correct on the two methods you listed. You can also use the point-in-time-view recipe, which will render the scene the “classic” way using rpict.

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Hi Mikkel,

Thank you for your response.

I got some strange results from DC image-based component. I found that hourly DGP values from this component are lower than other methods (like 3P, 5P, ClimateStudio, even imageless DGP).

Is that true that sun disc is supposed to be very small, like a single point?

When I defined the glass as a BSDF type, the sun values are almost 0. The combined results (total - direct + sun) actually simply removes the direct values:

With a glass type, the results look more reasonable. However, the sun disc is still not visible.
Is that true that sky patches will not be obvious like they are in the 3P method?

It looks like 2P does not work well with BSDF types. Is that true that even when BSDFs are assigned in the imageless component, they are not being used? Or it is better use a glass type in the imageless component?

I wonder whether you would recommend using the point-in-time-view recipe in Honeybee-Radiance. May I know the reason why 3P/5P image-based recipe is not available?

Thank you for you time and help.