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Glare calculations with the matrix based method in Radiance

asked 2019-04-18 10:26:16 -0500

Diba's avatar

I am using the matrix-based method in radiance to do illuminance calculations for a Complex Fenestration System and was wondering if there is any way I can also take care of glare analysis with the same method?

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Suggestion, describe the fenestration system: Dynamic/static, in plane of the fenestration or non-co-planar shading, is there a large direct component to the transmittance of daylight (is the sun in view of the occupant)?

Which method are you currently considering (2,3,...)phase?

Also fig.1 in 'Subramaniam - Daylighting Simulations with Radiance using Matrix-based Methods' might help you make decisions

Samuel de Vries's avatar Samuel de Vries  ( 2019-04-19 02:38:39 -0500 )edit

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answered 2019-04-19 13:10:01 -0500

There are two common methods to perform annual glare analysis with a matrix method.

The first is to use vertical illuminance at the eye with simplified DGP (DGPs). For this method you calculate vertical illuminance in the same way you're calculating workplane illuminance at points. See equation 1 in this paper for how to calculate DGPs from vertical illuminance: (also this paper is a good resource for understanding your question in general).

The second method is to use a rendered view matrix, create hourly renderings using dctimestep, and then running evalglare on the hourly renderings. This option takes much more time computationally, but is necessary to get an accurate assessment of glare in cases where glare sources are relatively small. Sarith's tutorial covers how to use vwrays with rfluxmtx to generate a rendered view or daylight coefficient matrix (

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Asked: 2019-04-18 10:26:16 -0500

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Last updated: Apr 19 '19