Glare Calculation

Hi everyone,

I'm doing a glare study with radiance and Ecotect.

Fristly i've created my 3d model in Ecotect, then i've exported it in radiance to calculte the lumiance in cd/m².
No problem for this part.

Secondly I'm using the function findglare and then glarendx, to compute a glare index.
When i'm writing my function findglare in my command window like this: findglare -p RCP_c3.pic > glaresult.glr
I've got en error message: "findglare: picture read error"

or if i'm using the method glare, i've got the same problem: "must have view or picture"

How can i fix it?

Thanks for your help,

Regards,

Alexis Loubeyre.

I'm doing a glare study with radiance and Ecotect.

Fristly i've created my 3d model in Ecotect, then i've exported it in
radiance to calculte the lumiance in cd/m².
No problem for this part.

Secondly I'm using the function findglare and then glarendx, to compute a
glare index.

Are you aware of the shiny new 'evalglare'?

When i'm writing my function findglare in my command window like this:
findglare -p RCP_c3.pic > glaresult.glr
I've got en error message: "findglare: picture read error"

Is the picture a complete Radiance HDR image? Can you display
it in the Ecotect picture viewer? Have you modified the picture after
the rendering (reduced size, pcond)?

What do you get when you type the command

     getinfo RCP_c3.pic

Regards,
Thomas

···

On Wed, Nov 17, 2010 at 10:55 AM, alexis Loubeyre <[email protected]> wrote:

Hi Alexis,

How did you set up your view for RCP_c3.pic? Findglare expects a fisheye (180h x 180v) view. If it does not get it then it reports an error/warning message.

Note also there is the new program evalglare for glare analysis:

http://www.ise.fraunhofer.de/areas-of-business-and-market-areas/applied-optics-and-functional-surfaces/lighting-technology/lighting-simulations/radiance/radiance?set_language=en&cl=en

Regards,

-Jack

···

--
# Jack de Valpine
# president
#
# visarc incorporated
# http://www.visarc.com
#
# channeling technology for superior design and construction

On 11/17/2010 10:55 AM, alexis Loubeyre wrote:

Hi everyone,

I'm doing a glare study with radiance and Ecotect.

Fristly i've created my 3d model in Ecotect, then i've exported it in radiance to calculte the lumiance in cd/m².
No problem for this part.

Secondly I'm using the function findglare and then glarendx, to compute a glare index.
When i'm writing my function findglare in my command window like this: findglare -p RCP_c3.pic > glaresult.glr
I've got en error message: "findglare: picture read error"

or if i'm using the method glare, i've got the same problem: "must have view or picture"

How can i fix it?

Thanks for your help,

Regards,

Alexis Loubeyre.

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

You can now even do annual daylight glare probability calculations using Daysim 3.1 which contains a new subprogram written by Jan Wienold called gen_dgp_profile.

Christoph

···

From: [email protected] [mailto:[email protected]] On Behalf Of Jack de Valpine
Sent: Wednesday, November 17, 2010 11:22 AM
To: Radiance general discussion
Subject: Re: [Radiance-general] Glare Calculation

Hi Alexis,

How did you set up your view for RCP_c3.pic? Findglare expects a fisheye (180h x 180v) view. If it does not get it then it reports an error/warning message.

Note also there is the new program evalglare for glare analysis:

http://www.ise.fraunhofer.de/areas-of-business-and-market-areas/applied-optics-and-functional-surfaces/lighting-technology/lighting-simulations/radiance/radiance?set_language=en&cl=en

Regards,

-Jack

--
# Jack de Valpine
# president
#
# visarc incorporated
# http://www.visarc.com
#
# channeling technology for superior design and construction

On 11/17/2010 10:55 AM, alexis Loubeyre wrote:

Hi everyone,

I'm doing a glare study with radiance and Ecotect.

Fristly i've created my 3d model in Ecotect, then i've exported it in radiance to calculte the lumiance in cd/m².
No problem for this part.

Secondly I'm using the function findglare and then glarendx, to compute a glare index.
When i'm writing my function findglare in my command window like this: findglare -p RCP_c3.pic > glaresult.glr
I've got en error message: "findglare: picture read error"

or if i'm using the method glare, i've got the same problem: "must have view or picture"

How can i fix it?

Thanks for your help,

Regards,

Alexis Loubeyre.

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

Hi Jack and Thomas,

Thank you for your help, I tried evalglare yesterday and he worked well.
But regarding my results have got couple of questions:

- i'm doing a glare study for an office (10m depth). I think glare will not be a problem for a person located at 9m away from the window, isn't it?
- when my calculation is completed, i've 2 warnings messages:
        low brightness scene
        vertical illumiance < 380 lux.
Do they impact the calcul?
So should i proceed a glare study only for the first 5m from the window?

How can i fix the warnings?

Regards,

Alex

···

Date: Wed, 17 Nov 2010 11:22:18 -0500
From: [email protected]
To: [email protected]
Subject: Re: [Radiance-general] Glare Calculation

Hi Alexis,

How did you set up your view for RCP_c3.pic? Findglare expects a fisheye (180h x 180v) view. If it does not get it then it reports an error/warning message.

Note also there is the new program evalglare for glare analysis:

http://www.ise.fraunhofer.de/areas-of-business-and-market-areas/applied-optics-and-functional-surfaces/lighting-technology/lighting-simulations/radiance/radiance?set_language=en&cl=en

Regards,

-Jack
--
# Jack de Valpine
# president
#
# visarc incorporated
# http://www.visarc.com
#
# channeling technology for superior design and construction
On 11/17/2010 10:55 AM, alexis Loubeyre wrote:

Hi everyone,

I'm doing a glare study with radiance and Ecotect.

Fristly i've created my 3d model in Ecotect, then i've exported it in radiance to calculte the lumiance in cd/m².
No problem for this part.

Secondly I'm using the function findglare and then glarendx, to compute a glare index.
When i'm writing my function findglare in my command window like this: findglare -p RCP_c3.pic > glaresult.glr
I've got en error message: "findglare: picture read error"

or if i'm using the method glare, i've got the same problem: "must have view or picture"

How can i fix it?

Thanks for your help,

Regards,

Alexis Loubeyre.

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

_______________________________________________ Radiance-general mailing list [email protected] http://www.radiance-online.org/mailman/listinfo/radiance-general

Hi!

Thank you for your help, I tried evalglare yesterday and he worked well.
But regarding my results have got couple of questions:

- i'm doing a glare study for an office (10m depth). I think glare will
not be a problem for a person located at 9m away from the window, isn't it?

Hm, that may be to easy... e.g. if your office is on the West facade and you directly look into the sun, it may be even worse at 9m distance...

- when my calculation is completed, i've 2 warnings messages:
low brightness scene
vertical illumiance < 380 lux.
Do they impact the calcul?
So should i proceed a glare study only for the first 5m from the window?

Evalglare includes the vertical illuminance into its glare predictions, and (Jan can tell more about this) has been developed under conditions with higher vertical illuminance. So look at all the 9m, but be careful with those low-illuminance-locations.

How can i fix the warnings?

No way to fix, it is a warning to catch your attention, not a bug to fix :wink:

Cheers, Lars.

Hi Jack and Thomas,

Thank you for your help, I tried evalglare yesterday and he worked well.
But regarding my results have got couple of questions:

- i'm doing a glare study for an office (10m depth). I think glare will not
be a problem for a person located at 9m away from the window, isn't it?
- when my calculation is completed, i've 2 warnings messages:
low brightness scene
vertical illumiance < 380 lux.

If you assume a standard workplace lighting level you could
introduce artificial lighting to raise the vertical illuminance to
500 lux. Evalglare might be happier with that (or it expects far
more than that; I honestly don't know).

Do they impact the calcul?

Evalglare has been verified in a study on a small office space.
I'm sure Jan has put some thought into the general application
for this new metric. You can find his dissertation here:

http://www.ise.fraunhofer.de/veroeffentlichungen/nach-jahrgaengen/2010/buecher-und-beitraege-zu-buechern/dayligth-glare-in-offices

So should i proceed a glare study only for the first 5m from the window?

I would first verify that evalglare produces reliable results
in this office space. And then just go ahead and test the
full depth of the office. If you get a low probability for glare
that's also something to show.

How can i fix the warnings?

Nothing to fix; just make sure your using the right tool here.

Regards,
Thomas

···

On Thu, Nov 18, 2010 at 4:49 AM, alexis Loubeyre <[email protected]> wrote:

Hi!

- i'm doing a glare study for an office (10m depth). I think glare will not
be a problem for a person located at 9m away from the window, isn't it?
- when my calculation is completed, i've 2 warnings messages:
         low brightness scene
         vertical illumiance< 380 lux.

If you assume a standard workplace lighting level you could
introduce artificial lighting to raise the vertical illuminance to
500 lux. Evalglare might be happier with that (or it expects far
more than that; I honestly don't know).

One note on the terminology, as this causes confusion often. Evalglare intruduces illuminance on the eye plane (if you think of a human eye as a flat sensor) into the calculation, which stabilizes results for extended, non-uniform sources (window seen from close with a lot of detail behind). This is referred to as vertical illuminance (as illuminance on a vertical plane). And completely different from the typically workplane illuminance, which would be referred to as horizontal illuminance or illuminance that a infinitely small imaginary horizontal surface at e.g. 0.9m heigth would receive.

Cheers, Lars.