[Radiance-general] Glare analysis

Sun Mar 25 11:36:22 PDT 2018

Hi Melody,

the fact that you got a result from Diva at all indicates that an old 
version (e.g. 0.9) of evalglare is included in your Diva installation. 
These old versions relied on the user to input a valid view, while 
current evalglare (1.x) will check the image header to prevent user errors.

As Christopher already explained, without a fisheye covering a full 
hemisphere it is not possible to compute the vertical eye illuminance 
from the pixel values. As long as you know the illuminance a priori, 
e.g. from a measurement or a separate computation, you could still pass 
it as a command line option to evalglare. This is why current evalglare 
supports other view types than fisheye projections.

However, for any glare evaluation you need to know the solid angle 
represented by each pixel to find the size of the glare source in the 
field of view. Therefore parallel views will not work out even if 
illuminance is known.

So this is not a limitation of evalglare or findglare, but you just do 
not provide the information that the glare metrics you are interested in 
rely on.

Cheers, Lars.

20.03.18 at 11:02 Melody Wong YT wrote:
> Dear all,
>
> I have frustrated with the command "evalglare" and "findglare" in Radiance.
>
> As I tried with DIVA before, and the function "point-in-time glare analysis" can be used with parallel rhino saved view for Radiance "evalglare" function.
>
> However, when I used the same function in Radiance, error message popped "view must not be parallel". Does there anyone know why there are difference in the same function of "evalglare" and "findglare" in different software?
> Can Radiance evaluate glare in rhino saved view rather than only fisheye view?
>
> Apart from the above question, the time for simulating the glare in radiance and Diva are hugely difference. Does there any one experience Diva function and Radiance function before? And have insight about the calculation method between these two simulation softwares.
>
> I have made the summaries the calculation file as below to see if it helps with the understanding.
>
>
>
> Radiance (glare script)
>
> Diva (Glare)
>
> Sky file
>
> !gensky 7 15 13:0 +s -a 22.33 -o -114.18 -m -120.00 -t 2.00 | xform -rz 0.00
>
> skyfunc glow sky_glow
> 0
> 0
> 4 .986 .986 1.2020135 0
>
> sky_glow source sky
> 0
> 0
> 4 0 0 1 180
>
> skyfunc glow ground_glow
> 0
> 0
> 4 1 .7 .25 0
>
> ground_glow source ground
> 0
> 0
> 4 0 0 -1 180
>
> !gensky 12 15 08 +s -a 22 -o -114 -m -120
>
> skyfunc glow sky_mat
> 0
> 0
> 4
> 1 1 1 0
>
> sky_mat source sky
> 0
> 0
> 4
> 0 0 1 180
>
> skyfunc glow ground_glow
> 0
> 0
> 4
> 1 .8 .5 0
>
> ground_glow source ground
> 0
> 0
> 4
> 0 0 -1 180
>
> Glare evaluation
>
> rad -v view model_M12D15T8.rif REP=1
>
> model_M12D15T8.rif :
> ZONE = I 0 1 0 1 0 1
> scene = SrdBldg.rad
> scene = Bridge.rad
> scene = Topo.rad
> scene = Skylight.rad
> scene = Roof.rad
> scene = Glazing.rad
> scene = Wall.rad
> scene = BIPV.rad
> materials = materials.mat
> scene = sky_M12D15T8.rad
> #add illum if needed
> #illum=window.rad
> view= view -vf view.vf
> OCTREE= model.oct
> EXPOSURE= 1
> UP= Z
> RESOLUTION= 512 512
> QUALITY= M
> PENUMBRAS= F
> INDIRECT= 1
> DETAIL= M
> VARIABILITY= M
> OPTFILE= model.opt
> oconv= -f
> #@mkillum= -ab 3 -ad 512 -as 256
> render= -st .001 -dj .02 -ad 2048
> pfilt= -2
> #@northarrow= nonedefined xform -rz 0
> # AMBFILE= Amb_M12D15T8.amb
>
>
> oconv material.rad Mikki_sky.rad Mikki.rad > Mikki.oct
>
> rpict -t 15 -vtv -vp 131.593 -15.381 43.05 -vd 97.297 -128.425 -16.081 -vu 0 0 1 -vh 75.8026519334564 -vv 53.9156001928024 -vs 0 -vl 0 -af Mikki.amb -x 1600 -y 1200 -ps 8 -pt .15 -pj .6 -dj 0 -ds .5 -dt .5 -dc .25 -dr 0 -dp 128 -st .85 -ab 2 -aa .25 -ar 128 -ad 1024 -as 1024 -lr 4 -lw .05 Mikki.oct > Mikki_Mikki_L.overture
>
> del Mikki_Mikki_L.overture
>
> rpict -t 15 -vtv -vp 131.593 -15.381 43.05 -vd 97.297 -128.425 -16.081 -vu 0 0 1 -vh 75.8026519334564 -vv 53.9156001928024 -vs 0 -vl 0 -af Mikki.amb -x 1600 -y 1200 -ps 8 -pt .15 -pj .6 -dj 0 -ds .5 -dt .5 -dc .25 -dr 0 -dp 128 -st .85 -ab 2 -aa .25 -ar 128 -ad 1024 -as 1024 -lr 4 -lw .05 Mikki.oct > Mikki_Mikki_L.unf
> pfilt -r .6 -x /2 -y /2 Mikki_Mikki_L.unf  > Mikki_Mikki_L.pic
>
> del Mikki_Mikki_L.unf
>
> evalglare -c Mikki_Mikki_L_evalglare.pic Mikki_Mikki_L.pic >Mikki_Mikki_L_evalglare.txt
>
>
> Thank you very much.
>
> Regards,
> Melody Wong
> Building Sustainability - Building 5
> Arup
> Level 5  Festival Walk,  80 Tat Chee Avenue  Kowloon Tong  Kowloon,  Hong Kong
> d: +852 2908 4915 (ext. 84915)
>
>
>
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