[Radiance-general] Luminance predictions in a plane

[Marija Velickovic]

Hi,

To calculate Luminance instead of Illuminance just remove "-I+" flag
from your rtace command:

rtrace -w -af /tmp/bpi.amb -as 512 -ar 64 -aa 0.15 -ab 2 -h lab.oct |
rcalc -e '$1=($1*0.265+$2*0.670+$3*0.065)* 179'

I also propose you to set higher ambient parameters ( for example -as
1024 -ar 200 -aa 0.1 -ab 5), since you only have calculation in few
points.

Hope this helps,
Marija.


2008/5/19 sokol dervishi <dervishi_sokol at yahoo.com>:
>
> Dear all,
>
> I have a question regarding the luminance prediction (cd/m2) on the plane
> for certain points. and any help would really be appreciated.
>
> I have measured  certain points with an luminance meter. I have used also
> image-based for the same points to extract the luminance and I have very
> similar results. I need to use also simulation-based luminance values for
> the same points and compare the results with the measured and image based
> ones.
>
> Before,  I have simulated only Illuminances. How can I measure the
> Luminances?
>
> Here is the code I use to predict the illuminance:
>
> # commands to run
> commands = ["rm -f /tmp/bpi.amb",
>             "oconv env.rad lab_surfaces_corrected_moved.rad
> lab_windows_and_doors.rad strato_sokol2.rad> lab.oct",
>
> "echo '4.52    0.85 0.74 0 0 1 " +
>         "3.74    1.13 0.74 0 0 1 " +
>         "4.52    1.13 0.74 0 0 1 " +
>         "5.30    1.13 0.74 0 0 1 " +
>         "3.74    2.13 0.74 0 0 1 " +
>         "4.52    2.13 0.74 0 0 1 " +
>         "5.30    2.13 0.74 0 0 1 " +
>         "3.74    3.13 0.74 0 0 1 " +
>         "4.52    3.13 0.74 0 0 1 " +
>         "5.30    3.13 0.74 0 0 1 " +
>
>
>             "' | rtrace -w -af /tmp/bpi.amb -as 512 -ar 64 -aa 0.15 -ab 2
> -I+ -h lab.oct | rcalc -e '$1=($1*0.265+$2*0.670+$3*0.065)* 179'",
>
>
>             ]
>
>
> Any help would be really appreciated,
>
> Thank you very much
>
> Best regards,
>
> Sokol Dervishi
>