Dear Radiance list,

I have build up a model of a room with external glass blinds. The aim with

my simulations is to obtain the light transmittance of the glass blinds, and

for the entire system (blinds + window).

The blinds are modeled as polygons with the trans material. This means that

the blinds have no thickness in the model, but the reflectance and

transmittance values correspond to the information from the glass

manufacturer (r=0.31 and LT=0.65).

My approach is to obtain illuminance at three different locations:

1) Before the blinds, externally;

2) Between the blinds and the window, externally;

3) After the window, internally.

I have therefore made a grid of points in these locations. The orientation

of my measuring points is outwards, perpendicular to the façade.

My results show that the illuminance level is increased at loaction 2

compared to location 1, which is a result I do not find reliable! I have

placed calculation points in the entire height of the window with a spacing

of 0.01, to be sure not to have the result affected by high illuminance

levels locally. I would have expected higher illuminance levels locally due

to the redirecting of light in the glass blinds, but I would not have

expected a higher average illuminance level. My simulation approach is

given below – please let me know if you can find any mistakes.

Thanks in advance

/Anne

# /az 30,

#Room.rad includes room geometry,

#LamelSystem.rad includes geometry of the blinds,

#Syst2.rad includes geometry of the window system for mkillum

oconv materials.mat CIE.sky Room.rad LamelSystem30.rad Syst2.rad >

./profil30az0alt30/scene_window_prof30alt30az0.oct

cat Syst2.rad | mkillum -ab 4

./profil30az0alt30/scene_window_prof30alt30az0.oct

./profil30az0alt30/scene_window_prof30alt30az0_i.rad

oconv materials.mat Room.rad

./profil30az0alt30/scene_window_prof30alt30az0_i.rad CIE.sky >

./profil30az0alt30/window_ii.oct

#points in grid inside the room

cat points.xyz | rtrace -w -h -I+ -ab 3 -aa 0.1 -ad 1026 -as 256 -ar 512 -ds

.3 -oov ./profil30az0alt30/window_2ii.oct | rcalc -e

'$1=179*($4*0.265+$5*0.670+$6*0.065)' >

./profil30az0alt30/prof30al30az0_2.dat

#points before and after the blind

cat extpoints.xyz | rtrace -w -h -I+ -ab 3 -aa 0.1 -ad 1026 -as 256 -ar 512

-ds .3 -oov ./profil30az0alt30/window_2ii.oct | rcalc -e

'$1=179*($4*0.265+$5*0.670+$6*0.065)' >

./profil30az0alt30/prof30al30az0_2ext.dat