# Working plane

Dear all,

I am an undergraduate student trying to model a 10m x 10m room with
one corner touching the origin and a window on the south facing wall. I
have been trying to model this room with a film of translucent white
plastic on the window, and am really really stuck and need help
urgently, any advice would help a lot!

Firstly, I have a translucent white plastic material with a
reflectivity value of 0.518 and Transmissivity value 0.046, how would
you do the parameters for this material?

secondly, I have a model set up, and I really need to get a working
plane with lux values on it, how do you do this in either Control Panel
or radiance itself? I have tried to use Ecotect, but it doesnt seem to
be able to model a translucent material very accurately.

Sasa

Read through the following recent post regarding making a definition of your plastic:

And for workplane calculations on a grid see the following thread:

You can probably find a lot more help throughout the forum archives.

The following command process is generalized from that post. The cnt command cycles through a two-dimensional array of values (substitute your quantity of points for Xn and Yn), the rcalc command converts to XYZ and direction vector coordinates (adjust Xo and Yo for your first point, and Xd and Yd for spacing between points, and this assumes meter facing straight up, all at same Z coordinate), rtrace does the calculation (adjust calculation options as needed), and rcalc converts the RGB output to illuminance (this is assuming lux).

cnt Xn Yn | rcalc -e \
'\$1=Xo+Xd*\$1;\$2=Yo+Yd*\$2;\$3=Zo' \
-e '\$4=0;\$5=0;\$6=1' | rtrace -I -h [options] octree \

rcalc -e '\$1=179*(.265*\$1+.670*\$2+.065*\$3)' >

output.dat

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Dear Sasa,

Please refer to: http://www.nrc-cnrc.gc.ca/obj/irc/doc/pubs/nrcc48165/nrcc48165.pdf to find a description of how to set the Radiance material parameters for a translucent panel.

Christoph

···

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of [email protected]
Sent: Thursday, February 11, 2010 12:29 PM
To: [email protected]

Dear all,

I am an undergraduate student trying to model a 10m x 10m room with
one corner touching the origin and a window on the south facing wall. I
have been trying to model this room with a film of translucent white
plastic on the window, and am really really stuck and need help
urgently, any advice would help a lot!

Firstly, I have a translucent white plastic material with a
reflectivity value of 0.518 and Transmissivity value 0.046, how would
you do the parameters for this material?

secondly, I have a model set up, and I really need to get a working
plane with lux values on it, how do you do this in either Control Panel
or radiance itself? I have tried to use Ecotect, but it doesnt seem to
be able to model a translucent material very accurately.