When place lights in Radiance, how to deal with the height of luminaires?

1

Hi everyone,

I have a question when I place the lights on the ceiling. If the height of the ceiling is 2.8 and the height of the luminaires is 0.05. When I use xform to place the lights on the ceiling, I should set the height of lights as 2.75 as follows:

!xform -t 1.2 1.3 2.75 -a 5 -t 2.4 0 0 -a 3 -t 0 2.7 0 led1.rad

Besides, the material definition is shown as follows. My second question is if I want to change the lumen output of a luminaire like decreased to 50%, Will reducing the RGB value by 50% accomplish this?

Am I getting it right?

Cheers,

Hao

2

I believe this is correct. You can always check the geometric bounds of any Radiance scene file with the getbbox command. For example, try:

xform -t 1.2 1.3 2.75 -a 5 -t 2.4 0 0 -a 3 -t 0 2.7 0 led1.rad | getbbox -

to make sure the Z-dimension does not exceed 2.8, your ceiling height.

Best,
-Greg

1 Like
3

Hi Greg,

Thank you so much for your reply. The getbbox is helpful.

Best regards,

Hao