How to read the rad file of luminaries generated by ies2rad and how change the lumen output of a luminaire by modifying the rad file？

radiance-general
1

Hi all,

Recently, I used ies2rad to read the ies file and got two files- rad and data file. Part of the rad file is shown as follows and I am confused about the fourth line. The 0.158 1.268 0.05 is the dimension of the luminaire but what is the mean of 1?

‘void’ brightdata ‘thorn_dist’
5 boxcorr ‘~/radiance/kindling1/data/thorn.dat’ source.cal src_phi4 src_theta
0
4 1 0.158 1.268 0.05

‘thorn_dist’ light ‘thorn_light’
0
0
3 1 1 1

Kind regards,

Hao

2

If you look in the header of “source.cal” in ray/src/cv/, you will see a description of the arguments. A1 is an optional multiplier, which is probably set by the ies2rad -m option.

Best,
-Greg

1 Like
3

Hi Greg,

Thank you very much for your reply. With your suggestion, I read the header of “source.cal” in ray/src/cv/ and other material. I also did some tests. Based on my experience, it can be determined that A1 is the “candela multiplier factor” and will be applied to all candela values in the dat file.

Best regards,

Hao