Hi Greg,
Apologies to jump on a old thread.
I am looking into the exact topic and wanted to clarify a few things.
Firstly, I want to clarify the transmittance only scenario.
I found an old thread of yours (modeling trees in Radiance)
where you have suggested to define the 7 parameters as
7 T T T 0 0 1 1
However, Jakubiec and Balakrishnan on above the link write the 7 parameters as
7 1 1 1 0 0 T 1
I tried to experiment with both options in a simple room scenario with a single face object in front and found that Jakubiec and Balakrishnan’s parameter definition gives higher than expected result. (I compared the with and without the single face.)
Once I understand this, I want to try/understand the scenario including the reflectance.
Regards
Jiva