Hi @OlivierDambron, I didn’t realize you tagged me until @mostapha answered the question, My apology.
Mostapha developed many Radiance primitives, all that you have to do is write your own Python component based on the Python Radiance materials files in the following directory:
C:\Users\userName\AppData\Roaming\McNeel\Rhinoceros\5.0\scripts\honeybee\radiance\material
For example, a trans material that has R,G,and B reflectance of 60% can be defined like this:
from honeybee.radiance.material.trans import Trans
Some_Material = Trans.by_single_reflect_value("Trans_Material", .60)
This code will write the following material:
void trans Trans_Material
0
0
7 0.6 0.6 0.6 0.0 0.0 0.0 0.0