Hi Stephen, thanks a lot for the thorough feedback. Well from your description it seems that even if I manage to translate the wavefront materials to radiance ones it would be like shooting in the dark without any warranty that my output would be 100% accurate.
The tools that I am using to extract the scene can be found here this translates the json file from my attached model on my second message to the .obj and .mtl files of my scene. From what I understand the material mapping to the .mtl is done during the reading of the scene since my room layouts and included objects are already predefined. Thus, I guess translating the .mtl files to .rad is my only option.
The point is that going with such kind of models is my only option for now since I cannot find any other large scale dataset with multiple rooms and objects that would follow a physical model. If you are aware of anything that I could use I would be happy if you could share some info. I’ve opened a corresponding thread here but so far there is no response.