It is a very broad term, but it is just about word for word how I recall Juraj suggesting the need for a specific cloth BDRF so I assumed that the smarter people in the room (than me) would know and perhaps have discussed the need for this already :)
Correct me if I'm wrong but I believe that we have not got PBR capability for cloth materials in Corona, we don't slap a diffuse colour or map in, put reflection level to 1 and play with the reflection glossiness to achieve physically correct representation of every cloth / fabric type material from towelling and carpet through to silks and velvets?
If I'm right on that - we're all then playing artistic games trying to FAKE cloths and fabrics.
I understand one of the main tools we all use to achieve more realistic "fake" towelling, carpets, upholstery, clothing, silk, Damask, Velvet etc is the falloff map. Personally in Vray I used (amongst others) the shadow / light facility which isn't supported by Corona. Thus the original question.
I find with Corona that I can achieve acceptable results (for my low standards) for most of these cloth/fabrics listed above that look good up close, but that they look awful when the camera is moved further away. I seem to need to have two different versions of the same material for whether the camera is close-up or further away.
Ironically I think Corona is too clean... it was Vray's noise that helped the carpets look better at greater distance but anyway that's irrelevant I love Corona and want to make these things work.
If I'm entirely missing a point somewhere perhaps it's time to do a "towelling, carpets, upholstery, clothing, silk, Damask, Velvet material up close and far away how to" video on your youtube channel.