Cloth/Fabric materials are imho most problematic of all, and often are the weakest point in many renders.
The regular ggx/blinn/whatever brdf is not really suitable, it always comes down to some fallof cheat or weird-ass anisotropy to
sort-of make it look
correct'ish, but comparing to actual scanned materials the result is not at all realistic
I saw this BTF + BRDF approach mentioned on Vray forums and thought to mention it here as well, as Corona seems open to ideas.
Here's an oldish paper
http://www.graphics.cornell.edu/pubs/2006/IM06.pdfand there is also a cloth shader plugin for vray/maya called
https://github.com/vidarn/ThunderLoomAnyway, I'm not a tech guy and have no idea if there's anything of worth in the links, but damn, I wish for a nice cloth material all the time. I know you guys make things happen :)
Is there any interest in this direction at all? I think a cloth shader would be amazing help for interiors which seem to be bread and butter for most Corona users.