Good idea, but what about textures?
this text you can find in vray-meterials.de
"Illegal textures.
Please be aware that we have to control every material concerning legal issues. If you notice any copyright-protected textures on this site, please report this immediately here."
for me.. Each user is responsible for what it share,
all the texture must be copyright free. materials with invalid texture will be deleted.
Jeff Patton's model is excellent to evaluate the materials . is a good starting point to create the model of Corona.
http://jeffpatton.net/2011/03/eliminate-the-mr-photographic-green-hue/