vray and vray rt questions

[z1pp3r]

is it possible to restrict working of RT to just region of image?
(might be useful when the complexity of the scene will slow it down alot and we would be able to fine tune just chosen material in region mode)

[MikeeMax]

this thread looks like a radio game where everyone is trying to guess with questions what an unknown object is.
some picsand moviez would be very helpul