Material Effect Channel - does it work?

[Daniele]

I've tried to assign different material ID to different vray materials, but in the rendered viewport I can't see them (totally grey). If I use the same ID, but with standard materials instead I can see differents colors as ID.
In fact, using material ID with psd-manager don't work.
Any solution?
(already activated the material id channel in g-buffer settings)

Thank-you