MultiMatte "material ID"

[voytov]

Hello, could anyone tell me please what's the proper setup for multimatte..?
When I activate "Use material ID" I can get no desired effect (no colours in multimatte channel).
Where actually is the "material ID" that I should set to correspond with R or G or B ?

Thanks for any help...

[bdancer]

Re: MultiMatte "material ID"

Index in R, G or B corresponds to PassIndex of object.