AutoMask  allows automatically create masks when rendering. Masks can be by layers, by object’s and material’s ID, by separate objects, as well as by custom mask sets – object sets analog.
Masks names correspond to the names of layers and objects. For normal masks creation layers and concrete objects must be called logical, and not use special characters.
Creating masks is possible in two modes: black-and-white, and RGB. The black-and-white mode, each mask – a separate file. In RGB mode, each file contains three masks.
One pass may contain only one Automask.
Automask working with Vray and Corona.