With the MultiMatte Channels Render Element , only three colors are possible: red, green, and blue. Compare with other matte render elements, which can include a multitude of colors to represent each material or object in a scene with a different color. With MultiMatte Channels , a single R, G, or B channel can be used directly as a matte, eliminating the step of selecting the color in the compositing software. This ease of use makes MultiMatte Channels a popular choice for compositors.
The Multimatte Render Element includes antialiasing.
To represent all the objects or materials in a scene with just the available red, green, and blue colors, several MultiMatte Channels Render Elements can be generated for a single rendering, each with different Material ID or Object ID settings.