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Node name – Creates mattes by node names.
Material name – Creates mattes based on the materials in the scene.
Node Name Hierarchy – Creates mattes by node names and takes the node hierarchy into account for linked or grouped objects.
Node User Attribute – Creates mattes with objects that include the User Attribute specified in the User attribute name field.

Num Levels – Specifies the number of levels for the render element, which determines the number of objects that can be distinguished per pixel. If multiple objects intersect at a single pixel, higher-order elements will contain non-zero results. The default value of 6 is normally enough for most cases.

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