Create multimatte here.
All mattes are created on the fly (nothing is created in your Maya scene, all is created on the fly during rendering).
This feature is useful because :
- you do not need to create ID or other. ID do not exist here.
- all is hierarchical. You can create one multimatte and add a group (transform) in the red, create another multimatte and sub-objects of the group in the red.
