Version 3.9
Mask (local)
This tab is available in the Channel, Fixture, Content, and Tracking Sheets.
It is used to define a local mask for a specific sheet. You can load a mask from the Mask Pool or you can create a new one. The mask is applied when "Enable Mask" is On. If "Follow Selected Mask" is also on, then the local mask is not applied, but instead the mask selected in the mask pool is applied.
Enable Mask and Follow Selected Mask is described in the Layer Mask topic.
Please read the What are Masks topic for information about masks in general.
The Create Masks topic describes how to make masks and it describes the different buttons seen in this tab.