Adding a mask Add node
This node adds two masks. At each vertex, the value of the output mask is the sum of the values of both input masks.
To add a node, right-click in the Graph Editor and select Create Node > Mask Composition > Add.
This node has no properties.
Linking to input masks
Link the Add node to two input nodes.
The maximum value for a mask is 1. At a given vertex, if the sum of the values of both masks exceeds 1, the output mask will have the value 1 at this vertex and not a value greater than 1. If both input masks do not have the same size or resolution, the size and resolution of the output mask is determined by the size and resolution of the first mask and the second mask is enlarged or decreased so that its size corresponds exactly to the size of the output mask, before being added to the first mask.
For example:
