SelectiveMatteExtraction Matchbox

SelectiveMatteExtraction is a Matchbox shader that extracts the matte from a Selective node, and makes it an Action pass output. It is only used in Action.

To extract a matte from a Selective:

1. Create a Surface object.
2. Right-click the Surface and select Add Selective.
3. Right-click the Selective node and select Add Selective FX, then select the SelectiveMatteExtraction matchbox.
   

   SelectiveMatteExtraction used to extract a matte created from ZDepth data

4. In Action Output menu, create a new Output Render Layer and assign it the Surface object created in step 1 (Right-click > View/Render > Add to Output) .

   This ensures it outputs the Selective result as a Matte in the Comp (Primary) output. See About Rendering Outputs from Action for information on render layer outputs.