operationSwitcher.py

# --------------------------------------------------------------
#  operationSwitcher.py
#  Version: 2.0.0
#  Last Updated: August 23rd, 2018
#  Thanks to Falk Hofmann for making improvements!
# --------------------------------------------------------------


# --------------------------------------------------------------
#  USAGE:
#
#  Shift+S toggles between over/under, mask/stencil, plus/from, etc.
#  Add this to menu.py
# --------------------------------------------------------------


# ----- TOGGLE TRACKER AND MERGE OPERATIONS -----------------------

def operationSwitcher():
    node = nuke.selectedNode()
    merge_ops = {'stencil': 'mask', 'over': 'under', 'from': 'plus', 'out': 'in'}
    if node.Class() == "Merge2":
        current_op = node['operation'].value()
        if current_op in merge_ops.keys():
            node['operation'].setValue(merge_ops[node['operation'].value()])
        elif current_op in merge_ops.values():
            node['operation'].setValue(merge_ops.keys()[merge_ops.values().index(current_op)])


# Add to edit menu
nuke.menu('Nuke').addCommand( 'Edit/Switch Operation', operationSwitcher, "ctrl+shift+s")