ViewerChangeToggle.py

# --------------------------------------------------------------
#  ViewerChangeToggle.py
#  Version: 1.0.0
#  Last Updated: January 11th, 2018
# --------------------------------------------------------------


# --------------------------------------------------------------
#  USAGE:
#
#  Shift+Home will toggle your Viewer Exposure & Gamma between it's changed state & default value.
#  All credit goes to Ben Dickson for helping me figure this out!
#  Add this to menu.py
# --------------------------------------------------------------

_viewer_prev_settings = {'gain': 1, 'gamma': 1}

def reset_expose_gain():
    global _viewer_prev_settings

    # Get magic ViewerWindow node
    viewer = nuke.activeViewer()

    # Get regular Viewer node which contains
    # exposure knob and such
    node = viewer.node()


    curgain = node['gain'].value()
    curgamma = node['gamma'].value()

    if curgain != 1.0 or curgamma != 1.0:
        # Values are non-default, store them in memory
        _viewer_prev_settings['gain'] = curgain
        _viewer_prev_settings['gamma'] = curgamma

        # Reset to defaults
        node['gain'].setValue(1)
        node['gamma'].setValue(1)
    else:
        # Values are default, restore previous settings if any
        node['gain'].setValue(_viewer_prev_settings['gain'])
        node['gamma'].setValue(_viewer_prev_settings['gamma'])


m_viewer = nuke.menu("Viewer")
m_viewer.addCommand("Zero Viewer", reset_expose_gain, "shift+home")