Source Code for Module nukescripts.trackerlinkingdialog

  1  import nuke 
  2  import nukescripts 
  3   
  4  ############################################################################## 
  5  # A quick-n-dirty storage of "last values" for knobs that we want to appear 
  6  # with the value they were assigned the last time the dialog was open during 
  7  # this GUI session. 
  8   
  9  _gLastState = {} 
 10   
 11 -def _getLastState( knob, defaultValue=None ): 
 12    """Return the given knob's stored last state value. 
 13    If none exists, defaultValue is returned. 
 14    Values are stored in a dict referenced by knob name, so names must be unique!""" 
 15    global _gLastState 
 16    if _gLastState.has_key( knob.name() ): 
 17      return _gLastState[knob.name()] 
 18    else: 
 19      return defaultValue 
 20   
 21 -def _setLastState( knob ): 
 22    """Store the knob's current value as the 'last state' for the next time the dialog is opened. 
 23    Values are stored in a dict referenced by knob name, so names must be unique!""" 
 24    global _gLastState 
 25    _gLastState[knob.name()] = knob.value() 
 26   
 27   
 28  ############################################################################## 
 29  # LinkToTrack Panel 
 30  # This panel offers the user a selection of Tracker nodes in the project and 
 31  # returns an expression referencing either the Tracker's 'translate' knob or 
 32  # computing the average value of the selected track points on the node. 
 33   
 34 -class LinkToTrackPanel( nukescripts.PythonPanel ): 
 35 -  def __init__( self, groupContext ): 
 36      nukescripts.PythonPanel.__init__( self, "Link to Tracker", "uk.co.thefoundry.LinkToTrackPanel" ) 
 37       
 38      # Show a list of trackers in the project. 
 39      trackers = [] 
 40      with nuke.toNode(groupContext): 
 41        for n in nuke.allNodes(): 
 42          if n.linkableKnobs(nuke.KnobType.eXYKnob): 
 43            trackers.append( n.name() ) 
 44      self._tracker = nuke.Enumeration_Knob( "trackers", "tracker node", trackers ) 
 45      self._tracker.setTooltip( "The Tracker node to link to." ) 
 46      self._tracker.setValue( _getLastState( self._tracker, trackers[0] ) ) 
 47      self.addKnob( self._tracker ) 
 48       
 49      # Choice of linking to the translate on the tracker or to track point positions. 
 50      self._link_to = nuke.Enumeration_Knob( "link_to", "link to", ["position", "translate", "translate as offset"] ) 
 51      self._link_to.setValue( _getLastState( self._link_to, 'translate' ) ) 
 52      self._link_to.setTooltip( "Choose whether to link to the translation computed in the Tracker's Transform tab or to a specific track point position. If multiple track points are chosen they will be averaged." ) 
 53      self.addKnob( self._link_to ) 
 54      self._link_to.setFlag( nuke.ENDLINE ) 
 55   
 56      # Display check boxes for selection of which track points should be linked. 
 57      # If more than one is selected the expression is set to average them. 
 58      # Tracker nodes are currently limited to 4 points. If that changes we will need 
 59      # to be smarter here and create the right number of booleans for the currently 
 60      # selected node (and update when the node selection is changed). 
 61      self._track_points = [] 
 62      for t in xrange(1,5): 
 63        knobname = 'track'+str(t) 
 64        point = nuke.Boolean_Knob( knobname, knobname ) 
 65        # By default the first point is enabled but not the rest, 
 66        # unless there is previous session state to restore. 
 67        point.setValue( _getLastState( point, (t==1) ) ) 
 68        point.setTooltip( "Use this track point when linking to 'position'." ) 
 69        self._track_points.append( point ) 
 70        self.addKnob( point ) 
 71   
 72      self._updatePointsEnabled() 
 73     
 74      # Show the expression that's going to set in case user wants to tweak or 
 75      # copy it before closing the dialog. 
 76      self._expression = nuke.EvalString_Knob( "expression" ) 
 77      self._expression.setTooltip( "This is the expression that will be applied. You can edit it before closing the dialog but changing settings on this panel will rebuild it, losing your changes." ) 
 78      self.addKnob( self._expression ) 
 79      self._updateExpression() 
 80   
 81   
 82 -  def _updateExpression(self): 
 83      """Update the expression to reflect the current settings.""" 
 84      if self._link_to.value() == 'translate': 
 85        self._expression.setValue( self._tracker.value() + ".translate" ) 
 86      elif self._link_to.value() == 'translate as offset': 
 87        self._expression.setValue( "curve + " + self._tracker.value() + ".translate" ) 
 88      else: 
 89        pointCount = 0 
 90        expr = " + ".join([self._tracker.value() + "." + point.name() for point in self._track_points if point.value()]) 
 91        pointCount = sum( (1 for point in self._track_points if point.value()) ) 
 92        if pointCount > 1: 
 93          expr = "(" + expr + ")/" + str(pointCount) 
 94        self._expression.setValue( expr ) 
 95     
 96     
 97 -  def _updatePointsEnabled(self): 
 98      """Enable the track point bools when linking to position; disable otherwise.""" 
 99      use_points = ( self._link_to.value() == 'position' ) 
100      for point in self._track_points: 
101        point.setEnabled( use_points ) 
102     
103     
104 -  def getExpression(self): 
105      """Return the expression field value.""" 
106      return self._expression.value() 
107     
108     
109 -  def knobChanged( self, knob ): 
110      _setLastState( knob ) 
111       
112      # If expression changes, don't try to update and possibly trash it. 
113      if knob == self._expression: 
114        return 
115   
116      self._updateExpression() 
117      if knob == self._link_to: 
118        self._updatePointsEnabled() 
119      elif knob == self._tracker: 
120        global _gLastTracker 
121        _gLastTracker = knob.value() 
122     
123 -  def addToPane( self ): 
124      nukescripts.PythonPanel.addToPane( self, pane=nuke.thisPane() ) 
125   
126   
127   
128 -def trackerlinkingdialog(groupContext):  
129    d = LinkToTrackPanel(groupContext) 
130    if d.showModalDialog() == True: 
131      return d.getExpression() 
132