tl;dr: save some of your precious time when using the Backdrop Node.
Typically, when you use a Backdrop node to group a bunch of nodes, you want to set up a nice, descriptive label, a font size, and probably also a cool, elegant color. The problem is that usually, those tasks are done after the Backdrop node is created, one after the other, and that gets somewhat repetitive, boring and time-consuming in the long run.
If you want to save the burden and get those three things done at the same time, here I share with you a little Python snippet that will let you deal with your backdrops the easy way, and just at once.
1 - How to use it
So first things first, let´s place the code where it can be reached, create a new Nuke Menu and set up a Hotkey. Let´s see how this works.
Distribute the code
Copy the script and save it as a Python file called "b_custom_bckdrp.py" where Nuke can find it. In other words, place it within the nuke.pluginPath() file structure. For more info, read my previous posts.
Edit the menu.py file
Now we have the Python module where Nuke can find it, we´re gonna add the following lines to our fantastic menu.py so that we can effectively use it:
n_menu = nuke.menu('Nuke')
b_menu = n_menu.addMenu('MenuName')
b_menu.addCommand('b_custom_bckdrp', 'b_custom_bckdrp.main_function()', 'ctrl+a')
Save the menu.py and restart Nuke.
2 - Try it
You'll notice that there is a new menu in your upper menu bar, listing the new 'b_custom_bckdrp' command and its Hotkey. Just select a bunch of nodes and press 'alt+a '(it´s the hotkey we set up earlier, obviously you can change this to any other of your convenience). A Nuke Panel like this one should appear:
Set the "note size" and "label" and click ok.
Now select a nice, elegant color (or leave it as is).
Finally, you should end up with something like this :D
code
import nuke
import nukescripts
######################################################################################
__author__ = "Boris Martinez Castillo"
__version__ = "1.0.1"
__maintainer__ = "Boris Martinez Castillo"
__email__ = "boris.vfx@outlook.com"
######################################################################################
def custom_backdrop(txt,fontsize):
node = nukescripts.autoBackdrop()
node['label'].setValue('<center><u><b>' + txt)
#node['bdwidth'].setValue(525)
prev_sel = nuke.selectedNodes()
for i in prev_sel:
i['selected'].setValue(False)
node['selected'].setValue(True)
node['note_font_size'].setValue(fontsize)
nukescripts.color_nodes()
class modalPanel(nukescripts.PythonPanel):
def __init__(self):
nukescripts.PythonPanel.__init__(self,"customize_backdrop")
#CREATE KNOBS
self.note_size = nuke.Int_Knob("Note Size:")
self.note_size.clearFlag(nuke.STARTLINE)
self.frame_display = nuke.String_Knob("Label:")
self.frame_display.clearFlag(nuke.STARTLINE)
self.set_note_size_default_value()
self.author = nuke.Text_Knob("written by Boris Martinez")
#ADD KNOBS
for i in (self.note_size , self.frame_display):
self.addKnob(i)
#SET KNOB DEFAULT VALUES
def set_note_size_default_value(self):
self.note_size.setValue(100)
def main_function():
panel = modalPanel()
if not panel.showModalDialog():
print "script aborted"
return
else:
fontsize = panel.note_size.getValue()
note = panel.frame_display.getValue()
custom_backdrop(note,fontsize)
if __name__ == "__main__":
main_function()tl;dr:A useful tweak to the “FrameHold” node that set by default its “frame” knob to the current frame in the timeline.
important: make sure to copy this code somewhere in your meny.py file to make it work. Enjoy!
snippet
.__autor__ Boris Martinez
# function to be passed later on to a addOnUserCreate callback.
def frame_hold_to_frame():
node = nuke.thisNode()
curr_frame = nuke.frame()
frame = node['first_frame'].setValue(curr_frame)
return curr_frame
# addOnUserCreate callback.
nuke.addOnUserCreate(frame_hold_to_frame,nodeClass ="FrameHold")
tl;dr: A useful custom knob that enables the user to to place objects in 3D while working in screen space.
important: make sure to copy this code somewhere in your meny.py file to make it work.
snippet
.__author__ Boris Martinez
# assign nuke.createNode() function to a variable for later use.
nuke_create_node = nuke.createNode
def create_my_nodes(node, knobs = "", inpanel = True):
"""
this function calls nuke_create_node and add a tab and a color picker knob based on the class
of the node created.
@param node: Node class.
@param knobs: Optional string containing a TCL list of name value pairs (like "size 50 quality 19")
@param inpanel: Optional boolean to open the control bin (default is True; only applies when the GUI is running).
@return: result
"""
result = nuke_create_node(node, knobs, inpanel) # call to nuke_create_node
if node == "Sphere" or node == "TransformGeo" or node == "Cube" or node == "Card2" or node == "Cylinder" or node \
== "Axis2":
tab = nuke.Tab_Knob('SmartPos', 'SmartPos')
col = nuke.Color_Knob('PickPos')
result.addKnob(tab)
result.addKnob(col)
return result
# overwrite nuke.createNode
nuke.createNode = create_my_nodes
# KnobChanged callable function
def smart_post_expression():
"""
This is the function to be called as the first argument for the AddKnobChanged callback later on.
Sets its context to nuke.thisNode() and picks up the changing knob by the nuke.thisKnob() command.
@return: None
"""
n = nuke.thisNode()
k = nuke.thisKnob()
if k.name() == "PickPos":
n['translate'].setExpression('PickPos.r', 0)
n['translate'].setExpression('PickPos.g', 1)
n['translate'].setExpression('PickPos.b', 2)
return None
# adding callbacks to certain node classes.
nuke.addKnobChanged(smart_post_expression, nodeClass="TransformGeo")
nuke.addKnobChanged(smart_post_expression, nodeClass="Sphere")
nuke.addKnobChanged(smart_post_expression, nodeClass="Cube")
nuke.addKnobChanged(smart_post_expression, nodeClass="Card2")
nuke.addKnobChanged(smart_post_expression, nodeClass="Cylinder")
nuke.addKnobChanged(smart_post_expression, nodeClass="Axis2")