nuke

Set up the ‘nuke’ module

This initializes Nuke’s internal modules and brings the symbols into this namespace

Functions

activeViewer	Return an object representing the active Viewer panel.
addAfterBackgroundFrameRender	Add code to execute after each frame of a background render. The call must be in the form of: def foo(context): pass.
addAfterBackgroundRender	Add code to execute after any background renders. The call must be in the form of: def foo(context): pass.
addAfterFrameRender	Add code to execute after each frame of a render
addAfterRecording	Add code to execute after viewer recording
addAfterRender	Add code to execute after any renders
addAfterReplay	Add code to execute after viewer replay
addAutoSaveDeleteFilter	Add a function to modify the autosave filename before Nuke attempts delete the autosave file.
addAutoSaveFilter	Add a function to modify the autosave filename before Nuke saves the current script on an autosave timeout.
addAutoSaveRestoreFilter	Add a function to modify the autosave restore file before Nuke attempts to restores the autosave file.
addAutolabel	Add code to execute on every node to produce the text to draw on it in the DAG.
addBeforeBackgroundRender	Add code to execute before starting any background renders. The call must be in the form of: def foo(context): pass.
addBeforeFrameRender	Add code to execute before each frame of a render
addBeforeRecording	Add code to execute before viewer recording
addBeforeRender	Add code to execute before starting any renders
addBeforeReplay	Add code to execute before viewer replay
addDefaultColorspaceMapper	Add a function to modify default colorspaces before Nuke passes them to Readers or Writers.
addFavoriteDir	Add a path to the file choosers favorite directory list.
addFilenameFilter	Add a function to modify filenames before Nuke passes them to the operating system.
addFormat	Create a new image format, which will show up on the pull-down menus for image formats.
addKnobChanged	Add code to execute when the user changes a knob The knob is availble in nuke.thisKnob() and the node in nuke.thisNode().
addNodePresetExcludePaths	:param paths Sequence of paths to exclude Adds a list of paths that will be excluded from Node preset search paths.
addOnCreate	Add code to execute when a node is created or undeleted
addOnDestroy	Add code to execute when a node is destroyed
addOnScriptClose	Add code to execute before a script is closed
addOnScriptLoad	Add code to execute when a script is loaded
addOnScriptSave	Add code to execute before a script is saved
addOnUserCreate	Add code to execute when user creates a node
addRenderProgress	Add code to execute when the progress bar updates during any renders
addSequenceFileExtension	Adds the input file extension to the list of extensions that will get displayed as sequences in the file browser.
addToolsetExcludePaths	:param paths Sequence of paths to exclude Adds a list of paths that will be excluded from Toolset search paths.
addUpdateUI	Add code to execute on every node when things change.
addValidateFilename	Add a function to validate a filename in Write nodes.
addView	Deprecated.
afterBackgroundFrameRender
afterBackgroundRender
afterFrameRender
afterRecording
afterRender
afterReplay
alert	Show a warning dialog box.
allNodes	List of all nodes in a group.
animation	Does operations on an animation curve.
animationEnd	Returns the last frame (or x value) for the currently selected animations.
animationIncrement	Returns a recommended interval between samples of the currently selected animation.
animationStart	Returns the starting frame (or x value) for the currently selected animations.
animations	Returns a list of animatable things the user wants to work on.
applyPreset	Applies a given preset to the current node.
applyUserPreset	Applies a given user preset to the current node.
ask	Show a Yes/No dialog.
askWithCancel	Show a Yes/No/Cancel dialog.
autoSaveDeleteFilter	Internal function.
autoSaveFilter	Internal function.
autoSaveRestoreFilter	Internal function.
autolabel
autoplace	Deprecated.
autoplaceSnap	Move node to the closest grid position.
autoplace_all	Performs autoplace of all nodes in current context group.
autoplace_snap_all	Performs autoplace snap of all nodes in current context group.
autoplace_snap_selected	Performs autoplace snap of all selected nodes in current context group.
beforeBackgroundRender
beforeFrameRender
beforeRecording
beforeRender
beforeReplay
cacheUsage	Get the total amount of memory currently used by the cache.
canCreateNode	This function can be used to determine whether it is possible to create a node with the specified node class.
cancel	Cancel an in-progress operation.
center	Return the center values of a group’s display, these values are suitable to be passed to nuke.zoom as the DAG center point.
channels	Deprecated.
choice	Shows a dialog box with the given title and prompt text, and a combo box containing the given options.
clearBlinkCache	Clear the Blink cache for all devices.
clearDiskCache	Clear the disk cache of all files.
clearRAMCache	Clear the RAM cache of all files.
clearTabMenuFavorites	Uncheck every favourite node in tab search menu.
clearTabMenuWeighting	Set the weight of each node to 0 in tab search menu.
clone	Create a clone node that behaves identical to the original.
cloneSelected	This makes a clone of all selected nodes, preserving connections between them, and makes only the clones be selected.
collapseToGroup	Moves the currently selected nodes to a new group, maintaining their previous connections.
collapseToLiveGroup	Moves the currently selected nodes to a new group, maintaining their previous connections.
connectNodes	Deprecated.
connectViewer	Connect a viewer input to a node.
createLiveInput	Creates a new LiveInput and populates the “file” and “liveGroup” knobs according to the filename and LiveGroup name of the parent group
createNode	Creates a node of the specified type and adds it to the DAG.
createScenefileBrowser	Pops up a scene browser dialog box.
createToolset	Creates a tool preset based on the currently selected nodes.
critical	Puts the message into the error console, treating it like an error.
debug	Puts the message into the error console, treating it like a debug message, which only shows up when the verbosity level is high enough.
defaultColorspaceMapper	Called by libnuke.
defaultFontPathname	Get the path to Nukes default font.
defaultNodeColor	Get the default node colour.
delete	The named node is deleted.
deletePreset	Deletes a pre-created node preset :param nodeClassName: Name of the node class to create a preset for.
deleteUserPreset	Deletes a pre-created user node preset :param nodeClassName: Name of the node class to create a preset for.
deleteView	Deprecated.
dependencies	List all nodes referred to by the nodes argument. ‘what’ is an optional integer (see below).
dependentNodes	List all nodes referred to by the nodes argument. ‘what’ is an optional integer (see below).
display	Creates a window showing the result of a python script.
duplicateSelectedNodes	Creates a duplicate of all selected nodes in the current script context group :return None.
endGroup	Deprecated.
error	Puts the message into the error console, treating it like an error.
execute	execute(nameOrNode, frameRangeSet, views, continueOnError = False) -> None.
executeBackgroundNuke	Run an instance of Nuke as a monitored sub process.
executeInMainThread	Execute the callable ‘call’ with optional arguments ‘args’ and named arguments ‘kwargs’ i n Nuke’s main thread and return immediately.
executeInMainThreadWithResult	Execute the callable ‘call’ with optional arguments ‘args’ and named arguments ‘kwargs’ in Nuke’s main thread and wait for the result to become available.
executeMultiple	Execute the current script for a specified frame range.
executing	Returns whether an Executable Node is currently active or not.
exists	Check for the existence of a named item.
expandSelectedGroup	Moves all nodes from the currently selected group node into its parent group, maintaining node input and output connections, and deletes the group.
expr	expression(s) -> float
expression	Parse a Nuke expression.
extractSelected	Disconnects the selected nodes in the group from the tree, and shifts them to the side.
filename	Return the filename(s) this node or group is working with.
filenameFilter
forceClone	return True if succeeded, False otherwise.
forceLoad	Force the plugin to be fully instantiated.
fork	Forks a new instance of Nuke optionally with the contents of the named file.
formats	return List of all available formats.
frame	Return or set the current frame number.
fromNode	Return the Node n as a string.
getAllUserPresets	gets a list of all current user presets :return: a list of tuples containing all nodename/presetname pairs.
getClipname	Pops up a file chooser dialog box.
getColor	Show a color chooser dialog and return the selected color as an int.
getColorspaceList	Get a list of all colorspaces listed in an enumeration knob.
getDeletedPresets	gets a list of all currently deleted presets :return: a pyDict containing all nodename/presetname pairs.
getFileNameList	:param dir the directory to get sequences from :param splitSequences whether to split sequences or not :param extraInformation whether or not there should be extra sequence information on the sequence name :param returnDirs whether to return a list of directories as well as sequences :param returnHidden whether to return hidden files and directories.
getFilename	Pops up a file chooser dialog box.
getFonts	Return a list of all available font families and styles
getFramesAndViews	Pops up a dialog with fields for a frame range and view selection.
getInput	Pops up a dialog box with a text field for an arbitrary string.
getNodeClassName	gets the class name for the currently selected node :return: a string containing the name.
getNodePresetExcludePaths	Gets a list of all paths that are excluded from the search for node presets.
getNodePresetID	gets the node preset identifier for the currently selected node :return: a string containing the ID.
getOcioColorSpaces	return list of strings
getPaneFor	Returns the first pane that contains the named panel or None if it can’t be found.
getPresetKnobValues	gets a list of knob values for a given preset :param nodeClassName: Name of the node class to get values for.
getPresets	gets a list of all presets for the currently selected node’s class :return: a pyList containing all nodename/presetname pairs.
getPresetsMenu	Gets the presets menu for the currently selected node.
getReadFileKnob	@brief Gets the read knob for a node (if it exists).
getRenderProgress	return The progress of the render. Can be 0 if there is no progress to report.
getToolsetExcludePaths	Gets a list of all paths that are excluded from the search for node presets.
getUserPresetKnobValues	gets a list of knob values for a given preset :param nodeClassName: Name of the node class to get values for.
getUserPresets	gets a list of all user presets for the currently selected node’s class :return: a pyList containing all nodename/presetname pairs.
hotkeys	Returns the Nuke key assignments as a string formatted for use in nuke.display().
inputs	Deprecated.
invertSelection	Selects all unselected nodes, and deselects all selected ones.
knob	@brief Returns or sets the entire state of a knob.
knobChanged
knobDefault	Set a default value for knobs in nodes that belong to the same class. All knobs with matching names, that are created after this command was issued, will default to the new value. If class. is missing or is “*.” then this default applies to all nodes with such a knob. If several values are supplied, the first value which is valid will be used as the default. knobDefault can be used to specify file format specific knobs. These are knobs that are added to Read, Write and other file format dependent nodes when the file name changes. To specify defaults, use the class name, followed by the file format extension, followed by the knob name, all separated by periods. An example is shown below.
knobTooltip	Set an override for a tooltip on a knob.
layers	Lists the layers in a node.
licenseInfo	return None
load	Load a plugin.
loadModuleFromPath	Load a Python file and return the module object
loadToolset	Loads the tool preset with the given file name.
localisationEnabled	Checks if localisation is enabled on a given Read_File_Knob.
localiseFiles	return None.
localizationEnabled	Checks if localization is enabled on a given Read_File_Knob.
makeGroup	Creates a new group containing copies of all the currently selected nodes.
maxPerformanceInfo	maxPerformanceInfo -> Get the max performance info for this session.
memory	Get or set information about memory usage.
menu	Find and return the Menu object with the given name.
message	Show an info dialog box.
modified	Deprecated.
nodeCopy	Copy all selected nodes into a file or the clipboard.
nodeDelete	Removes all selected nodes from the DAG.
nodePaste	Paste nodes from a script file or the clipboard.
nodeTypes	param force_plugin_load bool True to force loading all plugins on the path before querying node types (default False)
nodesSelected	returns true if any nodes are currently selected
numvalue	The numvalue function returns the current value of a knob.
oculaPresent	Check whether Ocula is present.
ofxAddPluginAliasExclusion	Adds the ofx effect name to a list of exclusions that will not get tcl aliases automatically created for them.
ofxMenu	Find all the OFX plugins (by searching all the directories below $OFX_PLUGIN_PATH, or by reading a cache file stored in $NUKE_TEMP_DIR), then add a menu item for each of them to the main menu.
ofxPluginPath	List of all the directories Nuke searched for OFX plugins in.
ofxRemovePluginAliasExclusion	Remove an ofx plugin alias exclusion that was previously added with .
onCreate
onDestroy
onScriptClose
onScriptLoad
onScriptSave
onUserCreate
openPanels	nodesSelected() -> List
pan	Return the pan values of a group’s display.
performanceProfileFilename	Returns the profile filename if performance timers are in use, otherwise returns None.
pluginAddPath	Adds all the paths to the beginning of the Nuke plugin path.
pluginAppendPath	Add a filepath to the end of the Nuke plugin path.
pluginExists	This function is the same as load(), but only checks for the existence of a plugin rather than loading it.
pluginInstallLocation	The system-specific locations that Nuke will look in for third-party plugins.
pluginPath	List all the directories Nuke will search in for plugins.
plugins	Returns a list of every loaded plugin or every plugin available.
recentFile	Returns a filename from the recent-files list.
redo	Perform the most recent redo.
registerFlipbook	Register a flipbook application name into Nuke.
removeAfterBackgroundFrameRender	Remove a previously-added callback with the same arguments.
removeAfterBackgroundRender	Remove a previously-added callback with the same arguments.
removeAfterFrameRender	Remove a previously-added callback with the same arguments.
removeAfterRecording	Remove a previously-added callback with the same arguments.
removeAfterRender	Remove a previously-added callback with the same arguments.
removeAfterReplay	Remove a previously-added callback with the same arguments.
removeAutoSaveDeleteFilter	Remove a previously-added callback with the same arguments.
removeAutoSaveFilter	Remove a previously-added callback with the same arguments.
removeAutoSaveRestoreFilter	Remove a previously-added callback with the same arguments.
removeAutolabel	Remove a previously-added callback with the same arguments.
removeBeforeBackgroundRender	Remove a previously-added callback with the same arguments.
removeBeforeFrameRender	Remove a previously-added callback with the same arguments.
removeBeforeRecording	Remove a previously-added callback with the same arguments.
removeBeforeRender	Remove a previously-added callback with the same arguments.
removeBeforeReplay	Remove a previously-added callback with the same arguments.
removeDefaultColorspaceMapper	Remove a previously-added callback with the same arguments.
removeFavoriteDir	Remove a directory path from the favorites list.
removeFilenameFilter	Remove a previously-added callback with the same arguments.
removeFilenameValidate	Remove a previously-added callback.
removeKnobChanged	Remove a previously-added callback with the same arguments.
removeOnCreate	Remove a previously-added callback with the same arguments.
removeOnDestroy	Remove a previously-added callback with the same arguments.
removeOnScriptClose	Remove a previously-added callback with the same arguments.
removeOnScriptLoad	Remove a previously-added callback with the same arguments.
removeOnScriptSave	Remove a previously-added callback with the same arguments.
removeOnUserCreate	Remove a previously-added callback with the same arguments.
removeRenderProgress	Remove a previously-added callback with the same arguments.
removeUpdateUI	Remove a previously-added callback with the same arguments.
render	execute(nameOrNode, start, end, incr, views, continueOnError = False) -> None.
renderProgress
rescanFontFolders	Rebuild the font cache scanning all available font directories.
resetPerformanceTimers	Clears the accumulated time on the performance timers.
restoreWindowLayout	Restores a saved window layout.
resumePathProcessing	Resume path processing.
root	Get the DAG’s root node.
runIn	Execute commands with a given node/knob/field as the ‘context’.
sample	Get pixel values from an image.
saveEventGraphTimers	Save events in the event graph.
saveToScript	Saves the fileContent with the given filename.
saveUserPreset	Saves a node’s current knob values as a user preset.
saveWindowLayout	Saves the current window layout.
scriptClear	Clears a Nuke script and resets all the root knobs to user defined knob defaults.
scriptClose	Close the current script or group.
scriptExit	Exit Nuke.
scriptName	Return the current script’s file name
scriptNew	Start a new script.
scriptOpen	Opens a new script containing the contents of the named file.
scriptReadFile	Read nodes from a file.
scriptReadText	Read nodes from a string.
scriptSave	Saves the current script to the current file name.
scriptSaveAndClear	Calls nuke.scriptSave and nuke.scriptClear :param filename: Save to this file name without changing the script name in the project. :param ignoreUnsavedChanges: Optional. If set to True scripSave will be called, ignoring any unsaved changes :return: True when sucessful. False if the user cancels the operation. In this case nuke.scripClear will not be called.
scriptSaveAs	Saves the current script with the given file name if supplied, or (in GUI mode) asks the user for one using the file chooser.
scriptSaveToTemp	Saves the script to a file without modifying the root information or the original script
scriptSource	Same as scriptReadFile().
script_directory
selectAll	Select all nodes in the DAG.
selectConnectedNodes	Selects all nodes in the tree of the selected node.
selectPattern	Selects nodes according to a regular expression matching pattern, entered through an input dialog.
selectSimilar	Selects nodes that match a node in the current selection based on matchType criteria.
selectedNode	Returns the ‘node the user is thinking about’.
selectedNodes	Returns a list of all selected nodes in the current group.
setPreset	Create a node preset for the given node using the supplied knob values :param nodeClassName: Name of the node class to create a preset for.
setReadOnlyPresets	Sets whether newly created presets should be added in read-only mode.
setUserPreset	Create a node preset for the given node using the supplied knob values :param nodeClassName: Name of the node class to create a preset for.
show	Opens a window for each named node, as though the user double-clicked on them.
showBookmarkChooser	Show bookmark chooser search box.
showCreateViewsDialog	Show a dialog to prompt the user to add or create missing views.
showDag	Show the tree view of a group node or opens a node control panel.
showInfo	Returns a long string of debugging information about each node and the operators it is currently managing.
showSettings	Show the settings of the current group.
splayNodes	Deprecated.
startEventGraphTimers	Start keeping track of events in the event graph.
startPerformanceTimers	Start keeping track of accumulated time on the performance timers, and display the accumulated time in the DAG.
stopEventGraphTimers	Stop keeping track of events in the event graph.
stopPerformanceTimers	Stop keeping track of accumulated time on the performance timers, and cease displaying the accumulated time in the DAG.
stripFrameRange	Strip out the frame range from a clipname, leaving a file path (still possibly with variables).
suspendPathProcessing	Suspend path processing.
tabClose	Close the active dock tab.
tabNext	Make the next tab in this dock active.
tcl	Run a tcl command.
thisClass	Get the class name of the current node.
thisGroup	Returns the current context Group node.
thisKnob	Returns the current context knob if any.
thisNode	Return the current context node.
thisPane	Returns the active pane.
thisParent	Returns the current context Node parent.
thisRoot	Returns the current context Root node.
thisView	Get the name of the current view.
toNode	Search for a node in the DAG by name and return it as a Python object.
toggleFullscreen	Toggles between windowed and fullscreen mode.
toggleViewers	Toggles all the viewers on and off.
toolbar	Find and return the ToolBar object with the given name.
tprint	Prints the values to a stream, or to stdout by default.
undo	Perform the most recent undo.
updateUI
usingOcio	usingOCIO() -> returns true if using OCIO instead of Nuke LUTs.
usingPerformanceTimers	Return true if performance timers are in use.
validateFilename
value	The value function returns the current value of a knob.
views	List of all the globally existing views.
waitForThreadsToFinish	Returns true if Nuke should wait for any Python threads to finish before exitting.
warning	Puts the message into the error console, treating it like a warning.
zoom	Change the zoom and pan of a group’s display.
zoomToFitSelected	Does a zoom to fit on the selected nodes in the DAG :return: None.

Classes

AColor_Knob
AnimationCurve
AnimationKey	A control point for an animation curve. @var x The horizontal position of the point @var y The vertical position of the point @var lslope The derivative to the left of the point. If interpolation does not have USER_SET_SLOPE then this may not be correct until after evaluate() has been called. @var rslope The derivative to the right of the point. If interpolation does not have USER_SET_SLOPE then this may not be correct until after evaluate() has been called. @var la The left ‘bicubic’ value. This represents the horizontal position of the left bezier handle end, where 1.0 means 1/3 of the distance to the previous point. If both handles for a span are 1.0 then the horizontal interpolation is linear and thus the vertical interpolation a cubic function. The legal values are 0 to 3. Setting outside of this range will produce undefined results. @var ra The right ‘bicubic’ value, again the legal range is 0 to 3. @var interpolation Used to calculate all the slopes except for the left slope of the first key and the right slope of the last key. Legal values are: - USER_SET_SLOPE: If this bit is on, the slopes are fixed by the user and interpolation and extrapolation are ignored. - CONSTANT: The value of the curve is equal to the y of the point to the left. - LINEAR: slopes point directly at the next key. - SMOOTH: same as CATMULL_ROM but the slopes are clamped so that the convex-hull property is preserved (meaning no part of the curve extends vertically outside the range of the keys on each side of it). This is the default. - CATMULL_ROM: the slope at key n is set to the slope between the control points n-1 and n+1. This is used by lots of software. - cubic: the slope is calculated to the only cubic interpolation which makes the first and second derivatives continuous. This type of interpolation was very popular in older animation software. A different cubic interpolation is figured out for each set of adjacent points with the CUBIC type. - for the smooth, CATMULL_ROM, and CUBIC interpolations, the first and last key have slopes calculated so that the second derivative is zero at them. @var extrapolation controls how to set the left slope of the first point and the right slope of the last point. Notice that this can be set differently on the first and last points, and is also remembered on all internal points so if end points are deleted old behavior is restored). - constant: the left slope of the first point, and the right slope of the last point, are set to zero. - linear: (and all other values): The left slope of the first point is set equal to it’s right slope (calculated by the interpolation). the right slope of the last point is set equal to it’s left slope. if there is only one point both slopes are set to zero. @var selected True if the point is selected in the curve editor.
Array_Knob	A knob which holds an array of values.
Axis_Knob	A knob which descibes a 3D affine transformation, by combining rotations around each principal axis, scaling, translation, skew and a pivot point.
BBox_Knob	A knob which holds a bounding box.
BackdropNode
BeginTabGroup_Knob	Begin a group of tabs.
Bitmask_Knob
Boolean_Knob	A knob which holds a boolean value.
Box	A 2-dimensional rectangle.
Box3_Knob	A 3-dimensional box.
CascadingEnumeration_Knob	Stores a single value between 0 and some maximum, and manages a set of keywords visible to the user.
ChannelMask_Knob
Channel_Knob	Constructor.
ColorChip_Knob	A knob which holds a single unsigned int that describes a user interface colour.
Color_Knob	A knob which holds a color.
Disable_Knob	A knob which holds a boolean value representing the disabled state of a node.
Double_Knob	A knob which holds one or more double-precision floating point values.
EditableEnumeration_Knob	Stores a single value between 0 and some maximum, and manages a set of Radio Buttons visible to the user.
EndTabGroup_Knob	End a group of tabs.
Enumeration_Knob	param name Name.
EvalString_Knob	A string-valued knob which evaluates it’s value as a TCL expression.
Eyedropper_Knob
File_Knob	A knob which holds a filename.
FnPySingleton
Font_Knob	A knob for choosing a font.
Format	A format.
Format_Knob
FrameRange	A frame range, with an upper and lower bound and an increment.
FrameRanges	A sequence of FrameRange objects with convenience functions for iterating over all frames in all ranges.
FreeType_Knob	A knob which holds a font family and style name.
GeoSelect_Knob	A knob which allows selection of parts of a 3D object.
Gizmo
GlobalsEnvironment	Dictionary-style object holding global Nuke state.
Group
Hash	A hash value for any number of objects.
Help_Knob
Histogram_Knob
IArray_Knob
Info	An info object stores x, y, w and h values.
Int_Knob	A knob which holds one or more integer values.
Keyer_Knob
Knob	A modifiable control that appears (unless hidden) in the panel for a node.
KnobType	Constants for use in parameters which require a knob type.
Layer	A layer is a set of channels.
Link_Knob
LinkableKnobInfo	A linkable knob description.
LiveGroup
LookupCurves_Knob	Provide a set of user-editable lookup curves.
Lut
Menu
MenuBar
MenuItem
MultiView_Knob
Multiline_Eval_String_Knob	A knob which evaluates it’s string value as a TCL expression.
Node
NodeConstructor
Nodes
Obsolete_Knob	For internal use only.
OneView_Knob
OutputContext	Describes a context in which expressions can be evaluated.
Panel
PanelNode
ParticleChannels_Knob
Password_Knob	A knob which holds a password string value.
Precomp
ProgressTask
Pulldown_Knob
PyCustom_Knob
PyScript_Knob	A button that executes a Python script.
PythonCustomKnob
PythonKnob	A string-valued knob which evaluates its value as a Python expression.
Radio_Knob	Stores a single value between 0 and some maximum, and manages a set of Radio Buttons visible to the user.
Range_Knob	A knob which the minimum and maximum for a range of values.
Root
RunInMainThread
Scale_Knob
SceneGraph_Knob	Displays a list of items as a hierarchy.
SceneView_Knob	Displays a list of items as a hierarchy.
Script_Knob	A button which executes a TCL script.
String_Knob	A knob which holds a string value.
Tab_Knob	Groups subsequent knobs onto a tab.
Text_Knob	A knob which holds a string value.
ToolBar
Transform2d_Knob
UV_Knob	A knob which describes a texture coordinate.
Undo
Unsigned_Knob	A knob which holds one or more unsigned integer values.
View	A named view.
ViewView_Knob
Viewer
ViewerProcess
ViewerWindow
WH_Knob	A knob which holds width and height values.
XYZ_Knob	A knob which holds a 3D coordinate.
XY_Knob	A knob which describes a 2D position.

Exceptions

CancelledError
ColorspaceLookupError	an excpetion that should be thrown when looking up the colorspace