Problem summary Within Nuke it is possible to use the modification of a knob in a gizmo or group as a callback mechanism in python, using the knobChanged function. https://learn.foundry.com/nuke/developers/latest/pythondevguide/callbacks.html#knobchanged
It has been discovered that when using the knobChanged function from a node's shutter offset 'custom' knob, the callback function does not work correctly and the knob becomes inaccessible when connected to a Viewer.
Customer reported version nuke.12.2v4
Customer reported platform
Steps to reproduce
1) Call the attached example Python script into Nuke (to create the custom node.)
2) When the custom node is created in the Node Graph, view the through a Viewer node and change to the 'custom' value in the shutter offset knob. Result: Unable to modify the slider in the node.
Expected behaviour The nodes shutter offset slider should be able to be modified when custom is selected
Actual behaviour The shutter offset slider is greyed out when custom is selected and the Viewer is connected
Workaround Unknown.
Reproduced by support This bug has been reproduced in: Nuke 12.2v4 - Windows 10 - CentOS 7 - MacOS 10.15.6 Nuke 12.2v1 - Windows 10 Nuke 12.1v1 - Windows 10 Nuke 11.0v1 - Windows 10 Nuke 10.5v1 - Windows 10- CentOS 7 - MacOS - regression
Unable to reproduce bug in: Nuke 10.0v6 - Windows 10 - CentOS 7 - MacOS
Earliest version tested Nuke 10.0v6 - This issue doesn't appear in this version and has regressed