Problem summary
Viewer not showing alpha when using OCIODisplay node as viewerProcess
Customer reported version
nuke.10.0v4
Customer reported platform
Linux Ubuntu
Steps to reproduce
1.
Register a ViewerProcess utilising the OCIODisplay node. We have a menu.py with this line:
nuke.ViewerProcess.register("OCIODisplay_bug",nuke.createNode,("OCIODisplay","view rec709 layer all"))
EDIT: You can also copy this in the script editor
2.
Luanch Nuke with attached script (it has a simple Roto shape producing an alpha in the center of the frame)
3.
In Viewer set viewerProcess to OCIODisplay_bug
4.
Open Viewer Settings, have these options set:
useGPUForViewer true
disableGPUDitherForViewer false
5.
With focus on the Viewer, hit A on the keyboard to view the alpha channel. The roto shape is an oval in the center, which appears to be black, though sampling the area yields the correct value 1.0.
5.
Change the viewerProcess to any default LUT and the alpha immediately is displayed according to its values (it's white).
Workaround
With the viewerProcess set to OCIODisplay_bug
Set Viewer settings:
useGPUForViewer true
disableGPUDitherForViewer true
or
useGPUForViewer false
or
Add a Shuffle node after the Roto node.
Reproduced by support
Nuke10.0v1 through 10.5v1 on OS10.10.5 when no GPU
Reported works in SOME GPU configs (OS/model/driver)
Expected behaviour
Alpha is show
Actual behaviour
Alpha not shown