ID 354257 - Viewer gamma and gain knob affect the viewer differently when use GPU for the viewer when possible is enabled and there is a viewer input process

Follow

Problem summary
Viewer gamma and gain knob effect the viewer differently when use GPU for the viewer when possible is enabled and there is a viewer input process 

The left shows the result with use GPU for the viewer when possible enabled where the right has it disabled


Customer reported version
nuke.11.1v4

Customer reported platform
centos7

Steps to reproduce

1) Open Nuke

2) Create a Checkerboard node, view it and change the Viewer gamma to 0.5

3) Create a Grade node, rename it to VIEWER_INPUT and set the blackpoint to 0.2

4) Press "S" on the Viewer and toggle the "use GPU for viewer when possible" knob, the image displayed in the viewer will change.

Reproduced by support
This bug has been reproduced in:
Nuke 11.1v4 - Windows 10 - CentOS 6.8 - MacOSX 10.13
Nuke 11.1v1 - Windows 10
Nuke 11.0v4 - Windows 10
Nuke 11.0v2 - Windows 10 - CentOS 6.8 - MacOSX 10.13 - regression

Unable to reproduce bug in:
Nuke 11.0v1 - Windows 10 - CentOS 6.8 - MacOSX 10.13

Earliest version tested
Nuke 11.0v1 - This issue no longer appears in this version and has regressed
Expected behaviour
For the viewer image to be the same when using GPU for the viewer

Actual behaviour
The image changed
 

    We're sorry to hear that

    Please tell us why