Problem summary
A pattern of pixels appears in the alpha channel when filtering is used in Transform nodes.
This has also appeared when a Constant node's format knob is set above 3921 pixels.
Customer reported version
Nuke 14.0v4
Customer reported platform
Windows 11
Steps to reproduce
1) In Nuke, create a Constant node.
2) In the Constant node Properties, set the channels to rgba and format knob to anything above 3921 pixels
2) Create a Reformat node, then an Invert node.
3) In the Properties of the Invert node, set the channels to alpha.
4) View the Invert node and hover the mouse in the Viewer, then press A to select the Alpha channel.
5) Set the Gamma/Gain to max values and observe the Viewer.
Expected behaviour
There should be no additional alpha created from the Reformat/Transform node filtering.
Actual behaviour
The alpha channel appears with a pattern from the Reformat/Transform node filtering.
Workaround
Setting the Reformat/Transform node's filter knob to Impulse (no filter) allows the alpha to appear as expected. If a Transform node is used where the scale knob is set below 1, setting the motionblur to above zero (0) could help to reduce the issue.
It's also been seen that adding a Blur node with a size value at or above .72 could also remove the filtering issue.
Reproduced by Support in:
Nuke 15.0v4 - Windows 10, macOS 13 Ventura
Nuke 12.0v1 - Windows 10
Earliest version tested
Nuke 12.0v1 - This issue appears to be in all tested versions of the product
