ID 131409 - Roto nodes with a format larger than the root format will create artifacts when motion blur is on

Follow
  1. The Foundry SANDBOX
  2. Bug Tracker
  3. Nuke

Problem summary
When adding motion blur to a Roto node, if the Roto nodes format is smaller that the projects format the bounding box will not adjust correctly and cause a streaking artifact.
 
This occurs with both the Roto and Rotopaint nodes.
 
Customer reported version
11.3v4
 
Customer reported platform
n.a.
 
Steps to reproduce
1) Open a new Nuke session, setting the project's full size format to 640x480
 
2) Create a Roto node and set the format of the Roto node to 1920x1080
 
3) Draw an Elipse in the center of the screen
 
4) Set a keyframe on frame 1, then move to frame 20 and relocate the Ellipse to the right hand side. (this will animate the Ellipse)
 
5) Move the playhead to the middle of the animation at frame 10
 
6) Within the Roto node, open the 'Motion Blur' tab and turn on the motion blur by using the 'on' checkbox
Result: The bounding box does not accommodate for added motion blur and causes an artifact.
 
 
Expected behaviour
Even if the project's resolution is lower than the Roto nodes resolution, the bounding box should accommodate for the motion blur.
 
Actual behaviour
The bounding box not expanding causes artifacting when motion blur is added
 
Workaround
A workaround for this issue would be to use a Reformat node as the input to the Roto node.
 
By setting a Reformat to the Roto node's size, this will avoid the resolution confusion that is being caused by the unconnected Roto node.
 
In this example, you would use the following settings:
 
Reproduced by support
This bug has been reproduced in:
Nuke 11.3v5 - Windows 7 - CentOS 7 - MacOS 10.14.5
Nuke 11.3v1 - Windows 7
Nuke 11.2v1 - Windows 7
Nuke 11.1v1 - Windows 7
Nuke 11.0v1 - Windows 7
Nuke 10.5v1 - Windows 7
Nuke 10.0v1 - Windows 7
Nuke 9.0v1 - Windows 7
Nuke 8.0v1 - Windows 7 - CentOS 7 - MacOS 10.14.5
 
Earliest version tested
Nuke 8.0v1
- This issue appears to be in all versions of the product

    We're sorry to hear that

    Please tell us why