ID 328383 - RayRender's interpolate animation option does not correctly interpret negative scale values from an input card when samples are increased

Problem summary
When using the RayRender node with an input of a card that has negative values in its scale parameters, if the RayRender node has 'interpolate animation' samples in excess of 1, the output of the image will produce unexpected artifacts.

Customer reported version
nuke.n/a

Customer reported platform
centos6

Steps to reproduce

Open the attached script 

or

1) Create a Checkerboard node

2) Create a Card node and use the Checkerboard image as the input image

3) From the Card's default position in 3D space, change the rotate y value to 45, the scale y value to -1 and the universal scale to 0.3.

4) Create a Camera node, setting the translate z at 1

5) Create a RayRender node and connect the Camera into the 'cam' input and the Card into the 'obj/scn' input

6) Turn of 'interpolate animation' in the 'MotionBlur' tab and change the samples value to 2.
Result: The interpolate animation sample values using the card's negative values causes artifacting of the image

7) To confirm the cause is the combination of both try turning of the 'interpolate animation' first and then toggle it back on, followed by altering the cards negative scale value from -1 to 1

Workaround
Unknown. Avoid using negative values in cards if using interpolate animation.

Reproduced by support
This bug has been reproduced in:

Nuke 11.1v1 - CentOS 6.9 - MacOSX 10.12 - Windows 7
Nuke 11.0v3 - CentOS 6.9
Nuke 11.0v1 - CentOS 6.9
Nuke 10.5v7 - CentOS 6.9
Nuke 10.5v1 - CentOS 6.9 - MacOSX 10.12 - Windows 7
Nuke 10.0v6 - CentOS 6.9
Nuke 10.0v5 - CentOS 6.9
Nuke 10.0v4 - CentOS 6.9 - MacOSX 10.12 - Windows 7 - regression

Earliest version tested
Nuke 10.0v3 - CentOS 6.9
- This issue no longer appears in this version and has regressed

Expected behaviour
The interpolate animation option inside of the RayRender node should not be producing artifacts with negative card value inputs

Actual behaviour
The interpolate animation option inside of the RayRender node produces artifacts when an input card has negative values