Operating system: windows
Slicer version: 4.11
Expected behavior: smoothy interpolation
Actual behavior: strip-line shows up
I did use with python code (3D-image):
transform2Node = slicer.mrmlScene.AddNode(slicer.vtkMRMLTransformNode())
then
transformStitchNode.ApplyTransform( myTransform )
it is observed that some strip-lines show up like this
Please try the latest versions (5.8.1 and the latest preview builds). If you still see the issue, try to reproduce it with publicly shareable data and the exact steps to reproduce.
It seems to me that image interpolation is disabled! Image interpolation should never be disabled, as interpolation is required to see the original continuous physical image signal. See more detailed explanation here:
If you disable interpolation then you will see discrete sample values and the abrupt intensity change at the boundary of every voxel, which were not present in the original continuous physical signal. The diagonal lines are also voxel boundaries, they appear like this when the slice view orientation is not aligned with the volume axis orientation. These lines are not real, they appear because you chose to see the sampled values instead of the reconstructed continuous signal.
So, everything is good, just make sure to keep interpolation enabled if you want to see the actual image (not the raw data that has not been reconstructed into image signal yet).
Thanks a lot. Not big issue anyway. Yes, interpolation will be there applied to get such lines off. 
