Hidden edges are visible on VTK 9.0.0

Support
1

Hi all!
I have recently encountered a problem when updating my code from VTK 8 to VTK 9 on my python/qt5/vtk app.
The only change in my installation is an update from VTK 8.1.2 to VTK 9.0.0 and this is the strange behavior I observed:
On every mesh I load a part of the edges that should be hidden by elements in front remains visible. Moreover when I select a node (done with an unstructured grid with SetPointSize to 10 and RenderPointsAsSpheresOn) the back edges comes in front of the sphere that is very inelegant and differs from what was done with vtk 8.

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Does anybody encountered this problem before? Is this a bad usage on my side or a bug in vtk 9 ?

Thanks in advance for your replies !

2

It’s a known issue: https://gitlab.kitware.com/vtk/vtk/-/issues/17936

3

Okay thank you for your answer!
It’s not clear for me if this is going to be corrected/modified in later updates? I tried to obtain results playing with SetRelativeCoincidentTopologyLineOffsetParameters but results is not really good and far of what it could be with vtk 8. And much more complicated as I have to update the offset relative to the camera scale…
It’s a bad news but I think I’m gonna remain in vtk 8 for a while.

4

@sankhesh do you expect your recent changes in https://gitlab.kitware.com/vtk/vtk/-/merge_requests/7480 will resolve issues like this?

5

@Flagada After changes in https://gitlab.kitware.com/vtk/vtk/-/merge_requests/7480, the offset is no more dependent on the prop bounds.

6

Great news! I wanted to test the current master version but as I only have mingw I was not able to build vtk on my own… I will wait for the wheel of the next version to be available :slight_smile:
Thanks!