VTK Examples - Graph Testing

Development
1

I have come across an interesting discrepancy in testing vtk-examples. The following five tests all pass in Windows but fail in Linux:

TestConstructGraph

for ConstructGraph, compare this with the Windows image here: ConstructGraph.

Alternatively this shows the mirroring around the central vertical line of the image more clearly:

TestScaleVertices

for ScaleVertices, compare this with the Windows image here: ScaleVertices.

The tests were run using Windows 10 Visual Studio 2019 16.4 and Kubuntu gcc (Ubuntu 10.2.0-13ubuntu1) 10.2.0 using the latest VTK Master.

Has anyone any ideas why these examples show this reflection in Linux when compared to Windows? If someone has time and a Mac I would be interested to know if the Mac image matches either Windows or Linux.

At this stage around 1000 of the C++ VTK Examples examples are tested with just two failures in Windows and these five failures in Linux (with an additional one: XGMLReader).

2

Perhaps it is not mirroring but showing the image from behind. i.e. flipping the z axis. Maybe left handed vs right handed coordinate systems for Windows vs Linux or vice versa?

3

That’s a possibility. However the labelling is Ok. This is puzzling because the same classes are used elsewhere in the examples and results are identical in Windows and Linux.

4

Can you display the camera axes in each?

Examples for shapes with a YZ plane of symmetry would appear to be identical.

5

That’ s a good point. I’ll have a go at that tomorrow.

6

The problem seems to be that the default layout: Simple 2D seems to give different results in Linux and Windows. I updated these examples to use Force Directed and the results now are consistent across Linux and Windows.

7

Please file an issue that Simple 2D is platform-dependent.

8

Done, please see: https://gitlab.kitware.com/vtk/vtk/-/issues/18212