vtkStreamTracer gives different results between VTK 8 and VTK 9

Support
1

Hi, we are using the vtkStreamTracer filter and noticed some differences between the versions 8.1.2 and 9.3.1 of VTK.

We wondered if it was possible to get back the previous results with a combination of settings in this specific filter.

We are currently using the following parameters on this filter:

ForceSerialExecution = true
IntegrationDirection = BACKWARD
IntegrationStepUnit = LENGTH_UNIT
MaximumPropagation = 1000
MaximumError = 1e-4
IntegratorType = RUNGE_KUTTA45

I will check whether new development in future versions of VTK changes those results. Thanks.

2

Hi @Olivier_D

Is the new result incorrect or is it only changes of behaviors ?

Could you share images of these changes ?

1 Like
3

As an example, here are some results that we got between VTK 8 and VTK 9 for the platforms Mac x86, Mac ARM, and Windows x86.

The differences are subtle visually and, while not incorrect, we’re investigating what could have triggered this change.

2025-02-06_vtkStreamTracer.zip (1.4 MB)

4

Given the kind of difference we see, looks like any kind of bugfixes in the integration logic could have made such changes.

5

Green is VTK 9, white is VTK 8

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