Difference between ParticleTracer and LangrarianParticleTracker

Hello,

I have been reading about the options to track particles within a flow field using Paraview and I found two methods that are plausible. The firs is the Particle Tracer filter (I actually used the particle tracer filter to track particles with somewhat success), and the second one is the LangrarianParticleTracker (LPT). Although I was able to know the interpolation methods that the LPT filter uses to track the particles, I couldn’t find info about the interpolation methods that the Particle Tracer filter uses to determine the position of a particle that changes in time. Does this filter also uses the MatidaIntegrationModel? I also wanted to know where I can find some examples on how to implement the LPT filter.

Thank you for all the support.
Best,
Sergio

ParticleTracer is designed for temporal datasets.
StreamTracer (and LPT) are designed for static datasets.

StreamTracer is simpler than LPT but does not let you create your own interpolation method.
LPT let you create your own interpolation method and provide a integration model as an example (Matida).

Matida is used only by the LPT.

The testing suite of ParaView contains testing dataset for the LPT, here they are : lpt.tgz (2.0 KB)
In the examples you can find a dummy example model plugin to replace matida.

In any case, unless you have very specific needs, you should use the StreamTracer.

Hi Mathieu,

I appreciate the information, and this may be a too of a simple follow up question but I just want to make sure. When you say static datasets, does it mean velocity fields that are invariant in time? So for example, I should not use LPT for a simulation of an open channel flow with time variant boundary conditions. Did I misunderstand you?

Mathieu, do you know where I can find the information about how the ParticleTracer operates? I would like to know how the filter determines the velocity of the position of the particle. Does it just use the cell velocity, or what kind of interpolation method uses to determine the change in position of the particle?

Thank you for all the help.

You are perfectly understanding me.

do you know where I can find the information about how the ParticleTracer operates?

https://blog.kitware.com/improvements-in-path-tracing-in-vtk/
https://vtk.org/doc/nightly/html/classvtkParticleTracer.html#details
https://gitlab.kitware.com/vtk/vtk/-/blob/master/Filters/FlowPaths/vtkParticleTracerBase.cxx
https://gitlab.kitware.com/vtk/vtk/-/blob/master/Filters/FlowPaths/vtkParticleTracer.cxx

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Thank you for the quick response and the information provided. It will be good to read all about it. It is just what I need.

Best,
Sergio

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