# Questions about the "ParticleTracer" filter
**URL:** https://discourse.paraview.org/t/questions-about-the-particletracer-filter/8549
**Category:** ParaView Support
**Created:** [December 2, 2021, 5:19pm UTC](https://discourse.paraview.org/t/questions-about-the-particletracer-filter/8549 "2021-12-02T17:19:56Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@fdekerme](https://discourse.paraview.org/u/fdekerme)
#### Post date: [December 2, 2021, 5:19pm UTC](https://discourse.paraview.org/t/questions-about-the-particletracer-filter/8549/1 "2021-12-02T17:19:56Z")
Hello,
I would like to do particle tracking with the “ParticleTracer” filter on a .vtu temporal file.
However, I have several questions:
-
1. Why do some particles disappear (apparently when they touch a surface?)
-
1. Some particles stick to the walls and get stuck. Is it possible to prevent this?
==\> Is it possible to make sure that all the particles that are simulated to enter eventually come out?
-
1. After some iterations, when some particles go out of the calculation domain, Paraview crashes. I have done several experiments and I don’t really understand why.
\*The parameters I use are the following: \*
\*Source point : \*
_Number of points: 100_
_Radius = 1_
\*ParticleTracer : \*
\*Force reinjection every Nsteps: 0 (only one particle pool is simulated) \*
_Select Input Vector: velocity_
Thanks in advance for your answers!
fdekerme
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [December 3, 2021, 9:13am UTC](https://discourse.paraview.org/t/questions-about-the-particletracer-filter/8549/2 "2021-12-03T09:13:46Z")
please share your data
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### Author:  [@fdekerme](https://discourse.paraview.org/u/fdekerme)
#### Post date: [December 3, 2021, 10:57am UTC](https://discourse.paraview.org/t/questions-about-the-particletracer-filter/8549/3 "2021-12-03T10:57:58Z")
I sent them by private message
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [December 3, 2021, 1:45pm UTC](https://discourse.paraview.org/t/questions-about-the-particletracer-filter/8549/4 "2021-12-03T13:45:37Z")
Your dataset contains only polydatas, no volumic unstructured grid.
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### Author:  [@fdekerme](https://discourse.paraview.org/u/fdekerme)
#### Post date: [December 3, 2021, 3:56pm UTC](https://discourse.paraview.org/t/questions-about-the-particletracer-filter/8549/5 "2021-12-03T15:56:12Z")
ah ok sorry I sent you the missing elements
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [December 13, 2021, 11:12am UTC](https://discourse.paraview.org/t/questions-about-the-particletracer-filter/8549/6 "2021-12-13T11:12:25Z")
I was not able to produce any particle tracing with your dataset, so something is off, however more investigation is needed to understand what is going on I’m afraid.
I have no quick fix to suggest.
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### Author:  [@fdekerme](https://discourse.paraview.org/u/fdekerme)
#### Post date: [December 14, 2021, 4:03pm UTC](https://discourse.paraview.org/t/questions-about-the-particletracer-filter/8549/7 "2021-12-14T16:03:49Z")
Ok I looked, the problem comes indeed from my data : the first timstep (Time = 0) is different from the others and makes the ParticleTracking crash. So I deleted it from the folder.
Sorry, I didn’t understand that the problem came from my data because I was using the temporal interpolator (resample factor = 10) and the simulation crashed only at Time = 11.
Now I have the attached error, and still the 2 following problems:
- Why do some particles disappear (apparently when they touch a surface?)
- Some particles stick to the walls and get stuck. Is it possible to prevent this?
[error\_report.txt](https://discourse.paraview.org/uploads/short-url/aRhLvoBr7cfkAqdhGWsFwZnvMmi.txt) (253.1 KB)
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [December 14, 2021, 4:05pm UTC](https://discourse.paraview.org/t/questions-about-the-particletracer-filter/8549/8 "2021-12-14T16:05:09Z")
> [@fdekerme](#):
>
> - Why do some particles disappear (apparently when they touch a surface?)
They go out of the domain, surface interaction is not supported by the Particle Tracer
> Some particles stick to the walls and get stuck. Is it possible to prevent this?
This is how your data is, no velocity on the walls edge I suppose ?
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### Author:  [@fdekerme](https://discourse.paraview.org/u/fdekerme)
#### Post date: [December 15, 2021, 1:52pm UTC](https://discourse.paraview.org/t/questions-about-the-particletracer-filter/8549/9 "2021-12-15T13:52:01Z")
Yes, you are right.
Apparently neither the LagrangianParticleTracker nor the ParticleTracer is suitable for my case. I will look for a new solution! 🤔
Thank you very much for your help! 👍