# Choppy streamlines
**URL:** https://discourse.paraview.org/t/choppy-streamlines/6560
**Category:** ParaView Support
**Created:** [February 26, 2021, 11:54am UTC](https://discourse.paraview.org/t/choppy-streamlines/6560 "2021-02-26T11:54:06Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@30Kaz](https://discourse.paraview.org/u/30Kaz)
#### Post date: [February 26, 2021, 11:54am UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/1 "2021-02-26T11:54:07Z")
 
Hello. I’m trying to draw streamlines, but for some reason, the stream lines are so choppy as in the photos. I tried both point cloud seed and line seed, but neither was good.
Can I fix this by tuning paramters?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [February 26, 2021, 1:24pm UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/2 "2021-02-26T13:24:57Z")
Looks like you have way too high velocity. use smaller steps or even divide your velocity with the calculator.
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### Author:  [@30Kaz](https://discourse.paraview.org/u/30Kaz)
#### Post date: [February 26, 2021, 3:32pm UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/3 "2021-02-26T15:32:48Z")
Could you explain what exactly “smaller steps” mean, as there are multiple parameters that look relevant to me?
As for dividing velocity in calculator, the result looked the same as before.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [February 26, 2021, 3:35pm UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/4 "2021-02-26T15:35:22Z")
please share your data.
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### Author:  [@30Kaz](https://discourse.paraview.org/u/30Kaz)
#### Post date: [March 1, 2021, 12:03pm UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/5 "2021-03-01T12:03:31Z")
[pv.zip](https://discourse.paraview.org/uploads/short-url/iVXe6kovgOjK9uyiV1ehXMBhxbh.zip) (772.1 KB)
Sorry for the late reply. I use .txt files, and the columns relevant are: 1 - 3(coordinates), and 4 - 6(velocity).
Thanks in advance.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 1, 2021, 3:25pm UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/6 "2021-03-01T15:25:18Z")
The provided state file cant be opened as some files are missing.
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### Author:  [@30Kaz](https://discourse.paraview.org/u/30Kaz)
#### Post date: [March 1, 2021, 4:41pm UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/7 "2021-03-01T16:41:50Z")
To save the file size, I only uploaded files for time steps 91 - 99. Will it be still impossible to open files after selecting a time between these?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 2, 2021, 9:29am UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/8 "2021-03-02T09:29:04Z")
Click on “Velocity” in your pipeline browser
File → SaveData
Save a .vtu file
Share the file here
Thanks.
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### Author:  [@30Kaz](https://discourse.paraview.org/u/30Kaz)
#### Post date: [March 2, 2021, 10:14am UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/9 "2021-03-02T10:14:05Z")
Unfortunately, I wasn’t able to find .vtu extension. Is it vtk?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 2, 2021, 10:14am UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/10 "2021-03-02T10:14:43Z")
You dataset is a polydata ?
Ok save as a .vtp please.
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### Author:  [@30Kaz](https://discourse.paraview.org/u/30Kaz)
#### Post date: [March 2, 2021, 11:15am UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/11 "2021-03-02T11:15:21Z")
[a.zip](https://discourse.paraview.org/uploads/short-url/cjOslVkrBaS5GebjRe16Z6JDPay.zip) (683.7 KB)
Here is my vtp file.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 2, 2021, 12:23pm UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/12 "2021-03-02T12:23:10Z")
Ok, the problem is that you are using the Streamlines on the output of the Glyph filter, this is incorrect.
Use it on the output of the calculcator instead.
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### Author:  [@30Kaz](https://discourse.paraview.org/u/30Kaz)
#### Post date: [March 2, 2021, 12:44pm UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/13 "2021-03-02T12:44:16Z")
I see. However, I suppose that further tuning of parameters is required, as no lines are present after creating a stream tracer from the output of the calculator.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 2, 2021, 12:45pm UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/14 "2021-03-02T12:45:18Z")
Well, then please share the output of the calculcator.
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### Author:  [@30Kaz](https://discourse.paraview.org/u/30Kaz)
#### Post date: [March 2, 2021, 2:10pm UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/15 "2021-03-02T14:10:13Z")
[calculator\_velocity.vtp](https://discourse.paraview.org/uploads/short-url/8CqbgA8CUGQ8Hilg69VJLuZGYj0.vtp) (296.2 KB)
Here is the result of calculator.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 3, 2021, 8:17am UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/16 "2021-03-03T08:17:45Z")
Your dataset is a point cloud, you can’t compute streamlines on a point cloud.
What is your objective here ?
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### Author:  [@30Kaz](https://discourse.paraview.org/u/30Kaz)
#### Post date: [March 3, 2021, 10:24am UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/17 "2021-03-03T10:24:07Z")
The objective is to see the flow pattern and make a comparison with existing research works, which normally use streamlines.
> you can’t compute streamlines on a point cloud
Is there any solution to this? Or is it inherenty impossible for data of particles?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 3, 2021, 10:26am UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/18 "2021-03-03T10:26:16Z")
Your point cloud is coming from a volumic dataset, it would be better to recover this dataset.
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### Author:  [@30Kaz](https://discourse.paraview.org/u/30Kaz)
#### Post date: [March 3, 2021, 11:25am UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/19 "2021-03-03T11:25:56Z")
To do so, could you tell me what action exactly I need to take?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 3, 2021, 12:44pm UTC](https://discourse.paraview.org/t/choppy-streamlines/6560/20 "2021-03-03T12:44:44Z")
Where is your txt file coming from ?
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