# Stream tracer greyed out
**URL:** https://discourse.paraview.org/t/stream-tracer-greyed-out/13726
**Category:** ParaView Support
**Created:** [January 17, 2024, 12:20pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726 "2024-01-17T12:20:16Z")
**Posts on this page:** 18
**Page:** 1
### Author:  [@Alice\_Williams](https://discourse.paraview.org/u/Alice_Williams)
#### Post date: [January 17, 2024, 12:20pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/1 "2024-01-17T12:20:16Z")
Hi when i run my vtu file on paraview stream tracer is greyed out. I created my file on Freefem. İ need to great stream lines on a slice of 3d velocity . How can I do?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [January 17, 2024, 12:20pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/2 "2024-01-17T12:20:45Z")
please share your data
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### Author:  [@Alice\_Williams](https://discourse.paraview.org/u/Alice_Williams)
#### Post date: [January 17, 2024, 12:24pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/3 "2024-01-17T12:24:00Z")
[u.vtu](https://discourse.paraview.org/uploads/short-url/2pWd2p9RT0OV3Sdn1UDhm6C4kKC.vtu) (108.0 KB)
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [January 17, 2024, 12:30pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/4 "2024-01-17T12:30:06Z")
Your data does not contain any vectors
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### Author:  [@Alice\_Williams](https://discourse.paraview.org/u/Alice_Williams)
#### Post date: [January 17, 2024, 12:32pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/5 "2024-01-17T12:32:27Z")
How can I add ?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [January 17, 2024, 12:54pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/6 "2024-01-17T12:54:46Z")
Not sure what you mean. You have `u`, `scalars1` and `scalars2`, do you want to create a 3D vector fromt them ?
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### Author:  [@Alice\_Williams](https://discourse.paraview.org/u/Alice_Williams)
#### Post date: [January 17, 2024, 1:02pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/7 "2024-01-17T13:02:44Z")
Yes. İ obtained this data from freefem as solution 3d velocity. İ need to get its streamlines but i don’t know how to add vectors to the data
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [January 17, 2024, 1:04pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/8 "2024-01-17T13:04:57Z")
Add a MergeVectorComponents filter and configure it as wanted
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### Author:  [@Alice\_Williams](https://discourse.paraview.org/u/Alice_Williams)
#### Post date: [January 17, 2024, 1:08pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/9 "2024-01-17T13:08:02Z")
Thank you I’m going to try.
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### Author:  [@Alice\_Williams](https://discourse.paraview.org/u/Alice_Williams)
#### Post date: [January 17, 2024, 2:26pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/10 "2024-01-17T14:26:21Z")
Hi to get this which filter did you use? İ did merge filter components and select stream tracer. Mine didn’t turn out like this
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [January 17, 2024, 2:40pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/11 "2024-01-17T14:40:59Z")
Please share a screenshot
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### Author:  [@Alice\_Williams](https://discourse.paraview.org/u/Alice_Williams)
#### Post date: [January 17, 2024, 3:43pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/12 "2024-01-17T15:43:25Z")
The first one is after i applied stream tracer.
The second one is after i applied merge vector components
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [January 17, 2024, 3:54pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/13 "2024-01-17T15:54:34Z")
Here is what I did:
- Open ParaView
- File → Open → u.vtu, Apply
- Filters → MergeVectorComponents, XArray = u, YArray = scalars2, ZArray = scalars3, Apply
- Filters → StreamTracer → Apply
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### Author:  [@Alice\_Williams](https://discourse.paraview.org/u/Alice_Williams)
#### Post date: [January 17, 2024, 4:07pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/14 "2024-01-17T16:07:21Z")
İ did the steps. This happened
Also i need to display streamlines generated by line segment source { (0.5,0.5,z) :0\
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [January 17, 2024, 4:08pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/15 "2024-01-17T16:08:05Z")
Which is good ?
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### Author:  [@Alice\_Williams](https://discourse.paraview.org/u/Alice_Williams)
#### Post date: [January 17, 2024, 4:15pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/16 "2024-01-17T16:15:20Z")
Yours is better. İ want to get like this how can I do it
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [January 17, 2024, 4:18pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/17 "2024-01-17T16:18:07Z")
- Click on the “MergeVectorsComponent” in the pipeline browser
- Show it by clicking the eye
- Set opacity to the representation to 0.2
You may want to read the tutorial though: [Self-directed Tutorial — ParaView Documentation 5.11.0 documentation](https://docs.paraview.org/en/latest/Tutorials/SelfDirectedTutorial/index.html)
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### Author:  [@Alice\_Williams](https://discourse.paraview.org/u/Alice_Williams)
#### Post date: [January 17, 2024, 4:42pm UTC](https://discourse.paraview.org/t/stream-tracer-greyed-out/13726/18 "2024-01-17T16:42:16Z")
Well thank it worked. My main aim is too get a vote like the one I attached now. How can I do
 :0\