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[General] Stream tube visualization

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Old   March 7, 2017, 04:33
Default Stream tube visualization
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Is there any chance to set up a flow visualization with stream tubes in paraview?
I know that you can compute stream lines and then add the "tubes" filter afterwards. But that does not come close to the usual definition of a stream tube.
https://www.princeton.edu/~asmits/Bi...treamline.html
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Old   March 13, 2017, 03:22
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Quote:
Originally Posted by flotus1 View Post
Is there any chance to set up a flow visualization with stream tubes in paraview?
I know that you can compute stream lines and then add the "tubes" filter afterwards. But that does not come close to the usual definition of a stream tube.
https://www.princeton.edu/~asmits/Bi...treamline.html
Hello Alex,

With respect to the definition of a stream tube you should be able to achieve this with a simple manipulation of the streamlines seed source.

There is probably many different ways to do this, but i normally first create a cylinder (Sources -> Cylinder, increase resolution to ~20), which I then slice in the transverse direction to get a circle (Filters -> Alphabetical -> Slice ). On this circle i then apply a mask points filter (Filters -> Alphabetical -> Mask Points) with the "generate vertices" activated (tune the parameters in this filter to get the correct number of seed points). Then one can use the transform filter (Filters -> Alphabetical -> Transform) to position this circle with points to the correct seeding place in the domain.
Last step is then to apply a "stream tracer with custom source", select your volume mesh domain as "input" and the points circle as "seed source".

This should then do the trick to create a stream tube, hope this will work for you and good luck with your work.

Cheers
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Old   March 13, 2017, 05:41
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Thanks for your input, this is really close to what I had in mind.
With 20 seed points the result looks like this for a sample dataset:
streamtube_20.png
Of course I can increase the number of seed points to a maximum of 512 to get a more "tube-like" appearance.
streamtube_512.png
This would be perfect with some method to create a surface from the streamlines to get the appearance of a closed tube.
Edit: and would make it possible to get a better idea of the shape due to correct lighting. Lines are not ideal in this context.
Do you have any hint how to do this?

Last edited by flotus1; March 13, 2017 at 09:19.
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Old   June 4, 2017, 05:49
Default Smoothing the appearance of the tubes
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Hello Alex and Swempa,

I have created Tubes filter on streamlines for my case, the snapshot of which is attached.

This screenshot image from paraview appears with blurs or steps on the surface of the tubes.

How to make the surface of the tubes smooth without the blurs or steps?

Thanks!


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File Type: png Screenshot from paraview.png (67.1 KB, 81 views)
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Old   June 4, 2017, 06:47
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Quote:
Originally Posted by vidyadhar View Post
Hello Alex and Swempa,

I have created Tubes filter on streamlines for my case, the snapshot of which is attached.

This screenshot image from paraview appears with blurs or steps on the surface of the tubes.

How to make the surface of the tubes smooth without the blurs or steps?

Thanks!


vidyadhar
Hi Vidyadhar,

Your issue seems just to be connected to the resolution of the exported screenshot ( in your case 223x819 pixels), when saving the screenshot try to increase the "Select resolution for the image to save", and keeping the aspect ration by applying the "lock aspect" before adjusting the resolution.

Cheers
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