Is there a way to "Threshold" based on Stream Line lenght? Or generally not show "Short" streamlines?

Have been working literally for weeks to make a picture with good streamlines but cant get it to work.

So I was thinking maybe I can somehow “cut” the shorter streamlines and only show the lengthy ones

I don’t think it does quite what you want, but try using the Append Arc-Length filter. Then you can threshold or clip by arc length.

yes but it doesnt “cut” the lines. Just shows the part of the line within thte threshhold

You can use the Cell Size filter to compute the length of each streamline. You can then use the Threshold filter to remove streamlines with a small Length.

Yeah that was it! It’s wroking now! By any chance. Maybe you know how to even add “tube” filter on Threshold/Filter, meaning of the remaining Stream Lines? (doesnt work on Tube , the Cell Size) But still! really helpfull, Wireframe representation is not that bad

Run Extract Surface on the output of Threshold. You can then run Tube on that.

The problem you encountered is that Threshold is turning the poly data of the stream tracer into an unstructured grid (for technical reasons I won’t get in to). But the Tube filter expects a poly data input. You can convert the data back to poly data by running the Extract Surface. The point of this filter is technically to extract the outer surface of volumes, but the filter will pass vertices, lines, and polygons to the output as their own surface.

Alternately, you can turn on the Render Lines As Tubes option in the properties panel. You will also have to set the line width to greater than 1.