Hello everyone
I wanted to know if there exists any approach to plot streamlines on a 2D slice of a 3D domain.
Based on the discussions in this forum, I have managed to generate Surface LIC  a good way of visualizing streamlines on a 2D slice of a 3D domain with the following steps :

I load the .pvd file in the attachment below.

Use a calculator to compute the velocity vector (named vel) from the physical velocity components.

Slice the domain using the slice filter.

Visualize vel using Surface LIC
Paraview screen below :
Unfortunately, the density of these lines is very high which makes it difficult for the reader to visualize the corner vortex structures if put on a paper. So, I wanted to know if any alternative approach exists.
For the case of a 2D domain, I adopt a usual approach  generate points using the Mask points filter and apply the Stream Tracer With Custom Source filter to visualize the streamlines. By controlling the number of mask points, I can appropriately control the density of these streamlines.
I have tried a similar approach for the current 3D case by using the Mask points filter after slicing the domain. Unfortunately, I get an error  “No points to mask” with an empty figure in the layout.
For reference the attachment can be found in this link.
Thanks
Sthavishtha