Electric/magnetic field lines seem to be a problem in Paraview by default. Especially magnetic lines, because magnetic field does not have a flow source.
You can not follow this tutorial, because THE FIELD is not made of particles. And vectors do not follow the energy transfer path, like particles do (more often, vectors are orthogonal to the energy transfer, but it is not a strict rule… I mean you need a complete set to understand the energy flow, equivalent of “speed field”, if you are not familiar with Poynting vector. But usually we are interested just in one component’s static picture, and other components are not available)
Displaying bent lines with density proportional to the field magnitude is not implemented in the filter set.
So, maybe there is a way to stack filters for adequate representation, like it was made foe particle flow by the link above?
input: nonuniformly spaced 3D grid of field vectors. the grid spacing is NOT related to the density of field lines.
goal: bent field lines or a set of sequential (end-to-tail) bent arrows folowing interpolated vector field, with density of placement proportional to the (vector) field magnitude.
Like here:
Or here:
which are pretty standard representations in electromagnetics