From my own code.
Does your own code manipulate volumic data at any point ? Is it a point based simulation ?
It is point based. For that reason, in the first post, particles are seen in the figure on the right.
Since your data set does not look too big, I would suggest using one of the Delaunay filters to draw triangles or tetrahedra. If your points are on a 2D plane, use the Delaunay 2D filter. If your points are in general 3D position, use Delaunay 3D.
There are other ways to estimate grids between discrete points, but this will probably be easiest for your data.
I was able to draw streamlines by this method. Thank you very much.