Lambertus Hesselink and Thierry Delmarcelle visualize velocity fields by
extracting its topological sceleton.
The above image shows how a flow near the body of a hemisphere
cylinder is visualized by extracting the topology of the Jacobian
of the velocity field: critical points (foci, saddles, attracting and
repelling nodes) are located then and connected by integrating
streamlines along the saddle points.

In image 7 we show how a similar method is
can be applied to a general tensor field.