With that out of the way, I tried comparing the results of my filter to the ones obtained with this plugin: VCG - Vortex Criteria - ParaView Plugin - Visual Computing Group - Heidelberg University
Had to go back to PV version 5.6 to use it though.
The results don’t look too promising. With Lambda2 as a criterion to identify vortices in turbulent flows, the results on the left (from the plugin) are much more plausible.
Bottom row of images is an iso-surface with a value of -5e9.
