I'm loving the particle work and motion tracking, but am not terribly familiar with the former in particular (pun not intended). Most of the stuff I end up doing is character-based or on the broadcast-news end of things.
Maybe some of you more experienced particle/motion-track folks could weigh in on this one. How was this built out? I'm definitely not expecting details or long breakdowns of the process - y'all have work to do! - but I'd be eager to hear from you even in brief!
There are quite a number of techniques involved, but the basic ones are 3D camera tracking that does most of the work, as then the Plexus effect will seem to live in the same world as the footage. Then there are some individual 3D points that have been selected out to be connected. You can generate nulls with the 3D camera tracker and tell Plexus to use the nulls. You can set an individual group for the nulls (in Plexus) so that they don't interact with every other nearby point, but with just the ones you want.
Plexus has many ways of generating points, I'm sure other methods were used here as well.