I gathered some bits and a code parts from an old project of mine and merged them into a single Processing sketch to test the possibilities of data transferring from Processing to Grasshopper. The gHowl add-on for GH enables this process by receiving Udp signals. The hard part in this case, if you already have a sketch you want to test, is the method to store and transfer the data. The code is quite simple, but it needs to be combined with a class or to get the data from an ArrayList, the speed of the transfer depends on that.
As far as the Processing algorithm is concerned, the process that takes place is a flocking group of agents (coded based on this sketch by Alasdair Turner) that adapt their behaviour to a set of attractors. I am not going to get into detail about the steering rules but many interesting patterns emerge, which could also lead to interesting geometrical and topological configurations in Grasshopper ( a simple example is the image above) .
I am going to upload the Processing sketch(with part of the code) and the Grasshopper definition in the [Sub]Code page.
You will need both the gHowl add-on and the Udp library for Processing for the script to run. Special thanks to the creators of gHowl.