This picture has been obtained with the Tulip 3.5.0-svn release , in that release that graph can be explored in
real time due to the huge improvement of the rendering engine.
The graph is the great lakes graph from DIMACS challenge (all the USA great lakes roads):
see the video here : http://www.youtube.com/user/TulipSoftware#p/u/0/wxjU1gCRhCA
We use the DIMACS import plugin to import it into tulip and the Path Finder interactor to find weighted oriented shortest path between places (in pink in the picture)..