original paper: http://www.jessefagan.com/linksviz/forcebundles_eurovis.pdf
This paper described how edge bundling removes clutter and shows edge patterns and how they did it without hierarchy or control mesh. The edges were flexible springs, and the nodes were fixed positions. The self organization technique using physics is very intuitive. They presented both inverse linear and inverse quadratic models in the paper. They also described how bundled edges can differ greatly in length. I liked the section on smoothing using a Gaussian kernel. Figures 7-9 were very clear and effective in expressing the results of their work and without these I may have been a little lost.