What is Edge Bundling?
Edge Bundling is an algorithm that can bundle a large number of lines and display them for easy viewing. This method which called force-directed edge bundling, comprehensively judges and bunds the angle, length, position, and visibility, so you can express lines more beautifully.

Download Source Code
This program is in the Processing-Edge-Bundling repository and, available under the MIT license.
Nekodigi/Processing-Edge-Bundling
Contribute to Nekodigi/Processing-Edge-Bundling development by creating an account on GitHub.
References
This is an explanation video using Houdini by Mr. Horikawa Junichiro.
This project is based on this paper.
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.212.7989&rep=rep1&type=pdf