Merge/update a forked git repository

First add the "upstream" remote:


git remote add upstream https://github.com/mrdoob/three.js.git

Then fetch it:


git fetch upstream

Merge it with your local code:


git merge upstream/master

Resolve any possible conflicts (i.e. go through each file and edit it as necessary), commit and push them, and you're done!

Hopefully the network graph will show you a nicely updated graph in your timeline ;)

Git network graph