Top three rules for optimization: Profile PROFILE PROFILE!!!!! Until you profile any attempts at optimization are just shots in the dark. There are a million things you could speed up, and 97% of them won't help because they're not part of the bottleneck! So: open your scene in Chrome, hit ctrl+shifti+J to open the dev tools, then go to the "Profiles" tab and make sure "Collect JS CPU profile" is selected. Once there, hit the little start button in the upper left, w