mrdoob/three.js — comment on commit 72065046485771874b6f14ae61fda783c30e9b33
File:  line 0
By alteredq:

This is not good, controls now feel pretty broken :S

We lost "autonomous" behaviors of `TrackballControls` - before it was possible to have "momentum" type of response where user initiated behavior continued for a while with damping till motion didn't stop completely. This makes for nicer "feel" of controls.

That's why controls needs to be "powered" from the outside and not just respond to events.