We first heard about Valve's plans for a new SteamVR controller back in October when a few pictures and basic impressions started leaking out of the press-free Steam Dev Days conference. Now we're getting more details about the upcoming VR hardware—code-named Knuckles—thanks to documents posted on SteamVR's Knuckles Dev Kit group page.
The most important confirmation in the new documents is that the Knuckles controllers allow for full, independent tracking of all five fingers. Embedded, capacitive sensors in the handle of the unit track the position of the middle, ring, and pinky fingers, while similar sensors in the trigger and face buttons track the index finger and thumb. A ring of sensors around the thumbpad and the back of the hand helps track the unit in space through the standard Lighthouse system.