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.

Combined with a cinch-able soft strap that locks the controller around your palm (and through the crook between your thumb and index finger), you get a handheld controller that lets you move and flex your fingers independently at will without the risk of dropping it. This goes even farther than the Oculus Touch controllers, which only let you open your fingers slightly while tracking the three non-index fingers together via an analog trigger. A screenshot from a new version of SteamVR Home even shows a Knuckles user throwing up the horns in virtual reality.

For the non-thumb fingers, the Knuckles capacitive sensors "return a curl value between zero and one, where zero indicates that the finger is pointing straight out and one indicates that the finger is fully curled around the controller," according to a posted overview. In other words, these sensors can detect fine gradations in the position of your fingers as you open and close them around the controller, rather than just a two-state, digital "closed" or "open" status. The face button sensors, on the other hand, appear to simply detect whether the thumb is resting on a button or not (and, if so, which one).

Knuckles' finger-sensing capabilities are dependent on a calibration process that sets the controller up to work with a user's particular "skin capacitance," according to the documents. These values are recalibrated continuously as you use the controller during play to account for changes in your hand over time (sweat, etc.). The Knuckles controller can also be configured to work automatically in games that were designed for older SteamVR controllers, using the capacitive sensors to emulate either the trigger or the grip buttons on those controllers.

The current Knuckles controller dev kit reportedly has a battery life of three hours and requires an hour of USB Micro charging to fill up (similar in both respects to the current Vive controllers).

While we'll obviously have to try the Knuckles controllers for ourselves before giving our impressions, the details here make it sound like a distinct step up from the current state-of-the-art in consumer virtual reality hand-tracking. Hopefully Oculus and Vive will continue pushing each other to create more accurate and comfortable ways to track all sorts of motion in VR.

Listing image by Valve / SteamVR