As its virtual reality headset nears release, Oculus has acquired yet another company. This time around, it's Pebbles Interfaces, a five-year-old Israeli company working on high-definition hand-tracking technology. "Pebbles Interfaces will be joining the hardware engineering and computer vision teams at Oculus to help advance virtual reality, tracking, and human-computer interactions," says Oculus in a blog post. It's not confirming any further terms of the deal, but a spokesperson said that the group would be moving to Oculus' main campus in Menlo Park, California.

On a very basic level, Pebbles' hardware is similar to the Leap Motion controller. In a Geektime interview from May, the company's marketing manager suggested that it improved on Leap by creating an actual model of a user's hand, not just mapping the motion onto an avatar. It can also provide details about the environment using its depth sensor. Oculus embedded a Pebbles video from May that shows off the technology:

This demo is, relatively speaking, extremely precise. One of the biggest problems with hand-tracking hardware is that it often breaks down the moment your hands get too close to each other (no cracking your knuckles in VR), something that's almost totally absent in this video. That said, a video lets developers clip out any flaws, and we haven't tried it ourselves.

This is at least the fifth company that Oculus has bought since being acquired by Facebook in March 2014, and it's the fourth dedicated to mapping real-world objects. It was preceded by Nimble VR and 13th Lab in December, then by Surreal Vision, which was acquired in May. All these companies do slightly different things, but together they focus on both tracking hands and developing a model of objects and spaces around a subject. When the Oculus Rift ships in early 2016, it will be with an Xbox One gamepad, but Oculus has also said that it's got a research group looking at long-term VR interface design. It showed off a prototype motion controller called the Touch (seen above) at E3 last month.

At that point, CEO Brendan Iribe seemed unenthusiastic about the idea of pure hand tracking, saying that players wanted something physical to grasp. But the Touch has a rudimentary system that recognizes where your thumb and forefinger are, and Oculus seems to be focusing on the very long game of VR design. And signs point to the idea that understanding a player's surroundings and physical body will be very, very important.