At the company’s 2015 pre-E3 show in San Francisco, California, Oculus VR founder and Oculus Rift creator Palmer Luckey introduced a new positional tracking system called Constellation. “We actually have an external sensor that mounts and it can detect the infrared light that is in the headset. We’ve actually got a constellation of infrared, LED light emitters underneath the fabric, and this fabric is actually infrared transparent so it looks black to us, but the infrared light … passes right through,” Luckey explained the reasoning behind the name.
The introduction of the tracking system was urged by Valve’s reveal of their SteamVR virtual reality system, which includes a laser-based tracking solution called Lighthouse. Just like Lighthouse, “constellation will allow for a bigger room area so you will be able to move around in it. And we have a number of different things that we are going to be talking about as we move forward on this,” said Oculus CEO Brendan Iribe.
The Constellation sensor was designed in collaboration with Carbon Design, a design team behind the original Xbox 360 controllers. The shape of the sensor resembles a modern desk lamp consisting of a simple, slim stand that is about ten inches tall and a cylindrical head with an infrared camera inside.
To start using the sensor, a user has to simply place it on their desk and plug it into a computer. During the official announcement of the sensor, the company has stressed that they wanted it to be as unobtrusive and simple to use as possible.
There is a special filter in front of the camera that blocks out everything but infrared light, allowing the camera to track the infrared LED lights built into the Rift precisely. “The visible light filter restricts the light coming into the image sensor to the IR spectrum, meaning the IR LEDs on the headband will shine bright like stars,” states iFixit.
The Constellation system has been designed as an extendable single-camera solution. This gives customers the option to play with various sensor configurations and extend the tracking ability of the system for use with Oculus Touch controllers.
Single Tracking Sensor
Each Rift comes with one tracking sensor, which is enough to track the headset itself. Those who also purchase the Touch controllers get another sensor to prevent the issue “that the single sensor could be easily confused and occluded by one or more of the Touch controllers,” explains TechRadar.
Multiple Tracking Sensors
Touch requires, at least, two sensors to operate correctly. Oculus’s advice is that the sensors should be placed in parallel on your desk and be facing forward. This allows for standing front-facing Touch experiences. Two cameras pointed in opposite directions, on the other hand, allow for standing 360-degree Touch experiences. "Two cameras placed in opposite corners of the room will provide a large play space, but this risks placing them so far away from the headset that they have trouble seeing the markers clearly; this is ‘room-scale’ capable and a full 360° degree experience, but not terribly robust," explains Oculus.
After connecting the controllers to an open USB 3.0 port, users are required to complete a setup process. According to Oculus, the front-facing two-sensor-setup is expected to be the most popular. The company believes that most home users will see two front-facing cameras as the most practical solution.
For true room-scale VR, Oculus requires a third sensor. Such sensor can be purchased separately for $79. Some tech reviewers have noted that the final sensor setup is considerably less elegant than what the company’s competitors use. The third sensor enables Oculus to see you when the user turned around in a space up to an 8×8 feet large. "However, we found that this space limitation is mostly artificial. By spreading that third sensor out farther and moving the two main sensors a bit further apart, we were able to get closer to 9 ft. or 10 ft. tracking in either direction," commented Upload VR.
Oculus wants to allow third-party peripheral manufacturers to create their own devices that are tracked by the system. Oculus founder Palmer Luckey told Road to VR that he believes the company’s Touch controller is “making the right set of compromises and tradeoffs to make a pretty universal VR input,” adding, “it’s never going to be better than truly optimized VR input for every game. For example, racing games: it’s always going to be a steering wheel. For a sword fighting game, you’re going to have some type of sword controller. For things that are really about fine-grain finger interactions, it’s probably going to be maybe even some type of glove or computer-vision-based hand tracking solution.”