Low-power semi-passive relative six-degree-of-freedom tracking

A computer-implemented method, comprising:

• detecting, by a camera of a head mounted display (HMD), at least one marker on an external device within a field of view of the camera, the external device being paired with the HMD, the at least one marker including a known screen state of the external device due to the paired state of the external device and the HMD;
• detecting, by a processor of the HMD, position data of the external device based on the detection of the at least one marker;
• combining, by the processor, the detected position data with acceleration data and orientation data received from the external device;
• and
• determining, by the processor, a six-degree-of-freedom (6DOF) position of the external device relative to the HMD based on the combined position data, acceleration data and orientation data.

A non-transitory, computer-readable medium having instructions stored thereon that, when executed by a computing device, cause the computing device to:

• detect, by a camera of the computing device, at least one marker, on an external device that is within a field of view of the camera, the external device being paired with the computing device, the at least one marker including a known screen state of the external device due to the paired state of the external device and the computing device;
• detect, by a processor of the computing device, position data of the external device based on the detection of the at least one marker;
• combine, by the processor, the detected position data with acceleration data and orientation data received from the external device;
• and
• determine, by the processor, a six-degree-of-freedom (6DOF) position of the external device relative to the computing device based on the combined position data, acceleration data and orientation data.