Method and apparatus for self-relative tracking using magnetic tracking

A method of providing an avatar of the body of a user wearing a head-mounted display (HMD) to the user, the HMD covering the user's field of vision, the HMD including a HMD tracking system for determining an absolute position and orientation of the HMD relative to a fixed position in the physical world, the method comprising:

• attaching two pluralities of magnetic coils to the user, one plurality of coils to the HMD and the other plurality of magnetic coils to a limb of the user;
• generating a magnetic field from one of the pluralities of magnetic coils;
• generating magnetic sensor data by sensing the magnetic field using the other plurality of coils;
• generating and outputting, by a processor, instructions to the HMD to display on the HMD an augmented reality;
• determining, by the processor, a relative position and orientation of the user's limb relative to the HMD using the magnetic sensor data;
• determining, by the processor, an absolute position and orientation of the user's limb relative to the fixed position in the physical world by combining the relative position and orientation of the user's limb with the absolute position and orientation of the HMD;
• and
• generating and outputting, by the processor, instructions to the HMD to display on the HMD a virtual limb in the augmented reality, the virtual limb in an apparent position and orientation corresponding to the determined absolute position and orientation of the user's limb.

A non-transitory computer readable storage medium having embodied thereon instructions for causing a computing device to execute a method of providing an avatar of the body of a user wearing a head-mounted display (HMD) to the user, the HMD covering the user's field of vision, the HMD including a HMD tracking system for determining an absolute position and orientation of the HMD relative to a fixed position in the physical world, the method comprising:

• generating and outputting, by a processor, instructions to the HMD to display on the HMD an augmented reality;
• determining, by the processor, a relative position and orientation of the user's limb relative to the HMD using magnetic sensor data generated by one plurality of magnetic coils, attached to a limb of the user, sensing a magnetic field generated by another plurality of magnetic coils attached to the HMD;
• determining, by the processor, an absolute position and orientation of the user's limb relative to the fixed position in the physical world by combining the relative position and orientation of the user's limb with the absolute position and orientation of the HMD;
• and
• generating and outputting, by the processor, instructions to the HMD to display on the HMD a virtual limb in the augmented reality, the virtual limb in an apparent position and orientation corresponding to the determined absolute position and orientation of the user's limb.