Pose tracking pipeline

A method of computer modeling a human subject, the method comprising:

• receiving from a source a depth image of a scene including the human subject, the depth image including a depth for each of a plurality of pixels;
• and
• modeling the human subject with a plurality of shapes, each of the plurality of shapes characterized by a machine readable position variable, the machine readable position variable for each shape defining a position of that shape within a volume occupied by the human subject.

A data-holding subsystem holding instructions executable by a logic subsystem to:

• receive from a source a depth image of a scene including the human subject;
• and
• model the human subject with a plurality of spheres, each of the plurality of spheres characterized by a machine readable position variable, the machine readable position variable for each sphere defining a centroid position of that sphere such that the plurality of spheres collectively occupy a volume of the human subject.