Systems, methods, and apparatuses for tracking a body or portions thereof

Systems, methods and apparatuses for tracking at least a portion of a body by fitting data points received from a depth sensor and/or other sensors and/or "markers" as described herein to a body model. For example, in some embodiments, certain of such data points are identified as "super points," and apportioned greater weight as compared to other points. Such super points can be obtained from objects attached to the body, including, but not limited to, active markers that provide a detectable signal, or a passive object, including, without limitation, headgear or a mask (for example for VR (virtual reality)), or a smart watch. Such super points may also be obtained from specific data points that are matched to the model, such as data points that are matched to vertices that correspond to joints in the model.