14. The computer readable storage device of claim 13 , further bearing computer-executable instructions that, when executed on the computer, cause the computer to perform operations comprising: mapping the model to an on-screen avatar.
13. A computer readable storage device for tracking a user, the computer readable storage medium having stored thereon computer executable instructions that, when executed on a computer, cause the computer to perform operations comprising: receiving a depth image; identifying an estimated location or position of a part of the user in the depth image; adjusting a model of the user based on the estimated location or position of the part of the user; and in response to a failure to identify a location or position of the part of the user in a second depth image, associating the part of the user with a portion of the second depth image based on a location or position of a default position of the part of the user.