Point pattern matching has been extensively studied
 and has 
                     many applications. The paper "Using k-d
 Trees 
                     for Robust 3D Point Pattern Matching" by Li
 
                     and Holstein propose to use k-d trees to solve
 problems in 
                     marker-based optical motion capture (MoCap).
                    
                   Movies with 3D animated character and computer
 games need 
                     to have realistic motion of humanoid body to animate
 their 
                     characters. Although, faking the character motion is
 possible 
                     with software such as "character studio" in 3DS 
                     Max, it is not as realistic and we can usually tell
 the difference 
                     between a real motion capture from a person and an
 algorithm 
                     based walk.
                     
                     Other domains such as sports studies and clinical
 gait analysis 
                     absolutely need real and accurate motion of a
 person.
                     
                     With MoCap, the motion of markers attached to a
 human subject 
                     is recorded as motion of 3D points in space. The
 problem is 
                     that each point has to be manually labeled which can
 be costly 
                     in a commercial situation. Using s k-d tree, it is
 possible 
                     to automatically label points. The points of a
 reference subject 
                     in a specified pose have to be manually labeled
 once, 
                     but from this reference pose, it is possible to
 automatically 
                     label the points set of another human subject in the
 same 
                     pose by matching points with the reference subject.
 We will refer to the points on the reference subject as the model
 set, and to the points of the other human subject as the match
 set.