1. A non-transitory computer readable medium that stores instructions that once executed by a computer cause the computer to execute the stages of: calculating first curvature attributes of first areas of a first representation of a first three dimensional object; calculating second curvature attributes of second areas of a second representation of a second three dimensional object; selecting first points of interest of the first representation in response to the first curvature attributes; selecting second points of interest of the second representation in response to the second curvature attributes; classifying the first points of interest to first classes; classifying the second points of interest to second classes; calculating multiple sets of first vectors that are indicative of spatial relationships between first points of interest, wherein different sets out of the multiple sets of the first vectors are associated with different first classes; calculating multiple sets of second vectors that are indicative of spatial relationships between second points of interest, wherein different sets out of the multiple sets of the second vectors are associated with different second classes; and determining a misalignment between the first and second representations of the first and second objects in response to relationships between the multiple sets of first vectors and the multiple sets of the second vectors.