1. A computerized method for transferring an expression from a plurality of source rigs characterizing a plurality of animated characters to a target rig characterizing a target animated character, each of the source rigs and the target rig characterized by a set of joints and a skin mesh having a plurality of vertices, each vertex, in turn, characterized by a matrix of weights relating a response of the vertex to movement of associated joints, the method comprising: a. defining neutral and goal expressions for each of the multiplicity plurality of source rigs relative to a neutral expression of each source rig; b. building a mathematical model mapping neutral shape to goal expression offsets on a basis of the neutral and goal expressions defined for the plurality of source rigs; c. applying the mathematical model to an unseen neutral expression shape to calculate required expression offsets; and d. vectorially adding the calculated set of offsets to a neutral expression of the target rig in such a manner as to implement the goal expression on the target rig, thereby transforming the target rig; e. transferring a set of skin weights between a selected source rig of the plurality of source rigs and the target rig, the target rig characterized by an associated target skin; f. mapping joints of the target rig to joints of the selected source rig of the plurality of source rigs by means of a transform function derived on the basis of interpolation; g. transforming vertices of the associated target skin by means of the said transform function thereby deriving a plurality of transformed target vertices; h. identifying a plurality of source skin polygons intersecting a normal to a specified transformed target vertex; i. choosing a source skin polygon to associate with each transformed target vertex; and j. identifying each transformed target vertex with the intersection of a normal to said transformed target vertex with the chosen source skin polygon.