A method for achieving a representation of an object within a data structure for a Computer Aided Design system employing a Medial Axis Transformation (MAT), the representation of the object comprising a set of adjacent bounded surface elements called MAT faces, the MAT faces being bound by sets of MAT edges, which are portions of curves lying on a surface of the MAT faces on either side of the edge, and points where several MAT faces meet are called MAT vertices. The method comprises at least defining each of the MAT vertices as points in a space domain; assigning a radius function to each of the MAT vertices, based on only a single value; defining each of the MAT edges as a curve in space; defining limits of each of the MAT edges as two MAT vertexes which lie on the curve; assigning a radius function to each of the MAT edges; defining each of MAT faces as a surface in space; defining the limits of each of the MAT faces as a MAT loop, comprising at least three MAT edges, sharing each a MAT node, whereby a direction, clockwise or counter-clockwise, of the MAT loop defines on which side of the MAT loop the MAT face will be formed; defining the MAT links as the edges which are shared by at least two MAT faces; assigning a radius function to each of the MAT faces; and defining a MAT object as a connected set of MAT faces, edges and vertices.