1. A method of producing a finite-element model of a unique body of complex shape having an outer surface that is known by a first cloud of points describing said surface analytically or algebraically in a determined frame of reference, comprising the steps of: a) using a generic finite-element model which is parameterizable by means of parameters, the model being made up of simple geometrical volumes that are representative of a family to which the unique body belongs, this model comprising internal finite-elements having surface nodes on outer surfaces of the simple geometrical volumes; b) adapting the model as a function of parameters describing the unique body that is to be modeled; c) within the frame of reference, adjusting position and/or the parameters of the generic finite-element model and causing surface nodes of the parameterized model to correspond with points of the outer surface of the body defined by the first cloud of points by projecting said surface nodes of the outer surfaces of the simple geometrical volumes onto said outer surface of the body along a direction that is normal to the outer surfaces of the generic model creating finite element nodes on the outer surface of the body; and d) using the finite element nodes on the outer surface of the body as a first set of control points in a three-dimensional interpolation method in order to personalize the internal finite elements of the generic finite-element model.