1. A computer based method for optimizing a design using free form deformation, comprising: determining a transformation function the free form deformation, using the computer, wherein the transformation function is defined by spline function that transforms a first space in which the design is defined into a second space in which a modified design is defined, wherein a parameter of the spline function determines a parameter of the transformation function; and modifying the design using the transformation function for the free form deformation, wherein the free form deformation is used as a representation for evolutionary computation; wherein the parameter of the spline function defines a parameter of an evolutionary optimization algorithm; wherein a mutation operator of the evolutionary computation acts directly on the representation of the design us the second space in order to introduce or delete control points of the spline function defining the transformation function transforming the spline; wherein the introduction or deletion of control points of the spline function that defines the transformation function transforming the spline does not require altering a shape of the design.