1. A method for determining a radial function and distribution of a three-dimensional object model, comprising: retrieving a three-dimensional object model in a CAD system; sampling, by the CAD system, random points on the surface of the object model; determining, by the CAD system, a normal vector corresponding to each of the random points; determining, by the CAD system, a radial function corresponding to each normal vector and respective random point; determining, by the CAD system, a radial distribution corresponding to at least two of the radial functions; and storing the radial distribution and average values of the radial functions in the CAD system.