Patent ID: 8243066

Claim:
A method for creating an object model data set of a predetermined surface having a three dimensional shape, said model comprised of a plurality of patches, each of said patches comprised of at least two points associated with a predetermined mathematical function corresponding to said surface, where each point has a corresponding at least one coordinate whose location is calculated using a computer in dependence on the predetermined mathematical function, at least one tangent vector and at least one curvature value, comprising the steps of: for each of the plurality of patches, calculating using the computer for each of the at least two points associated with said corresponding predetermined mathematical function, at least one tangent vector by means of calculating a first partial derivative of said corresponding predetermined mathematical function and at least one curvature value by means of calculating a second partial derivative of said corresponding predetermined mathematical function by retrieving from a storage device the numerical values representing the coordinates of said at least two points and using as input into said computer said numerical values representing the coordinates, wherein the plurality of patches resemble at least part of said surface of said model and the entire surface of said model represented by only a single mathematical function said single mathematical function being the said corresponding predetermined mathematical function, and storing on a data storage device said plurality of calculated numerical values representing said corresponding at least one tangent vectors and at least one curvature values.