Patent ID: 7898540

Claim:
A method for inputting boundary data of an object to an apparatus comprising a computer operably coupled to receive boundary data from an external data input means, and converting the boundary data by using the computer into cell inner shape data in a cell complex comprising rectangular parallelepiped cells without gaps between the rectangular parallelepiped cells, wherein each rectangular parallelepiped cell has boundary surfaces perpendicular to each other, wherein the method comprises the steps of: (a) using the external data input means of the apparatus to input boundary data of the object; (b) using the computer to perform a cutting point calculation step that includes defining the cell complex that contains the boundary data, and calculating a cutting point where the boundary data cuts an edge or vertex of the rectangular parallelepiped cell of the cell complex; (c) using the computer to perform a cycle formation step that includes classifying the rectangular parallelepiped cells into a boundary cell having the cutting point and a nonboundary cell having no cutting point, and acquiring a cutting segment between a cell surface and boundary data for each boundary cell, and forming a cutting segment cycle that is closed by connecting the cutting points and the cutting segments alternately in sequence; (d) using the computer to perform a cycle internal division step that includes dividing an inside of the cutting segment cycle into cycle inner triangles sharing an adjacent side, for each boundary cell; and (e) using the computer to perform a simplification step that includes unifying a plurality of cutting points on each edge, and registering the cycle inner triangles in the cell, for each boundary cell.