Abstract: Method of generating tool movement path data 9 includes determining a tool constraining surface (12) which is offset from a three-dimensional surface (22) to be generated, by a distance equal to a radial dimension of rotary machining tool (20), in a direction normal to the three-dimensional surface, determining tool path constraining surfaces (32) for constraining the tool according to the geometry of the three-dimensional surface, and obtaining three-dimensional curved line equations representing intersection lines (34) between the constraining surfaces (12, 32). Since desired curved surfaces may be used as the tool path constraining surfaces (32), the tool movement path can be suitably determined with high freedom depending upon the geometry of the three-dimensional surface (22) to be generated.

Abstract: A process of generating discrete points to be followed by a cutter during movements of the cutter to machine a workpiece, including a step of operating a computer including a data processor, to select at least one of different discrete point generating conditions stored in a memory of the computer, according to a command entered by an operator of the computer, each discrete point generating condition including at least one requirement that should be satisfied when the discrete points are generated so as to define a cutter path, a step of operating the computer to calculate an interval of the discrete points, according to the selected discrete point generating condition or conditions, and a step of operating the computer to generate the discrete points on the basis of the calculated interval, such that the discrete points are spaced apart from each other by the interval. The discrete point generating conditions may include requirements associated with velocities of the cutter during machining of the workpiece.