System and Method for Performing Undo and Redo Operations during Machining Simulation

A method for determining an intermediate representation of a workpiece corresponding to an intermediate instruction from a set of machining instructions simulating a machining of the workpiece, comprising:

• associating each geometrical element with the machining instruction changing a type of a geometrical element in forming a composite surface of the workpiece to produce at least part of an association, such that the geometrical element is associated at least with one or combination of a machining instruction causing the geometrical element to start forming a part of the composite surface of the workpiece and a machining instruction causing the geometrical element to stop forming the part of the composite surface of the workpiece;
• identifying, using the association and in response to receiving a command to undo a simulation of the machining to the intermediate machining instruction, a subset of geometrical elements forming the composite surface of the workpiece at time of the simulation by the intermediate machining instruction;
• and
• determining the intermediate representation of the workpiece using the subset of geometrical elements, wherein steps of the method are performed by a processor.

A numerically controlled (NC) machining simulation system, comprising:

• a memory storing a computer aided design (CAD) model of a workpiece,
• a NC machining console for determining a set of machining instructions;
• a processor for simulating machining of the workpiece according to the machining instructions, wherein the processor associates each geometrical element with the machining instruction changing a type of a geometrical element in forming a composite surface of the workpiece to produce an association;
• and
• a display device, wherein the processor is configured to render an intermediate representation of the machined workpiece corresponding to an intermediate machining instruction based on the association.