Abstract: Because the pitch is the non-circular curve, the machining process of non-circular gear is
complex, and the simulation is difficult. In this paper, for the manufacturing of non-circular gear,
simulation of virtual gear shaping process from blank to finished product is realized, namely in
accordance with the prior preparation of the G code (NC program), to drive virtual slotting machine
in order to remove a virtual blank material. Through discretizing the blank model, in the cutting
process, the cutting material node is removed from the scene to realize the machining simulation;
through the tree scene graph structure, the virtual machining environment is built effectively; with the
coordinated operation of the complex motion of NC gear shaper processing process, the simulation of
machining process based on G code is realized. Using Visual Studio 2008 as a development platform,
combined with open scene graph (OSG) graphics library, the forming process of the work piece is
well reproduced, providing useful reference and improvement for product processing.

Key words: non-circular gear, modeling, cutting simulation, open scene graph