Data Structure of FSMTS

Traditional CSG + B-Rep data structure is not oompetent to express product feature information, since the CSG model is used only as an input facility, and once the shape defined, the CSG model and B-Rep model are separated, so that the product informations have to be attached to CSG model or B-Rep model londy. On the purpose of satisfying the requirements of Feature Solid Modeling Tool System, this paper propose a hybrid data structure from the CSG model and the B-Rep model The main features of the data structure are that it is convenient to set up a parametric product model and. to modify the product model on the interactive state.