Abstract: The CAD system includes primary-geometric data extraction means for extracting primary geometric data from a CAD object selected; primary-geometric-condition determination means for deriving a geometric condition from the primary geometric data; automatic recognition means for performing automatic recognition of a CAD object that satisfies the geometric condition with respect to the selected CAD object; secondary-geometric data extraction means which extracts secondary geometric data from the additionally selected CAD object; and secondary-geometric-condition determination means for deriving a geometric condition from the secondary geometric data. The automatic recognition means performs automatic recognition of a CAD object that satisfies the geometric condition derived by the secondary-geometric-condition determination means with respect to the first selected CAD object, the automatically recognized CAD object that satisfies the first derived geometric condition, and the additionally selected CAD object.

Abstract: A CAD system and a CAD cooperative system maintain correspondence between a two-dimensional design plane and a three-dimensional design space (hereinafter referred to as a model), and between models for the same target. The correspondence between models is managed by an intra-model correspondence management unit, and the reference between models is managed by an inter-model reference management unit. Thus, there can be an interlocking operation between a two-dimensional design plane and a three-dimensional design space. furthermore, a three-dimensional reference can be automatically set for a three-dimensional design space to another model.