Abstract: A CAD system enables a designer to freely modify a model of a design without regenerating a history of the model, as in traditional parametric feature based modeling. The CAD system automatically determines whether the modifications to the model invalidate current features associated with the model and whether the modifications create new features that should be added to the model. Such a CAD system enables a designer to quickly edit designs and simultaneously preserve design intent without requiring the significant computational resources of historical based approaches that regenerate a geometry upon every edit made by a designer.

Abstract: A CAD system enables a designer to freely modify a model of a design without regenerating a history of the model, as in traditional parametric feature based modeling. The CAD system automatically determines whether the modifications to the model invalidate current features associated with the model and whether the modifications create new features that should be added to the model. Such a CAD system enables a designer to quickly edit designs and simultaneously preserve design intent without requiring the significant computational resources of historical based approaches that regenerate a geometry upon every edit made by a designer.