Numeric and curve parameters for freeform surface feature models
自由曲面特征模型中的数值和曲线参数*

A successful feature modeling system, largely depends on whether it can provide a user-friendly way to specify and change feature models. Aiming at this point, this paper introduced several new facilities. The first, presented numeric and curve parameters for specification and variation of freeform surface feature models. The second, other parameters could be added to a feature model, including intersection curves between features. To provide these facilities, introduced a new three-level structure, which included three parts, the highest level, called the unevaluated model, the lowest level of the feature model was the evaluated model, a new intermediate level, called the partially evaluated model. The latter linked the features at the highest level to the geometric model at the lowest level, but also intersectioned between features to both their definitions at the highest level and the geometric model at the lowest level.