支持模型重用的三维参数化特征造型

THREE DIMENSIONAL REUSABLE PARAMETRIC FEATURE-BASED MODELING

本文提出了三维参数化特征造型的一种新的思路和方法。特征分为广义几何特征和应用特征，应用特征的几何信息可用广义几何特征表示；三维参数化特征建立在浮动基准体系上，在勾画平面上勾画二维参数化轮廓，勾画时可以引用三维模型在勾画平面上的投影，勾画轮廓经过广义扫描生成三维参数化特征，特征的定义过程用过程语义描述；隐式基准和虚索引对象为特征“剪贴”的实现提供了必要的保证，同时特征“剪贴”支持模型的重用、应用特征库的定义和用这些应用特征进行设计。

A new methodology on three-dimensional parametric feature-based modeling is presented. Feature is classified into generalized geometric feature and application feature; The geometric information of application feature can be represented by generalized geometric feature. Three-dimensional parametric features are attached to floating datum system, and its shapes can be constructed by the sweeping of sketched profiles. Two-dimensional parametric profile is sketched on sketching plane, and can use the projection of three dimensional model on the sketching plane as constrain reference. Process semantics is used to represent the generation process. Virtual datum and virtual reference object are the base of cut & paste operation that supports model reusing, the definition of application feature library and the design by the use of these application features.