草图与特征双向关联方法的研究及实现

Bi-directional Association between 2D Sketch and 3D Feature in Parametric Modeling

变量化草图与特征双向关联是特征造型系统中关键问题之一。文中提出了一套以投影参考几何为核心,基于约束求解并依靠特征标识的二维草图与三维特征双向关联方法。利用投影参考几何,重点解决了草图定位问题,以及由此引起的草图更新问题。该方法在基于ACIS开发的系统FeatureMaker中实现了投影参考几何的创建、约束求解、更新,实现了草图与特征的双向关联。经过系统初步验证,方法可行有效。

Bi-directional association between variational sketches and features is one of the key issues in a featurebased modeling system. This paper proposes an effective approach for hi-directional association between 2D sketch and 3D feature. The approach is based on constraint solving and relies on feature identity. By the use of projection reference geometry, it is focused on the solution of the problem that how to constrain and update sketch characteristics by 3D feature. This approach implements projection reference geometry＇s creation, constraint and update in the FeatureMaker system based on ACIS. After primary system verification, this approach is proved to be feasible and effective.