一种基于STEP的CAD模型直接分层方法

提出了一种基于产品模型数据交换标准的3维计算机辅助设计实体模型直接分层方法，零件的原始计算机辅助设计模型以产品模型数据交换标准中性文件的格式输入分层系统，系统提取其几何拓扑信息并重建计算机内部几何模型。用户选择零件的制作方向并指定分层厚度后，系统自动对计算机辅助设计模型进行直接分层，分层结果可直接送到各种快速成型系统加工。基于产品模型数据交换标准的计算机辅助设计模型直接分层不依赖任何特定的计算机辅助设计系统，通用性、灵活性好，而且产品模型数据交换标准文件的数据量大大小于STL文件，有利于网络化设计与制造环境下的数据传输与交换。

Direct slicing of CAD solid models based on STEP

A STEP(standard for the exchange of product model data)-based approach of direct slicing of three-dimensional Computer Aided Design(CAD) solid models outside CAD system for rapid prototyping was presented. Original CAD model was imported into slicing system from CAD system by STEP standard format. Using OpenGL graphics libraries, the solid model was then displayed and specified before being sliced directly. Then the CAD model was sliced automatically after customer defined the layer thickness. The sliced contours were exported by Security Socket Layer (SSL) file format and could be sent to rapid prototyping machines for fabrication directly. STEP-based direct slicing does not rely on any specific CAD system and has better universality and flexibility. The size of a component's STEP file is much smaller than the Standard Template Library (STL) file, which makes it convenient for the data transfer and exchange in Internet-based design and manufacturing.