中文摘要：

为了降低光固化快速成型中成型件的表面粗糙度，解决现有偏置算法中效率低、轮廓自相交和互相交等问题，提出一种基于直骨架的偏置算法．该算法采用多边形单调链分解的方法来提高直骨架计算速度，适用于二维多连通区域；求取偏置多边形前，通过标记偏置分裂及退化的偏置点，用栈的数据组织形式提取偏置多边形顶点，提高了算法稳定性．实验结果表明，在快速成型中，采用该算法的多重轮廓扫描方式能有效降低成型件的表面粗糙度并提高制作效率．

英文摘要：

In order to reduce the roughness on the surfaces of parts in the rapid prototyping, a new algorithm based on the straight skeleton is put forward to solve some problems, such as self-intersecting and mutual-intersecting in existing contour offsetting algorithm. The algorithm can improve the computation speed by decomposing the contours as monotone chains and is suitable for multiply connected two-dimensional domains. Before getting the offsetting contours, some offsetting points which may split contour or be degenerated are marked so that the spilt and degenerated contours can be determined by using stacks. Experimental results show that the scanning mode of multi-contour scanning using the algorithm in the rapid prototyping can effectively reduce the roughness of parts and improve the efficiency production.