Abstract: To improve the efficiency of 3D model reconstruction in product conceptual design, a sketch-based mesh extruding deformation method was designed. Extruding area was selected in multi-mode interaction way, and mesh model topology in extruding area was adjusted by system adaptively. By using projection method, 2D extruding curve of freeform or non-freeform was transformed into space 3D curve. The boundary curve of extruding area was swept, and the adjacent curves were sewed to form extruding mesh model. The effectiveness and feasibility of this method was verified on the self-developed software platform.

Key words: sketch technology, mesh, extruding deformation, extruding area, extruding curve, surface fairing

摘要： 为提高产品概念设计中三维模型重构的效率，设计了一种基于草绘技术的网格曲面拉伸变形方法。以多模式交互方式选择拉伸区域，系统自适应调整拉伸区域网格模型拓扑结构；利用投影方法将自由形式或非自由形式二维拉伸轨迹曲线转化为空间三维曲线；将拉伸区域边界曲线进行扫掠处理，进而对已形成的相邻扫掠曲线进行连接，最终形成拉伸网格曲面模型。通过在自主开发的软件平台上进行多种工业模型拉伸变形测试，验证了该算法的有效性和工程可行性。

关键词: 草绘技术, 网格曲面, 拉伸变形, 拉伸区域, 拉伸轨迹曲线, 曲面光顺