中文摘要：

广义重心坐标已被广泛应用于三维网格模型的编辑与变形中,而cage是广义重心坐标编辑的重要载体.为此提出一种全自动的cage生成方法.首先对给定三维网格模型做适当简化,然后建立简化网格的距离场,再抽取指定距离值的offset网格,最后根据指定顶点数或误差阈值简化offset网格,从而得到该网格模型的等距cage.其中,最耗时的距离场生成过程可以通过GPU加速使得算法接近实时.实验结果表明,文中方法生成的等距cage能很好地应用于广义重心坐标的网格编辑中.

英文摘要：

The generalized barycentric coordinates have been widely used in mesh editing and deformation,and generation of cages is the basis of the coordinates editing.We propose a simple method to produce cages automatically for a given triangular mesh model to be edited or deformed.The algorithm consists of four steps： firstly,the model is decimated using quadric error metric（QEM） simplification;then a distance field is built upon the simplified model;thirdly,an offset mesh is extracted according to a specified distance value;finally,mesh simplification is performed again on the offset mesh to yield the cage.It almost achieves a real-time rate due to the reason that establishment of distance fields,which is the most time-consuming step,can be sped up by GPU.Experiments show that equidistance cages created by our method exhibit good behavior when applied to mesh editing and deformation based on generalized barycentric coordinates.