Abstract: A digital watermarking scheme proposed for the copyright protection of 3D mesh model using normal vector distribution of each patch.The key idea is to divide the 3D mesh model，replace center of mass of the whole 3D model by that of each patch，then generate the unit of each patch.At the basis of incurring minimal cost in terms of visual sensation system adjusting center of mass of each patch to embed individual bits of information which are spread over the whole surface of the model.Experimental results show that the proposed algorithm has robustness against various attacks such as cropping，affine transform，noise and simplification，and maximized the number of watermarking locations and enable to control the degree of redundancy if required.

Key words: copyright protection, digital watermarking, 3D model, normals, robustness

摘要： 针对三维网格模型数据的版权保护提出一种基于块矢量分布的三维网格模型数字水印算法。对三维网格模型进行分块，用块质心集代替原模型质心，构造模型块曲面的基本几何单元，视觉系统产生最小代价的基础上，调整块质心来嵌入单位水印信息，从而改变顶点位置使水印信息遍布整个模型。实验结果表明该算法对剪切，仿射变换、随机噪声和网格简化等攻击有较好的鲁棒性，具有较高的水印信息嵌入量和信息的冗余度。

关键词: 版权保护, 数字水印, 3D模型, 矢量, 鲁棒性