三维几何数据的交互式着色算法

获取三维模型的纹理信息是计算机图形学领域的一个重要研究问题.传统的方法往往通过纹理映射来完成这个任务,其局限是需要一幅合适的纹理图像.为了能够更简便地得到模型的纹理,提出一种交互式着色算法.对于网格模型,首先进行显著特征的提取和分类来减少用户对重复出现的特征的交互量,进而由用户在不同区域上交互几条颜色曲线作为种子曲线.然后结合位置、法向和曲率信息来衡量相邻顶点的相似度,以防止相邻区域之间出现渗色,并通过随机游走算法计算出每个顶点到每条种子曲线的跳转概率;最后以跳转概率作为权值对各条种子曲线的颜色进行加权平均,得到每个网格顶点的颜色.进一步地,还将上述算法应用到点云模型上.实验结果表明,该算法能够准确地区分不同的区域,鲁棒地为三维模型着色.

An Interactive Colorization Algorithm for 3D Models

It is a fundamental problem to obtain texture information of 3D models in computer graphics. Texture mapping was often used to complete this task. However, texture mapping needed a suitable texture image. Therefore, an interactive colorization algorithm is proposed in this paper to obtain texture information more easily. For a mesh model, salient features are first extracted and classified to reduce user’s interaction on repetitive features, and then user can scribble some curves with desired colors in various regions as seed curves. Secondly, position, normal, and curvature information are combined to measure vertices similarity to avoid color bleeding between neighboring regions, and random walk algorithm is adopted to compute the probability from each vertex to each seed curve. Finally, weighted by these probabilities, the color of each vertex can be expressed as the weighted average of seed curves’ color. Furthermore, the above algorithm is applied to colorize point clouds. Experiment results show that our algorithm can distinguish different regions accurately, and colorize 3D models robustly.