基于最大内切球拟合的网格模型骨架提取

Skeleton Extraction of 3D Meshes by Fitting Maximal Inscribed Spheres

作为三维模型的一维表示方式,模型骨架表示和提取技术在计算机图形学和计算机视觉领域具有广泛的应用.为了有效地从输入网格模型中提取高质量的骨架,提出了一种新的基于最大内切球拟合的骨架提取方法.首先,用户分别交互选取模型主干内任意一点以及各分枝末端任意一点作为骨架提取的初始点;其次,根据选取的初始点利用最大内切球拟合和提取算法得到初始最大内切球,取球心为模型骨架点,并利用该最大内切球沿模型主干迭代扩散,寻找其余的模型最大内切球和相应的模型骨架点,同时将主干骨架周围区域设为影响域;然后,根据交互选取得到的分枝末端点,以类似方法沿末端到主干影响域寻找分枝骨架点;最后,基于距离优先算法选取合适的骨架汇合点生成完整的模型骨架.针对AIM@SHAPE提供的实验用模型,利用该方法提取的模型骨架点能准确地位于模型的中轴位置,同时通过调整参数值能保证提取的模型各分枝骨架的平滑性.

Model skeleton is a 1D-representation of 3D models,which has been widely used in the areas of computer graphics and computer vision.In order to effectively extract high quality skeletons from the input meshes,a novel skeleton extraction algorithm is proposed which is based on the maximal inscribed sphere fitting.Firstly,the user can select one point in the main trunk of the given model and one point at the end of each branch,which can be considered as initial points for skeleton extraction;Secondly,the initial inscribed sphere can be generated using our maximal inscribed sphere extraction algorithm and its center can be selected as skeleton point.Iteratively spreading the fitting ball along the main trunk,the algorithm can also find the rest skeleton points and setting the area around the main skeletons as the impact domain.Then,from the picked point at the end of each branch,our skeleton point selection method can be adopted to find the branch skeleton points along the end point towards the main trunk.Finally,the appropriate skeleton convergence point is selected using distance-first algorithm for connecting the skeleton of main trunk and branches.Taking the models provided by AIM@SHAPE as examples,the skeleton points selected by our algorithm always locate near the model medial axes which demonstrates that our approach can efficiently extract the smooth skeletons of the given 3D mesh models.