【作者】 邹林灿；

【导师】 彭群生； 陈为；

【作者基本信息】 浙江大学 ， 计算机应用技术， 2007， 硕士

【摘要】 基于网格表示的动画设计在诸多领域有着广泛的应用,如计算机视频游戏,三维动画电影,虚拟现实等。随着数字扫描仪的推广应用,网格业已成为表示和处理场景几何的标准方式,交互的网格动画的编辑成为近年来计算机图形学的研究热点之一。本文提出并实现了一个基于梯度域的网格动画编辑系统。我们首先实现并探讨了基于multi-level的编辑算法[1]。尽管该算法能满足大部分编辑要求,对于某些特殊模型的编辑效果并不理想。经过研究实验,我们提出了基于拉普拉斯方程的梯度域网格动画编辑新算法。算法采用关键帧编辑的思想,首先考虑用户对某些关键帧网络的几何约束,然后将这些约束传播到整个网格动画序列,从而产生满足用户编辑要求的新的网格动画。在关键帧编辑时,我们提出了交替最小二乘算法,充分利用子空间变形技术和两步线性法来获得高质量的编辑效果。同时,我们还提出了一系列实用技巧来帮助用户指定模型变化的约束条件,简化用户的编辑操作。实验结果表明,我们的网络动画编辑系统对各种场景都能快速获得令人满意的效果。更多还原

【Abstract】 Deforming mesh sequences has been heavily used in many areas of computer graphics, including computer games, 3D animation films, and virtual reality. Recently, due to the boosting usages of digital scanning devices and mesh, the research on editing of deforming mesh sequences has been paid much attention in computer graphics community.In this thesis, we design and develop a gradient domain based algorithm for deforming mesh sequences editing. First, we implement and analyze the multi-level algorithm proposed in [1]. Although this algorithm can meet most editing requirements, it does not work for a set of specialized mesh deforming tasks. We then propose a novel deforming mesh editing algorithm that is based on gradient domain and takes the similar technical way of the key-frame based mesh animation. Given a set of sparse and irregularly distributed constraints at unevenly space key-frames, our solution first adjusts the meshes of key-frames to satisfy these constraints, and then smoothly propagates these constraints to the whole sequence to generate new deforming mesh sequence. To achieve convenient and intuitive key-frame editing, we present an efficient alternating least-squares technique, which harnesses the power of subspace deformation and two-pass linear methods to achieve high quality results. We have also developed an effective algorithm to help users define the boundary conditions for mesh sequence, which avoids most of unnecessary editing operations. Our mesh deformation system has been successfully applied to a number of editing scenarios and achieved visually pleasing results.更多还原