首页> 外文OA文献 >Dynamic Modeling with Implicit Surfaces and Polygonal Meshes
【2h】

Dynamic Modeling with Implicit Surfaces and Polygonal Meshes

机译:隐式曲面和多边形网格的动态建模

摘要

In this thesis, a novel adaptive method for tracking moving surfaces is presented. Our methods are based on a framework for surface propagation, called face offsetting, that moves the mesh faces independently, and reconstructs vertex locations using an eigendecomposition of an error metric together with a viscosity adjustment. Our method prevents local self-intersections, which was a significant roadblock in moving surface meshes. This new framework offers a compelling alternative to level set methods for geometric processing of surface meshes because of its convenience, higher efficiency, and volume conservation.Utilizing the face-offsetting framework, we also develop a new technique for surface smoothing that preserves volume locally (instead of globally) via keeping track of a height function. Volume preservation is critical in many applications, but typical preserving methods rely on a global perturbation to the surface and hence suffer from undesirable side effects.The level sets method propagates a surface represented as an isosurface of a volume of scalar values that automatically accommodates the self-intersection and topology changes that can occur during propagation. The level set method propagates the isosurface in its normal direction according to a user-defined speed function evaluated over it, by deriving and integrating a corresponding time derivative of the voxel values.We apply the power of the level set method to the propagation of an implicit surface represented not as the interpolation of voxel values but more conventionally through the conglomeration of simpler primitive shapes.The proposed strategy retains topological benefits of the implicit representation of evolving surfaces while avoiding the drawbacks of a fixed resolution voxel array. This propagation of course occurs within the limits of the implicit's parametrization, and our method creates a least-squares optimal fit of the implicit to the shape specified by the geometric flow.Morse theory reveals the topological structure of a shape based on the critical points of a real function over the shape. This thesis solves a relaxed form of Laplace's equation to find a "fair" Morse function with a user-controlled number and configuration of critical points.
机译:本文提出了一种新颖的跟踪运动表面的自适应方法。我们的方法基于表面传播的框架(称为面偏移),该框架可独立移动网格面,并使用误差度量的特征分解和粘度调整来重建顶点位置。我们的方法可以防止局部自相交,局部相交是移动曲面网格中的重要障碍。这个新框架由于方便,高效和节省体积而提供了一种可替代水平集方法进行表面网格几何处理的方法。利用面偏移框架,我们还开发了一种新的表面平滑技术,可以局部保留体积(而不是全局)来跟踪高度函数。体积保存在许多应用中至关重要,但是典型的保存方法依赖于对表面的整体扰动,因此会遭受不良的副作用。水平集方法会传播表示为标量值的等值面的表面,该表面会自动适应自身-传播期间可能发生的交叉点和拓扑更改。水平集方法通过推导并积分体素值的相应时间导数,根据对它进行评估的用户定义的速度函数沿等值线在其法线方向上传播。隐式表面不表示为体素值的插值,而是更常规地通过更简单的原始形状的聚集来表示。所提出的策略保留了不断发展的表面的隐式表示的拓扑好处,同时避免了固定分辨率的体素阵列的缺点。当然,这种传播发生在隐式参数化的范围内,我们的方法创建了隐式与几何流指定的形状的最小二乘最优拟合。摩尔斯理论基于的临界点揭示了形状的拓扑结构。形状上的真正功能。本文解决了拉普拉斯方程的一种松弛形式,以找到一个“公平的”摩尔斯函数,该函数具有用户控制的临界点数量和配置。

著录项

  • 作者

    Ni Xinlai;

  • 作者单位
  • 年度 2007
  • 总页数
  • 原文格式 PDF
  • 正文语种 {"code":"en","name":"English","id":9}
  • 中图分类

相似文献

  • 外文文献
  • 中文文献
  • 专利

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号