CGV: Small: Mesh-based Simulation of Thin Liquid Structures

CGV：小型：基于网格的薄液体结构模拟

• 批准号: 1319483
• 负责人: Eitan Grinspun
• 金额: $ 50万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1319483&HistoricalAwards=false
• 关键词: CGV; Small; Mesh; based; Simulation

In this research the PI will develop efficient mesh-based algorithms to simulate the dynamics and interactions of thin liquid structures such as sheets, jets, bubbles, and films. The thin geometry of these liquid phenomena poses tremendous difficulties for traditional techniques, leading to long runtimes and excessive memory consumption. The PI argues that a fundamentally different approach that recognizes and exploits the unique geometry of thin liquids is needed in order to simulate them efficiently and accurately (by analogy with the special treatment of thin elastic bodies such as rods, plates, shells). The project is comprised of three thrusts. First, the PI will develop algorithms for the dynamic simulation of liquid bodies composed of high viscosity threads and sheets, including physical modeling, collision processing, topology changes, and mixed dimensional remeshing. Second, he will address the specific challenges of low viscosity jets and sheets, considering in particular the enhanced influence of surface tension, sheet breakup, and the choice of Eulerian vs. Lagrangian evolution. Finally, he will examine the deformations of films, bubbles, and foams, using a new mesh-based representation for deforming multi-region interfaces, coupled to the fluid dynamics of the surrounding air. In each thrust, the predictive power of the techniques developed will be validated against both experimental observations and theoretical results from the literature.To these ends, the PI will bring several geometric and computational techniques from the dynamics of thin elastica to bear on the dynamics of thin fluids. The PI believes this cross-pollination of ideas has the potential to provide dramatic improvements in efficiency and accuracy, while yielding computational tools that complement theory and experiment in the study of thin fluid phenomena. By considering a thin material as a lower dimensional object (curve or surface) with an associated thickness, the dimension of the problem can be reduced, yielding improved numerical properties and better allocation of degrees of freedom. This perspective has never before been applied to develop computational techniques for three-dimensional thin liquids. The use of non-manifold meshes to represent mixed bodies of thin liquids also opens up previously unexplored challenges in mixed dimensional remeshing and the handling of topological transitions. Furthermore, the proposed surface tracking representation builds on robust collision-processing techniques originally applied to cloth animation, and will offer the first surface mesh-based technique for the evolution of multi-material interfaces. This will allow for more accurate tracking of bubbles and general multiphase flows than can be achieved with state-of-the-art implicit surface approaches.Broader Impacts: Thin liquids are crucial to a broad class of problems in computer graphics, engineering, and scientific applications. Liquid animations are increasingly prevalent in visual effects-driven films, yet thin splashes remain among the most difficult effects to animate. Thin threads and sheets of viscous liquids arise in applications from food processing to cosmetics, from the geophysics of the earth's crust to the forming and blowing of elaborate glass artwork. They are the subject of substantial concurrent experimental and theoretical investigation, and complementary computational tools for these problems could offer vital new insights. The potential applications for low viscosity liquids and foams are equally wide-ranging. Project outcomes will be reported at major international venues including the SIGGRAPH conferences, and the associated computational tools will be made publicly available. A variety of education and outreach efforts, some of which specifically target minority middle school students, are also planned.

在这项研究中，PI 将开发高效的基于网格的算法来模拟薄片、射流、气泡和薄膜等薄液体结构的动力学和相互作用。 这些液体现象的薄几何结构给传统技术带来了巨大的困难，导致运行时间长和内存消耗过多。 PI 认为，需要一种根本不同的方法来识别和利用稀薄液体的独特几何形状，以便有效、准确地模拟它们（类似于对薄弹性体（如棒、板、壳）的特殊处理）。 该项目由三个重点组成。 首先，PI将开发由高粘度线和片组成的液体动态模拟的算法，包括物理建模、碰撞处理、拓扑变化和混合维度重新网格划分。 其次，他将解决低粘度射流和片材的具体挑战，特别考虑表面张力、片材破裂的增强影响以及欧拉与拉格朗日演化的选择。 最后，他将使用一种新的基于网格的表示来检查薄膜、气泡和泡沫的变形，使多区域界面变形，并与周围空气的流体动力学相结合。 在每个推力中，所开发技术的预测能力将根据实验观察和文献中的理论结果进行验证。为此，PI 将采用薄弹性动力学中的几种几何和计算技术来研究薄弹性体的动力学。稀薄的液体。 PI 认为，这种思想的交叉授粉有可能显着提高效率和准确性，同时产生补充稀薄流体现象研究中的理论和实验的计算工具。 通过将薄材料视为具有相关厚度的低维物体（曲线或表面），可以减少问题的维数，从而改善数值特性并更好地分配自由度。 这种观点以前从未被应用于开发三维稀薄液体的计算技术。 使用非流形网格来表示稀薄液体的混合体也为混合维度重新网格划分和拓扑转换处理带来了先前未探索的挑战。 此外，所提出的表面跟踪表示建立在最初应用于布料动画的强大碰撞处理技术的基础上，并将为多材料界面的演化提供第一个基于表面网格的技术。 与最先进的隐式表面方法相比，这将允许更准确地跟踪气泡和一般多相流。更广泛的影响：稀薄液体对于计算机图形、工程和科学领域的广泛问题至关重要应用程序。 液体动画在视觉效果驱动的电影中越来越普遍，但细小的飞溅仍然是最难制作动画的效果之一。 从食品加工到化妆品，从地壳的地球物理学到精致玻璃艺术品的成型和吹制，细丝和粘性液体片都出现在各种应用中。 它们是大量同时进行的实验和理论研究的主题，针对这些问题的补充计算工具可以提供重要的新见解。 低粘度液体和泡沫的潜在应用同样广泛。 项目成果将在包括 SIGGRAPH 会议在内的主要国际场所进行报告，相关的计算工具将公开发布。 还计划开展各种教育和宣传活动，其中一些专门针对少数民族中学生。