Robust Methods for the Physically-Based Animation of Large Deformations in Computer Graphics

计算机图形学中基于物理的大变形动画的鲁棒方法

• 批准号: 281466253
• 负责人: Professor Dr. Jan Stephen Bender
• 金额: --
• 依托单位: Visual Computing Institute
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/281466253?language=en
• 关键词: Robust; Methods; Physically; Based; Animation

The goal of this research project is the development of robust and efficient methods for the physically-based animation of large deformations in computer graphics applications. This project has been funded by the German Research Foundation (DFG) for 18 months. In this time period our research group first investigated the stability problems in finite element simulations caused by degenerate and inverted elements. We were able to solve these problems using a method based on an analytic polar decomposition. Further, in the first project phase we developed a novel, very efficient simulation method based on a corotated elasticity model, which is more than a hundred times faster than previous methods using the same model. This enabled us to perform animations with multiple hundred thousand elements in real-time. In computer graphics time integration is mostly performed using the implicit Euler method due to its good stability. However, this method suffers from numerical damping which leads to a loss of important details and realism. Therefore, our group developed a stable implicit time integration method of higher order, which provides more accurate results and which reduces the numerical damping significantly. In the continuation of this project we plan to investigate the application of new material models to robustly simulate large deformations. More precisely, we want to investigate micropolar models, which were already successfully used in computer graphics to simulate elastic rods and fluids. These models define additional rotational degrees of freedom which enable a better representation of the bending and torsion of a deformable body. The improved representation has the advantage that less elements are required in elastic rods simulations. Moreover, it was shown that the numerical damping could be significantly reduced in simulations of turbulent fluids using a micropolar model. In the next phase of this research project we plan to use micropolar material models for the animation of two- and three-dimensional deformable bodies. To the best of our knowledge this has not been done before in computer graphics. In this way we want to benefit from the advantages of micropolar models, especially when simulating large deformations with rotations. First, we plan to develop a simulation method for volumetric bodies. Then we want to extend this method to simulate two-dimensional shells. To perform the time integration, the method, which we developed in the first phase, should be extended to solve the additional equations required for the micropolar models. Further, we plan to investigate the animation of plastic deformations considering the rotational degrees of freedom. Finally, we want to use the additional degrees of freedom to realize a detailed visualization with high-resolution surface meshes.

该研究项目的目的是开发用于计算机图形应用程序中大变形的基于物理化的动画的强大而有效的方法。该项目由德国研究基金会（DFG）资助了18个月。在这段时间里，我们的研究小组首先研究了由堕落和倒置元素引起的有限元模拟中的稳定性问题。我们能够使用基于分析极性分解的方法解决这些问题。此外，在第一个项目阶段，我们基于固定弹性模型开发了一种新颖的，非常有效的仿真方法，该方法的弹性模型比使用相同模型的先前方法快100倍。这使我们能够实时执行数十亿个元素的动画。在计算机图形学中，由于其良好的稳定性，大多使用隐式Euler方法进行集成。但是，该方法受到数值阻尼的影响，这导致了重要的细节和现实主义的丧失。因此，我们的小组开发了一种稳定的隐式时间整合方法的高阶方法，该方法提供了更准确的结果并大大降低了数值阻尼。在继续该项目的继续，我们计划调查新材料模型的应用来鲁棒模拟大变形。更确切地说，我们想研究微极模型，这些模型已经成功地用于计算机图形中，以模拟弹性棒和流体。这些模型定义了额外的旋转自由度，从而可以更好地表示可变形物体的弯曲和扭转。改进的表示的优点是，在弹性杆模拟中需要更少的元素。此外，证明使用微极模型在湍流模拟中可以显着降低数值阻尼。在该研究项目的下一阶段，我们计划使用微极材料模型进行二维变形物体的动画。据我们所知，这在计算机图形方面尚未完成。通过这种方式，我们希望从微极模型的优势中受益，尤其是在模拟旋转的大变形时。首先，我们计划为体积物体开发一种模拟方法。然后，我们要扩展此方法以模拟二维外壳。为了执行时间积分，我们在第一阶段开发的方法应扩展以求解微极模型所需的其他方程。此外，我们计划研究自由度旋转程度的塑性变形动画。最后，我们希望使用额外的自由度来实现具有高分辨率表面网格的详细可视化。