Deformation of 2D flow fields using stream functions
Deformation of 2D flow fields using stream functions
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DOI：
10.1145/2669024.2669039
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发表时间：
2014-11
期刊：
影响因子：
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通讯作者：
Syuhei Sato;Y. Dobashi;Kei Iwasaki;Tsuyoshi Yamamoto;T. Nishita
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文献类型：
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作者：
Syuhei Sato;Y. Dobashi;Kei Iwasaki;Tsuyoshi Yamamoto;T. Nishita
近年来，流体的视觉模拟已成为许多应用的重要元素，如电影和电脑游戏。这些流体动画通常是通过基于物理的流体模拟创建的。然而，模拟通常需要非常昂贵的计算成本来创建逼真的流体动画。因此，当用户尝试创建各种流体动画时，必须反复执行流体模拟，这需要令人望而却步的计算时间。为了解决这一问题，本文提出了一种在保持无散度条件下对流体速度场进行变形的方法。本文主要研究基于网格的二维流体模拟。我们的系统允许用户从流体模拟生成的一组速度场中交互式地创建各种流体动画。在预处理中，我们的方法将输入速度场转换为表示流函数的标量场。在运行时，用户对表示标量流函数的网格进行变形，然后通过对变形的标量流函数应用旋度算子获得变形的速度场。该过程得到的速度场自然保持无散度条件。对于网格的变形，我们采用了一种基于移动最小二乘的方法。几个例子证明了我们方法的有效性。
Recently, visual simulation of fluids has become an important element in many applications, such as movies and computer games. These fluid animations are usually created by physically-based fluid simulation. However, the simulation often requires very expensive computational cost for creating realistic fluid animations. Therefore, when the user tries to create various fluid animations, he or she must execute fluid simulation repeatedly, which requires a prohibitive computational time. To address this problem, this paper proposes a method for deforming velocity fields of fluids while preserving the divergence-free condition. In this paper, we focus on grid-based 2D fluid simulations. Our system allows the user to interactively create various fluid animations from a single set of velocity fields generated by the fluid simulation. In a preprocess, our method converts the input velocity fields into scalar fields representing the stream functions. At run-time, the user deforms the grid representing the scalar stream functions and the deformed velocity fields are then obtained by applying a curl operator to the deformed scalar stream functions. The velocity fields obtained by this process naturally perseveres the divergence-free condition. For the deformation of the grid, we use a method based on Moving Least Squares. The usefulness of our method is demonstrated by several examples.