View-Dependent Multiscale Fluid Simulation
View-Dependent Multiscale Fluid Simulation
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DOI：
10.1109/tvcg.2012.117
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发表时间：
2013-02
影响因子：
5.2
通讯作者：
Yue Gao;Chenfeng Li;Bo Ren;Shimin Hu
中科院分区：
文献类型：
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作者：
Yue Gao;Chenfeng Li;Bo Ren;Shimin Hu
流体流动是高度非线性和非平稳的，湍流在不同的长度和时间尺度上发生和发展。在现实生活中的观察中，多尺度流会根据与观察者的距离产生不同的视觉效果。我们提出了一种新的流体模拟框架，可以根据观察者的位置自适应地分配计算资源。首先，开发了 3D 经验模态分解方案以获得湍流的速度谱。然后，根据与观察者的距离，流体域被划分为一系列嵌套的模拟分区。最后，速度谱中揭示的多尺度流体运动不均匀地分布到这些与视图相关的分区，并且使用不同的网格大小和时间步长分别求解不同分区上定义的混合速度场。流体流动以不同的时空分辨率求解，使得更接近观察者的高频运动以更高的分辨率求解，反之亦然。新的模拟器更好地利用计算能力，以更有效的方式产生具有真实精细细节的视觉上合理的结果。它特别适合观看者处于流体域内的大型场景。此外，由于在模拟中区分了高频流体运动和低频运动，有效地减少了数值耗散。
Fluid flows are highly nonlinear and nonstationary, with turbulence occurring and developing at different length and time scales. In real-life observations, the multiscale flow generates different visual impacts depending on the distance to the viewer. We propose a new fluid simulation framework that adaptively allocates computational resources according to the viewer's position. First, a 3D empirical mode decomposition scheme is developed to obtain the velocity spectrum of the turbulent flow. Then, depending on the distance to the viewer, the fluid domain is divided into a sequence of nested simulation partitions. Finally, the multiscale fluid motions revealed in the velocity spectrum are distributed nonuniformly to these view-dependent partitions, and the mixed velocity fields defined on different partitions are solved separately using different grid sizes and time steps. The fluid flow is solved at different spatial-temporal resolutions, such that higher frequency motions closer to the viewer are solved at higher resolutions and vice versa. The new simulator better utilizes the computing power, producing visually plausible results with realistic fine-scale details in a more efficient way. It is particularly suitable for large scenes with the viewer inside the fluid domain. Also, as high-frequency fluid motions are distinguished from low-frequency motions in the simulation, the numerical dissipation is effectively reduced.