Efficient and Conservative Fluids Using Bidirectional Mapping
Efficient and Conservative Fluids Using Bidirectional Mapping
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DOI：
10.1145/3306346.3322945
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发表时间：
2019-07-01
影响因子：
6.2
通讯作者：
Chen, Baoquan
中科院分区：
文献类型：
--
作者：
Qu, Ziyin;Zhang, Xinxin;Chen, Baoquan
在本文中，我们介绍了BiMocq(2)，这是一种无条件稳定的、基于纯欧拉法的平流格式，用于在长期流体模拟中高效地保持所有物理量的平流精度。我们的方法基于特征映射法（MCM）。我们不是对时间特征积分进行昂贵的计算，而是通过求解映射的平流方程来演化映射函数本身。采用双网格特征（DMC）方法来更精确地更新映射。此外，为了避免由重新初始化引入的诸如瞬间模糊和时间不一致等视觉伪影，我们引入了多级映射以及来回误差补偿。我们进行了全面的二维和三维基准实验，以便与其他平流格式进行比较。特别是在旋涡流和水平集实验中，我们的方法在仅使用两次半拉格朗日平流的代价下，几乎优于所有最先进的混合格式，包括FLIP、PolyPic和粒子 - 水平集格式。此外，我们的方法不依赖于粒子 - 网格传递操作，从而形成了一个高度可并行化的流程。因此，即使是将代码从CPU简单移植到GPU，也能实现超过45倍的性能加速。
In this paper, we introduce BiMocq(2), an unconditionally stable, pure Eulerian-based advection scheme to efficiently preserve the advection accuracy of all physical quantities for long-term fluid simulations. Our approach is built upon the method of characteristic mapping (MCM). Instead of the costly evaluation of the temporal characteristic integral, we evolve the mapping function itself by solving an advection equation for the mappings. Dual mesh characteristics (DMC) method is adopted to more accurately update the mapping. Furthermore, to avoid visual artifacts like instant blur and temporal inconsistency introduced by re-initialization, we introduce multi-level mapping and back and forth error compensation. We conduct comprehensive 2D and 3D benchmark experiments to compare against alternative advection schemes. In particular, for the vortical flow and level set experiments, our method outperforms almost all state-of-art hybrid schemes, including FLIP, PolyPic and Particle-Level-Set, at the cost of only two Semi-Lagrangian ad-vections. Additionally, our method does not rely on the particle-grid transfer operations, leading to a highly parallelizable pipeline. As a result, more than 45x performance acceleration can be achieved via even a straightforward porting of the code from CPU to GPU.