基于格子玻尔兹曼方法的涡量修正高效烟雾仿真算法

High Performance Vorticity Refinement Smoke Simulation Algorithm Based on Lattice Boltzmann Method

  • 摘要: 基于流体动力学模型的烟雾仿真研究是计算机图形学和计算机仿真领域的重要分支。本文提出通过追踪涡量的大小和方向并添加涡量修正力进行涡量补偿的格子玻尔兹曼算法实现烟雾的高效真实仿真。算法从纳维-斯托克斯方程以及亥姆霍兹方程出发分别对烟雾仿真过程中涡量的大小和方向进行追踪,并利用追踪到的涡量信息和对应时刻的速度场信息添加涡量修正力进行涡量补偿和烟雾细节的补充,保证烟雾仿真符合物理规律并提升仿真的真实度。这一烟雾仿真算法基于格子玻尔兹曼方法实现,对动量分布函数,涡量分布函数以及温度分布函数进行离散化,通过三个分布函数和涡量方向场的迭代更新实现烟雾仿真。与格子玻尔兹曼方法相同,该烟雾仿真算法通过分布函数项在格点之间的迁移仿真流体的流动过程,通过添加碰撞项和外力项仿真流体粒子之间的相互作用以及流体粒子受外力作用。烟雾仿真实验结果证明涡量修正格子玻尔兹曼算法可以高效的生成高真实度的仿真图像。该算法在单GPU加速的条件下在分辨率为64×64×128的网格上可以达到实时仿真的仿真效率。

     

    Abstract: Physically-based smoke simulation is an essential branch of computer graphics and computer simulation. This paper proposed Lattice Boltzmann method with vorticity refinement force calculated with tracked vorticity’s magnitude and direction to realize smoke simulation with high performance and realism. Vorticity’s magnitude and direction were tracked through Navier-Stokes equation and Helmholtz equation. Vorticity refinement force calculated with tracked vorticity and speed field information correspondingly was added to realize vorticity refinement and enrich details of smoke simulation, which made sure that smoke simulation results not only obey physical laws but also have high realism. Our smoke simulation model was based on Lattice Boltzmann method, which discretisizes momentum distribution function, vorticity distribution function and temperature distribution function. Smoke simulation was realized through updating of three distribution functions and vorticity direction field. Our method simulated flow process through distribution function items moving among grid points and simulated interaction between fluid particles and external force added to particles with collision terms and external force terms separately in accordance with Lattice Boltzmann method. Results of smoke simulation experiments prove that our method could simulate smoke motion with high realism and performance. As for grid resolution of 64×64×128, our algorithm could achieve real-time simulation with single GPU acceleration.

     

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