FFT-Upsampling for Fluid Animation

Fluid details are visually interesting but computationally challenging in animation. This paper introduces a simple frequency domain upsampling method to produce small scale details for smoke animation. Our method is based on a fluid solver combining fine grid advection with coarse grid projection. Different from previous work, we use a novel FFT-upsampling operator to reconstruct a fine velocity field from the coarse divergence-free velocity field. The upsampled velocity field is kept divergence-free without solving Poisson equation on the fine grid. We provide several examples to demonstrate that our method can significantly reduce the computational cost for simulation while still producing compelling high-frequency details for smoke animation. 

Publication: Jiaotuan Wang, Xubo Yang, Wenlong Lu. .ACM/Eurographics Symposium on Computer Animation, 2011. (Best Poster Award)

Preprint PDF: FFT.pdf

PPT: FFT.pptx