Guided bubbles and wet foam for realistic whitewater simulation

Abstract

We present a method for enhancing fluid simulations with realistic bubble and foam detail. We treat bubbles as discrete air particles, two-way coupled with a sparse volumetric Euler flow, as first suggested in [Stomakhin et al. 2020]. We elaborate further on their scheme and introduce a bubble inertia correction term for improved convergence. We also show how one can add bubbles to an already existing fluid simulation using our novel guiding technique, which performs local re-simulation of fluid to achieve more interesting bubble dynamics through coupling. As bubbles reach the surface, they are converted into foam and simulated separately. Our foam is discretized with smoothed particle hydrodynamics (SPH), and we replace forces normal to the fluid surface with a fluid surface manifold advection constraint to achieve more robust and stable results. The SPH forces are derived through proper constitutive modeling of an incompressible viscous liquid, and we explain why this choice is appropriate for "wet" types of foam. This allows us to produce believable dynamics from close-up scenarios to large oceans, with just a few parameters that work intuitively across a variety of scales. Additionally, we present relevant research on air entrainment metrics and bubble distributions that have been used in this work.

References

1. Nadir Akinci, Gizem Akinci, and Matthias Teschner. 2013. Versatile surface tension and adhesion for SPH fluids. 32, 6 (Nov. 2013), 1--8.
2. T. B. Anderson and R. Jackson. 1967. Fluid Mechanical Description of Fluidized Beds. Equations of Motion. Indust. & Eng. Chem. Fund. 6, 4 (Nov. 1967), 527--539.
3. Ryoichi Ando and Christopher Batty. 2020. A Practical Octree Liquid Simulator with Adaptive Surface Resolution. 39, 4, Article 32 (jul 2020), 17 pages.
4. C. Batty, F. Bertails, and R. Bridson. 2007. A Fast Variational Framework for Accurate Solid-fluid Coupling. ACM Trans. Graph. 26, 3, Article 100 (July 2007).
5. Markus Becker and Matthias Teschner. 2007. Weakly Compressible SPH for Free Surface Flows. Proceedings of the 2007 ACM SIGGRAPH/Eurographics Symposium on Computer Animation 9 (01 2007), 209--217.
6. Jan Bender, Dan Koschier, Tassilo Kugelstadt, and Marcel Weiler. 2019. Turbulent Micropolar SPH Fluids with Foam. IEEE Transactions on Visualization and Computer Graphics 25 (2019), 2284--2295.
7. Robert Bridson. 2015. Fluid Simulation for Computer Graphics, Second Edition. Taylor & Francis. https://books.google.com/books?id=7MySoAEACAAJ
8. Oleksiy Busaryev, Tamal K. Dey, Huamin Wang, and Zhong Ren. 2012. Animating bubble interactions in a liquid foam. 31, 4 (Aug. 2012), 1--8.
9. Simon Clavet, Philippe Beaudoin, and Pierre Poulin. 2005. Particle-based viscoelastic fluid simulation. In Proceedings of the 2005 ACM SIGGRAPH/Eurographics symposium on Computer animation - SCA '05. ACM Press.
10. Paul W. Cleary, Soon Hyoung Pyo, Mahesh Prakash, and Bon Ki Koo. 2007. Bubbling and Frothing Liquids. ACM Trans. Graph. 26, 3 (jul 2007), 97--es.
11. G. Daviet and F. Bertails-Descoubes. 2017. Simulation of Drucker-Prager granular flows inside Newtonian fluids. (Feb. 2017). Working paper or preprint.
12. Walter Dehnen and Hossam Aly. 2012. Improving convergence in smoothed particle hydrodynamics simulations without pairing instability. Monthly Notices of the Royal Astronomical Society 425, 2 (Aug. 2012), 1068--1082.
13. Luc Deike, W. Kendall Melville, and Stéphane Popinet. 2016. Air entrainment and bubble statistics in breaking waves. 801 (July 2016), 91--129.
14. F F Dunne, F Bolton, D Weaire, and S Hutzler. 2017. Statistics and topological changes in 2D foam from the dry to the wet limit. Philos. Mag. 97, 21 (July 2017), 1768--1781.
15. Douglas Enright, Stephen Marschner, and Ronald Fedkiw. 2002. Animation and Rendering of Complex Water Surfaces. ACM Trans. Graph. 21, 3 (July 2002), 736--744.
16. Yun (Raymond) Fei, Christopher Batty, Eitan Grinspun, and Changxi Zheng. 2018. A Multi-scale Model for Simulating Liquid-fabric Interactions. ACM Trans. Graph. 37, 4, Article 51 (Aug. 2018), 16 pages.
17. Chuyuan Fu, Qi Guo, Theodore Gast, Chenfanfu Jiang, and Joseph Teran. 2017. A Polynomial Particle-in-Cell Method. ACM Trans. Graph. 36, 6, Article 222 (nov 2017), 12 pages.
18. Ming Gao, Andre Pradhana, Xuchen Han, Qi Guo, Grant Kot, Eftychios Sifakis, and Chenfanfu Jiang. 2018. Animating Fluid Sediment Mixture in Particle-Laden Flows. ACM Trans. Graph. 37, 4, Article 149 (jul 2018), 11 pages.
19. Carlo Gualtieri, Dragutin Mihailovic, Hubert Chanson, Benoit Cushman-Roisin, Guelfo Doria, Paola Gualtieri, George Kallos, Joe Ackerman, and Borivoi Rajkovic. 2008. Fluid Mechanics of Environmental Interfaces.
20. Francis H. Harlow and J. Eddie Welch. 1965. Numerical Calculation of Time-Dependent Viscous Incompressible Flow of Fluid with Free Surface. Physics of Fluids 8 (1965), 2182--2189.
21. Xiaowei He, H Wang, Fengjun Zhang, Guoping Wang, and Kun Zhou. 2014. Robust Simulation of Small-Scale Thin Features in SPH-based Free Surface Flows. Life.Kunzhou.Net 1, 212 (2014), 1--8.
22. Jeong-Mo Hong, Ho-Young Lee, Jong-Chul Yoon, and Chang-Hun Kim. 2008. Bubbles Alive. In ACM SIGGRAPH 2008 Papers (Los Angeles, California) (SIGGRAPH '08). Association for Computing Machinery, New York, NY, USA, Article 48, 4 pages.
23. Christopher J Horvath. 2015. Empirical directional wave spectra for computer graphics (DigiPro '15). Association for Computing Machinery, 29--39.
24. Markus Ihmsen, Nadir Akinci, Gizem Akinci, and Matthias Teschner. 2012. Unified spray, foam and air bubbles for particle-based fluids. 28, 6--8 (April 2012), 669--677.
25. Chenfanfu Jiang, Craig Schroeder, Andrew Selle, Joseph Teran, and Alexey Stomakhin. 2015. The Affine Particle-in-Cell Method. ACM Trans. Graph. 34, 4, Article 51 (jul 2015), 10 pages.
26. Doyub Kim, Oh-young Song, and Hyeong-Seok Ko. 2010. A Practical Simulation of Dispersed Bubble Flow. ACM Trans. Graph. 29, 4, Article 70 (jul 2010), 5 pages.
27. A B J Kroezen, J Groot Wassink, and C A C Schipper. 1988. The flow properties of foam. 104, 10 (Oct. 1988), 393--400.
28. Steve Lesser, Alexey Stomakhin, Gilles Daviet, Joel Wretborn, John Edholm, Noh hoon Lee, Eston Schweickart, Xiao Zhai, Sean Flynn, and Andrew Moffat. 2022. Loki: A Unified Multiphysics Simulation Framework for Production. ACM Trans. Graph. 41, 4, Article 50 (jul 2022).
29. Frank Losasso, Frédéric Gibou, and Ron Fedkiw. 2004. Simulating Water and Smoke with an Octree Data Structure. In ACM SIGGRAPH 2004 Papers (Los Angeles, California) (SIGGRAPH '04). ACM, New York, NY, USA, 457--462.
30. Frank Losasso, Jerry Talton, Nipun Kwatra, and Ronald Fedkiw. 2008. Two-Way Coupled SPH and Particle Level Set Fluid Simulation. IEEE Transactions on Visualization and Computer Graphics 14, 4 (2008), 797--804.
31. J. J. Monaghan. 1992. Smoothed Particle Hydrodynamics. Vol. 30. 543--574 pages.
32. D. Morgenroth, S. Reinhardt, D. Weiskopf, and B. Eberhardt. 2020. Efficient 2D Simulation on Moving 3D Surfaces. 39, 8 (Nov. 2020), 27--38.
33. Matthias Müller, David Charypar, and Markus Gross. 2003. Particle-Based Fluid Simulation for Interactive Applications. In Proceedings of the 2003 ACM SIGGRAPH/Eurographics Symposium on Computer Animation (San Diego, California) (SCA '03). Eurographics Association, Goslar, DEU, 154--159.
34. Saket Patkar, Mridul Aanjaneya, Dmitriy Karpman, and Ronald Fedkiw. 2013. A Hybrid Lagrangian-Eulerian Formulation for Bubble Generation and Dynamics. In Proceedings of the 12th ACM SIGGRAPH/Eurographics Symposium on Computer Animation (Anaheim, California) (SCA '13). Association for Computing Machinery, New York, NY, USA, 105--114.
35. Andreas Peer, Markus Ihmsen, Jens Cornelis, and Matthias Teschner. 2015. An implicit viscosity formulation for SPH fluids. ACM Transactions on Graphics 34, 4 (July 2015), 1--10.
36. B. Persson and M. Dahlberg. 1994. A Simple Model For Predicting Foam Spread Over Liquids. 4 (1994), 265--276.
37. Jos Stam. 1999. Stable Fluids. In Proceedings of the 26th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH '99). ACM Press/Addison-Wesley Publishing Co., New York, NY, USA, 121--128.
38. Alexey Stomakhin, Craig Schroeder, Lawrence Chai, Joseph Teran, and Andrew Selle. 2013. A Material Point Method for Snow Simulation. ACM Trans. Graph. 32, 4, Article 102 (jul 2013), 10 pages.
39. Alexey Stomakhin, Joel Wretborn, Kevin Blom, and Gilles Daviet. 2020. Underwater bubbles and coupling. ACM.
40. Andre Pradhana Tampubolon, Theodore Gast, Gergely Klár, Chuyuan Fu, Joseph Teran, Chenfanfu Jiang, and Ken Museth. 2017. Multi-Species Simulation of Porous Sand and Water Mixtures. ACM Trans. Graph. 36, 4, Article 105 (jul 2017), 11 pages.
41. Dominic Vella and L. Mahadevan. 2005. The "Cheerios effect". 73, 9 (Sept. 2005), 817--825.
42. Denis Weaire and Stefan Hutzler. 2001. The Physics of Foams. Oxford University Press.
43. Yonghao Yue, Breannan Smith, Christopher Batty, Changxi Zheng, and Eitan Grinspun. 2015. Continuum Foam. 34, 5 (Nov. 2015), 1--20.
44. Yongning Zhu and Robert Bridson. 2005. Animating Sand As a Fluid. ACM Trans. Graph. 24, 3 (July 2005), 965--972.

Index Terms

• Computing methodologies

  • Computer graphics

    • Animation

      • Physical simulation

  • Modeling and simulation

    • Simulation types and techniques