“A Practical Guide to Thin Film and Drips Simulation”
Conference:
Type:
Entry Number: 72
Title:
- A Practical Guide to Thin Film and Drips Simulation
Presenter(s)/Author(s):
Abstract:
We present a practical approach to model close-up water interaction with characters. We specifically focus on high-fidelity surface tension and adhesion effects as water sheds off skin. We show that an existing particle-in-cell (FLIP/APIC) solver can be adapted to capture small-scale water-solid interaction dynamics and discuss the role and implementation details of the relevant key components: treatment of surface tension and viscosity, enforcement of contact angle, and maintenance of contact with fast-moving collision geometry. The method allows for resolution of effects on a scale of a fraction of a millimeter and is performant enough to be able to cover a whole human body with a layer of water. We demonstrate successful use of the approach in a shot from Alita: Battle Angel.
References:
N. Akinci, G. Akinci, and M. Teschner. 2013. Versatile Surface Tension and Adhesion for SPH Fluids. ACM Trans. Graph. 32, 6, Article 182 (Nov. 2013), 8 pages. C. Batty, F. Bertails, and R. Bridson. 2007. A Fast Variational Framework for Accurate Solid- uid Coupling. ACM Trans. Graph. 26, 3, Article 100 (July 2007). C. Batty and R. Bridson. 2008. Accurate Viscous Free Surfaces for Buckling, Coiling, and Rotating Liquids. In Proceedings of the 2008 ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA ’08). Eurographics Association, 219–228. F. Da, D. Hahn, C. Batty, C. Wojtan, and E. Grinspun. 2016. Surface-only Liquids. ACM Trans. Graph. 35, 4, Article 78 (July 2016), 12 pages.
C. Jiang, C. Schroeder, A. Selle, J. Teran, and A. Stomakhin. 2015. The A ne Particle in-cell Method. ACM Trans. Graph. 34, 4, Article 51 (July 2015), 10 pages. A. Stomakhin and A. Selle. 2017. Fluxed Animated Boundary Method. ACM Trans. Graph. 36, 4, Article 68 (July 2017), 8 pages.
H. Wang, P. Mucha, and G. Turk. 2005. Water Drops on Surfaces. ACM Trans. Graph. 24, 3 (July 2005), 921–929.
B. Zhu, M. Lee, E. Quigley, and R. Fedkiw. 2015. Codimensional non-Newtonian Fluids. ACM Trans. Graph. 34, 4, Article 115 (July 2015), 9 pages.
B. Zhu, E. Quigley, M. Cong, J. Solomon, and R. Fedkiw. 2014. Codimensional Surface Tension Flow on Simplicial Complexes. ACM Trans. Graph. 33, 4, Article 111 (July 2014), 11 pages.
Keyword(s):
Acknowledgements:
We would like to thank simulation, FX and leadership of Weta Digital for their support with the submission, and also Lightstorm Entertainment and Twentieth Century Fox Film Corporation for their permission to use the character model and the shot from Alita: Battle Angel.
