Jeff Schoner
COMP 259, Project Proposal

Motivation and Background

The extensive publication record for the simulation of deformable objects within the domain of computer graphics today spans over 25 years. Similarly, a great deal of work has been done with respect to the simulation of fluids. Somewhat less research has been carried out on the simulation of these two kinds of materials. Much of it has been concerned with a certain kind of coupled simulation, where one medium affects but is not affected by another [Carlson et al. 2004].

For example, if we simulate a tree blowing in the wind, it is reasonable to apply forces to the tree based on a time-varying vector field for the wind, while it would most likely not be necessary to simulate the effect the tree has on the wind field. However, for the simulation of the interaction between a ball and a tub of water, we would like each component to be able to affect the other.

State of the Art and New Challenges

Over the past two years, three papers in particular have been published concerning this problem of fluid/solid interaction [Genevaux et al. 2003, Müller et al. 2004 and Carlson et al. 2004]. Carlson focuses on the interaction of rigid bodies with fluids, employing a continuum model for the fluid. Genevaux also employs a continuum model for the fluid, but handles deformable objects (represented as spring-mass conglomerations) as well as rigid bodies. Finally, Müller takes a completely different approach, where solid and fluid components are both represented as particles with different kinds of forces.

Currently I am aware of no work in computer graphics, which focuses on the simulation of the interaction between fiber-like deformable solids (such as hair, rope or a myriad of other materials) and fluids. Extensive prior work on the simulation of hair alone in dry environments warrants the interest in simulating its interaction with immersive water.

Immediate Proposed Tasks

Get a reasonable 2D fluid simulator.
Code exists both online and in the GAMMA group for doing this.
Extend the fluid simulator to 3D.
Integrate a simple spring-mass representation of fiber-like objects into the fluid simulator.

Minimum Expected Accomplishments

My primary goal is to get a simple proof of concept system built that does two-way interaction of fiber-like deformable solids. Ideally, I would like to get it to be a stable and efficient as possible. However, because time is limited, I would be happy to be able to simulate only simple specific configurations of fluid and fibers.

Should developing a continuum based model for the fluid simulation prove too time consuming, I may instead use a unifed particle-based method and focus on producing a real-time simulation of the interaction.

Longer Term Goals

Hopefully, this work can eventually be extended to handle more general scenarios in a stable manner. In particular, I hope this work can eventually be combined down the road with my research on simulation of blood clotting, which involves the behavior of deformable fibers in a fluid medium.

Bibliography

Mark Carlson, Peter J. Mucha and Greg Turk. ``Rigid fluid: animating the interplay between rigid bodies and fluid'' in the Proceedings of ACM SIGGRAPH 2004.

Olivier Genevaux, Arash Habibi and Jean-Michel Dischler. ``Simulating Fluid-Solid Interaction'' in the Proceedings of Graphics Interface 2003.

Matthias Müller, Simon Schirm, Matthias Teschner, Bruno Heidelberger and Markus Gross. ``Interaction of Fluids with Deformable Solids'' in the Proceedings of Computer Animation and Social Agents (CASA) 2004.