Penetration-free Solid-Fluid Interaction on Shells and Rods

TL;DR

This paper presents a new optimization-based method for simulating fluid interactions with thin elastic solids like shells and rods, ensuring no penetration and handling complex behaviors.

Contribution

It introduces an explicit positional constraint resolution approach combined with a unified system for simulating fluid-solid interactions involving topology changes and dynamic behaviors.

Findings

Successfully simulates complex fluid-solid interactions including bouncing and splashing.

Ensures no penetration between fluids and thin elastic solids.

Handles topology changes and dynamic behaviors robustly.

Abstract

We introduce a novel approach to simulate the interaction between fluids and thin elastic solids without any penetration. Our approach is centered around an optimization system augmented with barriers, which aims to find a configuration that ensures the absence of penetration while enforcing incompressibility for the fluids and minimizing elastic potentials for the solids. Unlike previous methods that primarily focus on velocity coherence at the fluid-solid interfaces, we demonstrate the effectiveness and flexibility of explicitly resolving positional constraints, including both explicit representation of solid positions and the implicit representation of fluid level-set interface. To preserve the volume of the fluid, we propose a simple yet efficient approach that adjusts the associated level-set values. Additionally, we develop a distance metric capable of measuring the separation between an implicitly represented surface and a Lagrangian object of arbitrary codimension. By integrating the inertia, solid elastic potential, damping, barrier potential, and fluid incompressibility within a unified system, we are able to robustly simulate a wide range of processes involving fluid interactions with lower-dimensional objects such as shells and rods. These processes include topology changes, bouncing, splashing, sliding, rolling, floating, and more.