SPH Based Shallow Water Simulation

Barbara Solenthaler, Peter Bucher, Nuttapong Chentanez, Matthias Muller, Markus Gross

We present an efficient method that uses particles to solve the 2D shallow water equations. These equations describe the dynamics of a body of water represented by a height field. Instead of storing the surface heights using uniform grid cells, we discretize the fluid with 2D SPH particles and compute the height according to the density at each particle location. The particle discretization offers the benefits that it simplifies the use of sparsely filled domains and arbitrary boundary geometry. Our solver can handle terrain slopes and supports two-way coupling of the particle-based height field with rigid objects. An improved surface definition is presented that reduces visible bumps related to the underlying particle representation. It furthermore smoothes areas with separating particles to achieve better rendering results. Both the physics and the rendering are implemented on modern GPUs resulting in interactive performances in all our presented examples.

SPH Based Shallow Water Simulation

VRIPhys 2011 papers

The program for VRIPHYS 2011 is up, which includes the following physics-related papers:

• Simulating inextensible cloth using locking-free triangle meshes
• Adding physics to animated characters using oriented particles
• Focused ultrasound – Efficient GPU simulation methods for therapy planning
• Time adaptive approximate SPH
• Real-time simulation of stiff threads using large timesteps
• Interactive high-resolution boundary surfaces for deformable bodies with changing topology
• SPH based shallow water simulation
• Precomputed shape database for real-time physically-based simulation
• XML3D Physics: Declarative physics simulation for the web

Adding Physics to Characters Using Oriented Particles

Matthias Muller, Nuttapong Chentanez

We present a method to enhance the realism of animated characters by adding physically based secondary motion to deformable parts such as cloth, skin or hair. To this end, we extend the oriented particles approach to incorporate animation information. In addition, we introduce techniques to increase the stability of the original method in order to make it suitable for the fast and sudden motions that typically occur in computer games. We also propose a method for the semi-automatic creation of particle representations from arbitrary visual meshes. This way, our technique allows us to simulate complex geometry such as hair, thick cloth with ornaments and multi-layered clothing, all interacting with each other and the animated character.

Adding Physics to Characters Using Oriented Particles

Sketch-Based Dynamic Illustration of Fluid Systems

Bo Zhu, Michiaki Iwata, Ryo Haraguchi, Takashi Ashahara, Nobukuyuki Umetani, Takeo Igarashi, Kazuo Nakazawa

This paper presents a lightweight sketching system that enables interactive illustration of complex fluid systems. Users can sketch on a 2.5-dimensional (2.5D) canvas to design the shapes and connections of a fluid circuit. These input sketches are automatically analyzed and abstracted into a hydraulic graph, and a new hybrid fluid model is used in the background to enhance the illustrations. The system provides rich simple operations for users to edit the fluid system incrementally, and the new internal flow patterns can be simulated in real time. Our system is used to illustrate various fluid systems in medicine, biology, and engineering. We asked professional medical doctors to try our system and obtained positive feedback from them.

Sketch-Based Dynamic Illustration of Fluid Systems