Matthias Müller-Fischer

Fluid simulation: SIGGRAPH 2006 course notes Fedkiw and Muller-Fischer presenation videos are available from the citation page

These course notes are designed to give you a practical introduction to fluid simulation for graphics. The field of fluid dynamics, even just in animation, is vast and so not every topic will be covered. The focus of these notes is animating fully three-dimensional incompressible flow, from understanding the math and the algorithms to actual implementation. However, we will include a small amount of material on heightfield simplifications which are important for real-time animation.In general the approach is to make things as simple as possible, but no simpler. Constructing a fluid solver for computer animation is not the easiest thing in the world--there end up being a lot of little details that need attention-- but is perhaps easier than it may appear from surveying the literature. We will also provide pointers to some more advanced topics here and there.

Fluid simulation: SIGGRAPH 2007 course notes Video files associated with this course are available from the citation page

Animating fluids like water, smoke, and fire by physics-based simulation is increasingly important in visual effects and is starting to make an impact in real-time games. This course goes from the basics of 3D fluid flow to the state of the art in graphics. We will begin with an intuitive explanation of the important concepts in fluid simulation, and as we progress demonstrate how to implement an effective smoke and water simulation system, complete with irregular curved boundaries and surface tension. The last half of the course will cover advanced topics such as fire and explosions, adaptive grid methods, real-time-capable algorithms together with the latest technology in hardware acceleration, and non-Newtonian fluids like sand. Intuition and implementation details will be underscored throughout.

Long range attachments - a method to simulate inextensible clothing in computer games

Inextensibility is one of the most fundamental properties of cloth. Existing approaches to handle inextensibility often require solving global non-linear systems and remain computationally expensive for computer game uses. Real time performance can be achieved by allowing damping or stretching at reduced solver costs, but these compromise visual realism - the cloth either looks stretchy or fine wrinkles get lost. Our long range attachment (LRA) method exploits that typical game character clothing tends to be attached to some kinematic parts of the character. LRA method applies unilateral distance constraint between free particles of the cloth to distant attachment point on the character, preventing them from stretching away from the kinematically driven attachments (e.g. shoulder for a cape). This simple step provides an efficient shortcut for enforcing global inextensibility that can be readily implemented into existing game physics methods such as PBD.

Liquid simulation with mesh-based surface tracking

Animating detailed liquid surfaces has always been a challenge for computer graphics researchers and visual effects artists. Over the past few years, researchers in this field have focused on mesh-based surface tracking to synthesize extremely detailed liquid surfaces as efficiently as possible. This course provides a solid understanding of the steps required to create a fluid simulator with a mesh-based liquid surface. The course begins with an overview of several existing liquid-surface-tracking techniques and the pros and cons of each method. Then it explains how to embed a triangle mesh into a finite-difference-based fluid simulator and describes several methods for allowing the liquid surface to merge together or break apart. The final section showcases the benefits and further applications of a mesh-based liquid surface, highlighting state-of-the-art methods for tracking colors and textures, maintaining liquid volume, preserving small surface features, and simulating realistic surface-tension waves.

Large-scale interactive water simulation with directional waves

Simulating large bodies of water in real time has been a research goal for a few decades. Existing procedural approaches like FFT-based simulations typically lack dynamic response like boundary-wave reflections or general body-fluid interactions like splashes or boat wakes. On the other side of the spectrum, existing dynamic Eulerian wave simulations suffer from high memory consumption required for adequate grid sizes in large scenes. Dynamic Lagrangian simulations like wave particles suffer from a potentially prohibitive particle count.

Massive destruction in real time

In contrast to pre-fracturing techniques used in games today, this new method for fracturing 3D models in real time breaks objects dynamically depending on the impact location. The demonstration simulates destruction of a large arena by user-guided meteors.