Physics Based Animation

The booming computer games and animated movie industries continue to drive the graphics community's seemingly insatiable search for increased realism, believability, ad speed. To achieve the quality expected by audiences of today's games and movies, programmers need to understand and implement physics-based animation. To provide this understanding, this book is written to teach students and practitioners and theory behind the mathematical models and techniques required for physics-based animation. It does not teach the basic principles of animation, but rather how to transform theoretical techniques into practical skills. It details how the mathematical models are derived from physical and mathematical principles, and explains how these mathematical models are solved in an efficient, robust, and stable manner with a computer. This impressive and comprehensive volume covers all the issues involved in physics-based animation, including collision detection, geometry, mechanics, differential equations, matrices, quaternions, and more. There is excellent coverage of collision detection algorithms and a detailed overview of a physics system. In addition, numerous examples are provided along with detailed pseudo code for most of the algorithms. This book is ideal for students of animation, researchers in the field, and professionals working in the games and movie industries. Topics Covered: * The Kinematics: Articulated Figures, Forward and Inverse Kinematics, Motion Interpolation * Multibody Animation: Particle Systems, Continuum Models with Finite Differences, the Finite Element Method, Computational Fluid Dynamics * Collision Detection: Broad and Narrow Phase Collision Detection, Contact Determination, Bounding Volume Hierarchies, Feature-and Volume-Based Algorithms

Physics forms the basis for many of the motions and behaviors seen in both the real world and in the virtual worlds of animated films, visual effects, and computer games. By describing the underlying physical principles and then creating simulations based on these principles, these computer-generated worlds are brought to life. Physically Based Modeling and Animation goes behind the scenes of computer animation and details the mathematical and algorithmic foundations that are used to determine the behavior underlying the movement of virtual objects and materials. Dr. Donald House and Dr. John Keyser offer an approachable, hands-on view of the equations and programming that form the foundations of this field. They guide readers from the beginnings of modeling and simulation to more advanced techniques, enabling them to master what they need to know in order to understand and create their own animations Emphasizes the underlying concepts of the field, and is not tied to any particular software package, language, or API. Develops concepts in mathematics, physics, numerical methods, and software design in a highly integrated way, enhancing both motivation and understanding. Progressively develops the material over the book, starting from very basic techniques, and building on these to introduce topics of increasing complexity. Motivates the topics by tying the underlying physical and mathematical techniques directly to applications in computer animation.

Achieving believable motion in animation requires an understanding of physics that most of us missed out on in art school. Although animators often break the laws of physics for comedic or dramatic effect, you need to know which laws you’re breaking in order to make it work. And while large studios might be able to spend a lot of time and money testing different approaches or hiring a physics consultant, smaller studios and independent animators have no such luxury. This book takes the mystery out of physics tasks like character motion, light and shadow placement, explosions, ocean movement, and outer space scenes, making it easy to apply realistic physics to your work. Physics concepts are explained in animator’s terms, relating concepts specifically to animation movement and appearance. Complex mathematical concepts are broken down into clear steps you can follow to solve animation problems quickly and effectively. Bonus companion website at www.physicsforanimators.com offers additional resources, including examples in movies and games, links to resources, and tips on using physics in your work. Uniting theory and practice, author Michele Bousquet teaches animators how to swiftly and efficiently create scientifically accurate scenes and fix problem spots, and how and when to break the laws of physics. Ideal for everything from classical 2D animation to advanced CG special effects, this book provides animators with solutions that are simple, quick, and powerful.

A practical introduction, the second edition of Fluid Simulation for Computer Graphics shows you how to animate fully three-dimensional incompressible flow. It covers all the aspects of fluid simulation, from the mathematics and algorithms to implementation, while making revisions and updates to reflect changes in the field since the first edition. Highlights of the Second Edition New chapters on level sets and vortex methods Emphasizes hybrid particle–voxel methods, now the industry standard approach Covers the latest algorithms and techniques, including: fluid surface reconstruction from particles; accurate, viscous free surfaces for buckling, coiling, and rotating liquids; and enhanced turbulence for smoke animation Adds new discussions on meshing, particles, and vortex methods The book changes the order of topics as they appeared in the first edition to make more sense when reading the first time through. It also contains several updates by distilling author Robert Bridson’s experience in the visual effects industry to highlight the most important points in fluid simulation. It gives you an understanding of how the components of fluid simulation work as well as the tools for creating your own animations.

Physics-based animation is commonplace in animated feature films and even special effects for live-action movies. Think about a recent movie and there will be some sort of special effects such as explosions or virtual worlds. Cloth simulation is no different and is ubiquitous because most virtual characters (hopefully!) wear some sort of clothing. The focus of this book is physics-based cloth simulation. We start by providing background information and discuss a range of applications. This book provides explanations of multiple cloth simulation techniques. More specifically, we start with the most simple explicitly integrated mass-spring model and gradually work our way up to more complex and commonly used implicitly integrated continuum techniques in state-of-the-art implementations. We give an intuitive explanation of the techniques and give additional information on how to efficiently implement them on a computer. This book discusses explicit and implicit integration schemes for cloth simulation modeled with mass-spring systems. In addition to this simple model, we explain the more advanced continuum-inspired cloth model introduced in the seminal work of Baraff and Witkin [1998]. This method is commonly used in industry. We also explain recent work by Liu et al. [2013] that provides a technique to obtain fast simulations. In addition to these simulation approaches, we discuss how cloth simulations can be art directed for stylized animations based on the work of Wojtan et al. [2006]. Controllability is an essential component of a feature animation film production pipeline. We conclude by pointing the reader to more advanced techniques.

Linear complementarity problems (LCPs) have for many years been used in physics-based animation to model contact forces between rigid bodies in contact. More recently, LCPs have found their way into the realm of fluid dynamics. Here, LCPs are used to model boundary conditions with fluid-wall contacts. LCPs have also started to appear in deformable models and granular simulations. There is an increasing need for numerical methods to solve the resulting LCPs with all these new applications. This book provides a numerical foundation for such methods, especially suited for use in computer graphics. This book is mainly intended for a researcher/Ph.D. student/post-doc/professor who wants to study the algorithms and do more work/research in this area. Programmers might have to invest some time brushing up on math skills, for this we refer to Appendices A and B. The reader should be familiar with linear algebra and differential calculus. We provide pseudo code for all the numerical methods, which should be comprehensible by any computer scientist with rudimentary programming skills. The reader can find an online supplementary code repository, containing Matlab implementations of many of the core methods covered in these notes, as well as a few Python implementations [Erleben, 2011]. Table of Contents: Introduction / Numerical Methods / Guide for Software and Selecting Methods / Bibliography / Authors' Biographies

Flash is fading fast as Canvas continues to climb. The second edition of this popular book gets you started with HTML5 Canvas by showing you how to build interactive multimedia applications. You’ll learn how to draw, render text, manipulate images, and create animation—all in the course of building an interactive web game throughout the book. Updated for the latest implementations of Canvas and related HTML5 technologies, this edition includes clear and reusable code examples to help you quickly pick up the basics—whether you currently use Flash, Silverlight, or just HTML and JavaScript. Discover why HTML5 is the future of innovative web development. Create and modify 2D drawings, text, and bitmap images Use algorithms for math-based movement and physics interactions Incorporate and manipulate video, and add audio Build a basic framework for creating a variety of games Use bitmaps and tile sheets to develop animated game graphics Go mobile: build web apps and then modify them for iOS devices Explore ways to use Canvas for 3D and multiplayer game applications

Foundation HTML5 Animation with JavaScript covers everything that you need to know to create dynamic scripted animation using the HTML5 canvas. It provides information on all the relevant math you'll need, before moving on to physics concepts like acceleration, velocity, easing, springs, collision detection, conservation of momentum, 3D, and forward and inverse kinematics. Foundation HTML5 Animation with JavaScript is a fantastic resource for all web developers working in HTML5 or switching over from Flash to create standards-compliant games, applications, and animations that will work across all modern browsers and most mobile devices, including iPhones, iPads, and Android devices. You will learn how to utilize the amazing animation and physics-based code originally created by author Keith Peters in his hugely successful Foundation ActionScript Animation in all of your HTML5 applications. In no time at all, you'll understand the concepts behind scripted animation and also have the ability to create all manner of exciting animations and games.