This book constitutes the proceedings of the 4th International Workshop on Motion in Games, held in Edinburgh, UK, in November 2011. The 30 revised full papers presented together with 8 revised poster papers in this volume were carefully reviewed and selected from numerous submissions. The papers are organized in topical sections on character animation, motion synthesis, physically-based character motion, behavior animation, animation systems, crowd simulation, as well as path planning and navigation.

th Welcome to the proceedings of the 10 International Conference on Intelligent Virtual Agents (IVA), held 20-22 September, 2010 in Philadelphia, Pennsylvania, USA. Intelligent Virtual Agents are interactive characters that exhibit human-like qualities and communicate with humans or with each other using natural human modalities such as behavior, gesture, and speech. IVAs are capable of real-time perception, cognition, and action that allow them to participate in a dynamic physical and social environment. IVA 2010 is an interdisciplinary annual conference and the main forum for prese- ing research on modeling, developing, and evaluating Intelligent Virtual Agents with a focus on communicative abilities and social behavior. The development of IVAs - quires expertise in multimodal interaction and several AI fields such as cognitive modeling, planning, vision, and natural language processing. Computational models are typically based on experimental studies and theories of human-human and hum- robot interaction; conversely, IVA technology may provide interesting lessons for these fields. Visualizations of IVAs require computer graphics and animation te- niques, and in turn supply significant realism problem domains for these fields. The realization of engaging IVAs is a challenging task, so reusable modules and tools are of great value. The fields of application range from robot assistants, social simulation, and tutoring to games and artistic exploration. The enormous challenges and diversity of possible applications of IVAs have - sulted in an established annual conference.

This volume presents novel computational models for representing digital humans and their interactions with other virtual characters and meaningful environments. In this context, we describe efficient algorithms to animate, control, and author human-like agents having their own set of unique capabilities, personalities, and desires. We begin with the lowest level of footstep determination to steer agents in collision-free paths. Steering choices are controlled by navigation in complex environments, including multi-domain planning with dynamically changing situations. Virtual agents are given perceptual capabilities analogous to those of real people, including sound perception, multi-sense attention, and understanding of environment semantics which affect their behavior choices. The roles and impacts of individual attributes, such as memory and personality are explored. The animation challenges of integrating a number of simultaneous behavior and movement demands on an agent are addressed through an open source software system. Finally, the creation of stories and narratives with groups of agents subject to planning and environmental constraints culminates the presentation.

There are many applications of computer animation and simulation where it is necessary to model virtual crowds of autonomous agents. Some of these applications include site planning, education, entertainment, training, and human factors analysis for building evacuation. Other applications include simulations of scenarios where masses of people gather, flow, and disperse, such as transportation centers, sporting events, and concerts. Most crowd simulations include only basic locomotive behaviors possibly coupled with a few stochastic actions. Our goal in this survey is to establish a baseline of techniques and requirements for simulating large-scale virtual human populations. Sometimes, these populations might be mutually engaged in a common activity such as evacuation from a building or area; other times they may be going about their individual and personal agenda of work, play, leisure, travel, or spectator. Computational methods to model one set of requirements may not mesh well with good approaches to another. By including both crowd and individual goals and constraints into a comprehensive computational model, we expect to simulate the visual texture and contextual behaviors of groups of seemingly sentient beings. Table of Contents: Introduction / Crowd Simulation Methodology Survey / Individual Differences in Crowds / Framework (HiDAC + MACES + CAROSA) / HiDAC: Local Motion / MACES: Wayfinding with Communication and Roles / CAROSA: Functional Crowds / Initializing a Scenario / Evaluating Crowds