PAPER Special Section on Cyberworlds Web-based Constructive Shape Modeling Using Real Distance Functions

SUMMARY We present an approach and a web-based system implementation for modeling shapes using real distance functions. The system consists of an applet supporting the HyperFun modeling language. The applet is extended with primitives defined by Euclidean distance from a point to the surface of the shape. Set-theoretic operations (union, intersection, difference) that provide an approximation of the Euclidean distance to a shape built in a constructive way are introduced. Such operations have a controllable error of the exact Euclidean distance to the shape and preserve C 1 continuity of the overall function, which is an important condition for further operations and applications. The proposed system should help model various shapes, store them in a concise form, and exchange them easily between different entities on a network. The applet offers also the possibility to export the models defined in the HyperFun language to other formats for raytracing or rapid prototyping. key words: shape modeling, Euclidean distance, implicit surfaces, Java applet, computer graphics 1

INVITED PAPER Special Section on Cyberworlds 790 KUNII:. CYBERWORLDS-THEORY, DESIGN AND POTENTIAL-

SUMMARY Cyberworlds are being formed in cyberspaces as computational spaces. Now cyberspaces are rapidly expanding on the Web either intentionally or spontaneously, with or without design. Widespread and intensive local activities are melting each other on the web globally to create cyberworlds. The major key players of cyberworlds include e-finance that trades a GDPequivalent a day and e-manufacturing that is transforming industrial production into Web shopping of product components and assembly factories. Lacking proper theory and design, cyberworlds have continued to grow chaotic and are now out of human understanding and control..This research first presents a generic theoretical framework and design based on algebraic topology, and also provides an axiomatic approach to theorize the potentials of cyberworlds. Key words: Social impacts of cyberworlds, algebrai

PAPER Special Section on Cyberworlds New Goal Selection Scheme for Behavioral Animation of Intelligent Virtual Agents

SUMMARY One of the most challenging tasks in computer graphics and cyberworlds is the realistic animation of the behavior of virtual agents emulating human beings and evolving within virtual 3D worlds. In a previous paper, the authors presented a new, sophisticated behavioral system that allows the agents to take intelligent decisions by themselves [8]. A central issue of this process is the adequate choice of appropriate mechanisms for goal selection. This is actually the aim of the present contribution. In this paper a new scheme for goal selection is described. According to it, the goal’s priority is calculated as a combination of different agent’s internal states (given by mathematical functions also described in this paper) and external factors (which will determine the goal’s feasibility). The architecture of the goal selection module as well as its simulation flow are also analyzed in this paper. Finally, the excellent performance of this new scheme is enlightened by means of a simple yet illustrative example. key words: behavioral animation, intelligent virtual agents, virtual worlds, goal selection, internal states 1