摘要:

AbstractThis paper describes the design and implementation of a multimedia information management environment that is based on an open model for hypermedia. The model, known as Microcosm, is currently implemented in Microsoft Windows and supports many different media types. The open nature of the model and the separation of the links from the data, allows links to be applied across any application running under Windows or the OS/2 version 2 desktop, thus creating a truly integrated environment. One example, which is, discussed in the paper, is the integration of a hypermedia database with a geographical information system. The paper also discusses the application of novel interfaces to dynamic media within a hypermedia system, including the use of moving icons (micons).

ISSN:0167-7055    

DOI:10.1111/1467-8659.1130001

出版商:Blackwell Science Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractMultimedia applications can be seen as sets of autonomous parts, independent yet capable of working together. This assumption allows for the construction of multimedia applications in a “connectionist” fashion. In this paper we describe mechanisms for the visual composition of multimedia applications. These mechanisms allow for quick and flexible application construction by direct manipulation with reference to multiple composition models. An object‐oriented framework for multimedia systems will be introduced throughout the

ISSN:0167-7055    

DOI:10.1111/1467-8659.1130009

出版商:Blackwell Science Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractAn experimental workstation is described which supports digital video and audio in a distributed environment, and which presents this functionality to the user through the medium of a video‐extended implementation of the X Window System. The Pandora Workstation is built out of two quite separate parts. A standard UNIX machine (the Pandora Host) brings standard hardware and software computing resources to the system; a highly‐specialised processing engine (Pandora's Box) handles the high‐bandwidth, time‐critical, and device‐dependent processing. A 50 Mbit/second ATM network provides for real‐time data communication within the system. Nineteen Pandora Workstations have been deployed within Olivetti Research Ltd and the Cambridge University Computer Laboratory, and are used routinely to run distributed applications including video mail, video conferencing, and real‐time media deli

ISSN:0167-7055    

DOI:10.1111/1467-8659.1130023

出版商:Blackwell Science Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractWe describe an accurate method of rendering by scan‐conversion of closed regions bounded by NURBs, with particular comments on its application to computer‐based 2D animation. It is shown that the method is fast, analytically accurate, and can be readily extended to include anti‐aliasing and cli

ISSN:0167-7055    

DOI:10.1111/1467-8659.1130035

出版商:Blackwell Science Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractIn this paper, we present a general, systematic and consistent treatment of time and events for computer animation. We first formalize the concepts of events and create a time primitive called an event unit. We then present a succession of organization schemes to compose event units for generating complex motion sequences. We present a directed graph representation for the organization of time and events that suggests the form of an event‐based time programming language. Details of implementation of a general event simulation system are given. Our approach provides a clean partitioning for the problem of motion design, a hierarchical scheme to compose motion behaviors from time primitives and a programming model for organizing animation. Traditional methods of kinematic controls and key frame interpolation are special cases of our general scheme. In addition, our treatment of events can be combined with kinematics, dynamics or constraint‐based systems to generate powerful motion modeling syst

ISSN:0167-7055    

DOI:10.1111/1467-8659.1130045

出版商:Blackwell Science Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThis paper describes interactive facilities for simulating abstract muscle actions using Rational Free Form Deformations (RFFD). The particular muscle action is simulated as the displacement of the control points of the control‐unit for an RFFD defined on a region of interest. One or several simulated muscle actions constitute a Minimum Perceptible Action (MPA), which is defined as the atomic action unit, similar to Action Unit (AU) of the Facial Action Coding System (FACS), to build an expressio

ISSN:0167-7055    

DOI:10.1111/1467-8659.1130059

出版商:Blackwell Science Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractHAGI is an object‐oriented graphics system developed on top of the X window system. In addition to providing facilities that structured graphics systems such as GKS usually have, HAGI supports a high‐ level graphics paradigm with the following features:+In addition to graphical objects, the system provides a class of application objects with a higher level of abstraction than graphical objects.+Graphics manipulation operations can be issued simplyfrom application objects without explicitly referring to specific graphical objects. Thus graphics manipulation appears to be transparent to application programmers.+Graphical objects are designed to encompass more semantics, thus are at a level close to the application. For example, they useflexible visual objects to determine their visual appearance.HAGI provides such a high‐level application/graphics interface by maintaining a dependency relationship between graphical objects and application ob

ISSN:0167-7055    

DOI:10.1111/1467-8659.1130071

出版商:Blackwell Science Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe object‐oriented view of the user interface presented here is a model of object responsibilities‐sharing and cooperation for a typical user interface. The model regards the user interface as a three‐layer architecture, with the application contributing to one of the layers called the application exposure, The model seeks to promote user interface software reuse by coupling the user interface and the application with well‐defined message protocols, by properly allocating user interfacefunctions to the layers so as to reduce and discipline their dependencies, and byfactoring complex abstractions into reusable secondary com

ISSN:0167-7055    

DOI:10.1111/1467-8659.1130081

出版商:Blackwell Science Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractIn this paper a brief review of user interface management systems (UIMSs) and their advantages is given. Shortcomings of current UIMSs and open requirements imposed by industrial application areas are outlined. Among the most important requirements are uniform design mechanisms independent of interaction media, techniques, and styles as well as a straight forward end‐user adaptability of user interfaces.A new approach to interactive interface construction, called “direct composition”, is introduced. In this approach all interface objects contain the means for their own modification and design and therefore offer consistent interaction techniques for both the construction and usage of user interfaces. Moreover, end‐user adaptability is an inherent feature of direct composition interfaces.The user interface design environment SX/Tools is described to exemplify specific properties of user interface management systems following the principle of direct composition. The impacts of direct composition on user interface design include a uniform interface development process covering tool development, interface development, and “on‐usage” interface adaptation. It is argued that the direct composition approach can overcome many of the problems with trad

ISSN:0167-7055    

DOI:10.1111/1467-8659.1130093

出版商:Blackwell Science Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract:This paper presents a functional method for the visual simulation of 2‐D or 3‐D turbulent gaseous motion by using time‐varying fractals. The used function incorporates results from the “spectral theory of turbulence”, thereby providing a physics‐based approach adapted to the needs of computer graphics. The involved turbulence function is band‐limited, continuous, differentiable, anisotrop, and smooth, provides different fractal dimensions along each axis, may be evaluated locally with different parameters, and requires only minimal storage space, thus supporting an implementation on large parallel processing networks with small nodes. Inhomogeneity in the form of local disturbances of the turbulence field may also be easily considered. The parameters used to describe turbulent motion are rather intuitive, so that they may be utilized easily by users. Examples for modeling different types of clouds and f

ISSN:0167-7055    

DOI:10.1111/1467-8659.1130107

出版商:Blackwell Science Ltd    

年代:1992

数据来源: WILEY