Object-Oriented Programming in Pascal

xxx, 616 tr. ; 23 cm

WAXweb: Toward Dynamic MOO-based VRML

We describe the structure and development of WAXweb, a dynamic MOO-based hypermedia database which is being used as a VRML server. We also discuss the future of 3D MUD-like systems, describing the particular problems of highly-interactive, distributed 3D scenes. So that we can begin to experiment with these areas using commonly-available VRML browsers, this paper describes several extensions for VRML 1.x which will allow for simple dynamic multiuser interactions. 1 Introduction VRML [BPP95] was intended not only as a static 3D document format for the World-Wide Web, but also as a way to progress towards the development of distributed, collaborative work and play areas. Such ideas were inspired both by MUDs (Multi-User Domains), which are shared text-based virtual spaces on the Internet, and by the development of low-cost computers capable of interactive 3D graphics. 1.1 MUDs MUDs, or Multi-User Domains, evolved out of multi-player Adventure-style games in the early 80s. These began..

Three-Dimensional Widgets

The 3D components of today's user interfaces are still underdeveloped. Direct interaction with 3D objects has been limited thus far to gestural picking, manipulation with linear transformations, and simple camera motion. Further, there are no toolkits for building 3D user interfaces. We present a system which allows experimentation with 3D widgets, encapsulated 3D geometry and behavior. Our widgets are first-class objects in the same 3D environment used to develop the application. This integration of widgets and application objects provides a higher bandwidth between interface and application than exists in more traditional UI toolkit-based interfaces. We hope to allow user-interface designers to build highly interactive 3D environments more easily than is possible with today's tools. Keywords User Interface Design, Widgets, 3D Interaction, Virtual Reality 1 Introduction Modern user-interface software is built using widgets, objects with geometry and behavior used to control the ap..

Interactive Shadows

It is often difficult in computer graphics applications to understand spatial relationships between objects in a 3D scene or effect changes to those objects without specialized visualization and manipulation techniques. We present a set of three-dimensional tools (widgets) called "shadows" that not only provide valuable perceptual cues about the spatial relationships between objects, but also provide a direct manipulation interface to constrained transformation techniques. These shadow widgets provide two advancesover previous techniques. First, they provide high correlation between their own geometric feedback and their effects on the objects they control. Second, unlike some other 3D widgets, they do not obscure the objects they control. Keywords Direct Manipulation, 3D Widgets, Interactive Systems 1 Introduction A wide variety of techniques for visualizing and manipulating objects have beenimplemented in interactive 3D graphics applications for modeling, animation, simulation an..