Sketching communicates ideas rapidly through approximate visual images with low overhead (pencil and paper), no need for precision or specialized knowledge, and ease of low-level correction and revision. In contrast, most 3D computer modeling systems are good at generating arbitrary views of precise 3D models and support high-level editing and revision. TheSKETCH application described in this paper attempts to combine the advantages of each in order to create an environment for rapidly conceptualizing and editing approximate 3D scenes. To achieve this, SKETCH uses simple non-photorealistic rendering and a purely gestural interface based on simplified line drawings of primitives that allows all operations to be specified within the 3D world.

Introduction Today's user interfaces for most 3D graphics applications still depend heavily on 2D GUIs and keyboard input. There have been several recent attempts both to extend these user interfaces into 3D and to describe intermediary 3D widgets 1 that control application objects [3; 4; 5; 7; 13; 15]. Even though this style of interaction is a straightforward extension of interaction through intermediary 2D widgets such as dials or sliders, we know of no efforts to develop interactive 3D toolkits akin to UIMX or Garnet [11]. The Brown Graphics Group has had considerable experience using its Unified Graphics Architecture (UGA) system [16] to script 3D widgets such as deformation racks [14], interactive shadows [9], parameterized models, and other constrained 3D geometries. Using this experience, we have developed an interactive toolkit to facilitate the visual programming of the geometry and behavior of such interactive models. The toolkit provides both a co

This paper presents the architecture for an extensible toolkit used in construction and rapid prototyping of three dimensional interfaces, interactive illustrations, and three dimensional widgets. The toolkit provides methods for the direct manipulation of 3D primitives which can be linked together through a visual programming language to create complex constrained behavior. Features of the toolkit include the ability to visually build, encapsulate, and parameterize complex models, and impose limits on the models. The toolkit's constraint resolution technique is based on a dynamic object model similar to those in prototype delegation object systems. The toolkit has been used to rapidly prototype tools for mechanical modelling, scientific visualization, construct 3D widgets, and build mathematical illustrations. 3D Interface Toolkit April 21, 1994 3 1.0 Introduction There have been many advances in 2D user interface toolkits [8][10][11][12] which allow developers to rapidly prototyp...

Design of information presentation is undergoing significant changes. Documents are information interfaces that must dynamically reconfigure themselves based on their content, the medium in which they are displayed, and the intended use of the information they present. Increases in computational power and the increased bandwidth of interconnected networks provide greater access to information. These factors, combined with the realization that not all of this information can now be pre-designed, necessitate new tools and techniques to ensure the effective presentation of computer-based information. This dissertation exploits the structure of information to support the design of dynamic documents. From this structure, visual languages

CMon is a general-purpose performance monitoring system. It enables monitoring of long-running programs in a setting where the experimenters who are interested in the performance data are different from the users who run the programs that generate the data. Among other things, this permits programs to be monitored under real workload conditions. PSpec is a language and set of tools for performance assertion checking,an approach to automating the testing of performance properties of complex systems. It can be used in conjunction with the CMon system to produce a performance monitor that runs continuously, over the lifetime of a program, and automatically detects performance anomalies. In this report we describe the design and implementation of CMon and the continuous monitoring features of PSpec, and report on our experience using the systems. Contents 1 Introduction 1 2 Continuous Monitoring 2 2.1 Design................................ 3 2.2 ImplementationIssues ....................