The Amulet environment: new models for effective user interfacesoftware development

The Amulet user interface development environment makes it easier for programmers to create highly interactive, graphical user interface software for Unix, Windows and the Macintosh. Amulet uses new models for objects, constraints, animation, input, output, commands, and undo. The object system is a prototype instance model in which there is no distinction between classes and instances or between methods and data. The constraint system allows any value of any object to be computed by arbitrary code and supports multiple constraint solvers. Animations can be attached to existing objects with a single line of code. Input from the user is handled by “interactor” objects which support reuse of behavior objects. The output model provides a declarative definition of the graphics and supports automatic refresh. Command objects encapsulate all of the information needed about operations, including support for various ways to undo them. A key feature of the Amulet design is that all graphical objects and behaviors of those objects are explicitly represented at run time, so the system can provide a number of high level built-in functions, including automatic display and editing of objects, and external analysis and control of interfaces. Amulet integrates these capabilities in a flexible and effective manner     

Graceful interaction with graphical constraints

The graphical constraint editor (GRACE), a graphical editor that lets users define graphical, or geometric, constraints, is reviewed. Graphical constraints specify relationships among graphical objects that the system must maintain. Constraints are useful in graphical drawing editors, design activities supported by CAD systems, and graphical user interface construction. GRACE provides mechanisms for explicit and implicit constraint specification using simple and natural means. These include simple direct manipulation methods and a constraints-by-demonstration facility that incorporates both novel heuristics for inferring user-demonstrated relations in an economical fashion and a natural-language explanation tool that helps the user understand the system's inferencing behavior. An overview of GRACE's user interface is presented and details about how users specify graphical relations and query the system to obtain information about them are provided     

An interactive example-driven approach to graphics recognition in engineering drawings

An interactive example-driven approach to graphics recognition in engineering drawings is proposed. The scenario is that the user first interactively provides an example of a graphic object; the system instantly learns its graphical knowledge and uses the acquired knowledge to recognize the same type of graphic objects. The proposed approach represents the graphical knowledge of an object in terms of its structural components and their syntactical relationships. We summarize four types of geometric constraints for knowledge representation, based on which we develop an algorithm for knowledge acquisition. Another algorithm for graphics recognition using the acquired graphical knowledge is also proposed, which is actually a sequential examination of these constraints. In the algorithm, we first guess the next component’s attributes (e.g., size, position and orientation) by reasoning from an earlier found component and the constraint between them, and then search for this hypothetical component in the drawing. If all of the hypothetical components are found, a graphic object of this type is recognized. For improving the system’s recognition accuracy, we develop a user feedback scheme, which can update the graphical knowledge from both positive (missing) and negative (mis-recognized) examples provided by the user for subsequent recognition. Experiments have shown that our proposed approach is both efficient and effective for recognizing various types of graphic objects in engineering drawings. This paper is an extension of our papers published in ICDAR2003 and GREC2003.     

基于相似性学习的三维模型最优视图选择算法

针对已有最优视图度量难以适用于不同类型的三维模型,提出基于用户知识、在模型库中为各类模型建立最优视图样例,并在此基础上进行相似性学习,根据相似性度量获得输入模型最优视图的选择算法.首先采用AdaBoost算法对输入三维模型形状特征进行相似性学习,得到该模型的最优视图样例;然后将输入模型从不同视点得到的渲染视图和最优视图样例进行形状相似性分析,以相似度最高者作为输入模型的最优视图.实验结果表明,采用文中算法得到的最优视图不仅可以有效地逼近用户选择结果,而且具有较好的稳定性.     

Object management in a programming-by-example,parametric, computer-aided-design system

We present the handling of graphical objects in a programming-by-example, CAD system. The object-naming mechanism described here supports the automatic generation of parameter-independent object references in parametric programs. These programs are produced via user interaction during the construction of parametric objects. We use standard programming language control structures and modularity for the parametrisation of variants, repetitive similarities and flexible hierarchical object structure. The object management of parametric entities with varying topology ensures the correctness of their instantiating parametric programs for large domains of parameter values.     

Parameterization of arbitrary geometrical structures for automated electromagnetic optimization

This paper presents the theoretical foundation of the geometry capture technique. Geometry capture facilitates user‐parameterization, through graphical means, of arbitrary 2D and 3D geometrical structures. This makes it possible to optimize the shape and dimensions of geometrical objects in an automated electromagnetic design process by adjusting the user‐defined parameters subject to explicit numerical bounds and implicit geometrical constraints. ©1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 73–85, 1999     

一个面向对象的交互式图形工具箱OOIGT

在开发交互式图形应用过程中，一个主要难题是如何表示和建立代表应用模型数据及操作的图形对象并提供直接操作的交互方式，另一个难题是如何有效地表示和管理图形对象之间的关系。ＯＯＩＧＴ是作者设计和实现的一个交互式图形建造工具箱，其目的是为解决上述个有效的解，ＯＯＩＧＴ提供了一相可扩充，用于表示应用模型并集成了事件模型的图形对象集，使应用不人需定义对象，而毋须了解如何作图，且容易处理在这些对象上的交互式直     

Graphical objects

We introduce the concept of graphical objects, the abstraction paradigms to study them, and their applications in computer graphics. Intuitively, graphical objects encompass all the entities manipulated in a graphics system. This notion makes it possible to unify similar research topics appearing in the literature separately. We study the problem of object metamorphosis, which includes the problem of image metamorphosis. Although we are not primarily concerned with implementation issues in this paper, the concepts we introduce can be exploited for system design and development that use object-oriented programming.     

Object-oriented specification and formal verification of real-time systems

An object-oriented approach for specification and verification of real-time systems is described in this paper. It is motivated by taking advantage of object-oriented techniques to produce real-time software that is easy to understand, maintain, and reuse. The approach specifies the structural, behavioral, and control aspects of objects in one model with a textual representation as well as a graphical representation. For ease to comprehend and use, the model encapsulates object states and allows an analyst to focus on specifying object operations one at a time. System behavior from individual objects can be deduced and analyzed. For safety considerations, the approach supports specification of failures to object behavior and their resultant faults. The approach also supports modeling of timed temporal constraints for specifying and verifying desirable real-time properties. An object timed temporal logic OTTL is defined for expressing the syntax and semantics of these constraints. Decision procedures for their verification are also presented.     

Environment for rapidly creating interactive design tools

The Garnet toolkit was specifically designed to make highly interactive graphical programs easier to design and implement. Visual, interactive, user-interface design tools clearly fall into this category. At this point, we have used the Garnet toolkit to create three different interactive design tools: Gilt, a simple interface builder for laying out widgets; Lapidary, a sophisticated design tool for constructing application-specific graphics and custom widgets; and C32, a spreadsheet interface to constraints. The features of the Garnet toolkit that made these easier to create include use of a prototype-instance object system instead of the usual class-instance model, integration of constraints with the object system, graphics model that supports automatic graphical update and saving to disk of on-screen objects, separation of specifying the graphics of objects from their behavior, automatic layout of graphical objects in a variety of styles, and a widget set that supports such commonly used operations as selection, moving and growing objects, and displaying and setting their properties.     

Supporting cartoon animation techniques in direct manipulation graphical user interfaces

If judiciously applied, the techniques of cartoon animation can enhance the illusion of direct manipulation that many human computer interfaces strive to present. In particular, animation can convey a feeling of substance in the objects that a user manipulates, strengthening the sense that real work is being done. This paper describes algorithms and implementation issues to support cartoon style graphical object distortion effects for direct manipulation user interfaces. Our approach is based on suggesting a range of animation effects by distorting the view of the manipulated object. To explore the idea, we added a warping transformation capability to the InterViews user interface toolkit.     

Which animation effects improve indirect manipulation?

This paper describes an experiment to explore the effectiveness of animation in improving indirect manipulation operations. Indirect manipulation operations are those initiated by command menus and buttons to perform a transformation on a graphical object or set of graphical objects. The particular improvement is an operation's ability to show both what would happen if the operation were committed and what would happen if it were cancelled while an operation is being considered. The experiment required subjects to watch a simple alignment operation for a set of graphical objects. They were then asked to record the original placement of those graphical objects. Each task used one of four visual cues: modified telltale, wiggle, colour, or no visual cue. We found the modified telltale, wiggle, and colour visual effects significantly more effective than no visual feedback for cuing the user as to original position of the graphical objects. The modified telltale and colour effects were significantly more effective than the wiggle effect. The major conclusion drawn from this experiment is the use of visual feedback improves a user's ability to remember the previous position of graphical objects after an alignment operation.     

On labeling in graph visualization

When visualizing graphs, it is essential to communicate the meaning of each graph object via text or graphical labels. Automatic placement of labels in a graph is an NP-Hard problem, for which efficient heuristic solutions have been recently developed. In this paper, we describe a general framework for modeling, drawing, editing, and automatic placement of labels respecting user constraints. In addition, we present the interface and the basic engine of the Graph Editor Toolkit - a family of portable graph visualization libraries designed for integration into graphical user interface application programs. This toolkit produces a high quality automated placement of labels in a graph using our framework. A brief survey of automatic label placement algorithms is also presented. Finally we describe extensions to certain existing automatic label placement algorithms, allowing their integration into this visualization tool.     

MPGS: an interactive tool for the specification and generation ofmultimedia presentations

Multimedia presentations are composed of objects belonging to different data types such as video, audio, text and image. An important aspect is that, quite often, the user defining a presentation needs to express sophisticated temporal and spatial constraints among the objects composing the presentation. We present a system (called MPGS-Multimedia Presentation Generator System) which supports the specification of constraints among multimedia objects and the generation of multimedia presentations according to the specified constraints. The constraint model provided by MPGS is very flexible and powerful in terms of the kinds of object constraints it can represent. A large number of innovative features are supported including: asynchronous and simultaneous spatial constraints; components of interest and priority levels; motion functions. Obviously, the flexibility provided to the users requires the development of nontrivial techniques to check constraint consistency and to generate a presentation satisfying the specified constraints. We illustrate the solutions we have devised in the framework of MPGS     

Enhanced illustration using Magic Lens filters

In computerized 2.5D illustration systems such as Adobe Illustrator or CorelDraw, users construct pictures by layering geometrical shapes and specifying graphical properties such as line width, fill color, and transparency. In these systems, the act of applying a graphical property is closely tied to the way the individual objects in the design are constructed. For example, filled regions must be explicitly constructed and closed. Line and fill properties must be applied to complete outlines or line segments. Transformations can only be applied to complete objects or groups of objects. The designer must always plan to create object boundaries to define the extent of any visual effect. Effects that appear to cross object boundaries require the introduction of extra shapes and boundaries into the picture. We describe the value of including spatially bounded visual filters, called Magic Lens filters, as integrated elements in graphical illustrations. Because the effect of a Magic Lens filter is visible only within the lens' boundary, the extent of this effect can be manipulated independently of the boundaries of the objects seen through it. This adds a new design element to the standard illustration system paradigm, making many forms of illustration easier to create. Magic Lens filters were introduced in 1993 as components of see-through user interfaces (E.A. Bier et al., 1993)     

Views as first-class citizens in object-oriented databases

Extensibility and dynamic schema evolution are among the attractive features that lead to the wide acceptance of the object-oriented paradigm. Not knowing all class hierarchy details should not prevent a user from introducing new classes when necessary. Naive or professional users may define new classes either by using class definition constructs or as views. However, improper placement of such classes leads to a flat hierarchy with many things duplicated. To overcome this problem, we automated the process in order to help the user find the most appropriate position with respect to her class in the hierarchy regardless of her knowledge of the hierarchy. The system must be responsible for the proper placement of new classes because only the system has complete knowledge of the details of the class hierarchy, especially in a dynamic environment where changes are very frequent. In other published work, we proved that to define a view it is enough to have the set of objects that qualify to be in a view in addition to having message expressions (possible paths) that lead to desired values within those objects. Here, we go further to map a view that is intended to be persistent into a class. Then we investigate the proper position of that class in the hierarchy. To achieve this, we consider current characteristics of a new class in order to derive its relationship with other existing classes in the hierarchy. Another advantage of the presented model is that views that generate new objects are still updatable simply because we based the creation of new objects on existing identities. In other words, an object participates inside view objects by its identity regardless of which particular values from that object are of interest to the view. Values are reachable via message expressions, not violating encapsulation. This way, actual values are present in only one place and can be updated.Received: 19 March 1999, Accepted: 26 December 2003, Published online: 8 April 2004Edited by: R. Topor.     

Immersive manipulation of virtual objects through glove-based hand gesture interaction

Immersive visualisation is increasingly being used for comprehensive and rapid analysis of objects in 3D and object dynamic behaviour in 4D. Challenges are therefore presented to provide natural user interaction to enable effortless virtual object manipulation. Presented in this paper is the development and evaluation of an immersive human?Ccomputer interaction system based on stereoscopic viewing and natural hand gestures. For the development, it is based on the integration of a back-projection stereoscopic system for object and hand display, a hybrid inertial and ultrasonic tracking system to provide the absolute positions and orientations of the user??s head and hands, as well as a pair of high degrees-of-freedom data gloves to provide the relative positions and orientations of digit joints and tips on both hands. For the evaluation, it is based on a two-object scene with a virtual cube and a CT (computed tomography) volume created for demonstration of real-time immersive object manipulation. The system is shown to provide a correct user view of objects and hands in 3D with depth, as well as to enable a user to use a number of simple hand gestures to perform basic object manipulation tasks involving selection, release, translation, rotation and scaling. Also included in the evaluation are some quantitative tests of the system performance in terms of speed and latency.