In this paper, we propose a new 3D visualization technique for hierarchical information. This technique is based on the nested box metaphor, a familiar concept for any users. By using semi-transparent rendering, the system controls the complexity of the information presented to the user. With several 3D interaction techniques provided by the system, the user can recognize and inspect the information structure intuitively. Normally, the user puts on the VR equipment to use the system, but the system is also accessible through a conventional CRT display. 1 Introduction Today, we must face many kinds of information which are difficult to represent in 1D or 2D, because they are too complex and do not fit into the current display's size and resolution. Examples of such information include large software structures, database schemes, organization structures, a huge project's PERT chart, traffic control information, and network management. All of them are huge, and it is quite hard to visual...

In this paper we present an extensive experimental study...

INTRODUCTION Graph drawing addresses the problem of constructing geometric representations of graphs, and has important applications to key computer technologies such as software engineering, database systems, visual interfaces, and computer-aided-design. Research on graph drawing has been conducted within several diverse areas, including discrete mathematics (topological graph theory, geometric graph theory, order theory), algorithmics (graph algorithms, data structures, computational geometry, vlsi), and human-computer interaction (visual languages, graphical user interfaces, software visualization). This chapter overviews aspects of graph drawing that are especially relevant to computational geometry. Basic definitions on drawings and their properties are given in Section 1.1. Bounds on geometric and topological properties of drawings (e.g., area and crossings) are presented in Section 1.2. Section 1.3 deals with the time complexity of fundamental graph drawin

In order to realise the potential benefits of three--dimensional (3D) display of relational information, there is a need for effective 3D human--computer interface designs. Algorithms for automatically creating 3D visual representations of relational information are a significant component of these interfaces. One productive strategy for developing such algorithms has been via the graph as an intermediate representation of the relational information: the information is first expressed as a graph and then a layout algorithm is used to create a visual representation of the graph. This thesis examines some technical issues which arise when several common layout algorithms, developed originally for 2D display of graphs, are extended specifically to 3D display. Typical computer graphics display systems can only provide a limited resolution and display area. This places a limit on the size of graph which can be displayed effectively. Simplification of the graph can permit the display of lar...

Online Graph Drawing deals with huge graphs which are partially unknown. At any time, a tiny part of the graph is displayed on the screen. Examples include WWW graphs and graphs of links in distributed file systems. This paper discusses issues arising in the presentation of such graphs. The paper describes a system for dealing with WWW graphs using Online Graph Drawing. Keywords: graph drawing, information visualization, computer graphics. 1 Introduction As graphics workstations have now become common tools for software and information engineers, visualization of relational information has become an essential element of current software systems. Examples include web browsers, file system visualizers, CASE tools, database design systems, network design systems, visual programming interfaces, and reverse engineering systems. The effectiveness of visualizing relational information is widely recognized. Most systems use graphs to model relational structures: the entities are nodes, and th...

In this paper, we introduce a new graph model known as clustered graphs, i.e. graphs with recursive clustering structures. This graph model has many applications in informational and mathematical sciences. In particular, we study C-planarity of clustered graphs. Given a clustered graph, the C-planarity testing problem is to determine whether the clustered graph can be drawn without edge crossings, or edge-region crossings. In this paper, we present efficient algorithms for testing C-planarity and finding C-planar embeddings of clustered graphs. 1 Introduction Representing information visually, or by drawing graphs can greatly improve the effectiveness of user interfaces in many relational information systems [12, 17, 18, 5]. Developing algorithms for drawing graphs automatically and efficiently has become the interest of research for many computer scientists. Research in this area has been very active for the last decade. A recent survey citelabel13new of literature in this area inclu...

this article we describe the concepts we used for implementing an experimental system which controls the computer screen contents and its layout. We give two examples of different standard applications into which we included ADL successfully, namely hypertext for a window layout problem and graph-browser for a hierarchical graph layout problem within a particular window. The results show that automatic (and tool independent) display layout will be possible in the near future even in an interactive environment

In this paper we consider the class of directed acyclic graphs (DAGs), and present the results of an experimental study on four drawing algorithms specifically developed for DAGs. Our study is conducted on two large test suites of DAGs and yields more than 30 charts comparing the performance of the drawing algorithms with respect to several quality measures, including area, crossings, bends, and aspect ratio. The algorithms exhibit various trade-offs with respect to the quality measures, and none of them clearly outperforms the others.

Graphs and graph algorithms play an important role in undergraduate data structures and algorithms courses. However, they often also represent the first case where both the correctness and the underlying concepts of the algorithms are not evident. Both students and educators can therefore benefit from a simple yet expressive tool for coding graph algorithms and then conveniently visualizing them. We present such a tool, derived from a set of instructional requirements, and give an example application.

Graphs are often used to represent relational information. As the amount of information that we want to visualize becomes larger and more complicated, classical graph model tends to be insufficient. In this paper, we introduce and show how to draw a practical and simple graph structure known as clustered graphs. We present an algorithm which produces planar, straight-line, convex drawings of clustered graphs in O(n 2:5 ) time. We also demonstrate an area lower bound and an angle upper bound for straight-line convex drawings of C-planar graphs. We show that such drawings require\Omega\Gammaq n ) area and the smallest angle is O(1=n). Our bounds are unlike the area and angle bounds of classical graph drawing conventions in which area bound is \Omega\Gamma n 2 ) and angle bounds are functions of the maximum degree of the graph. Our results indicate important tradeoffs between line straightness and area, and between region convexity and area. 1 Introduction Many systems, particular...