ABSTRACT

This article focuses on the use of Virtual Reality in the creation of Information Visualization systems and applications aiming to generate more interactive and easy-friendly visualizations. The development of the InfoVis tool, created as part of a virtual environment, is described and discussed with emphasis on implementation aspects
 

Keywords

Information Visualization, Virtual Reality, Human-Computer Interaction.
 
 

1. INTRODUCTION

Information Visualization provides an interface between two powerful information processing systems: the human mind and the computer. Visualization is the process of transforming data, information and knowledge into a visual presentation form, using humans' natural capacity. With efficient visual interfaces, people interact with large volumes of data, quickly and effectively to discover hidden characteristics, patterns, and trends. In an increasingly information-rich society, research and development has fundamentally changed the way of presenting and understanding large complex data sets. The widespread and impact of visualization has led to new insights and more efficient problem learning and decision making [3].

Information Visualization is responsible for mapping data sets, usually available in a text-based format (with textual descriptions, numerical information displayed in tables, etc.) into a visual format, for the purpose of assisting users in exploring and understanding these data sets ([1], [2]). Visual presentations are much more attractive, concise, user-friendly, and intuitively understood by common users.

 Recently, the quality of Information Visualization applications have been increasingly improved by the use of 3D modeling and representations, combined with techniques to better incorporate effects of color, texture, lightening, etc. In addition, there is a crescent use of Virtual Reality, as a resource to improve the Information Visualization systems and applications. Virtual Reality technology has been pointed out as the more recent trend in the development of human-computer interfaces [6].

The primary characteristics of Virtual Reality-based interfaces are related to the level of interaction, immersion, and navigation provided to the users ([4], [8]). These characteristics are described below.

• Immersion. The system needs to create the impression that the user is present into the environment generated by the computer and participating of it. Usually, an immersive system is achieved by the use of non-conventional devices, although sound and control agents are also important for immersion immersion.
• Interaction. It enables to detect the user's inputs and instantly respond to them, by modifying the virtual world and the actions on it.
• Navigation. It is related to the possibility of the user explore the virtual environment, and visualize the components of the environment from any viewpoint.

Section 2 presents the development of the InfoVis tool, describing implementation aspects and displaying some screens. Then, section 3 presents complimentary aspects of metaphors and interactions. Finally, section 4 presents some concluding remarks.
 
 

2. DEVELOPMENT OF THE INFOVIS TOOL

2.1 General Context

The Information Visualizer (InfoVis) described here was developed for the purpose to support the presentation of data of an existing virtual world representing a Historical Museum - the Cerqueira César Museum. It is a cultural place of public visitation located in São Carlos, Brazil, which has historic objects and information, mainly related to the foundation period of the city.

The goal of InfoVis is to generate graphical representations of available information such as: frequency of visiting at the Museum per day of week, weekend, month, etc.; types and quantity of objects like furniture, domestic utensils, old coins, documents, garments, pictures and paintings, farm equipment, etc. The existing objects can be explored taking into account the whole Museum or a specific room. Additionally, the users can get textual explanations on the Museum.

Like the Virtual Museum, InfoVis is a Walk-Through environment, which is characterized by involving a type of interaction in which the user is free to walk around the virtual environment. Both virtual environments were developed according to a software development process especially proposed to create virtual applications [5].

The incorporation of Virtual Reality characteristics in a Visualization System requires the use of adequate software. InfoVis was developed by used three software from SENSE8 [7]: World Up Modeler (WUp), World Tool Kit (WTK), and World2World (W2W). WUp was used for modeling environment components, such as room, walls, furniture, pictures, graphics, etc. WTK is object-oriented, based on Visual C; it was used mainly to simulate the virtual environment. W2W allowed the execution of the application on a network platform, based on the client/server approach. So, multiple users can access the InfoVis and communicate among them.
 

2.2 Generation of Graphical Representations

An overview of the development process of the visualizations provided by the InfoVis is given in Figure 1.
 
 

In step 1, the user who is visiting the Virtual Museum can choose the type of information he/she is interested on - information on furniture, documents, domestic utensils, pictures, paintings, etc., related to the whole Museum or to a specific room. It is also possible to get information on the objects classified by date, origin, etc.

In step 2, the InfoVis, based on the user request, gather data and compose a corresponding text file. This file is the start point for the generation of the graphical visualizations.

In step 3, the type of intended graphical visualization is defined by the user and consecutively entered into the InfoVis.

In step 4, the InfoVis generates the requested graphical representation. For this, it is followed a specific process (including a formula) to compose each type of graphic created by the tool: pizza, bar, pyramid, and bubble graphic.

In step 5, the graphic representation requested by the user is displayed. Also, the user can obtain additional information, by clicking on visual metaphors placed in the visualization room.
 

2.3 Generation of Graphics

There are two ways to start the InfoVis: the fly way, which is triggered by directly clicking on the "Visualization Room" in the Museum layout; and the drive way, by navigating around the Museum until to arrive at the visualization room.

Since in the room, the user can choose among the four types of graphics created by the tool. For example, in the pizza graphic, small slices of pizza are built, taking into account the volume and percentage of data gathered from the corresponding text file. Thus, all the different data form the pizza in different colors and portions. A graphical representation is given in Figure 2.
 

In the bar graphic, the objects (bars) are built according to the volume and percentage of each data obtained from the text file. Different colors are applied to the bars, in order to make each type of data visible. This graphic is shown in Figure 3.

The creation of the two other types of graphics follows a similar process.
 

3. INTERFACES AND INTERACTION

The creation of appropriate interfaces and interactions was required to support, mostly non-expert users, not familiarized with the tool. In the InfoVis includes visual metaphors related the four types of visualization. When a metaphor is activated, the creation of the corresponding graphic is triggered.

Additionally, there are metaphors related to textual information on the Museum, on the visualizations, and on how to use the InfoVis. One way to obtain such information is leafing through a book or searching documents in a drawer of a filling cabinet. For this, some virtual books and the filling cabinet were modeled and placed in the Visualization Room (see Figure 4).

Also, InfoVis allows the visualization of different classes of data from multiple viewpoints at the same time. This presented in a screen with four windows, each containing a presentation from a viewpoint of the environment (from left side, right side, front view and static view). Thus, the user can have side views without losing the original, static view. This is shown in Figure 5.
 
 

Figure 5 – Multiple Views

4. CONCLUDING REMARKS

This article focused on the combined use of Information Visualization and Virtual Reality, presenting the InfoVis tool, which was developed to support different visualizations related to a virtual Museum.

The experience on development and use of InfoVis indicated that Virtual Reality technology represents a significant contribution to information visualization applications. The incorporation of virtual reality characteristics, such as immersion, navigation and interaction, make these applications more attractive and interactive and easy friendly.

The main difficulty in the InfoVis development was concerned to how to represent information in a clear way and create intuitive metaphors and interfaces.

Ongoing and future improvements in the InfoVis tool include: incorporation of non conventional virtual reality devices, like Head-Mounted Display; inclusion of additional information on the Museum; and creation of new types of graphics. Incorporation of metaphors to make easier and more attractive the utilization of InfoVis, and the visualization and interpretation of significant data, are also important in the present stage of the work.
 
 

Acknowledgements

The authors would like to thank the financial support provided by FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo, Brazil), Process 98/02215-2.
 

5. REFERENCES

[1] Carlis, J.V, and Konstans, J.A. Interactive Visualization of Serial Periodic Data. Proceedings of the IEEE Symposium on Information Visualization (1999) 29-38.

[2] Gershon, N.D., and Eick, S.G. Information Visualization Applications in the Real World. IEEE Computer Graphics and Applications, July/August 1997, 66-70.

[3] Gershon, N. D., Eick, S. G., and Card, S. New Visions of Human-Computer Interaction. ACM Interactions, March 1998, 8-15.

[4] Kirner, C., and Pinho, M. Introduction to Virtual Reality. Short Course (Recife, Brazil, July 1996), in Portuguese.

[5] Kirner, T.G., and Martins, V. F. A Model of Software Development Process for Virtual Environments: Definition and a Case Study. In: Proceedings of ASSET'99 (Richardson, TX, March 1999), IEEE Computer Society Press, 155-161.

[6] Meyers, B.A., Hollan, J., and Cruz, I. Strategic Directions in Human-Computer Interaction, ACM Computing Surveys 28, 4, 794-809.

[7] SENSE8 Corp. World Up Modeler, World Tool Kit, and World 2 World - Reference Manuals and User’s Guides. Mill Valley, CA, 1998.

[8] Vince J. Virtual Reality Systems. Addison-Wesley, Reading, Massachusetts, 1995.

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