Virtual Exhibitions
Digital media have grown to be an important factor in enhancing the didactic spectrum used in museums and exhibitions over the last years. They are used in various ways, from terminals acting as media stations indoors, to cultural heritage institutions providing additional information on Web sites on the Internet. The advantages of content in digital form are considerable as different media types can be made accessible on a single platform. The interested audience can benefit from the combination of textual information with images, audio, and video, and even three-dimensional animations, all at the same time.
Based on the three-dimensionality of the physical space, the same concepts can be used for virtual exhibition spaces in order to present the various digital objects adequately. Further, the availability of digital content opens up the possibility of presenting it on-line as well. These requirements necessitated an easy way for exhibition designers and curators to build virtual rooms to house the digital content that was available in the museum.
The ‘Technisches Museum Wien’ wanted an application that would allow exactly this. They approached software developers at the Institute of Information Systems & Information Management of the Graz-based research company JOANNEUM RESEARCH to help them with this task. Prior cooperation in similar fields has fostered a professional relationship between the organizations, and thus the project to build an easy-to-use editor for three-dimensional content was started.
The application is meant to build bridges to connect digital content such as images, audio and video, and three-dimensional representation of this content. The software allows filling virtual rooms with objects that can be built from various media formats and positioning those exhibits in the three-dimensional space of those rooms. With the help of a player, which is available as a stand-alone application, as well as a browser plug-in for on-line purposes, the target audience can view the exhibitions and even interact with the virtual objects.
Out of this project emerged the software product eXhibition:editor3D which is currently being used at the ‘Technisches Museum Wien’ to enhance the permanent exhibition ‘medien.welten’ by adding additional content and value.
eXhibition:editor3D
Purpose
At first the intended purpose of the software was to provide an easy way for curators to offer additional information in digital form. As supposedly the most exciting possibility for the visitor would be virtual showrooms, the developers went for this strategy. The audience should be captivated by the use of digital media, its presentation in three-dimensional space, and the opportunity to walk and interact freely within the given surroundings. The combination of various media formats allows for an especially rich experience. Textual information can be presented at the same time a video is shown, and pictures of objects can be enhanced with appropriate sound effects. The digital image of a typewriter in combination with the clicking sounds of the keys can enliven the whole experience as someone is learning about H.G. Wells, for example.
These little extra aspects add enormous value to exhibitions as they used to be. Almost all of the visitors’ senses (apart from olfactory sensation)can be stimulated at the same time for extra effect. By presenting the content and interactive animations on touch screens and using sound and moving images as well, the experience attains a new level of quality.
As there was no data presentation software that allowed for this variation in media use, and also as developers wanted to provide free navigation, a new application had to be developed with these aspects in mind.
Entering The Third Dimension
Choosing an appropriate format for visualizing three-dimensional content was important at the start of the development process. The possibilities ranged from proprietary 3D engines used by game developers to established standards for providing 3D content on the Web. The idea of using game engines ( i.e. letting the user change the virtual rooms at will and without the knowledge necessary to use 3D modeling software like Maya or 3D Studio Max) was declared useless for the goal. This left us with the technologies that are used to show 3D worlds on Web sites. The files used on the Web are relatively small, a distinct advantage.
The big player on this field seemed to be Shockwave 3D. Flash technology use is widespread, and the necessary plug-in for displaying flash content is well accepted and installed on the majority of personal computer systems. This led to the conclusion that the Shockwave 3D plug-in would also meet good acceptance from users. However, we decided against using Shockwave because it is a closed format. It does not allow alterations of its code (even though the possibility of injecting XML data in a Shockwave application exists).
The goal of the application was to provide a ‘one-stop’ solution. It should not be dependent upon other software, which would make it necessary to own and use the powerful software suite, but should be an easy to use tool on its own.
The necessity for alterations to the code and, preferably, the use of human readable characters was the main reason the successor of VRML (Virtual Reality Modeling Language) was chosen. This format is named Extensible 3D, or X3D for short, and was declared an international standard by the International Organization for Standardization (ISO) in 2004. It is based on XML (Extensible Markup Language, a format mainly used for data exchange between different systems) syntax, and therefore the code is understandable not only by computers but also by humans as well.
VRML is well established in the realms of creating three-dimensional content for the Web, and X3D as its successor has some additional advantages. Yet the main argument for using X3D is its clear structure and the ease of altering the resulting code. Because of its use of XML concepts such as nodes, children, properties and such, it is relatively easy to use data input in any other form and transform this data into valid X3D by using stylesheets (XSLT Extensible Stylesheet Language Transformation).
Take a look at the example below to get an idea:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE X3D PUBLIC "ISO//Web3D//DTD X3D 3.0//EN" "http://www.web3d.org/specifications/x3d-3.0.dtd">
<X3D profile="Immersive" version="3.0">
<head>
<meta name="Vizthumbnail" content="Thumb_cbtmp_x3d198868751129211859.jpg"/>
</head>
<Scene>
<NavigationInfo DEF="NavInfo1" avatarSize="0 1.8 .75" visibilityLimit="0" speed="2" headlight="true" type=""WALK""/>
<Transform DEF="dad_ObjekteSub1">
<Group DEF="ObjekteSub1">
<Group>
<Transform DEF="niimai" translation="3.44 0.0 9.72" rotation="0 1 -0 4.712388981460667">
<Shape>
<Appearance>
<ImageTexture url="C:\niimai.jpg"/>
</Appearance>
<Box size="0.01 1.2800001 0.96000004" solid="true"/>
</Shape>
</Transform>
</Group>
</Group>
</Transform>
<Viewpoint DEF="viewpoint 0" description="viewpoint 0" jump="true" fieldOfView="1.0" position="3.48 0.0 11.64" orientation="0 1 0 0"/>
</Scene>
</X3D>
The part in bold defines an object, in this case a box with an image attached as a texture to it. The surrounding code defines the world and provides meta information about the scene. You can also see that there is a node for a viewpoint. This is the representation of a camera object in the X3D world.
However, there is no need to go into more detail with this code. The main point is that this is the code a computer uses to render a three-dimensional object at its given coordinates on the screen. Changing the appearance of the object is easy to accomplish and requires no special training in a programming language.
Getting Technical
JOANNEUM RESEARCH built an application that uses common elements of user interaction like drag and drop and menus to achieve the same effect as altering the code in a text editor. The software comes with easy-to-use concepts and allows creating, saving and reopening projects containing the virtual rooms. An export mechanism allows the publishing of a finished exhibition with one single click.
Fig 1: Screenshot of the user interface (eXhibition:editor3D)
The application is based on Java and the Eclipse framework which allows for platform independence.
More specifically, it is based on the Eclipse Rich Client Platform (RCP). This provides certain features that have been incorporated into the program, like on-line help and undo mechanisms. Additionally, the use of the Graphical Editing Framework makes it possible to create a clear user interface which consists of several sub-windows and tabs. The main part of the user interface, the drawing area, is built with this framework. The drawing area, along with the repository, constitutes the heart of the editor. Digital media (audio, images and sound files) are managed with the so-called repository, a special container which provides access to folders on the system, on the local network, or even on the Internet. From these folders the necessary files are chosen and managed in the content area. It is as easy as grabbing a file with the mouse and dragging it to the drawing area to create an object in the three-dimensional space of the virtual room.
The object can, of course, be scaled and re-positioned at any time, and also the content of the object can be altered later on. This allows for maximum flexibility when building a virtual exhibition.
In order to make objects visible, viewpoints have to be positioned around the room. Connecting them creates paths along which the visitor will navigate later. These paths can act like virtual tours. As it is not always advisable or feasible to allow the viewers to navigate on their own, the navigation can be formed entirely by the use of viewpoints. This, of course, gives a lot of power to the designer as the order in which the exhibits are met is laid down during the creation process.
The use of a plug-in system guarantees a high degree of flexibility. Because of the modular nature of the software, future additions of features can be realized as plug-ins. Basically, each would be an additional folder in the file-system and would adds features to the application without the need to change anything in the core files. A possible use of a plug-in could be to connect the media management part of the editor with a content management system.
During the development stage a bug-tracking tool was used to keep record of bugs and enhancement requests. Additionally, a wiki was set up to collect information about the development process in general. In order to keep control of various versions of the software, designers used the tool Subversion as a version control system. The system also allows going back to older versions should a bug destroy the current line of development. This adds a lot of security to the development process. When building a demo version which incorporated some restrictions, designers found this system of utmost importance as it allowed building different parallel branches of the same project.
The Virtual media.worlds
In the context of the comprehensive permanent exhibition ‘medien.welten’ at the ‘Technisches Museum Wien,’ a digital exposition is currently being created to extend the experience. This can be understood as a step towards a museum of the future. Extraordinary virtual exhibition spaces arise and focus on special aspects of exhibits. The digital representations are not meant to substitute for the original physical objects on display. They rather allow the visitors to experience other facets as well, facets that used to be inaccessible with established forms of exhibitions. The support of digital formats makes it possible to bring historical media exponents to life. For example, rotating images combine to produce a movie-like experience, and the pages of richly decorated books can be flipped through. The visitor can even listen to original sound recordings of shellacs or other historical media while looking at a representation of the object.
Imagine the attraction of a phenakistoscope – still images which, put into rotation, suggest the impression of seeing a movie; or the animation of an early electric telegraph - enabling visitors to hear Morse code while watching the message coming in.
A special treat is an animation of the mysterious encryption machine ‘Enigma’ from the Second World War: it can be used by the museum’s visitors to decode messages. This playful approach allows the audience to experience history hands on.
Combined, these different aspects of media can provide a holistic view of media history.
The museum of the future can present material interactively and with the help of multi-media without sacrificing the real exhibits.
Fig 2: Screenshot of the Client as used at the museum
Additionally, visitors to the museum are able to create their own ‘digital backpacks’. By using a smart card which can be purchased at the museum’s entrance, views can save the contents of the exhibition ‘medien.welten’ and take material home for future reference. The smart card can be placed in a card reader that is incorporated at the terminals, and images and textual information will be stored into a database. With a unique login, the card can later be recognized by the system, and the data becomes available over an Internet connection. This concept allows visitors to revisit the parts of the exhibition they were most interested in.
The look and feel of the user interface is modeled upon the visitor’s real experience at the museum, and the structure of the exhibition is maintained.
Basically this technology would allow the whole virtual museum to become available on-line for everyone. Yet the amount of data would have to be adapted, as current bandwidth would not suffice for the massive data traffic necessary.
Conclusion and Outlook
The software is capable of a wide range of uses. For museums, it allows realistic planning of exhibitions by providing previews of the various show rooms. Digital representations of real objects can be positioned within the available room and the exhibition designer can compare different layouts. The impression of wandering through the exhibition and thus approaching objects is realistic and helps with finding the perfect positions for the various items on display.
In future releases, the editor will support 3D modeled objects as well - a virtual showroom can then consist of all the facts in textual form, with pictures, movies, sounds and interactive lifelike models as well.
References
exhibition3d.at, homepage of the project, http://www.exhibition3d.at
Moritsch, O., et al., Creating 3D Virtual Exhibitions, in International Cultural Heritage Informatics Meeting (ICHIM07): Proceedings, J. Trant and D. Bearman (eds). Toronto: Archives & Museum Informatics. 2007. Published September 30, 2007 at http://www.archimuse.com/ichim07/papers/moritsch/moritsch.html
Web3D Consortium, Open Standards for Real-Time 3D Communication, http://web3d.org
