In Proceedings of the Collaborative Virtual Environments, 2000. 47-56 Collaborative Augmented Reality Environments: Integrating VR, Working Materials, and Distributed Work Spaces Monika Büscher2, Michael Christensen1, Kaj Grønbæk1, Peter Krogh3, Preben Mogensen1, Dan Shapiro2, Peter Ørbæk1 2 3 1Department of Computer Science Department of Sociology Aarhus School of Architecture University of Aarhus Lancaster University Danish Center for Integrated Design DK-8200 Aarhus C, Denmark Lancaster LA1 4YL, UK DK-8000 Århus C {toby, kgronbak, pmogensen, {m.buscher, d.shapiro} [email protected] poe}@daimi.au.dk @lancaster.ac.uk ABSTRACT The documents that most CVEs support are low quality This paper describes Manufaktur , a prototype of a concept writing on the Whiteboard, i.e. manipulation of real office and infrastructure that goes beyond the classical CVE sys- documents and objects is not supported. This is a serious tems toward a collaborative augmented reality environ- barrier for bringing CVEs out of entertainment or research ment, where users' documents and objects appear as live [1] to real world work tasks. Such integration of documents representations in a 3D workspace. Manufaktur supports and objects is a main design issue in the work of this paper. collaborative, distributed work across platforms. It provides The work draws on experience and techniques from a num- the possibility of display on the MS Windows and the SGI ber of different fields: Collaborative Virtual Environments IRIX platforms with mono and stereographic displays rang- (CVE) [6], Open Hypermedia [19], and CSCW [14, 24]. In ing from a monitor built into a table to a Holobench. previous papers [3, 18] we described an early version of a The emphasis is on representing the materials with which system, the Manufaktur (‘craft workshop’), intended to people are working, and the actions they are taking with provide a computer-based environment to support the work them, and far less on the visual representation, e.g. through primarily of architects, landscape architects and other de- avatars, of the collaborating persons. It seeks to facilitate signers. This paper outlines a number of further develop- users’ collective self-organisation of environments, spaces ments to this system, some of which are well on the way to and traces that embody the trajectory of their work. realisation and others of which are in process. Keywords Design professionals use a great variety of materials – Virtual Reality, Working Material, Virtual Office/Project plans, sketches, diagrams, photographs, scale models, sam- Room, Roomware, CSCW, 3D Workspace. ples of materials, catalogues, etc. – and the system is based on observations of the ways in which they constantly ar- INTRODUCTION range, relate and rearrange these in three dimensions in A number of collaborative virtual environments have been their physical workspaces. We found that manipulating the developed in recent years. DIVE [5, 12] and MASSIVE [8] presence and absence of materials, bringing them into dy- are among the most well known. Both of these systems namic spatial relations, and referring between them, are not provide a combination of 3D worlds, avatars, video, sound just a context or prerequisite for doing the work; rather, and documents. Users are represented as simple avatars and they are an integral part of accomplishing the work itself. they can communicate by means of various media. For in- What is important is not just to create or change a docu- stance, avatars may walk up and share a Whiteboard where ment or other materials, but to do so in the presence of and they can manipulate 2D graphics, watch live video, write in relation to others. and draw simultaneously. They can also import 3D objects, which can be inspected from arbitrary positions. Docu- The environment is being designed on the basis of the ments are implemented as portable whiteboards that users Manufaktur system, which was originally designed as an can bring with them and be manipulated privately by a sin- MS Windows 3D environment, integrating documents and gle user. Documents can be placed on shared whiteboards design models in common workspaces for (landscape) ar- or conference tables. A conference table is a service to al- chitects. Manufaktur is now becoming a multi-platform low group discussion. A user joins the discussion when distributed concept for augmented reality work environ- his/her avatar gets sufficiently close to the table. ments, where design models and document objects (docu- ment representations) can be visualized either on a Win- CVE researchers have experimented with different ways of dows platform or on a Silicon Graphics platform, on mono mediating awareness and formation of groups and meetings or stereographic displays ranging from a monitor built into in virtual environments. However, the artifacts related to a table to a Holobench. Document objects and models are, the work of users have received less attention in this re- independently of their rendering and display, linked to the search, e.g., by not supporting native document formats. real documents and model sources, which may reside on 1 In Proceedings of the Collaborative Virtual Environments, 2000. 47-56 arbitrary servers on an Intranet, an Extranet or the Internet. references to objects in a certain spatial order. Thus the The environment supports distributed collaboration in a same object may be present in many workspaces, i.e. the variety of loosely and tightly coupled modes. Compared to same object is part of various contexts of work. Several earlier CVEs the environment provides collaboration sup- different types of objects can populate the space: port that focuses on the working materials. For instance, Document-objects - ‘Live’ documents from third party 2D users’ mutual awareness is supported through the material applications with an ActiveX document server, such as being worked on instead of showing an avatar. Tightly spreadsheets, drawing programs, CAD programs, etc. coupled collaboration is supported through synchronous The documents are displayed on objects in a 3D ren- sharing of workspaces and even the camera with which the dered OLE/ActiveX container. users see the workspace. The software infrastructure is ma- turing and we are working on setting up rooms to be tested 3D models – Various 3D models may be inserted into a by users from the domain of (landscape) architecture and workspace, as artefacts worked, objects providing to- industrial design. Among the important design issues dis- pology to the space, iconic reminders, etc. cussed in the paper are display and interaction techniques, ‘Implantations’ – objects or devices that support the cus- awareness support, portability of workspaces, and bridging tomising of a space to changing uses, for example, to gaps between physical objects in the room and their com- create spatial partitions or for imprinting specifically puter representations. expressive codes [15]. Objects to constrain space, semi-transparent objects to define areas, lights to indi- MANUFAKTUR cate particularities, shadows on the ‘ground’ to provide The Manufaktur provides a digital environment that sup- a sense of distance are all examples of ‘implantations’. ports relations between working materials. It supports the configuration of spatio-temporal order by allowing people Groupings – representations of sets of objects (including to construct familiar configurations of documents and ob- groups) that may be manipulated as a whole. Besides jects in a 3D virtual workspace. The same thing can be the the implicit grouping of placing objects in proximity, work object for one activity, background material or con- groups can be explicitly defined and manipulated. text for another activity, and would be an irrelevant distrac- Endpoints – representation of link anchors on document- tion for a third – all in ways that change on a moment-to- objects. By integrating and extending the Webvise [9, moment basis. The Manufaktur supports this through the 10] hypermedia system, we enable linking capability to situated creation and manipulation of context, awareness, parts of document-objects residing within Manufaktur . and action. Its basic features, presented in detail in [3, 18], A 3D environment like this not only makes it possible to are summarised below. have many documents visible at the same time, but it also, Manufaktur Workspace by spatial proximity, makes it possible to indicate the Figure 1 shows a screen dump from an early prototype of (changing) relevance of a document for work-in-progress, the Manufaktur. It shows an open workspace containing and its relation to other objects in the space. This means (references to) a set of objects. Double clicking any of the that there are in effect different ‘levels of openness’ of a document objects will launch it in its respective application document, which can still be identified from far away. We with that document, and changes to it will be updated see this as a possibility for supporting fluent relationships, within 3D Manufaktur in near real time. The objects can be and the flexibility to zoom into a detail and out to see the sized, moved, rotated, etc; light effects may be applied; whole, to simultaneously hold present a large number of documents can be made (semi) transparent; organized into parameters and their relationships. groups; and much more. Client architecture on the Windows Platform The Manufaktur application on the Microsoft Windows 2000 platform builds on the Microsoft