Toni Alatalo

VirtualOulu: collaborative, immersive and extensible 3D city model on the web

In this paper, we describe the creation of a photorealistic digital 3D representation of a real world city and its subsequent publication as an open and collaborative 3D virtual world on the web using an open source software platform. We present the guidelines and conventions used in the collaborative development process of the model. We report the design and implementation of the web user interface of the model that exploits on dynamic on demand (un)loading of assets during navigation to reduce memory consumption on user device. We demonstrate the extensibility of the model with example applications. We report an empirical performance evaluation of the web user interface in terms of download latencies and memory consumption, and frame rate achieved with three different types of user devices during navigation. We identify a rendering bottleneck in the current implementation and present a candidate solution for fixing it.

Gesture interaction for wall-sized touchscreen display

In order to improve the user experience in a large touchscreen, this research introduces gesture interaction into wall-sized touchscreen. According to the distance between user and display, we create two interaction modes for touch and body gesture respectively. Challenges encountered and prospects for further improvement are also investigated.

Hybrid avatars: enabling co-presence in multiple realities

Virtual reality (VR) and augmented reality (AR) technologies are quickly making their way into peoples everyday lives. Typically, these technologies are used separately to create either plain VR or AR applications rather than harnessing the possibilities of combining the two. In this position paper, we introduce a novel concept of hybrid avatar that enables avatar-based interactions between VR and AR users visiting the same place both in the real world and its virtual counterpart. We illustrate a generic architecture for implementing hybrid avatar interactions, present our prototype implementation and discuss the implementation related challenges. Main contribution of this paper is to provide new ideas for research on the areas of VR, AR, and hybrid reality.

Two real-world case studies on 3D web applications for participatory urban planning

3D Web is a potential platform for publishing and distributing 3D visualizations that have proven useful in enabling the participation of the general public in urban planning. However, technical requirements imposed by detailed and rich real-world plans and related functionalities are demanding for 3D web technologies. In this paper we explore the maturity of modern 3D web technologies in participatory urban planning through two real-world case studies. Applications built on Unity-based platform are published on the web to allow the general public to create, browse and comment on urban plans. The virtual models of seven urban development sites of different visual styles are optimized in terms of download sizes and memory use to be feasible on browsers used by the general public. We report qualitative feedback from users and present a technical analysis of the applications in terms of download sizes, runtime performance and memory use. We summarize the findings of the case studies into an assessment of the general feasibility of modern 3D web technologies in web-based urban planning.

Storm: using P2P to make the desktop part of the web

We present Storm, a storage system which unifies the desktop and the public network, making Web links between desktop documents more practical. Storm assigns each document a permanent unique URI when it is created. Using peer-to-peer technology, we can locate documents even though our URIs do not include location information. Links continue to work unchanged when documents are emailed or published on the network. We have extended KDE to understand Storm URIs. Other systems such as GNU Emacs are able to use Storm through an HTTP gateway.

Information Systems Development in Emergent Organizations

Traditional ISD methods have been criticized for placing too much emphasis, at least implicitly, on stability of IS development activities (Truex and Baskerville, 1998). Advocates of so-called lightweight methods (Beck, 2000; Cockburn, 2000) have presented similar thoughts. Discussions on IS development in emergent organizations (Truex et al., 1999) provide recent profound critique of ISD methods (Truex et al., 2000). In fact, advocates of IS development in emergent organizations have set new goals for developing ISs (Truex et al., 1999).

DRUMM: Dynamic viewing of large-scale 3D city models on the web

3D city models have become an important user interface for various applications, ranging from entertainment to civil engineering. Today, 3D city models can also be accessed on the web without installing any additional software, which has significantly widened their potential audience. However, visually accurate 3D city models are typically large in terms of file size, and hence, require ample network bandwidth for minimizing download delays and providing a smooth user experience. In this paper, we introduce a method called DRUMM, which enables dynamic resource management for viewing 3D city models on the web. DRUMM supports both the use of varying criteria for prioritizing the download order of 3D graphics, and the division of 3D graphics into chunks facilitating parallel downloads that can be suspended and later continued. The performance of DRUMM was evaluated in terms of (1) starting delay; (2) used network bandwidth; and (3) the number of buildings with textures in the view using the developed prototype implementation. Based on the results, DRUMM improves the usability of 3D city applications, particularly when the network bandwidth is scarce.

Comparative API complexity analysis of two platforms for networked multiplayer games using a reference game

In this paper we propose the quantitative analysis of the complexity of a simple reference game implemented on a particular gaming platform as means for characterizing how the platform succeeds in easing the development of networked multiplayer games. We first present our own open source tool based on Sneeds Object-Point (OP) method for the automatic quantitative assessment of the complexity of a software API by analyzing a source code using the API. We then apply our tool, together with the recently released JSComplexity tool based on classical software complexity metrics, to compare two platforms for networked multiplayer games, the open source realXtend Tundra SDK and the proprietary Union. As the reference games we use existing implementations of the simple Pong game atop the two platforms. Our data shows that these complexity metrics reveal API design tradeoffs, resulting in complexity differences in the reference games.