Vlasios Kasapakis

Pervasive gaming: Status, trends and design principles

Abstract Pervasive games represent a radically new game form that transfers gaming experiences out into the physical world, weaving ICTs into the fabric of players׳ real environments. This emerging gaming mindset is rather challenging for developers exploring technologies and methods to achieve a high quality interactive experience for users, and designing novel and compelling forms of content. This paper follows a systematic approach in exploring the landscape of pervasive gaming. First, we present 18 representative pervasive game projects, following a generations-based classification. Then, we present a comparative view of those projects with respect to several design aspects. Lastly, we shed light on technological status and trends, design principles, developer guidelines, and research challenges for pervasive games development.

The eCOMPASS multimodal tourist tour planner

Personalized near-optimal multiple-day tours (via several POIs) for tourists.eCOMPASS: the first mobile tour planner to consider public transit transfers among POIs.Incorporating lunch breaks in tour planning.Arbitrary start/end locations for each daily tour.High-performance tour planning algorithm tested on real tourist destinations. Tour planning represents a challenging task for individuals visiting unfamiliar tourist destinations, mainly due to the availability of numerous attractions (points of interest, POIs) and the complexity of metropolitan public transit networks. Several web and mobile tourist city guides already support personalized tour recommendations. However, they exclusively consider walking tours; namely, they fail in motivating tourists to use public transportation for reaching far located important POIs, thereby compromising the perceived overall attractiveness of recommended tours. In this paper, we introduce eCOMPASS, a context-aware web/mobile application which derives personalized multimodal tours via selected urban attractions. eCOMPASS is the only available research or commercial tour planner that assists the way arounds of tourists through public transit. Far beyond than just providing navigational aid, eCOMPASS incorporates multimodality (i.e. time dependency) within its routing logic aiming at deriving near-optimal sequencing of POIs along recommended tours so as to best utilize the time available for sightseeing and minimize waiting time at transit stops. Further advancing the state of the art, eCOMPASS allows users to define arbitrary start/end locations (e.g. the current location of a mobile user) rather than choosing among a fixed set of locations. Last, eCOMPASS may assist in scheduling lunch breaks at affordable restaurants, conveniently located along the recommended tours. The provision of the above mentioned unique features of eCOMPASS is based on modeling and solving a complex optimization problem which takes into account a long list of problem variables and constraints. This paper describes the routing algorithm which comprises the core functionality of eCOMPASS. Further, it discusses the implementation details of the web and mobile eCOMPASS applications using the metropolitan areas of Athens (Greece) and Berlin (Germany) as case studies. Evaluation results report positive user attitude as to the tour planning output with respect to attractiveness, meaningfulness and the overall perceived utility.

Blending history and fiction in a pervasive game prototype

Pervasive games represent an exciting development in gaming which leverages the use of sensor, visualization and networking technologies to provide immerse live-action game experiences. The field of pervasive games has been intensively researched in the recent years, as evidenced from the proliferation of available prototypes. Existing pervasive game projects commonly do not enable relocation of the game space while also overlooking several aspects which critically affect user acceptance and game experience such as scenario design, usability of employed technologies, game duration and intensity. This article introduces Barbarossa, an outdoor pervasive role-playing game. Barbarossa addresses the abovementioned issues featuring several portable game modes. It also takes into account concrete technology usage requirements for each game mode according to the game session duration and player effort required. Further, game experience is enhanced through incorporating several contextual parameters. User evaluation trials indicated warm reception of Barbarossa by players and confirmed that the main game design objectives have been largely achieved.

Scenic route planning for tourists

Tourists visiting unknown destinations become increasingly dependent on mobile city guides to locate tourist services and retrieve informative content about nearby points of interest (POIs). Several mobile guides already support the provision of personalized tour recommendations to assist tourists in making feasible plans and visiting the most interesting POIs within their available time. However, existing tourist tour planners only regard available attractions as sites lacking physical dimensions (i.e., POIs are treated as ‘points’). This restricts the modeling of POIs as attractions that may be entered/exited from a certain location (e.g., the main entrance). Although this is adequate for scheduling visits at museums, galleries, small squares or parks with single entry points, it fails to capture practical properties of typical tourist visiting styles in urban destinations. Tourists commonly appreciate strolling through pedestrian zones, market areas or urban areas of architectural, cultural and scenic value rather than only visiting sites of restricted access or taking the fastest route to move among city landmarks. Herein, we introduce Scenic Athens, a context-aware mobile city guide for Athens (Greece) which provides personalized tour planning services to tourists. Far beyond than just providing navigational aid, Scenic Athens derives near-optimal sequencing of POIs along recommended tours, taking into account a multitude of travel restrictions and POI properties, so as to best utilize time available for sightseeing. Unlike similar tools, our application incorporates scenic (walking) routes (in addition to point POIs), thereby supporting more experiential exploration of tourist destinations. This broader perception of tourist attractions substantially increases the complexity of the entailed optimization problem’s modeling. A user evaluation study validated the recommendation value, usability and perceived utility of the proposed application.

Augmented reality in cultural heritage: Field of view awareness in an archaeological site mobile guide

Over the past few years, augmented reality (AR) is increasingly diffused among location-based applications. A situation often encountered in AR applications is the partial or full occlusion of -physical or virtualobjects by physical obstacles. Existing outdoors AR applications overlook this issue displaying visual indicators about nearby annotated objects even when those are hidden behind a building, hence, being out of the users’ field of view (FoV). This paper presents a geolocative raycasting technique which enables real time building recognition towards the device’s pointing direction, thereby estimating the FoV of the users. The objective is either to hide or utilize appropriate visual metaphors for occluded objects / locations thereby improving the user’s perception about its surrounding space. The motivation for developing our occlusion handling technique has been drawn from KnossosAR, an outdoors mobile AR guide implemented for the archaeological site of Knossos (in Crete, Greece). We have conducted field trials which provided preliminary evidence of the efficiency, effectiveness and utility of KnossosAR (including the incorporated FoV estimation approach).

PacMap: Transferring PacMan to the Physical Realm

This paper discusses the implementation of the pervasive game PacMap. Openness and portability have been the main design objectives for PacMap. We elaborate on programming techniques which may be applicable to a broad range of location-based games that involve the movement of virtual characters over map interfaces. In particular, we present techniques to execute shortest path algorithms on spatial environments bypassing the restrictions imposed by commercial mapping services. Last, we present ways to improve the movement and enhance the intelligence of virtual characters taking into consideration the actions and position of players in location-based games.

Pervasive games field trials: recruitment of eligible participants through preliminary game phases

This paper investigates a novel methodological approach in performing user evaluation trials for pervasive games. The evaluation process of a pervasive role-playing game, Barbarossa, is used as a case study. Barbarossa involves a preliminary and a main execution phase. The former is freely available to anyone and may be played anytime/anywhere requiring no organizational and orchestration investments from the investigators team. The latter defines three interdependent player roles acted by players who need to collaborate in a treasure hunting game to achieve a common game goal. The eligibility of players for participating in the main game phase derives from those ranked relatively high in the preparatory phase. Drawing on concepts of cultural theory, we design the preparatory phase as an affective environment out of which the potential evaluators will emerge. The main hypothesis investigated is that the execution of such cost-effective preparatory phases may serve as a means for recruiting highly qualified subjects for user trials on pervasive game research prototypes, thereby increasing the reliability and quality of evaluation results. This hypothesis has been validated through the user evaluation trials performed on both the Barbarossa game phases.

Scenic Athens: A personalized scenic route planner for tourists

Several mobile guides for unknown destinations provide assistance to tourists (through personalized tour recommendations) in making feasible plans and visiting the most interesting POIs within their available time. However, existing tourist tour planners only regard available attractions as sites lacking physical dimensions (i.e. POIs are treated as points). Although this is adequate for scheduling visits at POIs with single entry/exit points, it fails to capture practical properties of typical tourist visiting styles in urban destinations (e.g. tourists typically enjoy walking on pedestrian zones, market areas and scenic neighborhoods). Herein, we introduce Scenic Athens, a context-aware mobile city guide for Athens (Greece) which delivers personalized tour planning services to tourists deriving near-optimal sequencing of POIs along recommended tours. Scenic Athens takes into account a multitude of travel restrictions and POI properties, also incorporating scenic (walking) routes (in addition to point POIs), thereby supporting more experiential exploration of tourist destinations. A user evaluation study validated the recommendation value, usability and perceived utility of the proposed application.

Determining Field of View in Outdoors Augmented Reality Applications

The use of augmented reality (AR) becomes increasingly common in location based application development. A situation often encountered in AR applications is the -partial or full- occlusion of virtual objects by physical artifacts; if not appropriately handled, the visualization of occluded objects often misleads users’ perception. This paper presents a Geolocative Raycasting technique aiming at assisting developers of outdoors augmented reality applications into generating a realistic field of view for the users by integrating real time building recognition, so as to address the occlusion problem.

A personalized multimodal tourist tour planner

Tourists become increasingly dependent on mobile city guides to locate tourist services and retrieve information about nearby points of interest (POIs) when visiting unknown destinations. Although several city guides support the provision of personalized tour recommendations to assist tourists visiting the most interesting attractions, existing tour planners only consider walking tours. Herein, we introduce eCOMPASS, a context-aware mobile application which also considers the option of using public transit for moving around. Far beyond than just providing navigational aid, eCOMPASS incorporates multimodality (i.e. time dependency) within its routing logic aiming at deriving near-optimal sequencing of POIs along recommended tours so as to best utilize time available for sightseeing and minimize waiting time at transit stops. Further advancing the state of the art, eCOMPASS allows users to define arbitrary start/end locations (e.g. the current location of a mobile user) rather than choosing among a fixed set of locations. This paper describes the routing algorithm which comprises the core functionality of eCOMPASS and discusses the implementation details of the mobile application using the metropolitan area of Berlin (Germany) as case study.