This paper proposes a size measurement system to be used in inspection tasks, based on the integration of fully immersive Virtual Reality visualization and haptic feedback at fingertip level. In particular, index finger and thumb are intuitively used to perform metric measurement on 3D point clouds visualized using a stereo vision Head Mounted Display. The haptic feedback consisting of contact transition and forces rendered at the fingertip is used to facilitate the user in the measurement task. Experimental results show similar performance of subjects in accomplishing the inspection task with and without the support of haptic feedback in terms of time and precision of measurements. However, qualitative questionnaire responses suggest a significant preference of subjects in using immersive environment enriched by haptic feedback.

In this work we describe a system composed by an optical see-through AR headset---a Microsoft HoloLens---, stereo projectors and shutter glasses. Projectors are used to add to the device the capability of occluding real-world surfaces to make the virtual objects to appear more solid and less transparent.

Social experience can deeply impact on gaming experience and is often used to increase enjoyment and retention. In the literature two main categories of social interaction can be identified: competition and collaboration. Player engagement has been widely studied under different conditions related to the type of social interaction taking place during the game. However, rich and newly available contexts based on emerging paradigms, such as those enabled by Natural User Interfaces, have not been yet extensively addressed. In the current study the impact of collaborative and competitive goal structures on player engagement, awareness and social presence is evaluated in the context of a jigsaw puzzle game taking place in a Shared Virtual Environment using a highly immersive setup exploiting natural user interaction.

This poster introduces a fully immersive Mixed Reality system we have recently developed, where the user is free to walk inside a virtual scenario while wearing a HMD. The novelty of the system lies in the fact that users can see and use their real hands — by means of a Kinect-like camera mounted on the HMD — in order to naturally interact with the virtual objects. Our working hypothesis are that the introduction of the photorealistic capture of users' hands in a coherently rendered virtual scenario induces in them a strong feeling of presence and embodiment without the need of using a synthetic 3D modelled avatar as a representation of the self. We also argue that the users' ability of grasping and manipulating virtual objects using their own hands not only provides an intuitive interaction experience, but also improves self-perception as well as the perception of the environment.

This paper introduces our ongoing work on the Foot Controller Device as an interface for navigation in Immersive Virtual Environments. The Foot Controller is a special, arduino-based control mat equipped with an array of pressure sensors and able to function as a touch surface for feet. What makes it special is that sensor cells can be accessed individually, allowing for a sophisticate control algorithms based on pressure distribution. The low-level software provides a set of recognition features which can be used to implement intuitive navigation metaphors. In this paper we introduce the device and its operating modes, present its use as a navigation interface, and discuss the results of a preliminary pilot user study aimed to evaluate its usability.

This paper presents a novel fully immersive Mixed Reality system that we have recently developed where the user freely walks in a life-size virtual scenario wearing an HMD and can see and use her/his own body when interacting with objects. This form of natural interaction is made possible in our system because the user's hands are real-time captured by means of a RGBD camera on the HMD. This allow the system to have in real-time a texturized geometric mesh of the hands and body (as seen from her/his own perspective) that can be rendered like any other polygonal model in the scene. Our hypothesis is that by presenting to the users an egocentric view of the virtual environment "populated" by their own bodies, a very strong feeling of presence is developed as well.

ABSTRACT The use of stereographic systems is spreading out in modern society, from the revolution of cinematography to its adoption in high‐tech products such as portable gaming devices or photo cameras. However, the fruition of immersive stereographic systems by more than one person at a time is still a research issue. In more detail, the class of passive stereo systems presents technological limitations of displaying correct multiuser perspectives. In fact, the stereo image projected onto the screen is usually rendered according to a unique point of view (PoV). Nevertheless, in multiuser systems, the selection of an appropriate PoV can minimize both optical discomfort and perspective distortion. This paper aims to evaluate which among existing PoV calculation methods provides the best performances in terms of projection realism, optical comfort and overall system usability in multiuser passive stereo systems. The performances have been evaluated in three different “distance” scenarios to take into account also the effects of binocular disparity in the PoV calculation. To accomplish this objective, we administered a questionnaire to nine couple subjects, evaluating each of the investigated PoV calculation methods for each of the three distance scenarios. Copyright © 2013 John Wiley & Sons, Ltd.

In the BEAMING project we have been extending the scope of collaborative mixed reality to include the representation of users in multiple modalities, including augmented reality, situated displays and robots. A single user (a visitor) uses a high-end virtual reality system (the transporter) to be virtually teleported to a real remote location (the destination). The visitor may be tracked in several ways including emotion and motion capture. We reconstruct the destination and the people within it (the locals). In achieving this scenario, BEAMING has integrated many heterogeneous systems. In this paper, we describe the design and key implementation choices in the Beaming Scene Service (BSS), which allows the various processes to coordinate their behaviour. The core of the system is a light-weight shared object repository that allows loose coupling between processes with very different requirements (e.g. embedded control systems through to mobile apps). The system was also extended to support the notion of presence awareness. We demonstrate two complex applications built with the BSS.

Real-time 3D content distribution over a network (either LAN or WAN) has many possible applications, but requires facing several challenges, most notably the handling of the large amount of data usually associated with 3D meshes. The scope of the present paper falls within the well-established context of real-time capture and streaming of OpenGL command sequences, focusing in particular on data compression schemes. However, we advance beyond the state-of-the-art improving over previous attempts of "in-frame" geometric compression on 3D structures inferred from generic OpenGL command sequences and adding "inter-frame" redundancy exploitation of the traffic generated by the typical architecture of interactive applications. Measurements reveal for this combination of techniques a very effective reduction of network traffic and a CPU overhead compatible with the requirements of interactive applications, suggesting a significant application potential for Internet-based 3D content streaming.

Augmented Reality (AR) is a technology which has become very popular in the last years. In this context also the idea of using of AR for training applications has become very important. AR offers a large potential for training only if the training is well focused to the skills that have to be trained and if the training protocol is well designed. On the other hand, the generation of the training content to be transferred via AR is a comprehensive problem that is addressed in this paper. Thus, this paper tries to describe the whole chain of implementations and general aspects involved in the creation of AR training applications, including examples for used multimodal devices. This chain starts with the capturing of expert actions to be hold in the "digital representation of skill". The digital representation of skill is transferred to the training protocol that specifies the storyboard of the AR training session. The paper includes two different implementations of AR training systems and describes the general idea of informational abstraction from low level data up to interaction and from design to application.

Real-time 3D content distribution over a network requires facing several challenges, most notably the handling of the large amount of data usually associated with 3D meshes. The scope of the present paper falls within the well-established context of real-time capture and streaming of OpenGL command sequences, focusing in particular on data compression schemes. However, we advance beyond the state-of-the-art improving over previous attempts of ¿in-frame¿ geometric compression on 3D structures inferred from generic OpenGL command sequences and adding ¿inter-frame¿ redundancy exploitation of the traffic generated by the typical architecture of interactive applications.

The work addresses the topic of software integration in the context of complex virtual reality applications. We propose a novel method to render in a single graphical context objects handled by separate programs based on different VR frameworks, even when the various applications are running on different machines. Our technique is based on a network rendering architecture, where both origin and destination applications communicate through a set of protocols that deliver compressed graphical instructions and keep the machines synchronized. Existing applications require minimal changes in order to be compatible with our system; in particular we tested the validity of our approach on a number of rendering frameworks (Ogre3D, OpenSceneGraph, Torque, XVR). We believe that our technique can solve many integration burdens typically encountered in practical situations.

The creation of applications of Virtual Reality enabled with Haptic interaction and dynamic simulation requires usually to cover many implementation details that increase the development time and the effectiveness of the application itself. This work presents one game application that has been developed using a Haptic toolkit for the rapid application development, that integrates 3D graphics,haptic feedback and dynamic simulation.The resulting application can be easily deployed on the Web directly to the final user.

The development of a complete Virtual Reality application is a complex activity that requires good knowledge of several time-critical tasks: Computer Graphics, real-time Physics, Haptics and network programming are examples of the components needing to coexist in a modern Virtual Reality system.Each of these building blocks constitutes a research field on its own and a vast literature exists on techniques and algorithms useful to address specific problems; still, from a more high level perspective, only through tight integration and balanced design can a complex framework achieve optimal performances.Having to address such a range of integration issues, the development of a Virtual Reality application can in practice turn out to be a very lengthy and difficult process, where fundamental design choices and their implications should be carefully considered. The choice of the right tools is also very important, as common everyday practice shows how difficult is still to put together a successful and robust system.This tutorial aims at giving an overview of what are the main components involved in the task, how they should interact, and what are the inherent difficulties to place everything together.The tutorial is divided in two parts: The second part will introduce a real-life and recent example of integrated framework, to be used as a reference and base of discussion for the design of the next generation of integrated development environment and their applications.

The global scope of the CREATE project is to develop a mixed-reality framework that enables highly interactive real-time construction and manipulation of photo-realistic, virtual worlds based on real data sources. This framework will be tested and applied to cultural heritage content in an educational context, as well as to the design and review of architectural/urban planning settings. The evaluation of the project is based on a human-centered, constructivist approach to working and learning, with special attention paid to the evaluation of the resulting mixed reality experience. Through this approach, participants in an activity "construct" their own knowledge by testing ideas and concepts based on their prior knowledge and experience, applying these to a new situation, and integrating the new knowledge gained with pre-existing intellectual constructs. CREATE project uses a high degree of interactivity, and includes provision for other senses (haptics and sound). The application developed in CREATE are designed to run on different platforms, and the targeted running systems are SGI and PC driven, with immersive stereo-displays such as a workbench, a ReaCTor (CAVE-like environment), and a wide projection screen.

Abstract Real‐time crowd visualization has recently attracted quite an interest from the graphics community and, asinteractive applications become even more complex, there is a natural demand for new and unexplored applicationscenarios. However, the interactive simulation of complex environments populated by large numbers of virtualcharacters is a composite problem which poses serious difficulties even on modern computer hardware. In thispaper we look at methods to deal with various aspects of crowd visualization, ranging from collision detectionand behaviour modeling to fast rendering with shadows and quality shading. These methods make extensive useof current graphics hardware capabilities with the aim of providing scalability without compromising run‐timespeed. Results from a system employing these techniques seem to suggest that simulations of reasonably complexenvironments populated with thousands of animated characters are possible in real‐time. ACM CSS: I.3.7 Three‐Dimensional Graphics and Realism—Animation

In this paper, we address the problem of shadow computation for large environments including thousands of dynamic objects. The method we propose is based on the assumption that the environment is 2.5D, which is often the case for virtual cities, thus avoiding complex visibility computation. We apply our method for virtual cities populated by thousands of walking humans, which we render with impostors, allowing real time simulation.In this paper, we treat the cases of shadows cast by buildings on humans, and by humans on the ground. To avoid 3D computation, we represent the shadows cast by buildings onto the environment with a 2.5D shadow map. When humans move, we quickly access the shadow information at the current location with a 2D grid. For each new position of a human, we compute its coverage by the shadow, and we render the shadow on top of the impostor with low cost using multi-texturing hardware. We also use the property of an impostor to display the shadow of humans on the ground plane, by projecting the impostor relatively to the light source.The method is currently limited to sharp shadows and a single light source. However approximations could be made to allow non-accurate soft-shadows. We show in the results that the computation of the shadows, as well as the display is done in real time, and that the method could be easily extended to real time moving light sources.