Franco Tecchia

Visualizing Crowds in Real-Time

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.

Image-based crowd rendering

Populated virtual urban environments are important in many applications, from urban planning to entertainment. At the current stage of technology, users can interactively navigate through complex, polygon-based scenes rendered with sophisticated lighting effects and high-quality antialiasing techniques. As a result, animated characters (or agents) that users can interact with are also becoming increasingly common. However, rendering crowded scenes with thousands of different animated virtual people in real time is still challenging. To address this, we developed an image-based rendering approach for displaying multiple avatars. We take advantage of the properties of the urban environment and the way a viewer and the avatars move within it to produce fast rendering, based on positional and directional discretization. To display many different individual people at interactive frame rates, we combined texture compression with multipass rendering.

Lowering the development time of multimodal interactive application: the real-life experience of the XVR project

In this paper we present XVR, an integrated development environment for the rapid development of Virtual Reality applications. Using a modular architecture and a VR-oriented scripting language, XVR contents can be embedded on a variety of container applications. This makes it suitable to write contents ranging from web-oriented presentations to more complex VR installations involving advanced devices, such as real-time trackers, haptic interfaces, sensorized gloves and stereoscopic devices, including HMDs. Some case studies are also presented to illustrate the development processes related to XVR and its features.

A flexible framework for wide-spectrum vr development

This paper presents results and experiences coming from 10 years of development and use of XVR, a flexible, general-purpose framework for virtual reality VR development. The resulting architecture, that comes under the form of a self-sufficient integrated development environment (IDE) organized around a dedicated scripting language and a virtual machine, is able to accommodate a wide range of applications needs, ranging from simple Web3D applications to motion-based simulators or complex cluster-based immersive visualization systems. Within the framework a common, archetypical structure is used for any application, showing how inhomogeneous needs and technologies can be effectively covered by using a single, rather simple, system organization. We also show how the framework flexibility allows for innovative development techniques such as multiple frameworks coexisting within a single, tightly integrated, VR application.

Real-Time Rendering of Densely Populated Urban Environments

In this paper we present some preliminary results concerning a realtime visualisation system for densely populated urban environments. In order to be able to render the large number of humans, we developed a method based on Image-Based Rendering techniques. To allow them to move freely in the city while avoiding collisions against the environment and other humans, we developed a simplified collision test that makes use of the graphics hardware to quickly generate a discretization of the environment. Although our research is at an early stage, the results are already quite promising; we are able to render in real-time a virtual city with thousands of walking humans on a standard PC. Several avenues for further investigation are finally proposed.

Evaluating virtual reality and augmented reality training for industrial maintenance and assembly tasks

The current study evaluated the use of virtual reality (VR) and augmented reality (AR) platforms, developed within the scope of the SKILLS Integrated Project, for industrial maintenance and assembly (IMA) tasks training. VR and AR systems are now widely regarded as promising training platforms for complex and highly demanding IMA tasks. However, there is a need to empirically evaluate their efficiency and effectiveness compared to traditional training methods. Forty expert technicians were randomly assigned to four training groups in an electronic actuator assembly task: VR (training with the VR platform twice), Control-VR (watching a filmed demonstration twice), AR (training with the AR platform once), and Control-AR (training with the real actuator and the aid of a filmed demonstration once). A post-training test evaluated performance in the real task. Results demonstrate that, in general, the VR and AR training groups required longer training time compared to the Control-VR and Control-AR groups, respectively. There were fewer unsolved errors in the AR group compared to the Control-AR group, and no significant differences in final performance between the VR and Control-VR groups, probably due to a ceiling effect created by the use of two training trials in the selected task for participants who were expert technicians. The results suggest that use of the AR platform for training IMA tasks should be encouraged and use of the VR platform for that purpose should be further evaluated.

3D helping hands: a gesture based MR system for remote collaboration

There is currently a strong need for collaborative systems with which two or more participants interact over a distance on a task involving tangible artifacts (e.g., a machine, a patient, a tool). The present paper focuses on the specific category of remote-collaboration systems where hand gestures are used by a remote helper to assist a physically distant worker to perform manual tasks. Existing systems use a combination of video capturing, 2D monitors or 2D projectors, however displaying a video of the remote workspace and allowing helpers to gesture over the video does not provide helpers with sufficient understanding of the spatial relationships between remote objects and between their hands and the remote objects. In this paper we introduce our tele-presence Mixed Reality system for remote collaboration on physical tasks based on real-time capture and rendering of the remote workspace and of the helpers hands. We improve on previous 2D systems introducing 3D capturing and rendering, and exploiting the possibility offered by the use of real 3D data to increase the feeling of immersion offered by the system using head tracking, stereoscopic rendering, inter-occlusion handling and virtual shadowing. We performed initial usability test of our system to verify if users are satisfied with the spatial awareness the system provides.

A haptic toolkit for the development of immersive and web-enabled games

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 3D interactive visit to Piazza dei Miracoli, Italy

This paper present an innovative VR application where the users, guided through structured narrative paths, are able to explore the space and the history of Piazza dei Miracoli in Pisa. The application was realized in the course of a research project whose objective was to create a complete multimedia system related to the renowned monumental complex. In order to be accessible from a wide audience, the application is hosted in a dedicated website. Several optimization techniques and a novel state-of-the-art 3D web technology were used to take in account issues related to VR real-time constraints and the limited web bandwidth.

HandsIn3D: Supporting remote guidance with immersive virtual environments

A collaboration scenario involving a remote helper guiding in real time a local worker in performing a task on physical objects is common in a wide range of industries including health, mining and manufacturing. An established ICT approach to supporting this type of collaboration is to provide a shared visual space and some form of remote gesture. The shared space and remote gesture are generally presented in a 2D video form. Recent research in tele-presence has indicated that technologies that support co-presence and immersion not only improve the process of collaboration but also improve spatial awareness of the remote participant. We therefore propose a novel approach to developing a 3D system based on a 3D shared space and 3D hand gestures. A proof of concept system for remote guidance called HandsIn3D has been developed. This system uses a head tracked stereoscopic HMD that allows the helper to be immersed in the virtual 3D space of the worker’s workspace. The system captures in 3D the hands of the helper and fuses the hands into the shared workspace. This paper introduces HandsIn3D and presents a user study to demonstrate the feasibility of our approach.