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Sound is an important, but often neglected, component for creating a self-motion illusion (vection) in Virtual Reality applications, for example, motion simulators. Apart from auditory motion cues, sound can provide contextual information representing self-motion in a virtual environment. In two experiments we investigated the benefits of hearing an engine sound when presenting auditory (Experiment 1) or auditory-vibrotactile (Experiment 2) virtual environments inducing linear vection. The addition of the engine sound to the auditory scene significantly enhanced subjective ratings of vection intensity in Experiment 1 and vection onset times but not subjective ratings in Experiment 2. Further analysis using individual imagery vividness scores showed that this disparity between vection measures was created by participants with higher kinesthetic imagery. On the other hand, for participants with lower kinesthetic imagery scores, the engine sound enhanced vection sensation in both experiments. A high correlation with participants' kinesthetic imagery vividness scores suggests the influence of a first person perspective in the perception of the engine sound. We hypothesize that self-motion sounds (e.g., the sound of footsteps, engine sound) represent a specific type of acoustic body-centered feedback in virtual environments. Therefore, the results may contribute to a better understanding of the role of self-representation sounds (sonic self-avatars), in virtual and augmented environments.

Decision making is vital in complex sporting tasks but is difficult to test and train. New technologies such as virtual and augmented reality offer novel opportunities for improving decision making, yet it remains unclear whether training gains using these new approaches will improve decision making on-field. To clarify the potential benefits, a clear conceptualization of decision making is required, particularly for invasive team sports such as football, basketball and field hockey, where decisions are complex with many possible options offered. Therefore, the aim of this position paper is to establish a framework for the design of virtual and augmented environments that help invasive team sport athletes to train their decision-making capacities. To achieve this, we propose a framework for conceptualising ‘natural’ decision making within the performance environment in invasive team sports that views decision making as a continuous cyclical process where the ball carrier interacts with teammates to create ‘windows of opportunity’, and where skilled decision makers often delay decisions to create time, and in turn new opportunities, rather than necessarily selecting the first option available to them. Within the framework, we make a distinction between decision making and anticipation, proposing that decision making requires a series of on-going anticipatory judgments. Based on the framework, we subsequently highlight the consequences for testing and training decision making using virtual and augmented reality environments, in particular outlining the technological challenges that need to be overcome for natural decision making to be represented within virtual and augmented environments.

Extended Reality (XR) offers a fascinating capability to transport individuals through time and space. However, are there ways to keep the users grounded in reality while exploring distant landscapes or unfamiliar places? We propose in this paper a Point of Interest portal-based navigation technique that takes full advantage of the available, often limited, physical space of the user while still facilitating natural walking in a virtual environment. This technique can be beneficial for the exploration of Points of Interest (PoIs), which is a recurrent situation in virtual museum visits. It ensures consistency between the physical workspace while a user moves from one PoI to the next, enabling applicability beyond Virtual Reality (VR) and into Mixed Reality (MR) scenarios. The connection of different PoIs in the virtual space is achieved with portals, which are strategically placed in the physical workspace. In order to evaluate the efficiency of this technique, in terms of time, presence and user subjective preference, we conducted an experiment with 19 participants who visited artefacts in various rooms of a fictitious virtual museum. The results indicated that the PoI-based portal technique delivers performance comparable to the most well-known navigation technique (teleportation), while maintaining a balance between immersion in the virtual environment and awareness of the physical space, and offering better spatial consistency. Therefore, it can be considered a viable solution for cross-reality interaction.

The needs for three-dimensional (3D) visualization and navigation within 3D-GIS environment are growing and expanding rapidly in a variety of fields. In a steady shift from traditional two-dimensional (2D) GIS toward 3D-GIS, a great amount of accurate 3D data sets (e.g. city models) have become necessary to be produced in a short period of time and provided widely on the market. This requires a number of specific issues to be investigated, e.g. 3D routing accuracy, appropriate means to visualize 3D spatial analysis, tools to effortlessly explore and navigate through large models in real time, with the correct texture and geometry. There had been a lot of study on 3D landscapes, urban and city models. The rapid advancement in science and technology had opened wide options for a change and development of current methods and concepts. Virtual Reality (VR) is one of those developments, which gives the sense of feel in virtual environment. It enables users to visualize, make query and exploring 3D data. Such system can, not only help laymen, who often have trouble in understanding or interpreting complex data, but they also can help experts in decision making. The objective of this paper is to discuss some initial requirements of the proposed solution towards 3D-GIS. Eventually, this paper will serve as a starting point for a more challenging research idea. The focus of this research is to investigate and implementing 3D navigation techniques and solutions for 3D-GIS. Investigation on the support of navigation in real world environment will be carried out. This will include a research on the benefits of using 3D network model (non-planar graph) compared to 2D, how to use visual landmarks in route descriptions and using 3D geometry to get more accurate routing (in buildings, or in narrow street, etc). And as for implementation, a GUI provides the users with means (e.g. fill-out forms) to specify SQL queries interact and visualize 3D outcomes in virtual reality environment. This has opened up the ability to distribute and navigate accurately in 3D virtual worlds. The initial study on Klang Valley will go through data conversion processes from different formats like Laser, VRML, CAD and Shape 3D in a first person view environment using a developed system using VRML, JAVA and .Net compiler. The dataset structure will be in the form of various 2D, 2.5D and 3D array of height fields.

Developing a virtual 3D environment by using game engine is a strategy to incorporate various multimedia data into one platform. The characteristic of game engine that is preinstalled with interactive and navigation tools allows users to explore and engage with the game objects. However, most CAD and GIS applications are not equipped with 3D tools and navigation systems intended to the user experience. In particular, 3D game engines provide standard 3D navigation tools as well as any programmable view to create engaging navigation thorough the virtual environment. By using a game engine, it is possible to create other interaction such as object manipulation, non playing character (NPC) interaction with player and/or environment. We conducted analysis on previous game engines and experiment on urban design project with Unity3D game engine for visualization and interactivity. At the end, we present the advantages and limitations using game technology as visual representation tool for architecture and urban design studies.

Users within a Virtual Environment often need support designing the environment around them with the need to find relevant content while remaining immersed. We focus on the familiar sketch-based interaction to support the process of content placing and specifically investigate how interactions from a tablet or desktop translate into the virtual environment. To understand sketching interaction within a virtual environment, we compare different methods of sketch interaction, i.e., 3D mid-air sketching, 2D sketching on a virtual tablet, 2D sketching on a fixed virtual whiteboard, and 2D sketching on a real tablet. The user remains immersed within the environment and queries a database containing detailed 3D models and replace them into the virtual environment. Our results show that 3D mid-air sketching is considered to be a more intuitive method to search a collection of models; while the addition of physical devices creates confusion due to the complications of their inclusion within a virtual environment. While we pose our work as a retrieval problem for 3D models of chairs, our results are extendable to other sketching tasks for virtual environments.

Experiencing virtual world teaching had always the purpose to understand its role and possible uses in education. It is easy to see a direct use of 3D worlds in teaching: give the possibility to the students to work and practice different things in a free and flexible environments. This was always the dream of teachers in our era, that tries to put at the centre of the education their students. Giving a sense to 3D world teaching is not only to define what, when and why it can be used. Other requirements to understand better this process are a positive response from past experimentations, to have a feedback to evaluate; and a basic “training” of professors with the aim to put them in the condition to efficiently use (before the students) those virtual environments. These can also be described as “augmented environments”, not always linked to 3D world because the intrinsic value of this definition.

We introduce different approaches to user interface devices that provide directed tactile feedback to the user's hand. The basic idea is to enhance the user's six degrees of freedom of interaction within virtual or augmented environments by offering an additional three-dimensional tactile feedback as an immediate, directed response from the virtual world. We also describe the prototype systems TactilePointer and TACTool, which utilize vibro-motors, alarm buzzers, and piezo bend elements as actuators in combination with magnetic and optical tracking. The prototypes have been informally tested within collision sensitive virtual environments.

In this course, we will take a detailed look at various breeds of spatial navigation interfaces that allow for locomotion in digital 3D environments such as games, virtual environments or even the exploration of abstract data sets. We will closely look into the basics of navigation, unraveling the psychophysics (including wayfinding) and actual navigation (travel) aspects. The theoretical foundations form the basis for the practical skillset we will develop, by providing an in-depth discussion of navigation devices and techniques, and a step-by-step discussion of multiple real-world case studies. Doing so, we will cover the full range of navigation techniques from handheld to full-body, highly engaging and partly unconventional methods and tackle spatial navigation with hands-on-experience and tips for design and validation of novel interfaces. In particular, we will be looking at affordable setups and ways to "trick" out users to enable a realistic feeling of self-motion in the explored environments. As such, the course unites the theory and practice of spatial navigation, serving as entry point to understand and improve upon currently existing methods for the application domain at hand.

The perception of rotation gain, defined as a modification of the virtual rotation with respect to the real rotation, has been widely studied to determine detection thresholds and widely applied to redirected navigation techniques. In contrast, Field of View (FoV) restrictions have been explored in virtual reality as a mitigation strategy for motion sickness, although they can alter user’s perception and navigation performance in virtual environments. This paper explores whether the use of dynamic FoV manipulations, referred also as vignetting, could alter the perception of rotation gains during virtual rotations in virtual environments (VEs). We conducted a study to estimate and compare perceptual thresholds of rotation gains while varying the vignetting type (no vignetting, horizontal and global vignetting) and the vignetting effect (luminance or blur). 24 Participants performed 60 or 90\(^\circ \) virtual rotations in a virtual forest, with different rotation gains applied. Participants have to choose whether or not the virtual rotation was greater than the physical one. Results showed that the point of subjective equality was different across the vignetting types, but not across the vignetting effect or the turns. Subjective questionnaires indicated that vignetting seems less comfortable than the baseline condition to perform the task. We discuss the applications of such results to improve the design of vignetting for redirection techniques.KeywordsVirtual RealityPerceptionRotation gainsVignetting

Mandibular reconstruction is a complicated task because of the complex nature of the regional anatomy. Computer-assisted tools are a promising means of improving the precision and safety of such complex surgeries. The digital techniques utilized in the reconstruction of mandibular defects based on medical data, computer-aided-design approaches, and three-dimensional (3D) printing are widely used to improve the patient’s aesthetic appearance and function, as well as the accuracy and quality of diagnosis, and surgical outcomes. Nevertheless, to ensure an acceptable aesthetical appearance and functional outcomes, the design must be based on proper anatomical reconstruction, mostly done in a virtual environment by skilled design engineers. Mirroring is one of the widely used techniques in the surgical navigation and reconstruction of mandibular defects. However, there are some discrepancies and mismatches in the mirrored anatomical models. Hence, in order to overcome these limitations in the mirroring technique, a novel approach called the cavity-filled technique was introduced. The objective of this study was to compare the accuracy of the newly recommended cavity-filled technique with the widely used mirror reconstruction technique in restoring mandibular defects. A prominent 3D comparison technique was employed in this work, where the resected and the reconstructed mandibles were superimposed to quantify the accuracy of the two techniques. From the analysis, it can be inferred that the cavity-filled technique with a root-mean-square value of 1.1019 mm produced better accuracy in contrast to the mirroring approach, which resulted in an error of 1.2683 mm. Consequently, by using the proposed cavity-filled design, the discrepancy between the reconstruction plate and the bone contour was mitigated. This method, owing to its high precision, can decrease the number of adjustments and the time of surgery, as well as ensure a quick recovery time with better implant tissue in-growth.

The richness of crossmodal feedback in car driving makes it an engaging, complex, yet “natural” activity. Audition plays an important role, as the engine sound, perceived in the cabin, conveys relevant cues about the vehicle motion. In this paper, we introduce a procedural and physically informed model for synthetic combustion engine sound, as an effective, flexible and computationally efficient alternative to sample-based and analysis/resynthesis approaches. The sound model, currently being developed as Max/MSP external, has been integrated in GeneCars, a driving simulator environment for industrial sound design, and SkAT Studio, a demonstration framework for the rapid creation of audio processing workflows.

Virtual and augmented environments are often dependent on human intervention for change to occur. However there are times when it would be advantageous for appropriate human-like activity to still occur when there are no humans present. In this paper, we describe the installation art piece Recognition, which uses the movement of human participants to effect change, and the movement of a performing agent when there are no humans present. The agent's Artificial Neural Network has learnt appropriate movements from a dancer and is able to generate suitable movement for the main avatar in the absence of human participants.

This paper describes the study of an object manipulation task in real, virtual and augmented environments using the VisiTact system, a virtual reality system that facilitates the integration of various immersed or desktop vision feedback devices with a three degree-of-freedom haptic force-feedback interface. VisiTact has a relatively large working volume and enables virtual objects to take on user-specified dynamic properties such as mass, gravity, viscous and drag force, and buoyancy. The VisiTact system is also capable of providing augmented reality applications with the aid of a chromakeying facility. The manipulation task adopted for the study involves picking up a surrogate object, placing it against a vertical surface, sliding it along the surface and inserting it into a horizontal hole. The time taken to complete the task is used as a measure of performance comparison. It has been found that for the same force feedback modes, the type of visual feedback and the position of cameras and monitors had little effect on the results. Modes employing virtual force feedback have up to 45% greater completion times compared with the task undertaken manually. The reasons for this are discussed, and preliminary analysis suggests that the discrepancies are greatest during the first parts of the task, in which large motions take place and are least during the most constrained parts of the task.

The emergence of serious or non-leisure uses of game technologies and virtual world applications has been swift and dramatic over the last few years. As a result, there has been little time to develop the theoretical and academic rigor in the emerging field. Another factor affecting the field has been the general aspect of convergence between new technologies, for example augmented reality, mobile technologies, GPS technologies, sensor technologies and social software. Together, this has presented potential for developing new technologies based upon immersive and interactive interfaces and has in parallel produced many unanswered questions in terms of the usage of the formats. As a result there is a clear need to consider new frameworks, theories, methods and design strategies for making serious applications of games and virtual world technologies more effective and useful. The term ‘Serious Games’ covers a broad range of applications from flash-based animations to totally immersive and code-driven 3D environments where users interface with large volumes of data through sophisticated and interactive digital interfaces. This shift towards immersive world applications marks the beginning of new challenges that offer real scope for collaborative and multi-disciplinary research solutions and real opportunities for innovative development. The 1st International Conference in Games and Virtual Worlds for Serious Applications (VS-GAMES’09) gathered individual researchers and games’ developers that focus on serious games methodologies, mobile games, virtual and augmented environments, and 3D social worlds.