Objects In Virtual Reality Research Articles

Simple virtual reality display of fetal volume ultrasound

Three-dimensional (3D) ultrasound volume acquisition, analysis and display of fetal structures have enhanced their visualization and greatly improved the general understanding of their anatomy and pathology. The dynamic display of volume data generally depends on proprietary software, usually supplied with the ultrasound system, and on the operator's ability to maneuver the dataset digitally. We have used relatively simple tools and an established storage, display and manipulation format to generate non-linear virtual reality object movies of prenatal images (including moving sequences and 3D-rendered views) that can be navigated easily and interactively on any current computer. This approach permits a viewing or learning experience that is superior to watching a linear movie passively.

Virtual reality and persecutory delusions: Safety and feasibility

ObjectiveVirtual reality (VR) has begun to be used to research the key psychotic symptom of paranoia. The initial studies have been with non-clinical individuals and individuals at high risk of psychosis. The next step is to develop the technology for the understanding and treatment of clinical delusions. Therefore the present study investigated the acceptability and safety of using VR with individuals with current persecutory delusions. Further, it set out to determine whether patients feel immersed in a VR social environment and, consequently, experience paranoid thoughts. MethodTwenty individuals with persecutory delusions and twenty non-clinical individuals spent 4 min in a VR underground train containing neutral characters. Levels of simulator sickness, distress, sense of presence, and persecutory ideation about the computer characters were measured. A one-week follow-up was conducted to check longer-term side effects. ResultsThe VR experience did not raise levels of anxiety or symptoms of simulator sickness. No side effects were reported at the follow-up. There was a considerable degree of presence in the VR scenario for all participants. A high proportion of the persecutory delusions group (65%) had persecutory thinking about the computer characters, although this rate was not significantly higher than the non-clinical group. ConclusionsThe study indicates that brief experiences in VR are safe and acceptable to people with psychosis. Further, patients with paranoia can feel engaged in VR scenes and experience persecutory thoughts. Exposure to social situations using VR has the potential to be incorporated into cognitive behavioural interventions for paranoia.

Virtual human animation in natural language visualisation

Simulation motion of Virtual Reality (VR) objects and humans has experienced important developments in the last decade. However, realistic virtual human animation generation remains a major challenge, even if applications are numerous, from VR games to medical training. This paper proposes different methods for animating virtual humans, including blending simultaneous animations of various temporal relations with multiple animation channels, minimal visemes for lip synchronisation, and space sites of virtual human and 3D object models for object grasping and manipulation. We present our work in our natural language visualisation (animation) system, CONFUCIUS, and describe how the proposed approaches are employed in CONFUCIUS’ animation engine.

A Linear Programming Solution for Exact Collision Detection

This paper addresses the issue of real-time collision detection between pairs of convex polyhedral objects undergoing fast rotational and translational motions. Accurate contact information between objects in virtual reality based simulations such as product design, assembly analysis, performance testing and ergonomic analysis of products are critical factors to explore when desired realism is to be achieved. For this purpose, fast, accurate and robust collision detection algorithms are required. The method described in the text models the exact collision detection problem between convex objects as a linear program. One of the strengths of the proposed methodology is its capability of addressing high speed interframe collision. In addition to the interframe collision detection, experimental data demonstrate that mathematical programming approaches offer promising results in terms of speed and robustness as well.

A model for exploring virtual reality environments

In current dynamic data models for VR environments, the focus has been the graphical presentation of objects and an efficient running of animations. In such models the objects’ semantics are almost always assumed by the observer and derived from the context of the application. In this paper we introduce a model to represent the evolution of VR Objects’ semantics over time. Based on this model, a new classification of virtual reality objects is proposed that captures semantics relative to the existence, visibility, and activity of objects. A set of six operations is presented to model the possible states of VR Objects. This paper also presents an animation model with high-level abstractions of objects’ behaviors and a rich set of operations to manipulate such behaviors. With such tools, users are able to create their own views of the environment, gain insight, and discover relationships among dynamic phenomena. This paper, therefore presents a rationale for modifying object semantics under manipulations by an observer of the object behavior.

Augmented Reality for teaching endotracheal intubation: MR imaging to create anatomically correct models.

Clinical procedures have traditionally been taught at the bedside, in the morgue and in the animal lab. Augmented Reality (AR) technology (the merging of virtual reality and real objects or patients) provides a new method for teaching clinical and surgical procedures. Improved patient safety is a major advantage. We describe a system which employs AR technology to teach endotracheal intubation, using the Visible Human datasets, as well as MR images from live patient volunteers.

Mind the gap: virtual reality and theatre history

This paper reviews some findings of the Pompey Project, an AHRB funded virtual reality (VR) based theatre historical project conducted by an international team led by the University of Warwick. It begins by examining methodological questions, and then publishes here for the first time some significant findings demonstrating how VR enhanced analysis reveals major hitherto unnoticed flaws in prior 2D archaeologically based reconstructions. Following this, an account of the project's reconstruction of the temple-theatre complex at Gabii outlines how this provided an important test of the extent to which the application of Vitruvian formulae gives a viable methodology for reconstructing pre-Principate theatre architecture. Finally, the article discusses the project's own ab initio reconstruction of the Theatre of Pompey, which combines the use of prior 2D hypotheses, old and new archaeological data, and Vitruvian principles. These three studies are framed by an assessment of how the apparently positivist project of reconstruction, which seems to deal with 'hard facts', can be informed by historiographical considerations, in particular by stressing the primacy of interpretation for both creators and viewers of VR objects.

Design for Presence: A Structured Approach to Virtual Reality System Design

The development and maintenance of a virtual reality (VR) system requires indepth knowledge and understanding in many different disciplines. Three major features that distinguish VR systems are real-time performance while maintaining acceptable realism and presence, objects with two clearly distinct yet inter-related aspects like geometry/structure and function/behavior, and the still experimental nature of multi-modal interaction design. Until now, little attention has been paid to methods and tools for the structured development of VR software that addresses these features. Many VR application development projects proceed by modeling needed objects on conventional CAD systems, then programming the system using simulation packages. Usually, these activities are carried out without much planning, which may be acceptable for only small-scale or noncritical demonstration systems. However, for VR to be taken seriously as a media technology, a structural approach to developing VR applications is required for the construction of large-scale VR worlds, and this will undoubtedly involve and require complex resource management, abstractions for basic system/object functionalities and interaction tasks, and integration and easy plug-ins of different input and output methods. In this paper, we assembled a comprehensive structured methodology for building VR systems, called CLEVR (Concurrent and LEvel by Level Development of VR System), which combines several conventional and new concepts. For instance, we employ concepts such as the simultaneous consideration of form, function, and behavior, hierarchical modeling and top-down creation of LODs (levels of detail), incremental execution and performance tuning, user task and interaction modeling, and compositional reuse of VR objects. The basic underlying modeling approach is to design VR objects (and the scenes they compose) hierarchically and incrementally, considering their realism, presence, behavioral correctness, performance, and even usability in a spiral manner. To support this modeling strategy, we developed a collection of computeraided tools called P-VoT (POSTECH-Virtual reality system development Tool). We demonstrate our approach by illustrating a step-by-step design of a virtual ship simulator using the CLEVR/P-VoT, and demonstrate the effectiveness of our method in terms of the quality (performance and correctness) of the resulting software and reduced effort in its development and maintenance.

Can bottom-up modelling in virtual reality replace conventional structural analysis methods?

Conventional structural analysis methods are typically based on describing the structure as a system of simultaneous algebraic equations and solving the system by iteration. A common feature of such methods is a top-down approach to modelling where there is a global algorithm that controls the solution process. The top-down approach requires the knowledge of the entire state space of the model in order to program the solution, which often involves simplification and consequent inaccuracy whilst its computational intensity does not allow user interaction in real-time. This paper describes an alternative, bottom-up approach in which the solution process is controlled by local interaction of the structural components acting as independent objects in virtual reality and where the system model is created spontaneously by interaction of the component models. Early results of this research show that it is possible to have analogue virtual reality models of structures capable of real-time user interaction from which forces and other design parameters could be obtained through measurement without conventional calculation.

Interactive animation of cloth‐like objects in virtual reality

AbstractModeling and animation of cloth have experienced important developments in recent years. As a consequence, complex textile models can be used to realistically drape objects or human characters in a fairly efficient way. However, real‐time realistic simulation remains a major challenge, even if applications are numerous, from rapid prototyping to e‐commerce. In this paper, we present a stable, real‐time algorithm for animating cloth‐like materials. Using a hybrid explicit/implicit algorithm, we perform fast and stable time integration of a physically based model with rapid collision detection and response, as well as wind or liquid drag effects to enhance realism. We demonstrate our approach through a series of examples in virtual reality environments, proving that real‐time animation of cloth, even on low‐end computers, is now achievable. Copyright © 2001 John Wiley & Sons, Ltd.

A GENERIC SPATIAL TEMPORAL COMPUTATION MODEL FOR SYSTEMIC MULTIMEDIA PRESENTATIONS

Relations among temporal intervals can be used to assist the automatic generation of multimedia presentations. In this paper, we analyze the domains of interval temporal relations. A set of algorithms is proposed to derive reasonable relations between intervals. Possible conflicts in the user specification are first detected and eliminated. Our mechanism then constructs partial order relations among temporal intervals before the presentation time chart is built. The algorithm is extended for objects in an arbitrary n-dimensional space. Thus, presentation layouts in 2-D space or Virtual Reality object representations in 3-D space can be constructed. We use our algorithms to design alpha reasoning system that generates the schedule and layout of multimedia presentations. Finally, our contribution is completed with the application of STIMEVIS, a structured methodology of systemic analysis in the computation model we present, adapted in the process of generating multimedia presentations of user specifications.

On computing temporal/spatial relations

In this paper, we analyze the domains of interval temporal relations. A set of algorithms is proposed to derive reasonable relations between intervals. Possible conflicts in the user specification are firstly detected and eliminated. The algorithm is extended for objects in an arbitrary n-dimensional space. Thus, presentation layouts in 2-D space, or Virtual Reality object representations in 3-D space can be constructed. We use our algorithms to design a reasoning system that generates the schedule and layout of multimedia presentations.

Dynamic force simulator for multifinger force display

In this paper, the authors present a dynamic force simulator (DFS) for force feedback in human-machine systems. They propose a virtual world model with two force flows: one is the force flow from human to an object, the other is the force flow from an object to human. To use this model, the DFS simulates object dynamics, contact models, and friction characteristics of the human hand interacting with the object in virtual reality. After the derivation of kinematic and force relations between hand and object space, they balance the two forces: one from the human and the other from the object in the contact force space in virtual world and then realize the adequate feedback forces to human operator. Interaction with the DFS allows calculation and feedback of appropriate forces to the force controlled actuators of the sensor glove they have developed. In this paper grasping of a cylinder in the virtual world is presented. During object grasping, they measure joint angles and torques using the sensor glove system. In the future, they will use this system to analyze human dextrous manipulations called human skill.

Options in Classification Available Through Modern Technology

Options in classification available through modern information technologies are explored and discussed in terms of system design options and user searching options. The integrated subject tool will give options for the simultaneous presentation of the types of catalogs desired-dictionary, divided, or classified, as well as the concurrent consultation of multiple classification systems. The problems of electronic union catalogs, including a union catalog in particular, are considered and enhancements made possible through classification are explored. The combined system of subject headines and classification is presented as the model of the integrated subject searching tool, which will meet individualized learning styles and user responsive vocabulary. The integrated subject tool box (including classification) for an effective modern subject system is discussed in particular as a searching tool to assist shelf browsing of virtual reality (VR) objects.