Abstract: The ability to locate, select and interact with objects
is fundamental to most Virtual Reality (VR) applications.
Recently, it was demonstrated that the virtual hand metaphor,
a technique commonly used for these tasks,
can also be employed to control the virtual camera,
resulting in improved performance and user evaluation
in visual search tasks.
In this work, we further investigate the effects
of hand-assisted viewing on user behavior in immersive
virtual environments. We demonstrate that hand-assisted
camera control significantly changes the way how people
operate their virtual hands, on motor, cognitive,
and behavioral levels.
Abstract: Cinematic-quality game engines, broadband networking, and VR technology advances are converging to where players will have shared, "better than life" experiences in persistent virtual worlds. The authors propose several steps that might help this merger happen sooner. Specifically, a mechanism of natural selection among players could solve the longstanding problem of limited access to VR hardware. The authors also discuss serious applications of VR games and their social impact.
Abstract: Mixing real and virtual components into one consistent environment often involves creating geometry models of physical objects. Traditional approaches include manual modeling by 3D artists or use of dedicated devices. Both approaches require special skills or special hardware and may be costly. We propose a new method for fast semi-automatic 3D geometry acquisition, based upon unconventional use of motion tracking equipment. The proposed method is intended for quick surface prototyping for Virtual, Augmented and Mixed reality applications (VR/AR/MR), where quality of visualization of scanned objects is not required or is of low priority.
Abstract: Objectives: Virtual reality (VR) environments offer potential advantages over traditional paper methods,
manikin simulation, and live drills for mass casualty training and assessment. The authors measured the
acquisition of triage skills by novice learners after exposing them to three sequential scenarios (A, B,
and C) of five simulated patients each in a fully immersed three-dimensional VR environment. The
hypothesis was that learners would improve in speed, accuracy, and self-efficacy.
Methods: Twenty-four medical students were taught principles of mass casualty triage using three short
podcasts, followed by an immersive VR exercise in which learners donned a head-mounted display
(HMD) and three motion tracking sensors, one for their head and one for each hand. They used a gesture-
based command system to interact with multiple VR casualties. For triage score, one point was
awarded for each correctly identified main problem, required intervention, and triage category. For
intervention score, one point was awarded for each correct VR intervention. Scores were analyzed using
one-way analysis of variance (ANOVA) for each student. Before and after surveys were used to measure
self-efficacy and reaction to the training.
Results: Four students were excluded from analysis due to participation in a recent triage research program.
Results from 20 students were analyzed. Triage scores and intervention scores improved significantly
during Scenario B (p < 0.001). Time to complete each scenario decreased significantly from A
(8:10 minutes) to B (5:14 minutes; p < 0.001) and from B to C (3:58 minutes; p < 0.001). Self-efficacy
improved significantly in the areas of prioritizing treatment, prioritizing resources, identifying high-risk
patients, and beliefs about learning to be an effective first responder.
Conclusions: Novice learners demonstrated improved triage and intervention scores, speed, and selfefficacy
during an iterative, fully immersed VR triage experience.
ACADEMIC EMERGENCY MEDICINE 2008; 15:1–6 ª 2008 by the Society for Academic Emergency
Medicine
Abstract: While sonification has enjoyed much attention in VR simulation studies, music has generally been incorporated as ambiance. This is partially due to difficulties with manipulating it interactively in real-time while maintaining a sensible musicality. This paper discusses how algorithmically generated music is used to provide ambiance, characterize the visual representation of molecular particle flow, provide orientation cues to the user, and enhance recognition of chemical gradient balances in a reified model of the kidney nephron. The technical obstacles related to the use of music in this context are also addressed.
Abstract: Several abstract concepts in medical education are difficult to teach and comprehend. In order to address this challenge, we have been applying the approach of reification of abstract concepts using interactive virtual environments and a knowledge-based design. Reification is the process of making abstract concepts and events, beyond the realm of direct human experience, concrete and accessible to teachers and learners. Entering virtual worlds and simulations not otherwise easily accessible provides an opportunity to create, study, and evaluate the emergence of knowledge and comprehension from the direct interaction of learners with otherwise complex abstract ideas and principles by bringing them to life. Using a knowledge-based design process and appropriate subject matter experts, knowledge structure methods are applied in order to prioritize, characterize important relationships, and create a concept map that can be integrated into the reified models that are subsequently developed. Applying these principles, our interdisciplinary team has been developing a reified model of the nephron into which important physiologic functions can be integrated and rendered into a three dimensional virtual environment called Flatland, a virtual environments development software tool, within which a learners can interact using off-the-shelf hardware. The nephron model can be driven dynamically by a rules-based artificial intelligence engine, applying the rules and concepts developed in conjunction with the subject matter experts. In the future, the nephron model can be used to interactively demonstrate a number of physiologic principles or a variety of pathological processes that may be difficult to teach and understand. In addition, this approach to reification can be applied to a host of other physiologic and pathological concepts in other systems. These methods will require further evaluation to determine their impact and role in learning.
Abstract: Access to the laboratory component of a class is limited by resources, while lab training is not currently possible for distance learning. To overcome the problem a solution is proposed to enable hands-on, interactive, objectively scored and appropriately mentored learning in a widely accessible environment. The proposed solution is the Virtual-Reality Motor-Skills trainer to teach basic fine-motor skills using Haptics for touch and feel interaction as well as a 3D virtual reality environment for visualization.
Abstract: Virtual Reality has been used for clinical application for about 10 years and has proved to be an effective tool for treating various disorders. In this paper, we want to share our experience in building a 3D, motion tracked, immersive VR system for pain treatment and biofeedback research.
Abstract: Medical knowledge and skills essential for tomorrow's healthcare professionals continue to change faster than ever before creating new demands in medical education. Project TOUCH (Telehealth Outreach for Unified Community Health) has been developing methods to enhance learning by coupling innovations in medical education with advanced technology in high performance computing and next generation Internet2 embedded in virtual reality environments (VRE), artificial intelligence and experiential active learning. Simulations have been used in education and training to allow learners to make mistakes safely in lieu of real-life situations, learn from those mistakes and ultimately improve performance by subsequent avoidance of those mistakes. Distributed virtual interactive environments are used over distance to enable learning and participation in dynamic, problem-based, clinical, artificial intelligence rules-based, virtual simulations. The virtual reality patient is programmed to dynamically change over time and respond to the manipulations by the learner. Participants are fully immersed within the VRE platform using a head-mounted display and tracker system. Navigation, locomotion and handling of objects are accomplished using a joy-wand. Distribution is managed via the Internet2 Access Grid using point-to-point or multi-casting connectivity through which the participants can interact. Medical students in Hawaii and New Mexico (NM) participated collaboratively in problem solving and managing of a simulated patient with a closed head injury in VRE; dividing tasks, handing off objects, and functioning as a team. Students stated that opportunities to make mistakes and repeat actions in the VRE were extremely helpful in learning specific principles. VRE created higher performance expectations and some anxiety among VRE users. VRE orientation was adequate but students needed time to adapt and practice in order to improve efficiency. This was also demonstrated successfully between Western Australia and UNM. We successfully demonstrated the ability to fully immerse participants in a distributed virtual environment independent of distance for collaborative team interaction in medical simulation designed for education and training. The ability to make mistakes in a safe environment is well received by students and has a positive impact on their understanding, as well as memory of the principles involved in correcting those mistakes. Bringing people together as virtual teams for interactive experiential learning and collaborative training, independent of distance, provides a platform for distributed "just-in-time" training, performance assessment and credentialing. Further validation is necessary to determine the potential value of the distributed VRE in knowledge transfer, improved future performance and should entail training participants to competence in using these tools.
Abstract: Project TOUCH (Telehealth Outreach for Unified Community Health) is a collaborative effort between University of New Mexico and University of Hawaii. The purpose of the project is to demonstrate the feasibility of using advanced technologies to overcome geographical barriers to delivery of medical education and to enhance the learning process within a group setting. This has led to the design and implementation of a new system that addresses the critical requirements for collaborative virtual environments: consistency, networking, scalability, and system integration. The objective of this study is to evaluate the performance of the collaborative system based on use patterns during Project TOUCH sessions.
Abstract: A ray-tracing algorithm is described for rendering implicit surfaces formed with C1-continuous bounded functions f(x, y, z). This class of functions includes such popular implicit models as blobby molecules, metaballs, soft objects and convolution surfaces. The algorithm employs analytical methods only, which makes it fast, robust, and numerically stable.
An earlier version of this work was presented at the 3rd International Workshop on Implicit Surfaces held in Seattle in 1998.
Abstract: A comprehensive analysis of various convolution kernels
is presented. Computational complexity and compatibility
between the kernels and a number of modeling primitives
are examined. A number of practical suggestions are given
how to choose the proper kernel function, with a special
attention to polynomial kernels. Mathematical formulations
for convolved line segments are given.
Abstract: Implicit surfaces obtained by convolution of multi-dimensional primitives with some potential function, are a generalisation of popular implicit surface models: blobs, metaballs and soft objects. These models differ in their choice of potential function but agree upon the use of underlying modelling primitives, namely, points. In this paper a method is described for modelling and rendering implicit surfaces built upon an expanded set of skeletal primitives: points, line segments, polygons, arcs and planes. An analytical solution to the convolution is described. This solution offers a more accurate and robust representation of the resultant implicit surface than previous methods. An algorithm for ray-tracing the surfaces formed through convolution of any combination of these primitives is also outlined.
Abstract: We propose a simple yet effective extension of ray-tracing algorithm that allows selective visibility of objects for specific rays. Typically, rays are classified as pixel, shadow, reflected and transmitted. We suggest adding a visibility mask to material descriptions, which controls how these rays interact with the material. This addition can be incorporated seamlessly into any ray-tracer and may help to generate visually interesting images.
Notes: images and extras:
http://jgt.akpeters.com/papers/Sherstyuk96/
Abstract: Abstract: In medical education, human patient simulators, or manikins, are a well established method of teaching medical skills. The current state of the art manikins are limited in their functions by a fixed number of in-built hardware devices, such as pressure sensors and motor actuators that control the manikin behaviors and responses. In this work, we review several research projects, where applied techniques from the fields of Augmented and Mixed Reality allowed to significantly expand manikin functionality. We will pay special attention to tactile augmentation, and describe in detail a fully functional `touch-enabled'' human manikin, developed at SimTiki Medical Simulation Center, University of Hawaii. Also, we will outline possible extensions of the proposed touch-augmented human patient simulator and share our thoughts on the future directions in use of Augmented Reality in medical education.
Abstract: Augmented Reality applications have already become a part
of everyday life, bringing virtual 3D objects into real life scenes.
In this paper, we introduce ``Virtual Roommates'', a system that
employs AR techniques to share people's presence, projected
from remote locations.
Virtual Roommates is a feature-based mapping between loosely
linked spaces. It allows to overlay multiple physical and virtual
scenes and populate them with physical or virtual characters.
As the name implies, the Virtual Roommates concept provides
continuous ambient presence for multiple disparate groups,
similar to people sharing living conditions, but without the
boundaries of real space.
Abstract: Life on Earth has many forms and every life form has its
own version of reality, as reflected in the eyes of the viewer.
These worlds are as real as the one that we know and all of
them are equally fascinating. The multiverse of such ``animal
realities'' can be explored in Virtual Reality,
as described in this concept work.
Abstract: Narrow field of view of common Head Mount Displays,
coupled with lack of adaptive camera accommodation and vergence
make it impossible to view virtual scenes using familiar eye-head-body
coordination patterns and reflexes. This impediment of natural habits
is most noticeable in applications where users are facing multiple tasks,
which require frequent switching between viewing modes, from wide range
visual search to object examination at close distances.
We propose a new technique for proactive control of the virtual camera
by utilizing a predator-prey vision metaphor. We describe
the technique, the implementation, and preliminary results.
Abstract: In Virtual Environments (VE), users are often facing tasks that involve direct manipulation of virtual objects at close distances, such as touching, grabbing, placement. In immersive systems that employ head-mounted displays these tasks could be quite challenging, due to lack of convergence of virtual cameras.
We present a mechanism that dynamically converges left and right cameras on target objects in VE. This mechanism simulates the natural process that takes place in real life automatically. As a result, the rendering system maintains optimal conditions for stereoscopic viewing of target objects at varying depths, in real time.
Building on our previous work, which introduced the eye convergence algorithm [Sherstyuk and State 2010], we developed a Virtual Reality (VR) system and conducted an experimental study on effects of eye convergence in immersive VE. This paper gives the full description of the system, the study design and a detailed analysis of the results obtained.
Abstract: Reliable and unobtrusive eye tracking remains a technical challenge
for immersive virtual environment, especially when Head Mounted Displays
(HMD) are used for visualization and users are allowed to move freely
in the environment. In this work, we provide experimental evidence
that gaze direction can be safely approximated by user head rotation,
in HMD-based Virtual Reality (VR) applications, where users actively
interact with the environment.
We discuss the application range of our approach and consider possible
extensions.
Abstract: Augmented Reality applications have already become a part of everyday life, bringing virtual 3D objects into real life scenes. In this paper, we introduce “Virtual Roommatesâ€, a system that employs AR techniques to share people's presence, projected from remote locations. Virtual Roommates is a feature-based mapping between loosely linked spaces. It allows to overlay multiple physical and virtual scenes and populate them with physical or virtual characters. As the name implies, the Virtual Roommates concept provides continuous ambient presence for multiple disparate groups, similar to people sharing living conditions, but without the boundaries of real space.
Abstract: We propose a novel framework for monitoring and evaluating user travel activity in Virtual Reality (VR), in real time. Using this framework, we examined how users progressed in mastering two common travel techniques: steering and target-based relocation. We identified three groups of subjects with distinctly different learning patterns, which we called advancing, neutral and regressing learners. In this paper, we explain our evaluation method in detail, describe the experimental study, discuss the results and practical applications of our findings.
Abstract: A virtual hand metaphor remains by far the most
popular technique for direct object manipulation
in immersive Virtual Reality (VR).
The utility of the virtual hand depends on a user's ability
to see it correctly in stereoscopic 3D, especially in tasks that
require continuous, precise hand-eye coordination.
We present a mechanism that dynamically converges
left and right cameras on target objects in VR,
mimicking the effect that naturally happens in real life.
As a result, the system maintains optimal conditions
for stereoscopic viewing at varying depths, in real-time.
We describe the algorithm, implementation details
and preliminary results from pilot tests.
Abstract: Developers are the first people who come to an empty world and make it habitable. In online virtual worlds, developers are 3D artists, architects, cloth designers and other talented and enthusiastic individuals with a passion for 3D modeling. Their joint creative efforts make virtual worlds possible.
In this report, we share our experience on close collaboration with a large community of developers in Blue Mars [2009] online virtual world, which was launched by Avatar Reality Inc (ARI), and now is experiencing explosive growth. From forum discussions, in-game meetings, question-and-answer sessions and from personal communications, we distilled and summarized some guidelines on how to keep the developers motivated and enthusiastic contributors.
Abstract: Game engines of cinematic quality, broadband networking and advances in Virtual Reality (VR) technologies are setting the stage to allow players to have shared, "better-than-life" experiences in online virtual worlds. We propose a mechanism of merit-based selection of players, as a solution to the long-standing problem of limited access to VR hardware.
Abstract: Two common limitations of modern Head Mounted Displays (HMD): the narrow field of view and limited dynamic range, call for rendering techniques that can circumvent or even take advantage of these factors. We describe a simple practical method of enhancing visual response from HMDs by using view-dependent control over lighting. One example is provided for simulating blinding lights in dark environments.
Abstract: Two common limitations of modern Head Mounted Displays (HMD): the narrow field of view and limited dynamic range, call for rendering techniques that can circumvent or even take advantage of these limiting factors. In order to improve visual response from HMDs, we propose a new method of creating various lighting effects, by using view-dependent control over lighting. Two implemented examples are provided: simulation of a blinding effect in dark environments, and contrast enhancement. The paper is intended for the audience interested in developing HMD-based Virtual Reality applications with improved scene illumination.
Abstract: Two common limitations of modern Head Mounted Displays (HMD):
the narrow field of view and limited dynamic range, call for
rendering techniques that can circumvent or even take advantage
of these limiting factors. In order to improve visual response
from HMDs, we propose a new method of creating various lighting
effects, by using view-dependent control over lighting.
Two implemented examples are provided: simulation of a blinding
effect in dark environments, and contrast enhancement.
The paper is intended for the audience interested in developing
HMD-based Virtual Reality applications with improved scene
illumination.
Abstract: We propose a method for overlaying CG elements onto real indoor scenes, without making a viewer wear special display devices, such as HMDs or monocles. The Virtual Mirror utilizes a computer display that operates in a mirror mode. It can be mounted on a wall or on a desktop, providing wide-angle viewing of the augmented scene.
Abstract: Mixing real and virtual elements into one environment often involves creating geometry models of physical objects. Traditional approaches include manual modeling by 3D artists or use of dedicated devices. Both approaches require special skills or special hardware and may be costly. We propose a new method for fast semi-automatic 3D geometry acquisition, based upon unconventional use of motion tracking equipment. The proposed method is intended for quick surface prototyping for Virtual, Augmented and Mixed reality applications where quality of visualization of objects is not required or is of low priority.
Abstract: Though often desirable, the integration of real and virtual elements in mixed reality environments can be difficult. We propose a number of techniques to facilitate scene exploration and object selection by giving users real instruments as props while implementing their functionality in a virtual part of the environment. Specifically, we present a family of tools built upon the idea of using real binoculars for viewing virtual content. This approach matches user expectations with the tool's capabilities enhancing the sense of presence and increasing the depth of interaction between the real and virtual components of the scene. We also discuss possible applications of these tools and the results of our user study.
This paper is an extended version of earlier work presented at the 4th International Workshop on the Tangible Space Initiative[5].
Abstract: A new wearable haptic system is proposed for interactive immersive Virtual Reality (VR) installations. The core of the system is a common cooling CPU fan attached to a user hand, tracked in 3D, and operated from a host computer. The proposed system is suitable for entertainment applications where immersed VR users interact with fuzzy, cloud-like or jelly-like objects, producing soft and gentle tactile sensations upon contact with user hands.
Abstract: The ability to manipulate objects is fundamental to most virtual reality (VR) applications. A multitude of metaphors have been developed to facilitate object selection and manipulation, including the virtual hand metaphor, which remains by far the most popular technique in this category. The utility of the virtual hand depends on the user's ability to see it. Unfortunately, ensuring this is not always easy, especially in immersive systems which employ head mounted displays (HMD) with limited field of view (FOV), typically ranging from 40 to 60 degrees diagonally.
Abstract: In medical education, human patient simulators, or
manikins, are a well established method of teaching medical
skills. The current state of the art manikins are limited
in their functions by a fxed number of in-built sensors and
actuators that control the manikin behaviors and responses.
We describe how applying standard techniques from the
felds of Virtual and Mixed Reality can signifcantly expand
manikin functionality, at relatively low costs. We describe a
working prototype of a Mixed Reality Manikin, with technical
implementation details and one complete scenario.
Also, we discuss a number of extensions and applications
of our technique.
Abstract: The ability to manipulate objects is fundamental to most
virtual reality (VR) applications. A multitude of metaphors
have been developed to facilitate object selection
and manipulation~\cite{Poup}, including
virtual hand~\cite{VirtualHand}, which remains by far the most
popular technique in this category.
The utility of the virtual hand depends on the user's ability to see it.
Unfortunately, ensuring this is not always easy, especially in immersive
systems which employ head mounted displays (HMD) with a limited
field of view.
Building on~\cite{Poster}, we show how the virtual hand metaphor
may be used effectively both to manipulate virtual
objects, and to guide the user's view in order to ensure
continuous visibility of the hand.
We provide implementation detail and
report experimental results from the user studies.
This paper is intended for an audience interested in building
HMD-based VR systems, where users are required to actively interact
with the environment by using their virtual hand.
Abstract: Optical sight is a new metaphor for selecting distant objects or precisely pointing at close objects in virtual environments. Optical sight combines ray-casting, hand based camera control, and variable zoom into one virtual instrument that can be easily implemented for a variety of Virtual, Mixed, and Augmented Reality systems. The optical sight can be modied into a wide family of tools for viewing and selecting objects. Optical sight scales well from desktop environments to fully immersive systems.
Abstract: Though often desirable, the integration of real and virtual elements in mixed reality environments can be difcult. We propose a number of techniques to facilitate scene exploration and object selection by giving users real instruments as props while implementing their functionality in a virtual part of the environment. Specically, we present a family of tools built upon the idea of using real binoculars for viewing virtual content. This approach matches user expectations with the tool's capabilities enhancing the sense of presence and increasing the depth of interaction between the real and virtual components of the scene. We also discuss possible applications of these tools and the results of our user study.
Abstract: Triage is a medical term that describes the process of prioritizing and delivering care to multiple casualties within a short time frame. Because of the inherent limitations of traditional methods of teaching triage, such as paper-based scenarios and the use of actors as standardized patients, computer-based simulations and virtual reality (VR) scenarios are being advocated. We present our system for VR triage, focusing on design and development of a pose and gesture based interface that allows a learner to navigate in a virtual space among multiple simulated casualties. The learner is also able to manipulate virtual instruments effectively in order to complete required training tasks
Abstract: This paper presents a complete design environment that explores the modeling capabilities of convolution surfaces and puts them to practice. The design system includes a number of implicit primitives and modeling techniques, that allow objects to be created by sculpturing their surfaces at all levels of detail. All techniques are illustrated using models of marine life forms and other objects of organic origin. Implementation and efficiency issues are discussed.
Abstract: A ray-tracing algorithm is described for rendering implicit surfaces formed with C1-continuous bounded functions f(x, y, z). This class of functions includes such popular implicit models as blobby molecules, metaballs, soft objects and convolution surfaces. The algorithm employs analytical methods only, which makes it fast, robust, and numerically stable.
Abstract: Implicit surfaces obtained by the convolution of mixed dimensional primitives g with some potential function f as shown above, are a generalization of popular implicit surface models: blobs, metaballs and soft objects. These models differ in their choice of potential function but agree upon the use of underlying modeling primitives, namely, points, which puts severe limitations on modeling process and restricts the application base of such models.
In this dissertation a method is described for creating and rendering convolution surfaces built upon an expanded set of skeletal primitives: points, line segments, polygons, curves and planes. Analytical solutions to the convolution integral are presented for a number of implicit primitives and potential functions. A comparative analysis for a number of convolution kernels is given.
In addition to conventional techniques, commonly used in implicit modeling, this dissertation describes a set of new modeling methods, which offer a better flexibility for modeling with implicit surfaces.
Finally, an efficient ray-tracing algorithm is presented, which is capable of producing high-quality images of objects modeled with convolution surfaces. The algorithm outperforms all ray-tracing algorithms in its class known to date.
Developing, modeling and rendering issues, discussed in this dissertation are illustrated by original images developed and rendered by the author.
Abstract: There are few objects in the natural world that can be adequately represented by linear, circular or planar primitives. We show that in the domain of implicit modeling such primitives are very useful. Lines, arcs and triangles, when used as skeletons of convolution surfaces, produce well-structured and compact datasets that are easy to manipulate and animate.
We discuss a number of new modeling techniques and a number of datasets, that yield visually convincing shapes, resembling various forms of marine life. We also present volumetric textures that alter the actual geometry of implicit surfaces and make them more realistic.
Abstract: We present an algorithm for ray-tracing implicit surfaces built around spatially extended primitives. The algorithm is based on interpolation of the volumetric density functions by piecewise polynomials. This allows fast analytical solving of the implicit equations, which makes the algorithm computationally effective and insensitive to camera-model orientation and image resolution. The algorithm supports modularity in handling primitives of various types, which provides more flexibility in modeling implicit surfaces.
