| Implicit 3D modeling and tracking for anywhere augmentation | | BIBAK | Full-Text | 19-28 | |
| Sehwan Kim; Stephen DiVerdi; Jae Sik Chang; Taehyuk Kang; Ronald Iltis; Tobias Höllerer | |||
| This paper presents an online 3D modeling and tracking methodology that uses
aerial photographs for mobile augmented reality. Instead of relying on models
which are created in advance, the system generates a 3D model for a real
building on the fly by combining frontal and aerial views with the help of an
optical sensor, an inertial sensor, a GPS unit and a few mouse clicks. A user's
initial pose is estimated using an aerial photograph, which is retrieved from a
database according to the user's GPS coordinates, and an inertial sensor which
measures pitch. To track the user's position and orientation in real-time,
feature-based tracking is carried out based on salient points on the edges and
the sides of a building the user is keeping in view. We implemented camera pose
estimators using both a least squares and an unscented Kalman filter (UKF)
approach. The UKF approach results in more stable and reliable vision-based
tracking. We evaluate the speed and accuracy of both approaches, and we
demonstrate the usefulness of our computations as important building blocks for
an Anywhere Augmentation scenario. Keywords: UKF, camera pose estimation, feature-based tracking, online modeling,
outdoor augmented reality | |||
| Real-time tracking of visually attended objects in interactive virtual environments | | BIBAK | Full-Text | 29-38 | |
| Sungkil Lee; Gerard Jounghyun Kim; Seungmoon Choi | |||
| This paper presents a real-time framework for computationally tracking
objects visually attended by the user while navigating in interactive virtual
environments. In addition to the conventional bottom-up (stimulus-driven)
features, the framework also uses topdown (goal-directed) contexts to predict
the human gaze. The framework first builds feature maps using preattentive
features such as luminance, hue, depth, size, and motion. The feature maps are
then integrated into a single saliency map using the center-surround difference
operation. This pixel-level bottom-up saliency map is converted to an
object-level saliency map using the item buffer. Finally, the top-down contexts
are inferred from the user's spatial and temporal behaviors during interactive
navigation and used to select the most plausibly attended object among
candidates produced in the object saliency map. The computational framework was
implemented using the GPU and exhibited extremely fast computing performance
(5.68 msec for a 256X256 saliency map), substantiating its adequacy for
interactive virtual environments. A user experiment was also conducted to
evaluate the prediction accuracy of the visual attention tracking framework
with respect to actual human gaze data. The attained accuracy level was well
supported by the theory of human cognition for visually identifying a single
and multiple attentive targets, especially due to the addition of top-down
contextual information. The framework can be effectively used for perceptually
based rendering without employing an expensive eye tracker, such as providing
the depth-of-field effects and managing the level-of-detail in virtual
environments. Keywords: attention tracking, bottom-up feature, saliency map, top-down context,
virtual environment, visual attention | |||
| Simultaneous 4 gestures 6 DOF real-time two-hand tracking without any markers | | BIBAK | Full-Text | 39-42 | |
| Markus Schlattman; Reinhard Klein | |||
| In this paper we present a novel computer vision based hand-tracking method,
which is capable of simultaneously tracking 6+4 degrees of freedom (DOFs) of
each human hand in real-time (25 frames per second) with the help of 3 (or
more) off-the-shelf consumer cameras. '6+4 DOF' means that the system can track
the global pose (6 continuous parameters for translation and rotation) of 4
different gestures. Different studies discovered the need for two-handed
interaction to enable an intuitive 3D Human-Computer-Interaction. Previously,
using both hands as at least 6 DOF input devices involved the use of either
datagloves or markers. Applying our two-hand-tracking we evaluated the use of
both hands as input devices for two applications: fly-through exploration of a
virtual world and a mesh editing application. Keywords: hand tracking, interaction techniques, virtual reality | |||
| A semi-automatic realtime calibration technique for a handheld projector | | BIBAK | Full-Text | 43-46 | |
| Vinh Ninh Dao; Kazuhiro Hosoi; Masanori Sugimoto | |||
| In this paper, a semi-automatic realtime calibration technique for a
handheld projector is described. The proposed technique always keeps a shape of
a projected screen rectangular on a specified projection surface, while a user
continuously changes his standing position or the pose of the projector. The
technique is especially useful for a future mobile phone with a built-in
projector that allows a user to project its screen onto any surface in any
location and share the screen with multiple people. Informal evaluations using
the technique have been conducted to identify the level of its acceptability by
users and to find problems to be improved. An example entertainment application
to explore possibilities of the proposed technique has been developed. Keywords: calibration, distortion correction, handheld projector, interaction
technique | |||
| Handheld AR indoor guidance system using vision technique | | BIBAK | Full-Text | 47-50 | |
| Eunsoo Jung; Sujin Oh; Yanghee Nam | |||
| We present a mobile augmented reality (AR) system for indoor guidance where
we apply vision technique without using markers. There are two main problems:
First, to augment suitable information according to users situation, it has to
be identified which place the user belongs to. Second, to put information into
the scene and to make it aligned with the target scene element, the basic
structure of the augmenting space should be grasped. For place recognition in
real time mobile system, we employ simple feature detection method combined
with graph based spatial connectivity representation. Also, Image-based
analysis method is applied to interpret the basic scene structure from the
video. Keywords: augmented reality, computer vision, mobile guidance | |||
| Supporting the creation of dynamic, interactive virtual environments | | BIBAK | Full-Text | 51-54 | |
| Kristopher J. Blom; Steffi Beckhaus | |||
| Virtual Reality's expanding adoption makes the creation of more interesting
dynamic, interactive environments necessary in order to meet the expectations
of users accustomed to modern computer games. In this paper, we present initial
explorations of using the recently developed Functional Reactive Programming
paradigm to support the creation of such environments. The Functional Reactive
Programming paradigm supports these actions by providing tools that match both
the user's perception of the dynamics of the world and the underlying hybrid
nature of such environments. Continuous functions with explicit time
dependencies describe the dynamic behaviors of the environment and discrete
event mechanisms provide for modifying the active behaviors of the environment.
Initial examples show how this paradigm can be used to control dynamic,
interactive Virtual Environments. Keywords: dynamic virtual environments, functional reactive programming, interactive,
virtual reality | |||
| Stable and efficient miscible liquid-liquid interactions | | BIBAK | Full-Text | 55-64 | |
| Hongbin Zhu; Kai Bao; Enhua Wu; Xuehui Liu | |||
| In our surrounding environment, we may often see many various miscible
liquid-liquid mixture phenomena, like pouring honey or ink into water, Coca
Cola into strong wine etc., while few papers have devoted to the simulation of
the phenomena. In this paper, we use a two-fluid lattice Boltzmann method
(TFLBM) to simulate the underlying dynamics of miscible mixtures. By the
method, a subgrid model is applied to improve its numerical stability so that
the free surface of the mixture, accompanying with higher Reynolds number, can
be simulated. We also apply control forces to the mixture with interesting
animation created. By optimizing the memory structure and taking the advantage
of dual-core or multi-core systems, we achieve real time computation for a
domain in 64{sup:3} cells full of fluid mixtures. Keywords: control, free surface, lattice Boltzmann method, memory optimization,
miscible mixture, multicore system, stability, subgrid model | |||
| Simulating competitive interactions using singly captured motions | | BIBAK | Full-Text | 65-72 | |
| Hubert P. H. Shum; Taku Komura; Shuntaro Yamazaki | |||
| It is difficult to create scenes where multiple avatars are fighting /
competing with each other. Manually creating the motions of avatars is time
consuming due to the correlation of the movements between the avatars.
Capturing the motions of multiple avatars is also difficult as it requires a
huge amount of post-processing. In this paper, we propose a new method to
generate a realistic scene of avatars densely interacting in a competitive
environment. The motions of the avatars are considered to be captured
individually, which will increase the easiness of obtaining the data. We
propose a new algorithm called the temporal expansion approach which maps the
continuous time action plan to a discrete space such that turn-based evaluation
methods can be used. As a result, many mature algorithms in game such as the
min-max search and α-β pruning can be applied. Using our method,
avatars will plan their strategies taking into account the reaction of the
opponent. Fighting scenes with multiple avatars are generated to demonstrate
the effectiveness of our algorithm. The proposed method can also be applied to
other kinds of continuous activities that require strategy planning such as
sport games. Keywords: human simulation, motion capture, motion planning | |||
| State-annotated motion graphs | | BIBAK | Full-Text | 73-76 | |
| Bill Chiu; Victor Zordan; Chun-Chih Wu | |||
| Motion graphs have gained popularity in recent years as a means for re-using
motion capture data by connecting previously unrelated segments of a recorded
library. Current techniques for controlling movement of a character via motion
graphs have largely focused on path planning which is difficult due to the
density of connections found on the graph. We introduce "state-annotated motion
graphs," a novel technique which allows high-level control of character
behavior by using a dual representation consisting of both a motion graph and a
behavior state machine. This special motion graph is generated from labeled
data and then bound to a finite state machine with similar labels. At run-time,
character behavior is simply controlled by switching states. We show that it is
possible to generate rich, controllable motion without the need for deep
planning. We demonstrate that, when applied to an interactive fighting testbed,
simple state-switching controllers may be coded intuitively to create various
effects. Keywords: behavior control, human animation, motion capture | |||
| Interactive control of physically-valid aerial motion: application to VR training system for gymnasts | | BIBAK | Full-Text | 77-80 | |
| Franck Multon; Ludovic Hoyet; Taku Komura; Richard Kulpa | |||
| This paper aims at proposing a new method to animate aerial motions in
interactive environments while taking dynamics into account. Classical
approaches are based on spacetime constraints and require a complete knowledge
of the motion. However, in Virtual Reality, the user's actions are
unpredictable so that such techniques cannot be used. In this paper, we deal
with the simulation of gymnastic aerial motions in virtual reality. A user can
directly interact with the virtual gymnast thanks to a real-time motion capture
system. The user's arm motions are blended to the original aerial motions in
order to verify their consequences on the virtual gymnast's performance. Hence,
a user can select an initial motion, an initial velocity vector, an initial
angular momentum, and a virtual character. Each of these choices has a direct
influence on mechanical values such as the linear and angular momentum. We thus
have developed an original method to adapt the character's poses at each time
step in order to make these values compatible with mechanical laws: the angular
momentum is constant during the aerial phase and the linear one is determined
at take-off. Our method enables to animate up to 16 characters at 30hz on a
common PC. To sum-up, our method enables to solve kinematic constraints, to
retarget motion and to correct it to satisfy mechanical laws. The virtual
gymnast application described in this paper is very promising to help
sports-men getting some ideas which postures are better during the aerial phase
for better performance. Keywords: dynamics, interactivity, motion control, sports application, virtual human | |||
| Anticipation from example | | BIBAK | Full-Text | 81-84 | |
| Victor Zordan; Adriano Macchietto; Jose Medin; Marc Soriano; Chun-Chih Wu; Ronald Metoyer; Robert Rose | |||
| Automatically generated anticipation is a largely overlooked component of
response in character motion for computer animation. We present an approach for
generating anticipation to unexpected interactions with examples taken from
human motion capture data. Our system generates animation by quickly selecting
an anticipatory action using a Support Vector Machine (SVM) which is trained
offline to distinguish the characteristics of a given scenario according to a
metric that assesses predicted damage and energy expenditure for the character.
We show our results for a character that can anticipate by blocking or dodging
a threat coming from a variety of locations and targeting any part of the body,
from head to toe. Keywords: behavior control, human animation, motion capture | |||
| A robust method for real-time thread simulation | | BIBAK | Full-Text | 85-88 | |
| Blazej Kubiak; Nico Pietroni; Fabio Ganovelli; Marco Fratarcangeli | |||
| In this paper, we present a physically based model for real-time simulation
of thread dynamics. Our model captures all the relevant aspects of the physics
of the thread, including quasi-zero elasticity, bending, torsion and
self-collision, and it provides output forces for the haptic feedback. The
physical properties are modeled in terms of constraints that are iteratively
satisfied while the numerical integration is carried out through a Verlet
scheme. This approach leads to an unconditionally stable, controllable and
computationally light simulation [Müller et al. 2007]. Our results
demonstrate the effectiveness of our model, showing the interaction of the
thread with other objects in real time and the creation of complex knots. Keywords: physically based animation, surgical simulation | |||
| Accurate on-line avatar control with collision anticipation | | BIBAK | Full-Text | 89-97 | |
| Manuel Peinado; Daniel Meziat; Damien Maupu; Daniel Raunhardt; Daniel Thalmann; Ronan Boulic | |||
| Interactive control of a virtual character through full body movement has a
wide range of applications. However, there is a need for systems that
accurately reproduce the motion of a performer while accounting for surrounding
obstacles. We propose an approach based on a Prioritized Inverse Kinematics
constraint solver. Several markers are placed on the user's body. A set of
kinematic constraints make the virtual character track these markers. At the
same time, we monitor the instantaneous displacements of a set of geometric
primitives, called observers, attached to different parts of the virtual
character. When an observer enters the influence area of an obstacle, its
motion is damped by means of automatically created preventive constraints. The
IK solver satisfies both maker and preventive constraints simultaneously,
yielding postures of the virtual character that remain close to those of the
user, while avoiding collisions with the virtual environment. Our performance
measurements show the maturity of the IK technology for real-time full-body
interactions. Keywords: character animation, collision avoidance, inverse kinematics, motion
capture, virtual reality | |||
| Real-time navigation of independent agents using adaptive roadmaps | | BIBA | Full-Text | 99-106 | |
| Avneesh Sud; Russell Gayle; Erik Andersen; Stephen Guy; Ming Lin; Dinesh Manocha | |||
| We present a novel algorithm for navigating a large number of independent agents in complex and dynamic environments. We compute adaptive roadmaps to perform global path planning for each agent simultaneously. We take into account dynamic obstacles and inter-agents interaction forces to continuously update the roadmap by using a physically-based agent dynamics simulator. We also introduce the notion of 'link bands' for resolving collisions among multiple agents. We present efficient techniques to compute the guiding path forces and perform lazy updates to the roadmap. In practice, our algorithm can perform real-time navigation of hundreds and thousands of human agents in indoor and outdoor scenes. | |||
| Interactive control of real-time crowd navigation in virtual environment | | BIBAK | Full-Text | 109-112 | |
| Xiaogang Jin; Charlie C. L. Wang; Shengsheng Huang; Jiayi Xu | |||
| Interactive control is one of the key issues when simulating crowd
navigation in virtual environment. In this paper, we propose a simple but
practical method for authoring crowd scenes in an effective and intuitive way.
Radial Basis Functions (RBF) based vector field is employed as the governing
tool to drive the motion flow. With this basic mathematical tool, users can
easily control the motions of crowd by simply sketching velocities on a few
points in the scene. Our approach is fast enough to allow on-the-fly
modification of the vector field. Besides, the behavior of an individual in a
crowd can be interactively adjusted by changing the ratio between its
autonomous and governed movements. Keywords: crowd simulation, navigation control, radial basis functions, vector field | |||
| CrowdViewer: from simple script to large-scale virtual crowds | | BIBAK | Full-Text | 113-116 | |
| Tianlu Mao; Bo Shu; Wenbin Xu; Shihong Xia; Zhaoqi Wang | |||
| Visualization of large-scale virtual crowds is ubiquitous in many
applications of computer graphics. For reasons of efficiency in modeling,
animating and rendering, it is difficult to populate scenes with a large number
of individually animated virtual characters in real-time applications. In this
paper, we present an effective and readily usable solution to this problem. It
accepts simple script which includes motion state and position information of
each individual at each time step. Supported by material database and motion
database, various human models are generated from model templates, and then
driven by an agile on-line animation approach. A developed point-based
rendering approach is presented to accelerate rendering. We test our system
with script including 30,000 people evacuating from a sports arena. The results
demonstrate that our approach provides a very effective way to visualize
large-scale crowds with high visual realism in real-time. Keywords: animating, modeling, rendering, virtual crowds | |||
| Officer Garcia: a virtual human for mediating eyewitness identification | | BIBAK | Full-Text | 117-120 | |
| Brent Daugherty; Sabarish Babu; Brian Cutler; Larry Hodges | |||
| An analysis of court cases has revealed that the mistaken identification of
the wrong person by victims and witnesses of a crime is the single most common
error leading to the arrest and conviction of innocent people [Wells et al.
2006]. Recognizing the role of mistaken identification in erroneous conviction,
a growing number of states and police departments have reformed their
eyewitness identification procedures. In this paper, we investigate a new
procedural reform: the use of a virtual officer who does not know the identity
of the suspect in the lineup and therefore cannot bias the witness toward false
identification. Keywords: Officer Garcia, embodied conversational agents, human-computer interaction,
virtual humans, virtual officer | |||
| The benefits of immersion for spatial understanding of complex underground cave systems | | BIBAK | Full-Text | 121-124 | |
| Philip Schuchardt; Doug A. Bowman | |||
| A common reason for using immersive virtual environments (IVEs) in
visualization is the hypothesis that IVEs should provide a higher level of
spatial understanding for complex 3D structures, such as those found in
underground cave systems. Therefore, we aimed to explore the use of IVEs for
visualization of underground caves, and to determine the benefits of immersion
for viewing such models. We ran an experiment in which domain experts answered
questions with two different levels of immersion. The results show that for
certain tasks the more immersive system significantly improved accuracy, speed,
and comprehension over the non-immersive environment, and that 3D visualization
overall is a good match for the underground cave data. Keywords: cave, immersion, spatial understanding, visualization | |||
| Consistent interactive augmentation of live camera images with correct near-field illumination | | BIBAK | Full-Text | 125-132 | |
| Thorsten Grosch; Tobias Eble; Stefan Mueller | |||
| Inserting virtual objects in real camera images with correct lighting is an
active area of research. Current methods use a high dynamic range camera with a
fish-eye lens to capture the incoming illumination. The main problem with this
approach is the limitation to distant illumination. Therefore, the focus of our
work is a real-time description of both near -- and far-field illumination for
interactive movement of virtual objects in the camera image of a real room. The
daylight, which is coming in through the windows, produces a spatially varying
distribution of indirect light in the room; therefore a near-field description
of incoming light is necessary. Our approach is to measure the daylight from
outside and to simulate the resulting indirect light in the room. To accomplish
this, we develop a special dynamic form of the irradiance volume for real-time
updates of indirect light in the room and combine this with importance sampling
and shadow maps for light from outside. This separation allows object movements
with interactive frame rates (10-17 fps). To verify the correctness of our
approach, we compare images of synthetic objects with real objects. Keywords: augmented image synthesis, global illumination | |||
| Interactive rendering of optical effects in wet hair | | BIBAK | Full-Text | 133-140 | |
| Rajeev Gupta; Nadia Magnenat-Thalmann | |||
| Visually, wet hair is easily distinguishable from dry hair because of the
increased highlights and intense darkening displayed by them. It is therefore
essential for realism to capture these characteristics under certain real world
conditions. In this regard we propose a model for rendering wet hair at
interactive rates. We start by analyzing the physical aspect behind this
special effect in hair and then present a model for incorporating the
variations in visual appearance of the hair due to presence of water. For
simulating the increased specularity because of the water layer on hair, we
present a parameter controlled Gaussian-based model. To simulate darkening in
hair, for outer hair we consider total internal reflection at water-hair
interface as dominant and propose a probabilistic approach to determine the
amount of light absorbed. For inner hair, we consider that increase in opacity
due to water results in stronger self-shadow and propose a model that updates
the opacities based on water content and accumulates them to calculate the
self-shadow term. By preprocessing and optimising our algorithm both for the
self-shadow in dry hair and the special effects due to water presence, we can
get visually pleasing results at interactive rates. Furthermore, the model is
highly versatile and can easily be adaptable to other liquids and hair styling
products. Keywords: hair simulation, interactive rendering, self-shadow, wet hair rendering | |||
| Building high performance DVR via HLA, scene graph and parallel rendering | | BIBAK | Full-Text | 141-144 | |
| Hua Xiong; Zonghui Wang; Xiaohong Jiang; Jiaoying Shi | |||
| Distributed simulation and parallel rendering based on PC cluster have seen
great success in recent years. To improve the overall performance, there is a
trend to integrate modeling, simulation and visualization into a common
distributed environment. In this paper, we propose a unified framework of
building high performance distributed virtual reality (DVR) applications. The
core components of this framework include the High Level Architecture (HLA),
scene graphs and parallel rendering. The HLA supports interactive distributed
simulation. Scene graphs are efficient to organize and manipulate scene data.
And parallel rendering provides powerful rendering ability. This paper presents
the in-depth architectural analysis of each components and derives a design
that integrates them into a unified framework. Two DVR applications, including
a remote navigation of massive virtual scenes and a multi-player video game,
have been developed to evaluate the framework performance. Keywords: collaborative environments, distributed simulation, distributed virtual
reality, graphics cluster, high level architecture, parallel rendering, scene
graph | |||
| Real-time global illumination in the CAVE | | BIBAK | Full-Text | 145-148 | |
| Jesper Mortensen; Pankaj Khanna; Insu Yu; Mel Slater | |||
| Global illumination in VR applications remains an elusive goal. While it
potentially has a positive impact on presence, the significant real-time
computation and integration complexities involved have been stumbling blocks.
In this paper we present recent and ongoing work in the Virtual Light Field
paradigm for global illumination as a solution to this problem. We discuss its
suitability for real-time VR applications and detail recent work in integrating
it with the XVR system for real-time GPU-based rendering in a CAVE™. This
rendering method achieves real-time rendering of L(S|D)* E solutions in time
independent of illumination complexity and largely independent of geometric
complexity. Keywords: global illumination, light fields, virtual reality | |||
| Incremental wavelet importance sampling for direct illumination | | BIBAK | Full-Text | 149-152 | |
| Hao-da Huang; Yanyun Chen; Xing Tong; Wen-cheng Wang | |||
| Most of existing importance sampling methods for direct illumination exploit
importance of illumination and surface BRDF. Without taking the visibility into
consideration, they can not adaptively adjust the number of samples for each
pixel during the sampling process. As a result, these methods tend to produce
images with noise in partially occluded regions. In this paper, we introduce an
incremental wavelet importance sampling approach, in which the visibility
information is used to determine the number of samples at run time. For this
purpose, we present a perceptual-based variance that is computed from
visibility of samples. In the sampling process, the Halton sample points are
incrementally warped for each pixel until the variance of warped samples
converges. We demonstrate that our method is more efficient than existing
importance sampling approaches. Keywords: importance sampling, rendering, wavelets | |||
| The design and implementation of a VR-architecture for smooth motion | | BIBAK | Full-Text | 153-156 | |
| F. A. Smit; R. van Liere; B. Fröhlich | |||
| We introduce an architecture for smooth motion in virtual environments. The
system performs forward depth image warping to produce images at video refresh
rates. In addition to color and depth, our 3D warping approach records
per-pixel motion information during rendering of the three-dimensional scene.
These enhanced depth images are used to perform per-pixel advection, which
considers object motion and view changes. Our dual graphics card architecture
is able to render the 3D scene at the highest possible frame rate on one
graphics card, while doing the depth image warping on a second graphics engine
at video refresh rate.
This architecture allows us to compensate for visual artifacts, also called motion judder, arising when the rendering frame rate is lower than the video refresh rate. The evaluation of our method shows motion judder can be effectively removed. Keywords: VR, dual-GPU, judder, motion estimation, smooth motion, video refresh rate,
warping | |||
| Gesture-based interaction for a magic crystal ball | | BIBAK | Full-Text | 157-164 | |
| Li-Wei Chan; Yi-Fan Chuang; Meng-Chieh Yu; Yi-Liu Chao; Ming-Sui Lee; Yi-Ping Hung; Jane Hsu | |||
| Crystal balls are generally considered as media to perform divination or
fortune-telling. These imaginations are mainly from some fantasy films and
fiction, in which an augur can see into the past, the present, or the future
through a crystal ball. With the distinct impressions, crystal ball has
revealed itself as a perfect interface for the users to access and to
manipulate visual media in an intuitive, imaginative and playful manner. We
developed an interactive visual display system named Magic Crystal Ball (MaC
Ball). MaC Ball is a spherical display system, which allows the users to see a
virtual object/scene appearing inside a transparent sphere, and to manipulate
the displayed content with barehanded interactions. Interacting with MaC Ball
makes the users feeling acting with magic power. With MaC Ball, user can
manipulate the display with touch and hover interactions. For instance, the
user waves hands above the ball, causing clouds blowing from bottom of the
ball, or slides fingers on the ball to rotate the displayed object. In
addition, the user can press single finger to select an object or to issue a
button. MaC Ball takes advantages on the impressions of crystal balls, allowing
the users acting with visual media following their imaginations. For
applications, MaC Ball has high potential to be used for advertising and
demonstration in museums, product launches, and other venues. Keywords: 3D interaction, entertainment, haptics | |||
| Using an event-based approach to improve the multimodal rendering of 6DOF virtual contact | | BIBAK | Full-Text | 165-173 | |
| Jean Sreng; Florian Bergez; Jérémie Legarrec; Anatole Lécuyer; Claude Andriot | |||
| This paper decribes a general event-based approach to improve multimodal
rendering of 6DOF (degree of freedom) contact between objects in interactive
virtual object simulations. The contact events represent the different steps of
two objects colliding with each other: (1) the state of free motion, (2) the
impact event at the moment of collision (3) the friction state during the
contact and (4) the detachment event at the end of the contact. The different
events are used to improve the classical feedback by superimposing specific
rendering techniques based on these events. First we propose a general method
to generate these events based only on the objects' positions given by the
simulation. Second, we describe a set of different types of multimodal feedback
associated to the different events that we implemented in a complex virtual
simulation dedicated to virtual assembly. For instance, we propose a visual
rendering of impact, friction and detachment based on particle effects. We used
the impact event to improve the 6DOF haptic rendering by superimposing a high
frequency force pattern to the classical force feedback. We also implemented a
realistic audio rendering using impact and friction sound on the corresponding
events. All these first implementations can be easily extended with other
event-based effects on various rigid body simulations thanks to our modular
approach. Keywords: 6DOF, audio, contact, event-based, haptic, multimodal, rendering, visual | |||
| A classification scheme for multi-sensory augmented reality | | BIBAK | Full-Text | 175-178 | |
| Robert W. Lindeman; Haruo Noma | |||
| We present a new classification framework for describing augmented reality
(AR) applications based on where the mixing of real and computer-generated
stimuli takes place. In addition to "classical" visual AR techniques, such as
optical-see-through and video-see-through AR, our framework encompasses AR
directed at the other senses as well. This "axis of mixing location" is a
continuum ranging from the physical environment to the human brain. There are
advantages and disadvantages of mixing at different points along the continuum,
and while there is no "best" location, we present sample usage scenarios that
illustrate the expressiveness of this classification approach. Keywords: audio, augmented reality, gustatory, haptics, olfactory, video | |||
| Real-time auditory-visual distance rendering for a virtual reaching task | | BIBAK | Full-Text | 179-182 | |
| Luca Mion; Federico Avanzini; Bruno Mantel; Benoit Bardy; Thomas A. Stoffregen | |||
| This paper reports on a study on the perception and rendering of distance in
multimodal virtual environments. A model for binaural sound synthesis is
discussed, and its integration in a real-time system with motion tracking and
visual rendering is presented. Results from a validation experiment show that
the model effectively simulates relevant auditory cues for distance perception
in dynamic conditions. The model is then used in a subsequent experiment on the
perception of egocentric distance. The design and preliminary result from this
experiment are discussed. Keywords: 3-D sound, egocentric distance, multimodal interaction, virtual auditory
space | |||
| Enhancing VR-based visualization with a 2D vibrotactile array | | BIBAK | Full-Text | 183-186 | |
| Christoph W. Borst; Vijay B. Baiyya | |||
| We discuss methods to enable haptic visualization on vibrotactile arrays.
Our work is motivated by the potential for a tactile array to provide an
additional useful channel for information such as location cues related to
dataset features or remote user behaviors. We present a framework for array
rendering and several specific techniques. Novel aspects of our work include
the example application of a palm-sized tactile array to visualize dataset
features or remote user state in a VR system, a generalized haptic glyph
mechanism for 2D tactile arrays, and the extension of graphical visualization
techniques to haptics (glyphs, fisheye distortion, spatial anti-aliasing, gamma
correction). Keywords: haptic exploration, haptic glyphs, haptics, haptization, tactile map,
vibrotactile array | |||
| Towards a system for reusable 3D interaction techniques | | BIBAK | Full-Text | 187-190 | |
| Andrew Ray; Doug A. Bowman | |||
| Although 3D interaction techniques (3DITs) such as the Go-Go technique for
object manipulation can be conceptually very simple, implementing these
techniques can be a difficult task. Hidden complexities are often revealed at
the low-level implementation stage. VR toolkits, which are commonly used to
implement 3DITs, solve the problem of allowing applications to run in any
hardware environment, but rarely provide support for the technique development
process or technique reuse. Because VR toolkits are not interoperable, 3DIT
developers cannot share their working techniques with others. In this paper, we
describe IFFI, a toolkit that has been designed specifically to support 3DIT
development and to allow for reuse of techniques in different VR toolkits. We
are using IFFI to move towards the goal of implementing a library of reusable
3DITs to help increase their usage, increase consistency, and provide a
foundation for future technique development. Keywords: 3D interaction techniques, VR toolkits, virtual environments, virtual
reality | |||
| An immaterial depth-fused 3D display | | BIBAK | Full-Text | 191-198 | |
| Cha Lee; Stephen DiVerdi; Tobias Höllerer | |||
| We present an immaterial display that uses a generalized form of depth-fused
3D (DFD) rendering to create unencumbered 3D visuals. To accomplish this
result, we demonstrate a DFD display simulator that extends the established
depth-fused 3D principle by using screens in arbitrary configurations and from
arbitrary viewpoints. The performance of the generalized DFD effect is
established with a user study using the simulator. Based on these results, we
developed a prototype display using two immaterial screens to create an
unencumbered 3D visual that users can penetrate, enabling the potential for
direct walk-through and reach-through manipulation of the 3D scene. Keywords: 3D displays, depth-fused 3D, immeterial displays, user study | |||
| Active guideline: spatiotemporal history as a motion technique and navigation aid for virtual environments | | BIBAK | Full-Text | 199-202 | |
| Andreas Simon; Christian Stern | |||
| Users of virtual environments regularly have problems using 3D motion
interfaces and exhibit a disturbing tendency to become disoriented and get lost
quickly in large virtual worlds. We introduce the active guideline, a novel
auxiliary motion technique and navigation aid for virtual environments. Similar
to the ubiquitous Back-button interface for web navigation, the active
guideline implicitly records a history of the user's motion and allows
immediate and convenient travel back (and forth) along a trace of the
previously traveled path. This lets users revisit previous viewpoints, allowing
them to recover from being "lost in space" by enabling easy, continuous
backtracking all the way up to the "home" position. In contrast to bookmarking
of viewpoints, the active guideline is "always-on" and requires no active user
intervention or strategic planning to successfully function as a navigation
aid. This paper discusses the behavior and implementation of the active
guideline and presents results of an initial study exploring the usability of
the technique. Keywords: backtracking, navigation, virtual environments | |||
| Depth-of-field blur effects for first-person navigation in virtual environments | | BIBAK | Full-Text | 203-206 | |
| Sébastien Hillaire; Anatole Lécuyer; Rémi Cozot; Géry Casiez | |||
| This paper studies the use of visual blur effects, i.e., blurring of parts
of the image fed back to the user, for First-Person-Navigations in Virtual
Environments (VE). First, we introduce a model of dynamic visual blur for VE
which is based on two types of blur effect: (1) a Depth-of-Field blur (DoF
blur) which simulates the blurring of objects located in front or back of the
focus point of the eyes, and (2) a peripheral blur which simulates the blurring
of objects located at the periphery of the field of vision. We introduce two
new techniques to improve real-time DoF: (1) a paradigm to compute
automatically the focal distance, and (2) a temporal filtering that simulates
the accommodation phenomenon. Second, we describe the results of a pilot
experiment conducted to study the influence of blur effects on the performance
and preference of video gamers during multiplayer sessions. Interestingly, it
seems that visual blur effects did not degrade performance of gamers and they
were preferred and selected by nearly half of the participants to improve fun
and game-play. Taken together, our results suggest that the use of visual blur
effects could thus be suitable in videogames and in other virtual environments. Keywords: accommodation, depth-of-field blur, first-person-navigation, focalization,
peripheral blur, videogames, visual blur | |||
| Tour generation for exploration of 3D virtual environments | | BIBAK | Full-Text | 207-210 | |
| Niklas Elmqvist; M. Eduard Tudoreanu; Philippas Tsigas | |||
| Navigation in complex and large-scale 3D virtual environments has been shown
to be a difficult task, imposing a high cognitive load on the user. In this
paper, we present a comprehensive method for assisting users in exploring and
understanding such 3D worlds. The method consists of two distinct phases: an
off-line computation step deriving a grand tour using the world geometry and
any semantic target information as input, and an on-line interactive navigation
step providing guided exploration and improved spatial perception for the user.
The former phase is based on a voxelized version of the geometrical dataset
that is used to compute a connectivity graph for use in a TSP-like formulation
of the problem. The latter phase takes the output tour from the off-line step
as input for guiding 3D navigation through the environment. Keywords: navigation aids, navigation assistance, tour generation | |||
| Dynamic landmark placement as a navigation aid in virtual worlds | | BIBAK | Full-Text | 211-214 | |
| Daniel Cliburn; Tess Winlock; Stacy Rilea; Matt Van Donsel | |||
| In this paper, we explore the use of dynamically placed landmarks as
navigation aids when users search a virtual world for target objects. Subjects
were asked to search a virtual world four times for six red spheres. Eighty-six
subjects participated in one of four conditions: no landmarks, statically
placed landmarks, landmarks dynamically placed into the world at the subject's
discretion that disappeared from trial to trial, and landmarks dynamically
placed into the world at the subject's discretion that remained from trial to
trial. An analysis of the experimental results revealed that dynamic landmarks
which disappeared between trials had little impact on a subject's performance.
However, when landmarks remained in the world from one trial to the next,
subjects covered significantly less distance than those in the no landmark
condition, and obtained similar performance to those in the static landmark
condition. Results indicate that dynamically placed landmarks, which remain
between visits, can serve as effective navigation aids in virtual worlds
lacking obvious physical landmarks. Keywords: landmarks, navigation, virtual environment | |||
| AR façade: an augmented reality interactive drama | | BIBA | Full-Text | 215-216 | |
| Steven Dow; Manish Mehta; Blair MacIntyre; Michael Mateas | |||
| Our demonstration presents AR Façade, a physically embodied version of the interactive drama Façade, at the Beall Center in Irvine, CA. In this drama, players are situated in a married couple's apartment, and interact primarily through conversation with the characters and manipulation of objects in the space. Our demonstration will include two versions of the experience -- an immersive augmented reality (AR) version and a desktop computing based implementation, where players communicate using typed keyboard input. Our recent study cross media study revealed empirical differences between the versions [Dow et al. 2007]. Through interviews and observations of players, we found that immersive AR can create an increased sense of presence, confirming generally held expectations. However, we learned that increased presence does not necessarily lead to more engagement. Rather, mediation may be necessary for some players to fully engage with certain immersive media experiences. | |||
| Bimanual task division preferences for volume selection | | BIBA | Full-Text | 217-218 | |
| Amy Ulinski; Zachary Wartell; Larry F. Hodges | |||
| Using both hands for 3D interaction allows users to transfer ingrained interaction skills, significantly increase performance on certain tasks, and reduce training [Bowman et al. 2005]. Guiard's framework of Bimanual manipulation states that different classes of bimanual actions exist [1997]. The Bimanual Asymmetric classification consists of both hands, performing different actions, coordinated to accomplish the same task. The Bimanual Symmetric classification involves each hand performing identical actions, either synchronously or asynchronously. Latulipe et al. compared a symmetric, dual-mouse technique for manipulation of spline curves, to two asymmetric dual-mouse techniques and a standard single-mouse technique. The symmetric technique performed best and was most preferred by participants [2006]. | |||
| Design flexibility in seamless coded pattern for localization | | BIBA | Full-Text | 219-220 | |
| Atsushi Hiyama; Shigeru Saito; Tomohiro Tanikawa; Michitaka Hirose | |||
| Recent development in mobile and ubiquitous computing technology with
broadband wireless network has realizing the location based application for
mobile and wearable computers. According to the wide spreading number of
cellular phone with GPS receiver, it has become easy to provide location based
application in outdoor scene. On the contrary, there are several positioning
technologies for indoor scene, such using wireless sensors or image processing
technology. However, those technologies are still not utilized in daily
environment due to the cost inefficiency and the complexity in system setup.
Considering the problems in previous positioning system, it is necessary to
overcome the following four features to utilize the system in daily scene.
* The system is reasonable and easy to setup.
* The visual feature of the system must not ruin the design of daily
environment. * The system is capable of locating all the users inside the covered environment. * The system is able to extend in wide area such as public space in buildings. | |||
| Development of MR application families: an InTml-based approach | | BIBAK | Full-Text | 221-222 | |
| Pablo Figueroa; José Ferreira; Camilo Castro | |||
| We show an approach for the development of families of MR applications. A
family of MR applications is a set of applications that share some common tasks
but differ mainly in their user interfaces. The development of a family of
applications allows reusability of design and code, adaptability to new
hardware and context, and distributed and heterogeneous deployments. Some
examples are presented and future trends are discussed. Keywords: InTml, MR development, product lines | |||
| Evaluating a haptic-based virtual environment for venepuncture training | | BIBAK | Full-Text | 223-224 | |
| Shamus P. Smith; Susan Todd | |||
| Simulated medical environments allow clinical staff to practice medical
procedures for longer than traditional training methods without endangering
patients. Haptic devices are a key technology in such systems but it is unclear
how their usability can be evaluated. A user study has been performed with a
commercial haptic-based medical virtual environment using data logging, user
questionnaires and a modified think-aloud verbal protocol to support usability
analysis. However, the evaluator does not share the haptic feedback with the
participant and it was found that this can be problematic in shaping questions
during an evaluation session and interpreting the collected data. Keywords: haptic evaluation, medical training, usability, venepuncture, virtual
environments | |||
| Eye tracking and gaze vector calculation within immersive virtual environments | | BIBAK | Full-Text | 225-226 | |
| Adrian Haffegee; Vassil Alexandrov; Russell Barrow | |||
| Human vision is arguably our most powerful sense, with our eyes constantly
darting around in an almost subconscious manner to create a complete picture of
the visual scene around us. These movements can unveil information about the
way the brain is processing the incoming visual data into its mental image of
our surroundings.
In this paper we discuss a method of obtaining and preprocessing the eye movements of a user immersed within a controllable synthetic environment. We investigate how their gaze patterns can be captured and used to identify viewed virtual objects, and how this can be used as a natural method of interacting with the scene. Keywords: eye tracking, gaze interaction, immersive VR | |||
| Chloe@University: an indoor, mobile mixed reality guidance system | | BIBAK | Full-Text | 227-228 | |
| Achille Peternier; Xavier Righetti; Mathieu Hopmann; Daniel Thalmann; Matteo Repettoy; George Papagiannakis; Pierre Davy; Mingyu Lim; Nadia Magnenat-Thalmann; Paolo Barsocchi; Tasos Fragopoulos; Dimitrios Serpanos; Yiannis Gialelis; Anna Kirykou | |||
| With the advent of ubiquitous and pervasive computing environments, one of
promising applications is a guidance system. In this paper, we propose a mobile
mixed reality guide system for indoor environments, Chloe@University. A mobile
computing device (Sony's Ultra Mobile PC) is hidden inside a jacket and a user
selects a destination inside a building through voice commands. A 3D virtual
assistant then appears in the see-through HMD and guides him/her to
destination. Thus, the user simply follows the virtual guide. Chloe@University
also suggests the most suitable virtual character (e.g. human guide, dog, cat,
etc.) based on user preferences and profiles. Depending on user profiles,
different security levels and authorizations for content are previewed.
Concerning indoor location tracking, WiFi, RFID, and sensor-based methods are
integrated in this system to have maximum flexibility. Moreover smart and
transparent wireless connectivity provides the user terminal with fast and
seamless transition among Access Points (APs). Different AR navigation
approaches have been studied: [Olwal 2006], [Elmqvist et al.] and [Newman et
al.] work indoors while [Bell et al. 2002] and [Reitmayr and Drummond 2006] are
employed outdoors. Accurate tracking and registration is still an open issue
and recently it has mostly been tackled by no single method, but mostly through
aggregation of tracking and localization methods, mostly based on handheld AR.
A truly wearable, HMD based mobile AR navigation aid for both indoors and
outdoors with rich 3D content remains an open issue and a very active field of
multi-discipline research. Keywords: localization, mixed reality, real-time systems, sensor networks, virtual
human | |||
| Hybrid traveling in fully-immersive large-scale geographic environments | | BIBAK | Full-Text | 229-230 | |
| Frank Steinicke; Gerd Bruder; Klaus Hinrichs | |||
| In this paper we present hybrid traveling concepts that enable users to
navigate immersively through 3D geospatial environments displayed by arbitrary
applications such as Google Earth or Microsoft Virtual Earth. We propose a
framework which allows to integrate virtual reality (VR) based interaction
devices and concepts into such applications that do not support VR technologies
natively.
In our proposed setup the content displayed by a geospatial application is visualized stereoscopically on a head-mounted display (HMD) for immersive exploration. The user's body is tracked in order to support natural traveling through the VE via a walking metaphor. Since the VE usually exceeds the dimension of the area in which the user can be tracked, we propose different strategies to map the user's movement into the virtual world intuitively. Moreover, commonly available devices and interaction techniques are presented for both-handed interaction to enrich the navigation process. Keywords: hybrid traveling, navigation, virtual reality | |||
| Interactive smart character in a shooting game | | BIBA | Full-Text | 231-232 | |
| Chun-Chieh Chen; Tsai-Yen Li | |||
| Interactivity is a critical issue in designing a good game or similar virtual environments. As the computer hardware is continuously improved, more computing power can be invested in interactivity in addition to graphics rendering. For games with virtual characters, how a character interact with a user is usually specified at design time according to a given scene. Consequently, the characters in a game usually can only display canned motions at designated locations of a scene. After several runs of practice, the user may easily get bored because these actions become predictable. Therefore, it is highly desirable to have a smarter character that can plan its motions according to the inputs from the user as well as other constraints from the environments. | |||
| Mixed reality for enhancing business communications using virtual worlds | | BIBAK | Full-Text | 233-234 | |
| Muthukkumar S. Kadavasal; Krishna K. Dhara; Xiaotao Wu; Venkatesh Krishnaswamy | |||
| Online virtual worlds are attracting businesses that intend to offer new
enterprise class services. Often, these services in virtual worlds are closely
linked with the real enterprise resources. For a successful deployment of these
services, a mixed reality model with communications that extend the virtual
worlds to enterprise resources is required. In this paper, we take a look at
this new class of collaborative applications by using a customer service
application as an example. We discuss various issues in offering such a
service, lay out the requirements, propose an architecture for mixed reality
communications, and present our prototype implementation. We believe that this
example service can introduce a mixed reality based communication paradigm that
is applicable to a wide range of other business or enterprise services. Keywords: collaboration, communication, mixed reality, virtual reality | |||
| Motion picture production facility with liquid cooled 512 processor mobile super computing vehicle and virtual reality environment | | BIBA | Full-Text | 235-236 | |
| Mark J. Prusten | |||
| The motion picture production pipeline has evolved where super computers are needed at the filming location. This allows content from digital cinema cameras recorded on external raid hard drives, shooting 4K-8K content, to have immediate processing capabilities. This Mobile Super Computing Vehicle, MSCV, will provide a mobile nervous center for a 6-8 man production crew. This announcement describes the Linux based liquid cooled 512 processors producing a 30 Teraflops super computer with 5 racks that will be integrated into a tractor trailer vehicle. The electrical, thermal, and mechanical engineering design issues of this undertaking will be analyzed and presented. The thermal issues are resolved by a closed chilled water system running through a unique design carries away up to 95 percent of the heat generated by the system. A complete Linux production pipeline tool set for digital intermediate processing and visual effects will be presented. | |||
| Multi-agent systems applied to virtual environments: a case study | | BIBA | Full-Text | 237-238 | |
| A. Barella; C. Carrascosa; V. Botti; M. Martí | |||
| Computer game development covers many different areas, such as graphics, artificial intelligence (AI) and network communications. Nowadays, players demand more sophisticated and credible computer-controlled opponents, but results are sometimes unsatisfactory. This is due to the need of real-time processing constraints to reach an acceptable feeling of immersion for the user. The development of systems, tools and development environments can play an important role in the progress of this field. The combination of AI techniques and virtual reality (or virtual environments) has given birth to the field of intelligent virtual environments (IVEs). An IVE is a virtual environment simulating a physical (or real) world, inhabited by autonomous intelligent entities [Luck and Aylett 2000]. These entities have to interact in / with the virtual environment as if they were real entities in the real world. There are some other typical problems of an IVE that we have to solve, as explained in [Bierbaum et al. 2001]: independence of the underlying technologies, user interactions (not only displaying images, but using specific devices such as trackers, gloves), synchronization of both data and image (even in case of multiple displays). | |||
| Shakespearean karaoke | | BIBA | Full-Text | 239-240 | |
| Lauren Cairco; Sabarish Babu; Amy Ulinski; Catherine Zanbaka; Larry F. Hodges | |||
| Traditionally, students study plays by reading from a book. However, reading dialogue on paper does not always communicate the various emotions and actions that help people understand the significance of the person-to-person interactions that are represented. | |||
| Stride scheduling for time-critical collision detection | | BIBAK | Full-Text | 241-242 | |
| Daniel S. Coming; Oliver G. Staadt | |||
| We present an event-based scheduling method for time-critical collision
detection that meets time constraints by balancing and prioritizing computation
spent on intersection tests without starvation. Our approach tests each
potentially colliding pair of objects at a different frequency, with unbounded
temporal resolution. We preserve believability by adaptively prioritizing
intersection tests to reduce errors in collision detection, using information
about the objects and scene. By combining kinetic sweep and prune with stride
scheduling we interleave rendering, broad phase collision pruning, narrow phase
intersection testing, and collision response. This approach accrues no
per-frame overhead and allows interruption at any point in collision detection,
including the broad phase. Keywords: Collision Detection, dynamic scenes, many-body collision detection,
time-critical computing | |||
| Usability of multiple degree-of-freedom input devices and virtual reality displays for interactive visual data analysis | | BIBAK | Full-Text | 243-244 | |
| Elke Moritz; Hans Hagen; Thomas Wischgoll; Joerg Meyer | |||
| Interactive virtual reality applications commonly require two key
technologies: multiple degree-of-freedom input devices, and 2D or 3D displays.
The industry has developed a vast variety of devices for a growing consumer
market. Consumer magazines regularly publish test reports for new devices.
These reports are often focused on the gaming community, which is typically the
driving force behind new product development. Although many lessons can be
learned from the gaming industry, the scientific community is generally focused
on other criteria, such as precision, degrees of freedom, and user tracking. It
is expected that some of these criteria, which are currently in the state of
research, will eventually be incorporated into products for a mass market, just
like consumer graphics cards and certain input devices did in the past.
This study is an attempt to provide an overview of existing 2D and 3D input device and display technologies for interactive scientific visualization applications. Different types of input devices and displays were tested in combination with each other. The article explains why certain combinations of input devices and displays work together better than others. Keywords: displays, input devices, interactive rendering, navigation, virtual reality | |||
| View-dependent mesh streaming using multi-chart geometry images | | BIBAK | Full-Text | 245-246 | |
| Bin Sheng; Enhua Wu | |||
| Many mesh streaming algorithms have focused on the transmission order of the
polygon data with respect to the current viewpoint. In contrast to the
conventional progressive streaming where the resolution of a model changes in
the geometry space, we present an new approach which firstly partitions a mesh
into several patches, then converts these patch into multi-chart geometry
images(MCGIM). After all the MCGIM and normal map atlas are obtained by regular
re-sampling, we could construct the regular quadtree-based hierarchical
representation based on MCGIM. Experimental results have shown the
effectiveness of our approach where one server streams the MCGIM texture atlas
to the clients. Keywords: clustering, geometry image, mesh streaming, multiresolution rendering | |||
| Virtual vision: visual sensor networks in virtual reality | | BIBAK | Full-Text | 247-248 | |
| Faisal Z. Qureshi; Demetri Terzopoulos | |||
| The virtual vision paradigm features a unique synergy of computer graphics,
artificial life, and computer vision technologies. Virtual vision prescribes
visually and behaviorally realistic virtual environments as a simulation tool
in support of research on large-scale visual sensor networks. Virtual vision
has facilitated our research into developing multi-camera control and
scheduling algorithms for next-generation smart video surveillance systems. Keywords: reality emulator, smart cameras, virtual vision | |||
| VR-based visual analytics of LIDAR data for cliff erosion assessment | | BIBA | Full-Text | 249-250 | |
| Tung-Ju Hsieh; Michael J. Olsen; Elizabeth Johnstone; Adam P. Young; Neal Driscoll; Scott A. Ashford; Falko Kuester | |||
| The ability to explore, conceptualize and correlate spatial and temporal changes of topographical records, is needed for the development of new analytical models that capture the mechanisms contributing towards sea cliff erosion. This paper presents a VR-centric approach for cliff erosion assessment from light detection and ranging (LIDAR) data, including visualization techniques for the delineation, segmentation, and classification of features, change detection and annotation. Research findings are described in the context of a sea cliff failure observed in Solana Beach in San Diego county. | |||