| Michael A. J. Sweeney Award: Graphics 2009 Award Winner "Parallax Photography: Creating 3D Cinematic Effects from Stills" by Ke Zheng, Alex Colburn, Aseem Agarwala, Maneesh Agrawala, Brian Curless, David Salesin, Michael Cohen | | BIB | Full-Text | 01 | |
| Michael A. J. Sweeney Award: HCI 2009 Award Winner "Determining the Benefits of Direct-Touch, Bimanual, and Multifinger Input on a Multitouch Workstation" by Kenrick Kin, Maneesh Agrawala, Tony DeRose | | BIB | Full-Text | 02 | |
| Alain Fournier Award 2008: Samuel Hasinoff, University of Toronto, Canada, CHCCS/SCDHM Alain Fournier Award Recipient 2008 | | BIB | Full-Text | 03 | |
| Achievement Award 2009: Przemyslaw Prusinkiewicz, University of Calgary, Canada, CHCCS/SCDHM Achievement Award Recipient 2009 | | BIB | Full-Text | 04 | |
| Semantic graphics for more effective visual communication | | BIBA | Full-Text | 05 | |
| Vidya Setlur | |||
| Computers are becoming faster, smaller and more interconnected, creating a shift in their primary function from computation to communication. This trend is exemplified by ubiquitous devices such as mobile phones with cameras, personal digital assistants with video, and information displays in automobiles. As communication devices and viewing situations become more plentiful, we need imagery that facilitates visual communication across a wide range of display devices. In addition, producing effective and expressive visual content currently requires considerable artistic skill and can consume days. There is a growing need to develop new techniques and user interfaces that enhance visual communication, while making it fast and easy to generate compelling content. New algorithms in semantic graphics, i.e. combining concepts and methods from visual art, perceptual psychology, information processing, and cognitive science, help facilitate users in creating, understanding and interpreting computer imagery. In this talk, Vidya Setlur will present the usage of semantic graphics for various information visualization goals. | |||
| Graphics hardware & GPU computing: past, present, and future | | BIBA | Full-Text | 06 | |
| David Luebke | |||
| Modern GPUs have emerged as the world's most successful parallel
architecture. GPUs provide a level of massively parallel computation that was
once the preserve of supercomputers like the MasPar and Connection Machine. For
example, NVIDIA's GeForce GTX 280 is a fully programmable, massively
multithreaded chip with up to 240 cores, 30,720 threads and capable of
performing up to a trillion operations per second. The raw computational
horsepower of these chips has expanded their reach well beyond graphics.
Today's GPUs not only render video game frames, they also accelerate physics
computations, video transcoding, image processing, astrophysics, protein
folding, seismic exploration, computational finance, radioastronomy -- the list
goes on and on. Enabled by platforms like the CUDA architecture, which provides
a scalable programming model, researchers across science and engineering are
accelerating applications in their discipline by up to two orders of magnitude.
These success stories, and the tremendous scientific and market opportunities
they open up, imply a new and diverse set of workloads that in turn carry
implications for the evolution of future GPU architectures.
In this talk I will discuss the evolution of GPUs from fixed-function graphics accelerators to general-purpose massively parallel processors. I will briefly motivate GPU computing and explore the transition it represents in massively parallel computing: from the domain of supercomputers to that of commodity "manycore" hardware available to all. I will discuss the goals, implications, and key abstractions of the CUDA architecture. Finally I will close with a discussion of future workloads in games, high-performance computing, and consumer applications, and their implications for future GPU architectures. | |||
| Preserving sharp edges in geometry images | | BIBA | Full-Text | 1-6 | |
| Mathieu Gauthier; Pierre Poulin | |||
| A geometry image offers a simple and compact way of encoding the geometry of a surface and its implicit connectivity in an image-like data structure. It has been shown to be useful in multiple applications because of its suitability for efficient hardware rendering, level of detail, filtering, etc. Most existing algorithms generate geometry images by parameterizing the surface onto a domain, and by performing a regular resampling in this domain. Unfortunately, this regular resampling fails to capture sharp features present on the surface. In this paper, we propose to slightly alter the grid to align sample positions with corners and sharp edges in the geometric model. While doing so, our goal is to maintain the resulting geometry images simple to interpret, while producing higher quality reconstructions. We demonstrate an implementation in the planar domain and show results on a range of common geometrical models. | |||
| Fast visualization of complex 3D models using displacement mapping | | BIBA | Full-Text | 7-14 | |
| The-Kiet Lu; Kok-Lim Low; Jianmin Zheng | |||
| We present a simple method to render complex 3D models at interactive rates using real-time displacement mapping. We use an octree to decompose the 3D model into a set of height fields and display the model by rendering the height fields using per-pixel displacement mapping. By simply rendering the faces of the octree voxels to produce fragments for ray-casting on the GPU, and with straightforward transformation of view rays to the displacement map's local space, our method is able to accurately render the object's silhouettes with very little special handling. The algorithm is especially suitable for fast visualization of high-detail point-based models, and models made up of unprocessed triangle meshes that come straight from range scanning. This is because our method requires much less preprocessing time compared to the traditional triangle-based rendering approach, which usually needs a large amount of computation to preprocess the input model into one that can be rendered more efficiently. Unlike the point-based rendering approach, the rendering efficiency of our method is not limited by the number of input points. Our method can achieve interactive rendering of models with more than 300 millions points on standard graphics hardware. | |||
| Fast low-memory streaming MLS reconstruction of point-sampled surfaces | | BIBA | Full-Text | 15-22 | |
| Gianmauro Cuccuru; Enrico Gobbetti; Fabio Marton; Renato Pajarola; Ruggero Pintus | |||
| We present a simple and efficient method for reconstructing triangulated surfaces from massive oriented point sample datasets. The method combines streaming and parallelization, moving least-squares (MLS) projection, adaptive space subdivision, and regularized isosurface extraction. Besides presenting the overall design and evaluation of the system, our contributions include methods for keeping in-core data structures complexity purely locally output-sensitive and for exploiting both the explicit and implicit data produced by a MLS projector to produce tightly fitting regularized triangulations using a primal isosurface extractor. Our results show that the system is fast, scalable, and accurate. We are able to process models with several hundred million points in about an hour and outperform current fast streaming reconstructors in terms of geometric accuracy. | |||
| Interactive part selection for mesh and point models using hierarchical graph-cut partitioning | | BIBAK | Full-Text | 23-30 | |
| Steven Brown; Bryan Morse; William Barrett | |||
| This paper presents a method for interactive part selection for mesh and
point set surface models that combines scribble-based selection methods with
hierarchically accelerated graph-cut segmentation. Using graph-cut segmentation
to determine optimal intuitive part boundaries enables easy part selection on
complex geometries and allows for a simple, scribble-based interface that
focuses on selecting within visible parts instead of precisely defining part
boundaries that may be in difficult or occluded regions. Hierarchical
acceleration is used to maintain interactive speed on large models and to
provide connectivity when extending the technique to point set models. Keywords: graph cut, interactive modeling tools, mesh, model partitioning, point set,
scribble interface | |||
| Computing surface offsets and bisectors using a sampled constraint solver | | BIBA | Full-Text | 31-37 | |
| David E. Johnson; Elaine Cohen | |||
| This paper describes SCSolver, a geometric constraint solver based on adaptive sampling of an underlying constraint space. The solver is demonstrated on the computation of the offset to a surface as well as the computation of the bisector between two surfaces. The adaptive constraint sampling generates a solution manifold through a generalized dual-contouring approach appropriate for higher-dimensional problems. Experimental results show that the SCSolver approach can compute solutions for complex input geometry at interactive rates for each example application. | |||
| Depth of field postprocessing for layered scenes using constant-time rectangle spreading | | BIBA | Full-Text | 39-46 | |
| Todd J. Kosloff; Michael W. Tao; Brian A. Barsky | |||
| Control over what is in focus and what is not in focus in an image is an important artistic tool. The range of depth in a 3D scene that is imaged in sufficient focus through an optics system, such as a camera lens, is called depth of field. Without depth of field, the entire scene appears completely in sharp focus, leading to an unnatural, overly crisp appearance. Current techniques for rendering depth of field in computer graphics are either slow or suffer from artifacts, or restrict the choice of point spread function (PSF). In this paper, we present a new image filter based on rectangle spreading which is constant time per pixel. When used in a layered depth of field framework, our filter eliminates the intensity leakage and depth discontinuity artifacts that occur in previous methods. We also present several extensions to our rectangle spreading method to allow flexibility in the appearance of the blur through control over the PSF. | |||
| 3D-aware image editing for out of bounds photography | | BIBA | Full-Text | 47-54 | |
| Amit Shesh; Antonio Criminisi; Carsten Rother; Gavin Smyth | |||
| In this paper, we propose algorithms to manipulate 2D images in a way that
is consistent with the 3D geometry of the scene that they capture. We present
these algorithms in the context of creating "Out of Bounds" (OOB) images --
compelling, depth-rich images generated from single, conventional 2D
photographs (fig. 1). Starting from a single image our tool enables rapid OOB
prototyping; i.e. the ability to quickly create and experiment with many
different variants of the OOB effect before deciding which one best expresses
the users' artistic intentions. We achieve this with a flexible work-flow
driven by an intuitive user interface.
The rich 3D perception of the final composition is achieved by exploiting two strong cues -- occlusions and shadows. A realistic-looking 3D frame is interactively inserted in the scene between segmented foreground objects and the background to generate novel occlusions and enhance the scene's perception of depth. This perception is further enhanced by adding new, realistic cast shadows. The key contributions of this paper are: (i) new algorithms for inserting simple 3D objects like frames in 2D images requiring minimal camera calibration, and (ii) new techniques for the realistic synthesis of cast shadows, even for complex 3D objects. These algorithms, although presented for OOB photography, may be directly used in general image composition tasks. With our tool, untrained users can turn ordinary photos into compelling OOB images in seconds. In contrast with existing workflows, at any time the artist can modify any aspect of the composition while avoiding time-consuming pixel painting operations. Such a tool has important commercial applications, and is much more suitable for OOB prototyping than existing image editors. | |||
| One-click white balance using human skin reflectance | | BIBAK | Full-Text | 55-62 | |
| Jeremy Long; Amy A. Gooch | |||
| Existing methods for white balancing photographs tend to rely on skilled
interaction from the user, which is prohibitive for most amateur photographers.
We propose a minimal interaction system for white balancing photographs that
contain humans. Many of the pictures taken by amateur photographers fall into
this category. Our system matches a user-selected patch of skin in a photograph
to an entry in a skin reflectance function database. The estimate of the
illuminant that emerges from the skin matching can be used to white balance the
photograph, allowing users to compensate for biased illumination in an image
with a single click. We compare the quality of our results to output from three
other low-interaction methods, including commercial approaches such as Google
Picasa's one-click relighting [19], a whitepoint-based algorithm [16], and
Ebner's localized gray-world algorithm [7]. The comparisons indicate that our
approach offers several advantages for amateur photographers. Keywords: color constancy, computational photography, white balance | |||
| Rendering lunar eclipses | | BIBA | Full-Text | 63-69 | |
| Theodore C. Yapo; Barbara Cutler | |||
| Johannes Kepler first attributed the visibility of lunar eclipses to refraction in the Earth's atmosphere in his Astronomiae Pars Optica in 1604. We describe a method for rendering images of lunar eclipses including color contributions due to refraction, dispersion, and scattering in the Earth's atmosphere. We present an efficient model of refraction and scattering in the atmosphere, including contributions of suspended volcanic dusts which contribute to the observed variation in eclipse brightness and color. We propose a method for simulating camera exposure to allow direct comparison between rendered images and digital photographs. Images rendered with our technique are compared to photographs of the total lunar eclipse of February 21, 2008. | |||
| An analytical approach to single scattering for anisotropic media and light distributions | | BIBA | Full-Text | 71-77 | |
| Vincent Pegoraro; Mathias Schott; Steven G. Parker | |||
| Despite their numerous applications, efficiently rendering participating media remains a challenging task due to the intricacy of the radiative transport equation. While numerical techniques remain the method of choice for addressing complex problems, a closed-form solution to the air-light integral in optically thin isotropic media was recently derived. In this paper, we extend this work and present a novel analytical approach to single scattering from point light sources in homogeneous media. We propose a combined formulation of the air-light integral which allows both anisotropic phase functions and light distributions to be adequately handled. The technique relies neither on precomputation nor on storage, and we provide a robust and efficient implementation allowing for an explicit control on the accuracy of the results. Finally, the performance characteristics of the method on graphics hardware are evaluated and demonstrate its suitability to real-time applications. | |||
| Rendering the effect of labradoescence | | BIBA | Full-Text | 79-85 | |
| Andrea Weidlich; Alexander Wilkie | |||
| Labradorescence is a complex optical phenomenon that can be found in certain
minerals, such as Labradorite or Spectrolite. Because of their unique colour
properties, these minerals are often used as gemstones and decorative objects.
Since the phenomenon is strongly orientation dependent, such minerals need a
special cut to make the most of their unique type of colourful sheen, which
makes it desirable to be able to predict the final appearance of a given stone
prior to the cutting process. Also, the peculiar properties of the effect make
a believable reproduction with an ad-hoc shader difficult even for normal,
non-predictive rendering purposes.
We provide a reflectance model for labradorescence that is directly derived from the physical characteristics of such materials. Due to its inherent accuracy, it can be used for predictive rendering purposes, but also for generic rendering applications. | |||
| Structural differences between two graphs through hierarchies | | BIBA | Full-Text | 87-94 | |
| Daniel Archambault | |||
| This paper presents a technique for visualizing the differences between two graphs. The technique assumes that a unique labeling of the nodes for each graph is available, where if a pair of labels match, they correspond to the same node in both graphs. Such labeling often exists in many application areas: IP addresses in computer networks, namespaces, class names, and function names in software engineering, to name a few. As many areas of the graph may be the same in both graphs, we visualize large areas of difference through a graph hierarchy. We introduce a path-preserving coarsening technique for degree one nodes of the same classification. We also introduce a path-preserving coarsening technique based on betweenness centrality that is able to illustrate major differences between two graphs. | |||
| Sketch-based path design | | BIBA | Full-Text | 95-102 | |
| James McCrae; Karan Singh | |||
| We present Drive, a system for the conceptual layout of 3D path networks. Our sketch-based interface allows users to efficiently author path layouts with minimal instruction. Our system incorporates some new and noteworthy components. We present the break-out lens, a novel widget for interactive graphics, inspired by break-out views used in engineering visualization. We also make three contributions specific to path curve design: First, we extend our previous work to fit aesthetic paths to sketch strokes with constraints, using piecewise clothoid curves. Second, we determine the height of paths above the terrain using a constraint optimization formulation of the occlusion relationships between sketched strokes. Finally, we illustrate examples of terrain sensitive path construction in the context of road design: automatically removing foliage, building bridges and tunnels across topographic features and constructing road signs appropriate to the sketched paths. | |||
| Rig retargeting for 3D animation | | BIBA | Full-Text | 103-110 | |
| Martin Poirier; Eric Paquette | |||
| This paper presents a new approach to facilitate reuse and remixing in character animation. It demonstrates a method for automatically adapting existing skeletons to different characters. While the method can be applied to simple skeletons, it also proposes a new approach that is applicable to high quality animation as it is able to deal with complex skeletons that include control bones (those that drive deforming bones). Given a character mesh and a skeleton, the method adapts the skeleton to the character by matching topology graphs between the two. It proposes specific multiresolution and symmetry approaches as well as a simple yet effective shape descriptor. Together, these provide a robust retargeting that can also be tuned between the original skeleton shape and the mesh shape with intuitive weights. Furthermore, the method can be used for partial retargeting to directly attach skeleton parts to specific limbs. Finally, it is efficient as our prototype implementation generally takes less than 30 seconds to adapt a skeleton to a character. | |||
| Parallax photography: creating 3D cinematic effects from stills | | BIBAK | Full-Text | 111-118 | |
| Ke Colin Zheng; Alex Colburn; Aseem Agarwala; Maneesh Agrawala; David Salesin; Brian Curless; Michael F. Cohen | |||
| We present an approach to convert a small portion of a light field with
extracted depth information into a cinematic effect with simulated, smooth
camera motion that exhibits a sense of 3D parallax. We develop a taxonomy of
the cinematic conventions of these effects, distilled from observations of
documentary film footage and organized by the number of subjects of interest in
the scene. We present an automatic, content-aware approach to apply these
cinematic conventions to an input light field. A face detector identifies
subjects of interest. We then optimize for a camera path that conforms to a
cinematic convention, maximizes apparent parallax, and avoids missing
information in the input. We describe a GPU-accelerated, temporally coherent
rendering algorithm that allows users to create more complex camera moves
interactively, while experimenting with effects such as focal length, depth of
field, and selective, depth-based desaturation or brightening. We evaluate and
demonstrate our approach on a wide variety of scenes and present a user study
that compares our 3D cinematic effects to their 2D counterparts. Keywords: image-based rendering, photo and image editing | |||
| Determining the benefits of direct-touch, bimanual, and multifinger input on a multitouch workstation | | BIBAK | Full-Text | 119-124 | |
| Kenrick Kin; Maneesh Agrawala; Tony DeRose | |||
| Multitouch workstations support direct-touch, bimanual, and multifinger
interaction. Previous studies have separately examined the benefits of these
three interaction attributes over mouse-based interactions. In contrast, we
present an empirical user study that considers these three interaction
attributes together for a single task, such that we can quantify and compare
the performances of each attribute. In our experiment users select multiple
targets using either a mouse-based workstation equipped with one mouse, or a
multitouch workstation using either one finger, two fingers (one from each
hand), or multiple fingers. We find that the fastest multitouch condition is
about twice as fast as the mouse-based workstation, independent of the number
of targets. Direct-touch with one finger accounts for an average of 83% of the
reduction in selection time. Bimanual interaction, using at least two fingers,
one on each hand, accounts for the remaining reduction in selection time.
Further, we find that for novice multitouch users there is no significant
difference in selection time between using one finger on each hand and using
any number of fingers for this task. Based on these observations we conclude
with several design guidelines for developing multitouch user interfaces. Keywords: bimanual input, direct-touch input, mouse, multifinger input, multitarget
selection, multitouch | |||
| Heart rate control of exercise video games | | BIBAK | Full-Text | 125-132 | |
| Tadeusz Stach; T. C. Nicholas Graham; Jeffrey Yim; Ryan E. Rhodes | |||
| Exercise video games combine entertainment and physical movement in an
effort to encourage people to be more physically active. Multiplayer exercise
games take advantage of the motivating aspects of group activity by allowing
people to exercise together. However, people of significantly different fitness
levels can have a hard time playing together, as large differences in
performance can be demotivating. To address this problem, we present heart rate
scaling, a mechanism where players' in-game performance is based on their
effort relative to their fitness level. Specifically, heart rate monitoring is
used to scale performance relative to how closely a person adheres to his/her
target heart rate zone. We demonstrate that heart rate scaling reduces the
performance gap between people of different fitness levels, and that the
scaling mechanism does not significantly affect engagement during gameplay. Keywords: active games, exertion interfaces, heart rate input, kinetic interfaces,
multiplayer exercise video games | |||
| Exploring melodic variance in rhythmic haptic stimulus design | | BIBAK | Full-Text | 133-140 | |
| Bradley A. Swerdfeger; Jennifer Fernquist; Thomas W. Hazelton; Karon E. MacLean | |||
| Haptic icons are brief, meaningful tactile or force stimuli designed to
support the communication of information through the often-underutilized haptic
modality. Challenges to producing large, reusable sets of haptic icons include
technological constraints and the need for broadly-applicable and validated
design heuristics to guide the process. The largest set of haptic stimuli to
date was produced through systematic use of heuristics for monotone rhythms. We
hypothesized that further extending signal expressivity would continue to
enhance icon learnability. Here, we introduce melody into the design of
rhythmic stimuli as a means of increasing expressiveness while retaining the
principle of systematic design, as guided by music theory. Haptic melodies are
evaluated for their perceptual distinctiveness; experimental results from
grouping tasks indicate that rhythm dominates user categorization of melodies,
with frequency and amplitude potentially left available as new dimensions for
the designer to control within-group variation. Keywords: haptic UIs, multi-modal interfaces, user studies | |||
| Improving simulated borescope inspection with constrained camera motion and haptic feedback | | BIBA | Full-Text | 141-148 | |
| Deepak Vembar; Andrew T. Duchowski; Anand K. Gramopadhye; Carl Washburn | |||
| Results are presented from empirical evaluation of a borescope simulator developed for non-destructive inspection training. Two experiments were conducted, manipulating camera rotation constraint and provision of haptic feedback. Performance of experienced borescope inspectors is measured in terms of speed and accuracy, with accuracy clearly shown to improve by placing constraints on the simulator's camera tip rotation and by providing haptic response. This is important as damage avoidance of a real borescope is a critical criterion of borescope inspection training. These are likely to be the first such experiments to have been conducted with aircraft engine inspectors evaluating the potential of haptics in borescope simulation. | |||
| Who dotted that 'i'?: context free user differentiation through pressure and tilt pen data | | BIBA | Full-Text | 149-156 | |
| Brian David Eoff; Tracy Hammond | |||
| With the proliferation of tablet PCs and multi-touch computers, collaborative input on a single sketched surface is becoming more and more prevalent. The ability to identify which user draws a specific stroke on a shared surface is widely useful in a) security/forensics research, by effectively identifying a forgery, b) sketch recognition, by providing the ability to employ user-dependent recognition algorithms on a multi-user system, and c) multi-user collaborative systems, by effectively discriminating whose stroke is whose in a complicated diagram. To ensure an adaptive user interface, we cannot expect nor require that users will self-identify nor restrict themselves to a single pen. Instead, we prefer a system that can automatically determine a stroke's owner, even when strokes by different users are drawn with the same pen, in close proximity, and near in timing. We present the results of an experiment that shows that the creator of an individual pen strokes can be determined with high accuracy, without supra-stroke context (such as timing, pen-ID, nor location), and based solely on the physical mechanics of how these strokes are drawn (specifically, pen tilt, pressure, and speed). Results from free-form drawing data, including text and doodles, but not signature data, show that our methods differentiate a single stroke (such as that of a dot of an 'i') between two users at an accuracy of 97.5% and between ten users at an accuracy of 83.5%. | |||
| Recognizing interspersed sketches quickly | | BIBA | Full-Text | 157-166 | |
| Tracy A. Hammond; Randall Davis | |||
| Sketch recognition is the automated recognition of hand-drawn diagrams. When allowing users to sketch as they would naturally, users may draw shapes in an interspersed manner, starting a second shape before finishing the first. In order to provide freedom to draw interspersed shapes, an exponential combination of subshapes must be considered. Because of this, most sketch recognition systems either choose not to handle interspersing, or handle only a limited pre-defined amount of interspersing. Our goal is to eliminate such interspersing drawing constraints from the sketcher. This paper presents a high-level recognition algorithm that, while still exponential, allows for complete interspersing freedom, running in near real-time through early effective sub-tree pruning. At the core of the algorithm is an indexing technique that takes advantage of geometric sketch recognition techniques to index each shape for efficient access and fast pruning during recognition. We have stress-tested our algorithm to show that the system recognizes shapes in less than a second even with over a hundred candidate subshapes on screen. | |||
| Handle Flags: efficient and flexible selections for inking applications | | BIBAK | Full-Text | 167-174 | |
| Tovi Grossman; Patrick Baudisch; Ken Hinckley | |||
| There are a number of challenges associated with content selection in
pen-based interfaces. Supplementary buttons to enter a selection mode may not
be available, and selections may require a careful and error prone lasso
stroke. In this paper we describe the design and evaluation of Handle Flags, a
new localized technique used to select and perform commands on ink strokes in
pen-operated interfaces. When the user positions the pen near an ink stroke,
Handle Flags are displayed for the potential selections that the ink stroke
could belong to (such as proximal strokes comprising a word or drawing).
Tapping the handle allows the user to access the corresponding selection,
without requiring a complex lasso stroke. Our studies show that Handle Flags
offer significant benefits in comparison to traditional techniques, and are a
promising technique for pen-based applications. Keywords: Handle Flag, ink, lasso, pen input, selection | |||
| Separability of spatial manipulations in multi-touch interfaces | | BIBAK | Full-Text | 175-182 | |
| Miguel A. Nacenta; Patrick Baudisch; Hrvoje Benko; Andy Wilson | |||
| Multi-touch interfaces allow users to translate, rotate, and scale digital
objects in a single interaction. However, this freedom represents a problem
when users intend to perform only a subset of manipulations. A user trying to
scale an object in a print layout program, for example, might find that the
object was also slightly translated and rotated, interfering with what was
already carefully laid out earlier.
We implemented and tested interaction techniques that allow users to select a subset of manipulations. Magnitude Filtering eliminates transformations (e.g., rotation) that are small in magnitude. Gesture Matching attempts to classify the user's input into a subset of manipulation gestures. Handles adopts a conventional single-touch handles approach for touch input. Our empirical study showed that these techniques significantly reduce errors in layout, while the Handles technique was slowest. A variation of the Gesture Matching technique presented the best combination of speed and control, and was favored by participants. Keywords: multi-touch interaction, separability, tabletops | |||
| Presenting identity in a virtual world through avatar appearances | | BIBAK | Full-Text | 183-190 | |
| Carman Neustaedter; Elena Fedorovskaya | |||
| One of the first tasks that people must do when entering a virtual world
(VW) is create a virtual representation for themselves. In many VWs, this means
creating an avatar that represents some desired appearance, whether a
reflection of one's real life self, or a different identity. We investigate the
variety of ways in which people create and evolve avatar appearances in the VW
of Second Life® (SL) through contextual interviews. Our findings reveal
that users balance pressures from the societal norms of SL with the need to
create an appearance that matches a desired virtual identity. These identity
needs differ based on four types of users -- Realistics, Ideals, Fantasies, and
Roleplayers -- where each presents unique challenges for avatar design. Current
research tends to focus on the needs of only one of these user types. Keywords: appearance, avatar, identity, virtual worlds | |||
| Understanding and improving flow in digital photo ecosystems | | BIBAK | Full-Text | 191-198 | |
| Carman Neustaedter; Elena Fedorovskaya | |||
| Families use a range of devices and locations to capture, manage, and share
digital photos as part of their digital photo ecosystem. The act of moving
media between devices and locations is not always simple though and can easily
become time consuming. We conducted interviews and design sessions in order to
better understand the movement of media in digital photo ecosystems and
investigate ways to improve it. Our results show that users must manage
multiple entry points into their ecosystem, avoid segmentation in their
collections, and explicitly select and move photos between desired devices and
locations. Through design sessions, we present and evaluate design ideas to
overcome these challenges that utilize multipurpose devices, always-accessible
photo collections, and sharing from any device. These show how automation can
be combined with recommendation and user interaction to improve flow within
digital photo ecosystems. Keywords: capture, digital photos, display, ecosystems, sharing | |||
| A multi-level pressure-sensing two-handed interface with finger-mounted pressure sensors | | BIBA | Full-Text | 199-202 | |
| Masaki Omata; Manabu Kajino; Atsumi Imamiya | |||
| This paper proposes separating a pressure sensor off from an input device and attaching it directly onto a user's finger to allow the user to input pressure values into a computer with various devices and various places. This proposal solves the problem of requiring an individual pressure sensor for each pressure-sensing input device because we've attached a sensor to not a device which is pushed but rather a finger which pushes it. As an instance, we developed a multi-level pressure-sensing two-handed user interface by measuring the positions and pressure values of both the user's hands. The user can manipulate a screen object with the dominant hand and assist it by adjusting the position and the intensity of pressure of the dominant hand and non-dominant hand. We developed some GUI functions: cursor aura for expanding the sphere of its influence, non-dominant hand cursor for picking up a hidden window, and pressure-sensing keyboard input to add arousal to text. The advantages of our system are; (1) a user can use a favorite device and add pressure value, and (2) a user can enter a multi-level value by pressing heavily or lightly without looking at user's hands. | |||
| Potential field approach for haptic selection | | BIBAK | Full-Text | 203-206 | |
| Jean Simard; Mehdi Ammi; Flavien Picon; Patrick Bourdot | |||
| In a number of 3d applications and especially in Computer Aided Design
(CAD), the accuracy of the selection process is important for subsequent
operations. In this paper, we propose a mathematical model to manage haptic
selection of topological entities (vertices, edges, faces...) used in CAD. We
have developed an analytical expression with a generic and unified
representation based on potential fields. The result is a simplified model for
software implementation. Moreover, these functions introduce a smooth, accurate
and stable force profile. Keywords: CAD, haptic, potential field, selection, virtual reality | |||
| Haptic conviction widgets | | BIBAK | Full-Text | 207-210 | |
| Gerry Chu; Tomer Moscovich; Ravin Balakrishnan | |||
| We introduce a haptic mousewheel as a platform for design exploration of
haptic conviction widgets. Conviction is how strongly one wants to do
something, or how strongly one desires a parameter to be as it is. Using the
haptic mousewheel, the widgets allow users to communicate conviction using
force, where greater conviction requires greater force. These widgets include
buttons that take varying amounts of force to click, a trash can that requires
overcoming force to delete files, an instant message client that requires more
force to communicate a stronger emotion, and widgets that allow parameters to
be locked using force. Keywords: affect, conviction, haptic | |||
| MR Tent: a place for co-constructing mixed realities in urban planning | | BIBAK | Full-Text | 211-214 | |
| Maquil Valérie; Sareika Markus; Schmalstieg Dieter; Wagner Ina | |||
| This paper describes how mixed reality (MR) technology is applied in the
urban renewal process to help mixed groups of stakeholders collaboratively
construct, explore and discuss their vision of a particular urban project on
site. It introduces the MR Tent, a physical enclosing for a collection of MR
prototyping tools. We report findings from the most recent participatory
workshop with users on an urban planning site concerning the interaction space,
views, tangibility and representational formats. Keywords: architecture, mixed reality, participatory design, tangible user interfaces,
urban planning | |||
| QuickSelect: history-based selection expansion | | BIBAK | Full-Text | 215-221 | |
| Sara L. Su; Sylvain Paris; Frédo Durand | |||
| When editing a graphical document, it is common to apply a change to
multiple items at once, and a variety of tools exist for selecting sets of
items. However, directly selecting large sets can sometimes be cumbersome and
repetitive. We propose a method for helping users reuse complex selections by
expanding the set of currently selected items. We analyze a document's
operation history to determine which items have been frequently edited
together. When the user requests it, items that have been previously edited
with the current selection can be added to it. The new selection can then be
manipulated like any other selection. This approach does not require a semantic
model of the document or relations between items. Rather, each expansion is
based on what the user has done so far to create the document. We demonstrate
this approach in the context of vector graphics editing. Results from a pilot
study were encouraging. Reusing selections with pre-existing histories, users
were more efficient at editing tasks with our QuickSelect tool. Subjective
preferences from a usability study in a free drawing context indicate that
selection expansion is easy for users to learn and to apply. Keywords: 2D drawing, grouping, operation history, selection | |||
| ISO 9241-9 evaluation of video game controllers | | BIBAK | Full-Text | 223-230 | |
| Daniel Natapov; Steven J. Castellucci; I. Scott MacKenzie | |||
| Fifteen participants completed a study comparing video game controllers for
point-select tasks. We used a Fitts' law task, as per ISO 9241-9, using the
Nintendo Wii Remote for infrared pointing, the Nintendo Classic Controller for
analogue stick pointing, and a standard mouse as a baseline condition. The
mouse had the highest throughput at 3.78 bps. Both game controllers performed
poorly by comparison. The Wii Remote throughput was 31.5% lower, at 2.59 bps,
and the Classic Controller 60.8% lower at 1.48 bps. Comparing just the video
game controllers, the Wii Remote presents a 75% increase in throughput over the
Classic Controller. Error rates for the mouse, Classic Controller, and the Wii
Remote were 3.53%, 6.58%, and 10.2%, respectively. Fourteen of 15 participants
expressed a preference for the Wii Remote over the Classic Controller for
pointing tasks in a home entertainment environment. Keywords: Wiimote, Fitts' task, analogue stick, infrared, performance comparison,
target acquisition, video game controller | |||
| Mid-air text input techniques for very large wall displays | | BIBAK | Full-Text | 231-238 | |
| Garth Shoemaker; Leah Findlater; Jessica Q. Dawson; Kellogg S. Booth | |||
| Traditional text input modalities, namely keyboards, are often not
appropriate for use when standing in front of very large wall displays. Direct
interaction techniques, such as handwriting, are better, but are not well
suited to situations where users are not in close physical proximity to the
display. We discuss the potential of mid-air interaction techniques for text
input on very large wall displays, and introduce two factors,
distance-dependence and visibility-dependence, which are useful for segmenting
the design space of mid-air techniques. We then describe three techniques that
were designed with the goal of exploring the design space, and present a
comparative evaluation of those techniques. Questions raised by the evaluation
were investigated further in a second evaluation focusing on
distance-dependence. The two factors of distance- and visibility-dependence can
guide the design of future text input techniques, and our results suggest that
distance-independent techniques may be best for use with very large wall
displays. Keywords: interaction techniques, text input, wall displays | |||