689 research outputs found
An Introduction to 3D User Interface Design
3D user interface design is a critical component of any virtual environment (VE) application. In this paper, we present a broad overview of three-dimensional (3D) interaction and user interfaces. We discuss the effect of common VE hardware devices on user interaction, as well as interaction techniques for generic 3D tasks and the use of traditional two-dimensional interaction styles in 3D environments. We divide most user interaction tasks into three categories: navigation, selection/manipulation, and system control. Throughout the paper, our focus is on presenting not only the available techniques, but also practical guidelines for 3D interaction design and widely held myths. Finally, we briefly discuss two approaches to 3D interaction design, and some example applications with complex 3D interaction requirements. We also present an annotated online bibliography as a reference companion to this article
An initial evaluation of MathPad(2): A tool for creating dynamic mathematical illustrations
MathPad(2) is a pen-based application prototype for creating mathematical sketches. Using a modeless gestural interface, it lets users make dynamic illustrations by associating handwritten mathematics with free-form drawings and provides a set of tools for graphing and evaluating mathematical expressions and solving equations. In this paper, we present the results of an initial evaluation of the MathPad(2) prototype, examining the user interface\u27s intuitiveness and the application\u27s perceived usefulness. Our evaluations are based on both performance and questionnaire results including first attempt gesture performance, interface recall tests, and surveys of user interface satisfaction and perceived usefulness. The results of our evaluation suggest that, although some test subjects had difficulty with our mathematical expression recognizer, they found the interface, in general, intuitive and easy to remember. More importantly, these results suggest the prototype has the potential to assist beginning physics and mathematics students in problem solving and understanding scientific concepts. (c) 2007 Elsevier Ltd. All rights reserved
A ShortStraw-based algorithm for corner finding in sketch-based interfaces
We present IStraw, a corner finding technique based on the ShortStraw algorithm. This new algorithm addresses deficiencies with ShortStraw while maintaining its simplicity and efficiency. We also develop an extension for ink strokes containing curves and arcs. We compare our algorithm against ShortStraw and two other state of the art corner finding approaches, MergeCF and Sezgin\u27s scale space algorithm. Based on an all-or-nothing accuracy metric, IStraw shows significant improvements over these algorithms for ink strokes with and without curves. (C) 2010 Elsevier Ltd. All rights reserved
Effects of Clutter on Egocentric Distance Perception in Virtual Reality
To assess the impact of clutter on egocentric distance perception, we
performed a mixed-design study with 60 participants in four different virtual
environments (VEs) with three levels of clutter. Additionally, we compared the
indoor/outdoor VE characteristics and the HMD's FOV. The participants wore a
backpack computer and a wide FOV head-mounted display (HMD) as they
blind-walked towards three distinct targets at distances of 3m, 4.5m, and 6m.
The HMD's field of view (FOV) was programmatically limited to
165{\deg}110{\deg}, 110{\deg}110{\deg}, or
45{\deg}35{\deg}. The results showed that increased clutter in the
environment led to more precise distance judgment and less underestimation,
independent of the FOV. In comparison to outdoor VEs, indoor VEs showed more
accurate distance judgment. Additionally, participants made more accurate
judgements while looking at the VEs through wider FOVs.Comment: This paper was not published yet in any venue or conference/journal,
ACM conference format was used for the paper, authors were listed in order
from first to last (advisor), 10 pages, 10 figure
The Effects of Object Shape, Fidelity, Color, and Luminance on Depth Perception in Handheld Mobile Augmented Reality
Depth perception of objects can greatly affect a user's experience of an
augmented reality (AR) application. Many AR applications require depth matching
of real and virtual objects and have the possibility to be influenced by depth
cues. Color and luminance are depth cues that have been traditionally studied
in two-dimensional (2D) objects. However, there is little research
investigating how the properties of three-dimensional (3D) virtual objects
interact with color and luminance to affect depth perception, despite the
substantial use of 3D objects in visual applications. In this paper, we present
the results of a paired comparison experiment that investigates the effects of
object shape, fidelity, color, and luminance on depth perception of 3D objects
in handheld mobile AR. The results of our study indicate that bright colors are
perceived as nearer than dark colors for a high-fidelity, simple 3D object,
regardless of hue. Additionally, bright red is perceived as nearer than any
other color. These effects were not observed for a low-fidelity version of the
simple object or for a more-complex 3D object. High-fidelity objects had more
perceptual differences than low-fidelity objects, indicating that fidelity
interacts with color and luminance to affect depth perception. These findings
reveal how the properties of 3D models influence the effects of color and
luminance on depth perception in handheld mobile AR and can help developers
select colors for their applications.Comment: 9 pages, In proceedings of IEEE International Symposium on Mixed and
Augmented Reality (ISMAR) 202
ABSTRACT
Dance games are one of the most popular types of bodycontrolled console games, making them ideal candidates for initiating exertion in players who do not exercise regularly. However, in order to become effective tools for consistent cardiovascular exercise, dance games need to maintain interest over a long time span. One solution that could help with long-term engagement is the addition of more narrative, competitive, and decorative elements. While other gameplay genres utilize this content to keep players involved, motion-controlled dance games are just beginning to incorporate these elements. We built Dance Enhanced, a website designed to offer earnable content to players of the game Dance Central 2. We conducted a four-week study comparing a group of participants playing the game alone with a group that also had access to the website. In this paper, we discuss the methodology for designing and operating this study, as well as our results, which indicated the potential for higher interest in competition, characters and storylines when presented with extra content
Biometric analysis of seeds of genotypes of physic nut (Jatropha curcas L.).
Procurou-se investigar aspectos da morfologia das sementes de diferentes genótipos de pinhão-manso, em razão da pouca literatura existente em relação aos aspectos biométrico das sementes desta espécie. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema simples, sendo 15 nÃveis de genótipos (Diamantina, Tominaga, ParaÃso, Jales, CNPAE ? C2, CNPAE ? 171, G ? 2, AGE, 167, 200, 210, 315, 316, 1501 e 8001), com quatro repetições. As avaliações foram realizadas com parcelas de 100 sementes para cada repetição, mensurando as variáveis: medida de largura em mm (LAS), comprimento em mm (COS) e massa de 100 sementes e g (MCS), de sementes de pinhão-manso. No geral, para os 15 genótipos de pinhão-manso estudados houve a formação de 3 grupos de médias distintas em relação as variáveis biométricas, destacando-se os genótipos Paraiso e Jales e os acessos CNPAE ? C2 e AGE
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