549 research outputs found
A Tool for the Creation and management of level-of-detail models for 3D applications
Real-time visualization of 3D scenes is a very important feature of many computer graphics
solutions. Current environments require complex scenes which contain an increasing number of objects
composed of thousands or even millions of polygons. Nevertheless, this complexity poses a problem for
achieving interactive rendering. Among the possible solutions, stripification, simplification and level of detail
techniques are very common approaches to reduce the rendering cost. In this paper, we present set of techniques
which have been developed for offering higher performance when rendering 3D models in real-time
applications. Furthermore, we also present a standalone application useful to quickly simplify and generate
multiresolution models for arbitrary geometry and for tree
What May Visualization Processes Optimize?
In this paper, we present an abstract model of visualization and inference
processes and describe an information-theoretic measure for optimizing such
processes. In order to obtain such an abstraction, we first examined six
classes of workflows in data analysis and visualization, and identified four
levels of typical visualization components, namely disseminative,
observational, analytical and model-developmental visualization. We noticed a
common phenomenon at different levels of visualization, that is, the
transformation of data spaces (referred to as alphabets) usually corresponds to
the reduction of maximal entropy along a workflow. Based on this observation,
we establish an information-theoretic measure of cost-benefit ratio that may be
used as a cost function for optimizing a data visualization process. To
demonstrate the validity of this measure, we examined a number of successful
visualization processes in the literature, and showed that the
information-theoretic measure can mathematically explain the advantages of such
processes over possible alternatives.Comment: 10 page
Task-based Adaptation of Graphical Content in Smart Visual Interfaces
To be effective visual representations must be adapted to their respective context of use, especially in so-called Smart Visual Interfaces striving to present specifically those information required for the task at hand. This thesis proposes a generic approach that facilitate the automatic generation of task-specific visual representations from suitable task descriptions. It is discussed how the approach is applied to four principal content types raster images, 2D vector and 3D graphics as well as data visualizations, and how existing display techniques can be integrated into the approach.Effektive visuelle ReprĂ€sentationen mĂŒssen an den jeweiligen Nutzungskontext angepasst sein, insbesondere in sog. Smart Visual Interfaces, welche anstreben, möglichst genau fĂŒr die aktuelle Aufgabe benötigte Informationen anzubieten. Diese Arbeit entwirft einen generischen Ansatz zur automatischen Erzeugung aufgabenspezifischer Darstellungen anhand geeigneter Aufgabenbeschreibungen. Es wird gezeigt, wie dieser Ansatz auf vier grundlegende Inhaltstypen Rasterbilder, 2D-Vektor- und 3D-Grafik sowie Datenvisualisierungen anwendbar ist, und wie existierende Darstellungstechniken integrierbar sind
Distributed Wikis: A Survey
International audienceSUMMARY "Distributed Wiki" is a generic term covering various systems, including "peer-to-peer wiki," "mobile wiki," "offline wiki," "federated wiki" and others. Distributed wikis distribute their pages among the sites of autonomous participants to address various motivations, including high availability of data, new collaboration models and different viewpoint of subjects. Although existing systems share some common basic concepts, it is often difficult to understand the specificity of each one, the underlying complexities or the best context in which to use it. In this paper, we define, classify and characterize distributed wikis. We identify three classes of distributed wiki systems, each using a different collaboration model and distribution scheme for its pages: highly available wikis, decentralized social wikis and federated wikis. We classify existing distributed wikis according to these classes. We detail their underlying complexities and social and technical motivations. We also highlight some directions for research and opportunities for new systems with original social and technical motivations
Scalable exploration of highly detailed and annotated 3D models
With the widespread availability of mobile graphics terminals andWebGL-enabled browsers, 3D
graphics over the Internet is thriving. Thanks to recent advances in 3D acquisition and modeling
systems, high-quality 3D models are becoming increasingly common, and are now potentially
available for ubiquitous exploration.
In current 3D repositories, such as Blend Swap, 3D Café or Archive3D, 3D models available for
download are mostly presented through a few user-selected static images. Online exploration is
limited to simple orbiting and/or low-fidelity explorations of simplified models, since photorealistic
rendering quality of complex synthetic environments is still hardly achievable within the
real-time constraints of interactive applications, especially on on low-powered mobile devices or
script-based Internet browsers.
Moreover, navigating inside 3D environments, especially on the now pervasive touch devices,
is a non-trivial task, and usability is consistently improved by employing assisted navigation
controls. In addition, 3D annotations are often used in order to integrate and enhance the visual
information by providing spatially coherent contextual information, typically at the expense of
introducing visual cluttering.
In this thesis, we focus on efficient representations for interactive exploration and understanding
of highly detailed 3D meshes on common 3D platforms. For this purpose, we present several
approaches exploiting constraints on the data representation for improving the streaming and
rendering performance, and camera movement constraints in order to provide scalable navigation
methods for interactive exploration of complex 3D environments.
Furthermore, we study visualization and interaction techniques to improve the exploration
and understanding of complex 3D models by exploiting guided motion control techniques to aid
the user in discovering contextual information while avoiding cluttering the visualization.
We demonstrate the effectiveness and scalability of our approaches both in large screen museum
installations and in mobile devices, by performing interactive exploration of models ranging
from 9Mtriangles to 940Mtriangles
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