DSpace Kolekce:http://hdl.handle.net/11025/66292024-03-28T17:40:19Z2024-03-28T17:40:19ZDynamic Annotation of Interactive Environments using Object-Integrated BillboardsMaass, StefanDöllner, Jürgenhttp://hdl.handle.net/11025/68622020-07-02T08:29:52Z2006-01-01T00:00:00ZNázev: Dynamic Annotation of Interactive Environments using Object-Integrated Billboards
Autoři: Maass, Stefan; Döllner, Jürgen
Editoři: Jorge, Joaquim; Skala, Václav
Abstrakt: We present a technique for the dynamic annotation of three-dimensional objects in interactive virtual environments.
Annotations represent textual or symbolic descriptions providing explanatory or thematic information
associated with scene objects. In contrast to techniques that treat annotations as two-dimensional view-plane
elements, our technique models annotations as separate three-dimensional scene elements that are automatically
positioned and oriented according to the shape of the referenced object. The shape of such an object is generalized
by an annotation hull and skeleton used to determine an adequate position and orientation of the annotation
with respect to the viewing direction. During camera movements, annotations float along the surface of the annotation
hull. Additional constraints for the generalizations provide further control about geometric and dynamical
properties. In a case study, we show how this technique can be applied for annotating buildings and other
components of virtual 3D city models.2006-01-01T00:00:00ZMaass, StefanDöllner, JürgenA Novel Technique for Opus Vermiculatum Mosaic RenderingBattiato, S.Di Blasi, G.Farinella, G. M.Gallo, G.http://hdl.handle.net/11025/68612020-07-02T08:29:52Z2006-01-01T00:00:00ZNázev: A Novel Technique for Opus Vermiculatum Mosaic Rendering
Autoři: Battiato, S.; Di Blasi, G.; Farinella, G. M.; Gallo, G.
Editoři: Jorge, Joaquim; Skala, Václav
Abstrakt: In this paper we present a method to generate a digital mosaic starting from a raster input image. Mosaics
generation of artistic quality is challenging. The basic elements, the tiles, typically small polygons, must be packed
tightly, emphasizing orientations chosen by the artist. An adhoc
boundaries detection have to be performed
according to the directional guidelines. Different mosaic styles can be automatically rendered, depending on
artistic techniques considered (“opus musivum”, “opus vermiculatum”, etc.).
The proposed method is able to reproduce the colors of the original image emphasizing relevant boundaries by
placing tiles along their direction. The boundaries detection is based on the statistical region merging algorithm. In
particular the technique is able to reproduce the “opus vermiculatum” mosaic style.
Several examples reported in the paper show how the right mixture of mathematical tools together with century
proved ideas from mosaicists may lead to impressive results.2006-01-01T00:00:00ZBattiato, S.Di Blasi, G.Farinella, G. M.Gallo, G.Dealing with Optical Material Properties in Computer Graphics and VisionKlein, Reinhardhttp://hdl.handle.net/11025/68602020-07-02T08:29:52Z2006-01-01T00:00:00ZNázev: Dealing with Optical Material Properties in Computer Graphics and Vision
Autoři: Klein, Reinhard
Editoři: Jorge, Joaquim; Skala, Václav
Abstrakt: In the area of shape recognition tremendous advances were made during recent years.
But in contrast to this success the recognition of materials is still a big challenge although
for humans the identification of differnt materials is normally an easy task. In Computer
Graphics we face a similar situation. While the modeling of shapes is already a highlydeveloped
area the realistic modeling of the interaction of light with objects, i.e. the
modeling of optical material properties, is still a great challenge. In addition, while there
are straight forward techniques to measure differences between two shapes we need
more sophisticated methods to judge the difference of reflection properties. From the
rendering point of view these methods might even contain perceptual components.
One way to obtain realistic reflection properties are measurements of real world surfaces.
For arbitrary (non-fluorescent, non-phosphorescent) materials, the reflection properties
can be described by the 8D reflectance field of the surface, also called BSSRDF. Since
densely sampling an 8D function is currently not practical various acquisition methods
have been proposed which reduce the number of dimensions by restricting the
acquisition to specific classes of materials. A subsequent data modeling step is performed
to interpolate missing values and compress the measured data further.
In the first part of this talk we will give a brief overview over the different measurement
techniques and algorithms used to capture reflection properties of different classes of
objects targeted to the specific needs of computer graphics applications. Special
emphasis will be given to surfaces with complex meso-structure.
In the second part we will discuss some techniques we used for the validation of the
measurements and the resulting renderings. Strength and limitations of different
aquisition and validation techniques will be discussed and future challenges will be
identified.2006-01-01T00:00:00ZKlein, ReinhardReal Time Simulation of Elastic Latex Hand PuppetsWüthrich, Charles A.Augusto, JingBanisch, SvenWetzstein, GordonMusialski, PrzemyslawToll, ChrystophHofmann, Tobiashttp://hdl.handle.net/11025/68592020-07-02T08:29:51Z2006-01-01T00:00:00ZNázev: Real Time Simulation of Elastic Latex Hand Puppets
Autoři: Wüthrich, Charles A.; Augusto, Jing; Banisch, Sven; Wetzstein, Gordon; Musialski, Przemyslaw; Toll, Chrystoph; Hofmann, Tobias
Editoři: Jorge, Joaquim; Skala, Václav
Abstrakt: Children television productions have been using puppets for a long time. Since the early days of computer animation,
computer puppet simulation has been researched intensively. Complex motion capture equipment allows
nowadays the real time mapping of movement for virtual puppets (performance animation). However, the costs of
capturing equipment are too high and the difference in the workflow make it difficult for small production teams
to access and use such technology. This paper presents a system for the real time simulation of elastic latex hand
puppets which are used in television productions. After an analysis of the production processes of real puppets and
of the materials used for their production, the paper describes the components of the system simulating them. The
system connects a high resolution visual mesh to a three-layered 3D mass spring mesh, which is used for the elastic
simulation. Polygonal mesh decimation of the puppet surface model is used as a basis for generating the elastic
mesh. From the decimated mesh a new metod is proposed for generating the internal layers of the mass-spring
mesh. A data handglove is used for transmitting forces to the elastic mesh, indirectly moving the surface of the
virtual puppet in real time. Dataglove interaction maps in a natural way the hand movements of a puppeteer to the
computer model. The tradeoffs of the implementation on low cost hardware and its efficiency are also discussed.2006-01-01T00:00:00ZWüthrich, Charles A.Augusto, JingBanisch, SvenWetzstein, GordonMusialski, PrzemyslawToll, ChrystophHofmann, Tobias