2012 |
 |
- A. Amresh, J. Femiani, Ch. Fünfzig
- Methods for Approximating Loop Subdivision Using Tessellation Enabled GPUs,
8th Int. Symposium on Visual Computing, Rethymnon, Crete, Greece 2012, pp. 115-125.
- Subdivision surfaces provide a powerful alternative to polygonal rendering. The availability of tessellation supported hardware presents an opportunity to develop algorithms that can render subdivision surfaces in realtime. We discuss the performance of approximating Loop Subdivision surfaces using tessellation-enabled GPUs in terms of speed and quality of rendering for these methods as well as the implementation strategy. We also propose a novel one pass unified rendering setup for all three methods. Subdivision using the Loop method supports arbitrary triangle meshes and provides for easy transition from polygonal rendering of triangles to the parametric domain. Majority of graphics software applications, especially game engines, render polygons as triangles. The objectives of this paper are to evaluate the performance of smooth rendering algorithms developed to take advantage of tessellator enabled GPUs, provide an easy transition from polygonal to parametric rendering and propose an optimal way to achieve multi-level rendering dependent on performance and visual needs of the application.
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|
 |
- M. Boschiroli, Ch. Fünfzig, L. Romani, G. Albrecht
-
G1 rational blend interpolatory schemes: a comparative study, Graphical Models 74(2012), Issue 1, pp. 29-49.
- Interpolation of triangular meshes is a subject of great interest in many computer graphics related applications, as, for example, gaming and realtime rendering. One of the main approaches to interpolate the positions and normals of the mesh vertices is the use of parametric triangular Bézier patches. As it is well known, any method aiming at constructing a parametric, tangent plane G1 continuous surface has to deal with the vertex consistency problem. In this article, we propose a comparison of three methods appeared in the nineties that use a particular technique called rational blend to avoid this problem. Together with these three methods we present a new scheme, a cubic Gregory patch, that has been inspired by one of them. Our comparison includes an analysis of their computational costs on CPU and GPU, a study of their capabilities of approximating analytic surfaces and their response to different surface interrogation methods on arbitrary triangle meshes with a low triangle count that actually occur in their real-world use.
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|
 |
- Ch. Fünfzig, D. Michelucci, S. Foufou
-
Polytope-Based Computation of Polynomial Ranges,
Computer Aided Geometric Design 29(2012), Issue 1, pp. 18-29.
- Polynomial ranges are commonly used for numerically solving
polynomial systems with interval Newton solvers. Often ranges are
computed using the convex hull property of the tensorial Bernstein
basis, which is exponential size in the number n of variables. In this
paper, we consider methods to compute tight bounds for polynomials in n
variables by solving two linear programming problems over a polytope. We
formulate a polytope defined as the convex hull of the coefficients
with respect to the tensorial Bernstein basis, and we formulate several
polytopes based on the Bernstein polynomials of the domain. These
Bernstein polytopes can be defined by a polynomial number of halfspaces.
We give the number of vertices, the number of hyperfaces, and the
volume of each polytope for n=1,2,3,4, and we compare the computed range
widths for random n-variate polynomials for n<=10. The Bernstein
polytope of polynomial size gives only marginally worse range bounds
compared to the range bounds obtained with the tensorial Bernstein basis
of exponential size.
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2011 |
 |
- K. Müller, L. Heischbourg, Ch. Fünfzig, S. Petsch, H. Hagen
-
Virtual City Map Generation using Area Subdivision, Pacific Graphics 2011, Kaohsiung, Taiwan, pp. 55-60.
- In this paper we present a new approach to build typical street networks for urban and rural areas automatically.
Most street networks have a characteristic appearance which is a mixture between a kind of a regular spreading
of streets and various perturbations of the regular structure, e.g., caused by the terrain. Our City Map Generation
(CMG) algorithm gets as input an height field including watercourses and restricted areas such as nature protection
areas or mountain areas. Furthermore, the user can specify the urbanization by the number of city centers
or by a density map. The CMG algorithm produces a street map for the given landscape based on rules, which
the user can also modify to obtain an individual appearance. Additionally, the regular structure is varied by a set
of rules incorporating randomness. The results can be used to generate models for city areas, e.g., in movies and
commercials. Depending on the demands, our flexible approach can be adjusted to produce a variety of road maps
automatically. We show some examples and demonstrate that our algorithm is easy to implement and to use.
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|
 |
- L. Saini, N. Lissarague, G. Albrecht, L. Romani, Ch. Fünfzig, J.-P. Becar
-
Animation 3D : mouvements de caméra réalistes pour la stop motion,
Proc. Hypertext & Hypermedia, Products, Tools & Methods H2PTM,
October 2011, Metz, France.
- L article présente un système qui permet la simulation 3D suivie
de son exécution sur un plateau d un mouvement de caméra réaliste pour la
stop motion. Les travaux de recherche portent sur deux points:
un état de l art des outils actuels pour produire des mouvements de caméra
en animation stop motion; les moyens de reproduire sur un plateau de stop
motion une animation faite en 3D. Le système, en cours de développement,
permettra à terme à la chaîne des acteurs impliqués dans une animation
stop motion de prévisualiser et de produire des mouvements de
caméra réalistes en 3D. Ces mouvements, paramétrables interactivement
grâce à une interface haptique, reproductibles à l identique et modifiables
au cours de la prise de vue, donnent à la mise en scène une liberté accrue.
The article presents a system, specifically designed for the
animation technique of stop motion, that combines 3D simulation and on
stage execution of a realistic camera movement. We focus our attention
on the following two aspects: firstly we present a state of the art of
the existing tools for camera animation for stop motion, and secondly we
concentrate on the way to reproduce on a real stop motion stage a 3D
computer animation of the camera movement. The system, which is still
work in progress, will enable stop motion animators to preview and to
produce realistic 3D camera movements. A haptic interface will allow to
control these movements which can thus be modified during the shots. The
whole process will be reproducible and highly flexible.
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|
 |
- S.E.B. Thierry, P. Schreck, D. Michelucci, Ch. Fünfzig, J.-D. Génevaux
- Extensions of the witness method to characterize under-, over- and
well-constrained geometric constraint systems, Computer-Aided Design
43(2011), Issue 10, pp. 1234-1249.
- This paper describes new ways to tackle several important
problems encountered in geometric constraint solving, in the context of
CAD, and which are linked to the handling of under- and over-constrained
systems. It presents a powerful decomposition algorithm of such
systems.
Our methods are based on the witness principle whose theoretical
background is recalled in a first step. A method to generate a witness
is then explained. We show that having a witness can be used to
incrementally detect over-constrainedness and thus to compute a
well-constrained boundary system. An algorithm is introduced to check if
anchoring a given subset of the coordinates brings the number of
solutions to a finite number.
An algorithm to efficiently identify all maximal well-constrained parts
of a geometric constraint system is described. This allows us to design a
powerful algorithm of decomposition, called W-decomposition, which is
able to identify all well-constrained subsystems: it manages to
decompose systems which were not decomposable by classic combinatorial
methods.
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|
 |
- M. Boschiroli, Ch. Fünfzig, L. Romani, G. Albrecht
- A comparison of local parametric C0 Bezier interpolants for triangular meshes,
Computers & Graphics 35(2011), Issue 1, pp. 20-34.
- Parametric curved shape surface schemes interpolating vertices
and normals of a given triangular mesh with arbitrary topology are
widely used in computer graphics for gaming and real-time rendering due
to their ability to effectively represent any surface of arbitrary
genus. In this context, continuous curved shape surface schemes using
only the information related to the triangle corresponding to the patch
under construction, emerged as attractive solutions responding to the
requirements of resource-limited hardware environments. In this paper we
provide a unifying comparison of the local parametric C0 curved shape
schemes we are aware of, based on a reformulation of their original
constructions in terms of polynomial Bezier triangles. With this
reformulation we find a geometric interpretation of all the schemes that
allows us to analyse their strengths and shortcomings from a
geometrical point of view. Further, we compare the four schemes with
respect to their computational costs, their reproduction capabilities of
analytic surfaces and their response to different surface interrogation
methods on arbitrary triangle meshes with a low triangle count that
actually occur in their real-world use.
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2010 |
|
- D. Michelucci, Ch. Fünfzig
- Linear Programming for Bernstein Based Solvers,
LNCS (Proc. Automated Deduction in Geometry), Volume 6301, Springer.
- Some interval Newton solvers rely on tensorial Bernstein bases to compute sharp enclosures of multivariate polynomials on the unit hypercube. These solvers compute all coefficients with respect to tensorial Bernstein bases. Unfortunately, polynomials become exponential size in tensorial Bernstein bases. This article gives the first polynomial time method to solve this issue. A polynomial number of relevant Bernstein polynomials is selected. The non-negativity of each of these Bernstein polynomials gives a linear inequality in a space connected to the monomials of the canonical tensorial basis. We resort to linear programming on the resulting Bernstein polytope to compute range bounds of a polynomial or bounds of the zero set.
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|
 |
- Ch. Fünfzig, D. Michelucci, S. Foufou
- Optimizations For Tensorial Bernstein-Based Solvers By Using Polyhedral Bounds,
Int. Journal of Shape Modeling 16(2010), Issue 1-2, pp. 109-128.
- The tensorial Bernstein basis for multivariate polynomials in n
variables has a number 3^n of functions for degree 2. Consequently,
computing the representation of a multivariate polynomial in the
tensorial Bernstein basis is an exponential time algorithm, which makes
tensorial Bernstein-based solvers impractical for systems with more than
n = 6 or 7 variables. This article describes a polytope (Bernstein
polytope) with a number O(binom(n, 2)) of faces, which allows to bound a
sparse, multivariate polynomial expressed in the canonical basis by
solving several linear programming problems. We compare the performance
of a subdivision solver using domain reductions by linear programming
with a solver using a change to the tensorial Bernstein basis for domain
reduction. The performance is similar for n = 2 variables but only the
solver using linear programming on the Bernstein polytope can cope with a
large number of variables. We demonstrate this difference with two
formulations of the forward kinematics problem of a Gough-Stewart
parallel robot: a direct Cartesian formulation and a coordinate-free
formulation using Cayley-Menger determinants, followed by a computation
of Cartesian coordinates. Furthermore, we present an optimization of the
Bernstein polytope-based solver for systems containing only the
monomials xi and xi^2. For these, it is possible to obtain even better
domain bounds at no cost using the quadratic curve (xi, xi^2) directly.
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|
 |
- A. Amresh, Ch. Fünfzig
- Semi-Uniform, 2-Different Tessellation of Triangular Parametric Surfaces,
6th Int. Symposium on Visual Computing, Las Vegas, Nevada, 2010.
- With a greater number of real-time graphics applications
moving over to parametric surfaces from the polygonal domain, there
is an inherent need to address various rendering bottlenecks that could
hamper the move. Scaling the polygon count over various hardware platforms
becomes an important factor. Much control is needed over the
tessellation levels, either imposed by the hardware limitations or by the
application. Developers like to create applications that run on various
platforms without having to switch between polygonal and parametric
versions to satisfy the limitations. In this paper, we present SD-2
(Semi-uniform, 2-Different), an adaptive tessellation algorithm for triangular
parametric surfaces. The algorithm produces well distributed and
semi-uniformly shaped triangles as a result of the tessellation. The SD-2
pattern requires new approaches for determining the edge tessellation
factors, which can be fractional and change continuously depending on
view parameters. The factors are then used to steer the tessellation of
the parametric surface into a collection of triangle strips in a single pass.
We compare the tessellation results in terms of GPU performance and
surface quality by implementing SD-2 on PN patches.
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|
 |
- K. Müller, Ch. Fünfzig, L. Reusche, D. Hansford, G.E. Farin, H. Hagen
- Dinus: Double insertion, nonuniform, stationary subdivision
surfaces,
ACM Transactions on Graphics, Volume 29(2010), Issue 3, pp. 1-21.
- The Double Insertion, Nonuniform, Stationary subdivision surface
(DINUS) generalizes both the nonuniform, bicubic spline surface and the
Catmull-Clark subdivision surface. DINUS allows arbitrary knot
intervals on the edges, allows incorporation of special features, and
provides limit point as well as limit normal rules. It is the first
subdivision scheme that gives the user all this flexibility and at the
same time all essential limit information, which is important for
applications in modeling and adaptive rendering. DINUS is also amenable
to analysis techniques for stationary schemes. We implemented DINUS as
an Autodesk Maya plugin to show several modeling and rendering examples.
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- D. Michelucci, P. Schreck, S.E.B. Thierry, Ch. Fünfzig, J.-D. Génevaux
- Using the witness method to detect rigid subsystems of geometric constraints in CAD,
SPM '10: Proceedings of the 14th ACM Symposium on Solid and Physical Modeling, pp. 91-100.
- This paper deals with the resolution of geometric constraint
systems encountered in CAD-CAM. The main results are that the witness
method can be used to detect that a constraint system is
over-constrained and that the computation of the maximal rigid
subsystems of a system leads to a powerful decomposition method.
In a first step, we recall the theoretical framework of the witness
method in geometric constraint solving and extend this method to
generate a witness. We show then that it can be used to incrementally
detect over-constrainedness. We give an algorithm to efficiently
identify all maximal rigid parts of a geometric constraint system. We
introduce the algorithm of W-decomposition to identify all rigid
subsystems: it manages to decompose systems which were not decomposable
by classical combinatorial methods.
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|
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- Ch. Fünfzig, D. Michelucci, S. Foufou
-
- Optimizations for Bernstein-Based Solvers using Domain Reduction,
Int. Symposium on Tools and Methods of Competitive Engineering, Ancona 2010.
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|
 |
- Ch. Fünfzig, D. Michelucci, S. Foufou
-
- Polytope-Based Computation of Polynomial Ranges,
ACM Symposium on Applied Computing, Sierre 2010, pages 1248-1253.
- Polynomial ranges are commonly used for numerically solving
polynomial systems with interval Newton solvers.
Often ranges are computed using the convex hull property of the
tensorial Bernstein
basis, which is exponential size in the number n of variables.
In this paper, we consider methods to compute tight bounds for
polynomials in n variables by solving two linear programming problems
over a polytope. We formulate several polytopes based on the
tensorial Bernstein basis, and we formulate a polytope for the
quadratic patch Qn := (x_1, . . . , x_n, x_1^2, . . . , x_n^2, x_1x_2, . .
. , x_{n-1}x_{n}) by projections.
This Bernstein polytope has O(n^2) hyperplanes. We give the number
of vertices, the number of hyperplanes, and the
volume of each polytope for n = 1,2,3, 4, and we compare the range
widths computed with all of them for random n-variate
polynomials with n<=10. The Bernstein polytope of polynomial size
gives only marginally worse range bounds compared to the range
bounds obtained with the tensorial Bernstein basis of exponential
size.
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|
 |
- Ch. Fünfzig, P. Thomin, G. Albrecht
-
- Haptic Manipulation of Rational Parametric Planar Cubics Using Shape Constraints,
ACM Symposium on Applied Computing, Sierre 2010, pages 1254-1258.
- In this paper, we show how to deform a planar rational cubic based
on a local interpolation constraint while retaining the qualitative
shape of the curve. An impedance-type, parallel haptic device is
used to signal changes of the number of inflection points, cusps
and loops during the deformation. In this way, the user is provided
with an intuitive and natural guidance throughout the curves shape
generation process in CAD.
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2009 |
 |
- Ch. Fünfzig, D. Michelucci, S. Foufou
-
- Nonlinear systems solver in floating-point arithmetic using LP reduction,
ACM/SIAM Symposium on Solid and Physical Modeling, San Francisco 2009, pages 123-134.
- This paper presents a new solver for systems of nonlinear
equations. Such systems occur in Geometric Constraint Solving,
e.g., when dimensioning parts in CAD-CAM, or when computing the
topology of sets defined by nonlinear inequalities.
The paper does not consider the problem of decomposing the system
and assembling solutions of subsystems. It focuses on
the numerical resolution of well-constrained systems. Instead of
computing an exponential number of coefficients in the
tensorial Bernstein basis, we resort to linear programming for
computing range bounds of system equations or domain reductions
of system variables. Linear programming is performed on a so called
Bernstein polytope:
though, it has an exponential number of vertices (each vertex
corresponds to a Bernstein polynomial in the tensorial Bernstein basis),
its number of hyperplanes is polynomial: O(n2) for a system in n
unknowns and equations, and total degree at most two.
An advantage of our solver is that it can be extended to
non-algebraic equations. In this paper, we present the Bernstein
and LP polytope construction, and how to cope with floating point
inaccuracy so that a standard LP code can be used.
The solver has been implemented with a primal-dual simplex LP code,
and some implementation variants have been analyzed.
Furthermore, we show geometric-constraint-solving applications, as
well as numerical intersection and distance computation examples.
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|
 |
- Ch. Fünfzig, K. Müller, G. Albrecht
-
Visual Debugger for Single-Point-Contact Haptic Rendering,
SE 2009 - Workshop Human-Computer-Interaction and Visualization (HCIV), Achim Ebert and Peter Dannenmann editors,
Kaiserslautern, Germany, GI-Lecture Notes in Informatics (LNI) 2009.
- Haptic applications are difficult to debug due to their high update rate and
many factors influencing their execution.
In this paper, we describe a practical visual debugger for single-point-of-contact haptic
devices of impedance-type. The debugger can easily be incorporated into the running
haptic application. The visualization shows the position trajectory with timing information
and associated data like goal positions and computed feedback forces. Also,
there are several options for in detail analysis of the feedback force applied at each
time instance. We show with several use cases taken from practical experience that
the system is well suited for locating common and intricate problems of haptic applications.
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|
 |
- Ch. Fünfzig, T. Ullrich, D.W. Fellner, E.N. Bachelder
-
Terrain and Model Queries Using Scalar Representations With Wavelet Compression,
IEEE Transactions on Instrumentation and Measurement 2009.
- In this paper, we present efficient height/distance field data structures for line-of-sight
queries on terrains and collision queries on arbitrary 3D models. The data structure uses a pyramid
of quad-shaped regions with the original height/distance field at the highest
level and an overall minimum/maximum value at the lower levels. The pyramid can
be stored compactly in a waveletlike decomposition but using max and plus operations.
Additionally, we show how to get minimum/maximum values for regions in a wavelet
decomposition using real algebra.
For line-of-sight (LOS) calculations, we compare with a kd-tree representation
containing the maximum height values. Furthermore, we show that the LOS calculation is
a special case of a collision detection query. Using our wavelet-like approach, even general
and arbitrary collision detection queries can be answered efficiently.
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2008 |
 |
- Ch. Fünfzig, K. Müller, R. Janetzek, T. Techmann
-
A versatile hierarchical Mesh for Subdivision Surfaces,
IEEE Potentials, September/October 2008.
- In this article we present a hierarchical mesh data structure for subdivision surfaces (e.g. Catmull-Clark for quadrangle
meshes and Loop for triangle meshes). The mesh is especially suitable for advanced global illumination algorithms, where
long light paths with surface reflections and transmissions are simulated.
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|
 |
- Ch. Fünfzig, K. Müller, D. Hansford, and G. Farin
-
PNG1 Triangles for Tangent Plane Continuous Surfaces on the GPU,
Proceedings of Graphics Interface, Windsor, Ontario 2008.
- Improving the visual appearance of coarse triangle meshes is usually
done with graphics hardware with per-pixel shading techniques.
Improving the appearance at silhouettes is inherently hard,
as shading has only a small influence there and the geometry must
be corrected. With the new geometry shader stage released with
DirectX 10, the functionality to generate new primitives from an
input primitive is available. Also the shader can access a restricted
primitive neighborhood. In this paper, we present a curved surface
patch that can deal with this restricted data available in the geometry
shader. A surface patch is defined over a triangle with its vertex
normals and the three edge neighbor triangles. Compared to PN
triangles, which define a curved patch using just the triangle with
its vertex normals, our surface patch is G1 continuous with its three
neighboring patches. The patch is obtained by blending two cubic
Bezier patches for each triangle edge. In this way, our surface
is especially suitable for efficient, high-quality tessellation on the
GPU.
We show the construction of the surface and how to add special
features such as creases. Thus, the appearance of the surface patch
can be fine-tuned easily. The surface patch is easy to integrate into
existing polygonal modeling and rendering environments. We give
some examples using Autodesk Maya.
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2007 |
 |
- T. Ullrich, V. Settgast, U. Krispel, Ch. Fünfzig, and D.W. Fellner
-
Distance Calculation between a Point and a Subdivision Surface,
Workshop on Vision, Modeling, and Visualization, Saarbrücken 2007.
- This article focuses on algorithms for fast computation of the
Euclidean distance between a query
point and a subdivision surface. The analyzed algorithms include uniform
tessellation approaches,
an adaptive evalution technique, and an algorithm using Bezier
conversions. These methods are combined
with a grid hashing structure for space partitioning to speed up their
runtime. The results show that a pretessellated surface is
sufficient for small models. Considering the runtime, accuracy, and
memory usage an adaptive on-the-fly evaluation of the surface
turns out to be the best choice.
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|
 |
- Ch. Fünfzig, T. Ullrich, D.W. Fellner, E.N. Bachelder
-
Empirical Comparison of Data Structures for Line-Of-Sight Computation,
IEEE Workshop on Intelligent Signal Processing 2007, Madrid, Spain.
- Line-of-sight (LOS) computation is important for interrogation of heightfield grids
in the context of geo information and many simulation tasks like electromagnetic wave propagation
and flight surveillance.
Compared to searching the regular grid directly, more advanced data structures like a 2.5d kd-tree
offer better performance. We describe the definition of a 2.5d kd-tree from the digital elevation model
and its use for LOS computation on a point-reconstructed or bilinear-reconstructed terrain surface.
For compact storage, we use a wavelet-like storage scheme which saves one half of the storage space
without considerably compromising the runtime performance.
We give an empirical comparison of both approaches on practical data sets which show the method
of choice for CPU computation of LOS.
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|
 |
- T. Ullrich, Ch. Fünfzig, D.W. Fellner
-
Two Different Views On Collision Detection, IEEE Potentials Volume 26 (2007), Number 1.
- The realistic movement of geometry governed by
physics is necessary for many applications. Changes of movements
occur at events, where geometries collide. For real-time
applications the collision detection must be as fast as possible.
While conceptually simple, the collision detection excels in its
intrinsic complexity. Naive approaches to determine all collisions
of n objects require a runtime of O(n2), which will rapidly be
too much in practice.
Innumerable algorithms with reduced runtime complexity
have been developed in the last decades. They can be classified
according to different schemes regarding e.g. field of application
or solution strategy. This article differentiates by the algorithms’
background: computational geometry or signal processing, and
presents a representative of each domain. The main characteristics
of both algorithms are simplicity and efficiency.
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2006 |
 |
- Ch. Fünfzig, T. Ullrich, D.W. Fellner
-
Hierarchical Spherical Distance Fields for Collision Detection, IEEE
Computer Graphics and Applications Volume 26 (2006), Number 1.
- This article presents a fast collision detection technique for
all types of rigid bodies, demonstrated using polygon soups. The new
approach uses spherical distance fields, which are stored in a compact
representation.
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2005 |
 |
- Ch. Fünfzig
-
Iconic Drawing of Scenegraph Structure, 31st Annual Conference on Current Trends in
Theory and Practice of Informatics (SOFSEM), Liptovsky Jan 2005.
- In this paper we consider graph drawing for the application
of scenegraphs as encoded by VRML97/X3D. As these formats store
the structure and attributes of scenes in a directed acyclic graph, the
techniques for drawing rooted trees are suitable but require much drawing
space. Therefore we devised a smart, interactive drawing, which uses
a detailed view of the current point of interest and an iconic view of
subgraphs besides the current point of interest. This interactive method
balances detail and overview much better than classic techniques to cope
with limited space like fisheye views. Concerning implementation it is
easy to implement with a small lines-of-code count (in Java).
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2004 |
 |
- V. Settgast, K. Müller, Ch. Fünfzig, D.W. Fellner
-
Adaptive Tesselation of Subdivision Surfaces, Computers & Graphics 2004.
- For a variety of reasons subdivision surfaces have developed into a prominent member of the family of freeform
shapes. Based on a standard polygonal mesh a modeller can build various kinds of shapes using an arbitrary
topology and special geometrical features like creases. However, the interactive display of subdivision surfaces in
current scenegraph systems based on static levels of detail is unpractical, because of the exponentially increasing
number of polygons during the subdivision steps. Therefore, an adaptive algorithm choosing only the necessary
quads and triangles is required to obtain high-quality images at high frame rates. In this paper we present a
rendering algorithm which dynamically adapts to static surface properties like curvature as well as to view-
dependent properties like silhouette location and projection size. Without modifying the base mesh, the method
works patchwise and tesselates each patch recursively using a new data structure, called slate. Besides these
geometric properties the algorithm can also adapt to the graphics load in order to achieve a desired frame rate in
the scenegraph system OpenSG.
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2003 |
 |
- T. Neumann, Ch. Fünfzig, D.W. Fellner
-
TRIPS - A Scalable Spatial Sound Library for OpenSG, OpenSG Symposium, Darmstadt 2003.
- We present a Sound Library that is scalable on several computers and that brings the idea of a self-organized
scenegraph to the Sound Library’s interface. It supports the implementation of audio features right from the start
at a high productivity level for rapid prototypes as well as for professional applications in the immersive domain.
The system is built on top of OpenSG12 which offers a high level of functionality for visual applications and
research, but does not come with audio support. We show and compare the effort to implement audio in an OpenSG
application with and without TRIPS. Today’s audio systems only accept raw 3D-coordinates and are limited to
run on the same computer and the same operating system than the application runs on. Breaking these constraints
could give developers more freedom and ease to add high-quality spatial sound to their software. Therefore, users
benefit from the promising potential OpenSG offers.
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|
 |
- Ch. Fünfzig, D.W. Fellner
-
Easy Realignment of k-DOP Bounding Volumes, Graphics Interface, Halifax 2003.
- In this paper we reconsider pairwise collision detection
for rigid motions using a k-DOP bounding volume hierarchy.
This data structure is particularly attractive because
it is equally efficient for rigid motions as for arbitrary
point motions (deformations).
We propose a new efficient realignment algorithm,
which produces tighter results compared to all known algorithms.
It can be implemented easily in software and
in hardware. Using this approach we try to show, that
k-DOP bounding volumes can keep up with the theoretically
more efficient oriented bounding boxes (OBBs) in
parallel-close-proximity situations.
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2002 |
 |
- Ch. Fünfzig
-
GENVIS - Eine Bibliothek für Räumliche Strukturierungen auf OpenSG, OpenSG Symposium, Darmstadt 2002.
- A scene graph for the same scene contents can be structured in different ways
depending on the application. In this paper the library GENVIS for spatial structuring and some applications
on the scene graph OpenSG is presented. Concerning architecture
the flexible and efficient connection with OpenSG is especially important. As examples,
k-DOP bounding volume hierarchies and regular spatial grids are covered in detail.
Bounding volume hierarchies can be used for collision detection and for a spatialization of the scene contents.
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