@article{Ihm:1999:W3C,
   author = {Insung Ihm and Sanghun Park},
   title = {Wavelet-Based {3D} Compression Scheme for Interactive
	  Visualization of Very Large Volume Data},
   volume = {18},
   number = {1},
   journal = {Computer Graphics Forum},
   month = {March}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {3-15},
   note = {{ISSN} 1067-7055},
   annote = {Interactive visualization of very large volume data
has been recognized as a task requiring great effort in a
variety of science and engineering fields. In particular, such
data usually places considerable demands on run-time memory
space. In this paper, we present an effective {3D} compression
scheme for interactive visualization of very large volume data,
that exploits the power of wavelet theory. In designing our
method, we have compromised between two important factors: high
compression ratio and fast run-time random access ability. Our
experimental results on the Visual Human data sets show that our
method achieves fairly good compression ratios. In addition, it
minimizes the overhead caused during run-time reconstruction of
voxel values. This {3D} compression scheme will be useful in
developing many interactive visualization systems for huge
volume data, especially when they are based on personal
computers or workstations with limited memory. },
}
@article{Sumner:1999:ASM,
   author = {Robert Sumner and James F. O'Brien and Jessica K. Hodgins},
   title = {Animating Sand, Mud, and Snow},
   volume = {18},
   number = {1},
   journal = {Computer Graphics Forum},
   month = {March}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {17-26},
   note = {{ISSN} 1067-7055},
   annote = {Computer animations often lack the subtle
environmental changes that should occur due to the actions of
the characters. Squealing car tires usually leave no skid marks,
airplanes rarely leave jet trails in the sky, and most runners
leave no footprints. In this paper, we describe a simulation
model of ground surfaces that can be deformed by the impact of
rigid body models of animated characters. To demonstrate the
algorithms, we show footprints made by a runner in sand, mud,
and snow as well as bicycle tire tracks, a bicycle crash, and a
falling runner. The shapes of the footprints in the three
surfaces are quite different, but the effects were controlled
through only five essentially independent parameters. To assess
the realism of the resulting motion, we compare the simulated
footprints to human footprints in sand. },
}
@article{Hall:1999:NRB,
   author = {P. Hall},
   title = {Nonphotorealistic Rendering by {Q-mapping}},
   volume = {18},
   number = {1},
   journal = {Computer Graphics Forum},
   month = {March}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {27-39},
   note = {{ISSN} 1067-7055},
   annote = {We present Q-mapping which is a technique for
rendering three-dimensional objects using nonphotorealistic
cues, by applying Q-maps. Q-maps are three-dimensional textures
that make marks on objects, and thus provide visual cues for
shape, shade, and texture. Q-maps adapt to light intensity,
typically by making more marks in darker areas. Q-maps can
produce images with a very wide range of visual styles (e.g.
half tone shading, and pen-and-ink colour wash). The primary
contribution is that these styles reside in a single parametric
space. Importantly this space includes photorealism as a style,
which is therefore regarded as a special case of
nonphotorealistic image rendering in general. We illustrate our
explanation of Q-mapping using examples from scientific
visualisation and computer graphics - and provide a gallery of
images to show the versatility of the approach. },
}
@article{Dumont:1999:APA,
   author = {Reynald Dumont and Kadi Bouatouch and Philippe Gosselin},
   title = {A Progressive Algorithm for Three Point Transport},
   volume = {18},
   number = {1},
   journal = {Computer Graphics Forum},
   month = {March}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {41-56},
   note = {{ISSN} 1067-7055},
   annote = {When computing global illumination in environments
made up of surfaces with general Bidirectional Reflection
Distribution Functions, a three point formulation of the
rendering equation can be used. Brute-force algorithms can lead
to a linear system of equations whose matrix is cubic, which is
expensive in time and space. The hierarchical approach is more
efficient. Aupperle et al. proposed a hierarchical three point
algorithm to compute global illumination in the presence of
glossy reflection. We present in this paper some improvements we
brought to this method: shooting, "lazy" push-pull, photometric
subdivision criterion, etc. Then we will show how our new method
takes into account non-planar surfaces in the hierarchical
resolution process. },
}
@article{Hui:1999:TBA,
   author = {K. C. Hui and Z. H. Jiang},
   title = {Tetrahedra Based Adaptive Polygonization of Implicit
Surface Patches},
   volume = {18},
   number = {1},
   journal = {Computer Graphics Forum},
   month = {March}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {57-68},
   note = {{ISSN} 1067-7055},
   annote = {This paper presents a tetrahedra based adaptive
polygonization technique for tessellating implicit surface
patches. An implicit surface patch is defined as an implicit
surface bounded by its intersections with a set of clipping
surfaces and which lies within an enclosing tetrahedron. To
obtain the polygonization of an implicit surface patch, the
tetrahedron containing the patch is adaptively subdivided into
smaller tetrahedra according to the criteria introduced in the
paper. The result is a set of tetrahedra each containing a facet
approximating the surface. The intersections between the facets
and the clipping surfaces are used to locate the surface patch
boundary. Ambiguous results in generating the facets for highly
curved surfaces or surfaces with singular points are also
addressed. The result of the polygonization is a set of
triangular facets that can be used for visualization and
numerical analysis. The proposed method is also suitable for
locating the intersection of two implicit surfaces. },
}
@article{Chen:1999:ALS,
   author = {Jim X. Chen and Xhsheng Wang},
   title = {Approximate Line Scan-Conversion and Antialiasing},
   volume = {18},
   number = {1},
   journal = {Computer Graphics Forum},
   month = {March}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {69-78},
   note = {{ISSN} 1067-7055},
   annote = {This paper presents an approximate multiple segment
line scan-conversion method - the Slope Table Method. The
statistics show that the new method can increase the percentage
of multiple segment lines (i.e., lines with more than one
segment) in an NxN raster area from about 39% to more than 99%.
In software implementation for scan-conversion and antialiasing
of randomly generated lines, this method is on average more than
6 times faster than Gupta's antialiasing line algorithm.
Compared with other line scan-conversion methods, the method may
choose pixels which are not the closest to the line (i.e., error
pixels). Here the paper demonstrates that the visual effect is
acceptable in most applications with the error pixels. },
}
@article{Samavati:1999:MCA,
   author = {Faramarz F. Samavati and Richard M. Bartels},
   title = {Multiresolution Curve and Surface Representation:
Reversing Subdivision Rules by Least-Squares Data Fitting},
   volume = {18},
   number = {2},
   journal = {Computer Graphics Forum},
   month = {June}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {97-119},
   note = {{ISSN} 1067-7055},
   annote = {This work explores how three techniques for
defining and representing curves and surfaces can be related
efficiently. The techniques are subdivision, least-squares data
fitting, and wavelets. We show how least-squares data fitting
can be used to "reverse" a subdivision rule, how this reversal
is related to wavelets, how this relationship can provide a
multilevel representation, and how the
decomposition/reconstruction process can be carried out in
linear time and space through the use of a matrix
factorization.\\Some insights that this work brings forth are
that the inner product used in a multiresolution analysis
influences the support of a wavelet, that wavelets can be
constructed by straightforward matrix observations, and that
matrix partitioning and factorization can provide alternatives
to inverses or duals for building efficient decomposition and
reconstruction processes. We illustrate our findings using an
example curve, grey-scale image, and tensor-product surface. },
}
@article{Turner:1999:MAO,
   author = {Russell Turner and Song Li and Enrico Gobbetti},
   title = {Metis - An Object-Oriented Toolkit for Constructing
Virtual Reality Applications},
   volume = {18},
   number = {2},
   journal = {Computer Graphics Forum},
   month = {June}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {121-130},
   note = {{ISSN} 1067-7055},
   annote = {Virtual reality systems provide realistic look and
feel by seamlessly integrating three-dimensional input and
output devices. One software architecture approach to
constructing such systems is to distribute the application
between a computation-intensive simulator back-end and a
graphics-intensive viewer front-end which implements user
interaction. In this paper we discuss Metis, a toolkit we have
been developing based on such a software architecture, which can
be used for building interactive immersive virtual reality
systems with computationally intensive components. The Metis
toolkit defines an application programming interface on the
simulator side, which communicates via a network with a
standalone viewer program that handles all immersive display and
interactivity. Network bandwidth and interaction latency are
minimized, by use of a constraint network on the viewer side
that declaratively defines much of dynamic and interactive
behavior of the application. },
}
@article{Veltkamp:1999:GGP,
   author = {Remco C. Veltkamp},
   title = {Generic Geometric Programming in the Computational
Geometry Algorithms Library},
   volume = {18},
   number = {2},
   journal = {Computer Graphics Forum},
   month = {June}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {131-137},
   note = {{ISSN} 1067-7055},
   annote = {This paper describes a number of design issues and
programming paradigms that affect the development of Cgal, the
computational geometry algorithms library. Genericity of the
library is achieved by concepts such as templates, iterators,
and traits classes. This allows the application programmer to
plug in own types of containers and point types, for example.
The paper gives an explanation of these concepts and examples of
how they are used. },
}
@article{Sherstyuk:1999:FRT,
   author = {Andrei Sherstyuk},
   title = {Fast Ray Tracing of Implicit Surfaces},
   volume = {18},
   number = {2},
   journal = {Computer Graphics Forum},
   month = {June}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {139-147},
   note = {{ISSN} 1067-7055},
   annote = {A ray-tracing algorithm is described for rendering
implicit surfaces formed with C1-continuous bounded functions
f(x, y, z). This class of functions includes such popular
implicit models as blobby molecules, metaballs, soft objects and
convolution surfaces. The algorithm employs analytical methods
only, which makes it fast, robust, and numerically stable.\\An
earlier version of this work was presented at the 3rd
International Workshop on Implicit Surfaces held in Seattle in
1998. },
}
@article{Wyvill:1999:ETC,
   author = {Brian Wyvill and Andrew Guy and Eric Galin},
   title = {Extending the {CSG} Tree. Warping, Blending and
Boolean Operations in an Implicit Surface Modeling System},
   volume = {18},
   number = {2},
   journal = {Computer Graphics Forum},
   month = {June}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {149-158},
   note = {{ISSN} 1067-7055},
   annote = {Automatic blending has characterized the major
advantage of implicit surface modeling systems. Recently, the
introduction of deformations based on space warping and Boolean
operations between primitives has increased the usefulness of
such systems. We propose a further enhancement which will extend
the range of models that can be easily and intuitively defined
with a skeletal implicit surface system. We describe a
hierarchical method which allows arbitrary compositions of
models that make use of blending, warping and Boolean
operations. We call this structure the BlobTree. Blending and
space warping are treated in the same way as union, difference
and intersection, i.e. as nodes in the BlobTree. The traversal
of the BlobTree is described along with two rendering
algorithms; a polygonizer and a ray tracer. We present some
examples of interesting models which can be made easily using
our approach that would be very difficult to represent with
conventional systems. },
}
@article{Leu:1999:MAR,
   author = {Adrian Leu and Min Chen},
   title = {Modelling and Rendering Graphics Scenes Composed of
Multiple Volumetric Datasets},
   volume = {18 },
   number = {2 },
   journal = {Computer Graphics Forum },
   month = {June}, year = {1999},
   publisher = {Blackwell Publishers },
   pages = {159-171},
   note = {{ISSN} 1067-7055 },
   annote = {This paper presents a method for modelling graphics
scenes consisting of multiple volumetric objects. A two-level
hierarchical representation is employed, which enables the
reduction of the overall storage consumption as well as
rendering time. With this approach, different objects can be
derived from the same volumetric dataset, and {2D} images can be
trivially integrated into a scene. The paper also describes an
efficient algorithm for rendering such scenes on ordinary
workstations, and addresses issues concerning memory
requirements and disk swapping. },
}
@article{Savransky:1999:MAR,
   author = {Guillermo Savransky and Dan Dimerman and Craig
Gotsman},
   title = {Modeling and Rendering Escher-Like Impossible
Scenes},
   volume = {18},
   number = {2},
   journal = {Computer Graphics Forum},
   month = {June}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {173-179},
   note = {{ISSN} 1067-7055},
   annote = {Inspired by the drawings of "impossible" objects by
artists such as M.C. Escher, we describe a mathematical theory
which captures some of the underlying principles of their work.
Using this theory, we show how impossible three-dimensional
scenes may be modeled and rendered synthetically. },
}
@article{Elber:1999:ILA,
   author = {Gershon Elber },
   title = {Interactive Line Art Rendering of Freeform
Surfaces},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {1-12},
   note = {{ISSN} 1067-7055},
   annote = {In recent years, synthetically created line art
renderings have reached quality levels that are aesthetically
pleasing. Moreover, the sketch based approach was found to be
quite capable at conveying geometrical information in an
intuitive manner. While a growing interest in this type of
rendering method has yielded successful and appealing results,
the developed techniques were, for the most part, too slow to be
embedded in real time interactive display. This paper presents a
line art rendering method for freeform polynomial and rational
surfaces that is capable of achieving real time and interactive
display. A careful preprocessing stage that combines an a-priori
construction of line art strokes with proper classification of
these strokes, allows one to significantly alleviate the
computational cost, in real time, of the sketch based rendering,
and enables interactive line art display. },
}
@article{Veryovka:1999:CHO,
   author = {O. Veryovka and J. Buchanan},
   title = {Comprehensive Halftoning of {3D} Scenes},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {13-22},
   note = {{ISSN} 1067-7055},
   annote = {The display of images on binary output hardware
requires a halftoning step. Conventional halftoning algorithms
approximate image values independently from the image content
and often introduce artificial texture that obscures fine
details. The objective of this research is to adapt a halftoning
technique to {3D} scene information and thus to enhance the
display of computer generated {3D} scenes. Our approach is based
on the control of halftoning texture by the combination of
ordered dithering and error diffusion techniques. We extend our
previous work and enable a user to specify the shape, scale,
direction, and contrast of the halftoning texture using an
external buffer. We control texture shape by constructing a
dither matrix from an arbitrary image or a procedural texture.
Texture direction and scale are adapted to the external
information by the mapping function. Texture contrast and the
accuracy of tone reproduction are varied across the image using
the error diffusion process. We halftone images of {3D} scenes by
using the geometry, position, and illumination information to
control the halftoning texture. Thus, the texture provides
visual cues and can be used to enhance the viewer's
comprehension of the display. },
}
@article{Bordeux:1999:AEA,
   author = {Christophe Bordeux and Ronan Boulic and Daniel
Thalmann},
   title = {An Efficient and Flexible Perception Pipeline for
Autonomous Agents},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {23-30},
   note = {{ISSN} 1067-7055},
   annote = {Agents in virtual environments require a
combination of perception and action to behave in an autonomous
way. We extend a software architecture for the management of
actions blending, called AGENTlib, with a perception mechanism.
The perception system provides a uniform interface to various
techniques in the field of virtual perception, including
synthetic vision, database access and perception persistency. We
describe the framework we designed to efficiently filter
valuable information from the scene and we address concerns
about computation redundancy and data propagation through
multiple filtering modules. },
}
@article{Bielser:1999:ICT,
   author = {Daniel Bielser and Volker A. Maiwald and Markus H.
Gross},
   title = {Interactive Cuts through 3-Dimensional Soft Tissue},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {31-38},
   note = {{ISSN} 1067-7055},
   annote = {We describe a physically based framework for
interactive modeling and cutting of 3-dimensional soft tissue
that can be used for surgery simulation. Unlike existing
approaches which are mostly designed for tensorproduct grids our
methods operate on tetrahedral decompositions giving more
topological and geometric flexibility for the efficient modeling
of complex anatomical structures. We start from an initial
tetrahedralization such as being provided by any conventional
meshing method. In order to track topological changes tetrahedra
intersected by the virtual scalpel are split into substructures
whose connectivity follows the trajectory of the cut, which can
be arbitrary. For the efficient computation of collisions
between the scalpel and individual tetrahedra we devised a local
collision detection algorithm. The underlying physics is
approximated through masses and springs attached to each
tetrahedral vertex and edge. A hierarchical Runge-Kutta
iteration computes the relaxation of the system by traversing
the designed data structures in a breadth-first order. The
framework includes a force-feedback interface and uses real-time
texture mapping to enhance the visual realism. },
}
@article{Liebowitz:1999:CAM,
   author = {David Liebowitz and Antonio Criminisi and Andrew
Zisserman },
   title = {Creating Architectural Models from Images},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {39-50},
   note = {{ISSN} 1067-7055},
   annote = {We present methods for creating {3D} graphical models
of scenes from a limited numbers of images, i.e. one or two, in
situations where no scene co-ordinate measurements are
available. The methods employ constraints available from
geometric relationships that are common in architectural scenes
- such as parallelism and orthogonality - together with
constraints available from the camera. In particular, by using
the circular points of a plane simple, linear algorithms are
given for computing plane rectification, plane orientation and
camera calibration from a single image. Examples of image based
3D modelling are given for both single images and image pairs.
},
}
@article{Wonka:1999:OSF,
   author = {Peter Wonka and Dieter Schmalsteig},
   title = {Occluder Shadows for Fast Walkthroughs of Urban
Environments},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {51-60},
   note = {{ISSN} 1067-7055},
   annote = {This paper describes a new algorithm that employs
image-based rendering for fast occlusion culling in complex
urban environments. It exploits graphics hardware to render and
automatically combine a relatively large set of occluders. The
algorithm is fast to calculate and therefore also useful for
scenes of moderate complexity and walkthroughs with over 20
frames per second. Occlusion is calculated dynamically and does
not rely on any visibility precalculation or occluder
preselection. Speed-ups of one order of magnitude can be
obtained. },
}
@article{Decoret:1999:MIF,
   author = {Xavier Decoret and Fran{\c{c}}ois Sillion and
Gernot Schaufler and Julie Dorsey},
   title = {Multi-layered impostors for accelerated rendering},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {61-73},
   note = {{ISSN} 1067-7055},
   annote = {This paper describes the successful combination of
pre-generated and dynamically updated image-based
representations to accelerate the visualization of complex
virtual environments. We introduce a new type of impostor, which
has the desirable property of limiting de-occlusion errors to a
user-specified amount. This impostor, composed of multiple
layers of textured meshes, replaces the distant geometry and is
much faster to draw. It captures the relevant depth complexity
in the model without resorting to a complete sampling of the
scene. We show that layers can be dynamically updated during
visualization. This guarantees bounded scene complexity in each
frame and also exploits temporal coherence to improve image
quality when possible. We demonstrate the strengths of this
approach in the context of city walkthroughs. },
}
@article{Lee:1999:IME,
   author = {Seungyong Lee},
   title = {Interactive Multiresolution Editing of Arbitrary
Meshes},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {73-82},
   note = {{ISSN} 1067-7055},
   annote = {This paper presents a novel approach to
multiresolution editing of a triangular mesh. The basic idea is
to embed an editing area of a mesh onto a {2D} rectangle and
interpolate the user-specified editing information over the {2D}
rectangle. The result of the interpolation is mapped back to the
editing area and then used to update the mesh. We adopt harmonic
maps for the embedding and multilevel B-splines for the
interpolation. The proposed mesh editing technique can handle an
arbitrary mesh without any preprocessing such as remeshing. It
runs fast enough to support interactive editing and produces
intuitive editing results. },
}
@article{ElSana:1999:GVS,
   author = {Jihad El-Sana and Amitabh Varshney},
   title = {Generalized View-Dependent Simplification},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {83-94},
   note = {{ISSN} 1067-7055},
   annote = {We propose a technique for performing
view-dependent geometry and topology simplifications for
level-of-detail-based renderings of large models. The algorithm
proceeds by preprocessing the input dataset into a binary tree,
the view-dependence tree of general vertex-pair collapses. A
subset of the Delaunay edges is used to limit the number of
vertex pairs considered for topology simplification.
Dependencies to avoid mesh foldovers in manifold regions of the
input object are stored in the view-dependence tree in an
implicit fashion. We have observed that this not only reduces
the space requirements by a factor of two, it also highly
localizes the memory accesses at run time. The view-dependence
tree is used at run time to generate the triangles for display.
We also propose a cubic-spline-based distance metric that can be
used to unify the geometry and topology simplifications by
considering the vertex positions and normals in an integrated
manner. },
}
@article{Feixas:1999:AIT,
   author = {Miquel Feixas and Esteve del Acebo and Philippe
Bekaert and Mateu Sbert},
   title = {An Information Theory Framework for the Analysis of
Scene Complexity},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {95-106},
   note = {{ISSN} 1067-7055},
   annote = {In this paper we present a new framework for the
analysis of scene visibility and radiosity complexity. We
introduce a number of complexity measures from information
theory quantifying how difficult it is to compute with accuracy
the visibility and radiosity in a scene. We define the
continuous mutual information as a complexity measure of a
scene, independent of whatever discretisation, and discrete
mutual information as the complexity of a discretised scene.
Mutual information can be understood as the degree of
correlation or dependence between all the points or patches of a
scene. Thus, low complexity corresponds to low correlation and
vice versa. Experiments illustrating that the best mesh of a
given scene among a number of alternatives corresponds to the
one with the highest discrete mutual information, indicate the
feasibility of the approach. Unlike continuous mutual
information, which is very cheap to compute, the computation of
discrete mutual information can however be quite demanding. We
will develop cheap complexity measure estimates and derive
practical algorithms from this framework in future work. },
}
@article{Fontana:1999:AFF,
   author = {M. Fontana and F. Giannini and M. Meirana},
   title = {A Free Form Feature Taxonomy},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {107-118},
   note = {{ISSN} 1067-7055},
   annote = {In this paper the notion of free form feature for
aesthetic design is presented. The design of industrial products
constituted by free form surfaces is done by using {CAD} systems
representing curves and surfaces by means of {NURBS} functions,
which are usually defined by low level entities that are not
intuitive and require some knowledge of the mathematical
language. Similarly to the feature-based approach adopted by {CAD}
systems for classical mechanical design, a set of high level
modelling entities which provides commonly performed shape
modifications has been identified. Particularly, the paper
suggests a classification of the so-called detail features for
an aesthetic and/or functional characterization of predefined
free form surfaces. Feature types are formally described by
means of an analytical definition of the surface modification
through deformation and elimination laws. A topological
classification is then given according to the application domain
of such laws. A further sub-classification of morphological
types is then suggested according to geometric properties of
weak convexity and concavity for the resulting modified shape,
leading to a taxonomy of simple free form features meaningful
for aesthetic design. },
}
@article{Kobbelt:1999:ASW,
   author = {Leif P. Kobbelt and Jens Vorsatz and Ulf Labsik and
Hans-Peter Seidel},
   title = {A Shrink Wrapping Approach to Remeshing Polygonal
Surfaces},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {119-130},
   note = {{ISSN} 1067-7055},
   annote = {Due to their simplicity and flexibility, polygonal
meshes are about to become the standard representation for
surface geometry in computer graphics applications. Some
algorithms in the context of multiresolution representation and
modeling can be performed much more efficiently and robustly if
the underlying surface tesselations have the special subdivision
connectivity. In this paper, we propose a new algorithm for
converting a given unstructured triangle mesh into one having
subdivision connectivity. The basic idea is to simulate the
shrink wrapping process by adapting the deformable surface
technique known from image processing. The resulting algorithm
generates subdivision connectivity meshes whose base meshes only
have a very small number of triangles. The iterative
optimization process that distributes the mesh vertices over the
given surface geometry guarantees low local distortion of the
triangular faces. We show several examples and applications
including the progressive transmission of subdivision surfaces.
},
}
@article{Vollmer:1999:ILS,
   author = {J. Vollmer and R. Mencl and H. Muller},
   title = {Improved Laplacian Smoothing of Noisy Surface
Meshes},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {131-138},
   note = {{ISSN} 1067-7055},
   annote = {This paper presents a technique for smoothing
polygonal surface meshes that avoids the well-known problem of
deformation and shrinkage caused by many smoothing methods, like
e.g. the Laplacian algorithm. The basic idea is to push the
vertices of the smoothed mesh back towards their previous
locations. This technique can be also used in order to smooth
unstructured point sets, by reconstructing a surface mesh to
which the smoothing technique is applied. The key observation is
that a surface mesh which is not necessarily topologically
correct, but which can efficiently be reconstructed, is
sufficient for that purpose. },
}
@article{Zaninetti:1999:AAM,
   author = {Jacques Zaninetti and Pierre Boy and Bernard
Peroche},
   title = {An Adaptive Method for Area Light Sources and
Daylight in Ray Tracing},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {139-150},
   note = {{ISSN} 1067-7055},
   annote = {This paper proposes an adaptive method for taking
both (diffuse or not) planar area light sources and daylight
into account in a ray tracing environment which separates the
calculation of direct and indirect illumination. In a given
point, direct illumination due to a light source or to natural
light is represented by a vector, the direction and magnitude of
which being computed through an adaptive area approach, which is
driven by the solid angle according to which a part of the
source is seen from the current point. In the case of unoccluded
diffuse polygonal sources, an analytical formula is used which
gives an exact value for this vector. },
}
@article{Schirmacher:1999:AAO,
   author = {Hartmut Schirmacher and Wolfgang Heidrich and
Hans-Peter Seidel},
   title = {Adaptive Acquisition of Lumigraphs from Synthetic
Scenes},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {151-160},
   note = {{ISSN} 1067-7055},
   annote = {Light fields and Lumigraphs are capable of
rendering scenes of arbitrary geometrical or illumination
complexity in real time. They are thus interesting ways of
interacting with both recorded real-world and high-quality
synthetic scenes.\\Unfortunately, both light fields and
Lumigraph rely on a dense sampling of the illumination to
provide a good rendering quality. This induces high costs both
in terms of storage requirements and computational resources for
the image acquisition. Techniques for acquiring adaptive light
field and Lumigraph representations are thus mandatory for
practical applications.\\In this paper we present a method for
the adaptive acquisition of images for Lumigraphs from synthetic
scenes. Using image warping to predict the potential improvement
in image quality when adding a certain view, we decide which new
views of the scene should be rendered and added to the light
field. This a-priori error estimator accounts for both
visibility problems and illumination effects such as specular
highlights. },
}
@article{Neumann:1999:CMR,
   author = {L{\'{a}}szl{\'{o}} Neumann and Attila Neumann and
L{\'{a}}szl{\'{o}} Szirmay-Kalos},
   title = {Compact Metallic Reflectance Models},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {161-172},
   note = {{ISSN} 1067-7055},
   annote = {The paper presents simple, physically plausible,
but not physically based reflectance models for metals and other
specular materials. So far there has been no metallic {BRDF} model
that is easy to compute, suitable for fast importance sampling
and is physically plausible. This gap is filled by appropriate
modifications of the Phong, Blinn and the Ward models. The Phong
and the Blinn models are known not to have metallic
characteristics. On the other hand, this paper also shows that
the Cook-Torrance and the Ward models are not physically
plausible, because of their behavior at grazing angles. We also
compare the previous and the newly proposed models. Finally, the
generated images demonstrate how the metallic impression can be
provided by the new models. },
}
@article{Hamel:1999:CAR,
   author = {J. Hamel and T. Strothotte},
   title = {Capturing and Re-Using Rendition Styles for
Non-Photorealistic Rendering},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {173-182},
   note = {{ISSN} 1067-7055},
   annote = {Rendering high-quality non-photorealistic images of
a given geometric model is often associated with a considerable
amount of effort on the part of a user to fine-tune the
rendition. In this paper we introduce a method and tools for
re-using the user's effort invested in one model for the
rendering of other models.\\Our method uses templates to
describe rendition styles. The paper gives a number of examples
of the successful transfer of styles from one model to another.
},
}
@article{Mizunoy:1999:AID,
   author = {S. Mizunoy and M. Okadayy and J. Toriwakiy},
   title = {An Interactive Designing System with Virtual
Sculpting and Virtual Woodcut Printing},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {183-194},
   note = {{ISSN} 1067-7055},
   annote = {In this paper, we propose an interactive designing
method and a system based on it to create {3D} objects and {2D}
images. This system consists of two subsystems for virtual
sculpting to create a {3D} shape and virtual printing to produce a
picture with a printing block. In the virtual sculpting
subsystem, a user can form solid objects with curved surfaces as
if sculpting them. The user operates virtual chisels, and can
remove or attach arbitrary shapes of ellipsoids or cubes from or
to the workpiece. A {3D} object generated by virtual sculpting
looks like a real wooden sculpture. If using a board as a
workpiece, a user can generate a virtual printing block. In the
virtual printing subsystem, a user can synthesize a woodcut
printing image from the virtual printing block mentioned above,
a virtual paper sheet, and a printing brush. The user can
synthesize a realistic woodcut print with a procedure similar to
the actual woodcut printing. },
}
@article{Sousa:1999:CGP,
   author = {Mario Costa Sousa and John W. Buchanan},
   title = {Computer-Generated Graphite Pencil Rendering of {3D}
Polygonal Models},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {195-208},
   note = {{ISSN} 1067-7055},
   annote = {Researchers in non-photorealistic rendering have
investigated the display of three-dimensional worlds using
various display models. In particular, recent work has focused
on the modeling of traditional artistic media and styles such as
pen-and-ink illustration and watercolor painting. By providing
3D rendering systems that use these alternative display models
users can generate traditional illustration renderings of their
three-dimensional worlds. In this paper we present our graphite
pencil {3D} renderer. We have broken the problem of simulating
pencil drawing down into four fundamental parts: (1) simulating
the drawing materials (graphite pencil and drawing paper,
blenders and kneaded eraser), (2) modeling the drawing
primitives (individual pencil strokes and mark-making to create
tones and textures), (3) simulating the basic rendering
techniques used by artists and illustrators familiar with pencil
rendering, and (4) modeling the control of the drawing
composition. Each part builds upon the others and is essential
to developing the framework for higher-level rendering methods
and tools. In this paper we present parts 2, 3, and 4 of our
research. We present non-photorealistic graphite pencil
rendering methods for outlining and shading. We also present the
control of drawing steps from preparatory sketches to finished
rendering results. We demonstrate the capabilities of our
approach with a variety of images generated from {3D} models. },
}
@article{Suykens:1999:WMM,
   author = {Frank Suykens and Yves D. Willems},
   title = {Weighted Multipass Methods for Global Illumination},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {209-220},
   note = {{ISSN} 1067-7055},
   annote = {In multipass rendering, care has to be taken to
include all light transport only once in the final solution.
Therefore the different methods in current multipass
configurations handle a perfectly disjunct part of the light
transport. In this paper a Monte Carlo variance reduction
technique is presented that probabilistically weights
overlapping transport between different methods. A good
heuristic for the weights is derived so that strengths of the
respective methods are retained. The technique is applied to a
combination of radiosity and bidirectional path tracing and
significant improvement is obtained over the non-weighted
combination. This method promises to be a very useful extension
to other multipass algorithms as well. },
}
@article{Hasenfratz:1999:APA,
   author = {Jean-Marc Hasenfratz and Cyrille Damez and
Fran{\c{c}}ois Sillion and George Drettakis},
   title = {A Practical Analysis of Clustering Strategies for
Hierarchical Radiosity},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {221-232},
   note = {{ISSN} 1067-7055},
   annote = {The calculation of radiant energy balance in
complex scenes has been made possible by hierarchical radiosity
methods based on clustering mechanisms. Although clustering
offers an elegant theoretical solution by reducing the
asymptotic complexity of the algorithm, its practical use raises
many difficulties, and may result in image artifacts or
unexpected behavior. This paper proposes a detailed analysis of
the expectations placed on clustering and compares the relative
merits of existing, as well as newly introduced, clustering
algorithms. This comparison starts from the precise definition
of various clustering strategies based on a taxonomy of data
structures and construction algorithms, and proceeds to an
experimental study of the clustering behavior for real-world
scenes. Interestingly, we observe that for some scenes light is
difficult to simulate even with clustering. Our results lead to
a series of observations characterizing the adequacy of
clustering methods for meeting such diverse goals as progressive
solution improvement, efficient ray casting acceleration, and
faithful representation of object density for approximate
visibility calculations. },
}
@article{Szirmay-Kalos:1999:SIF,
   author = {L{\'{a}}szl{\'{o}} Szirmay-Kalos},
   title = {Stochastic Iteration for Non-diffuse Global
Illumination},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {233-244},
   note = {{ISSN} 1067-7055},
   annote = {This paper presents a single-pass, view-dependent
method to solve the rendering equation, using a stochastic
iterational scheme where the transport operator is selected
randomly in each iteration. The requirements of convergence are
given for the general case. To demonstrate the basic idea, a
very simple, continuous random transport operator is examined,
which gives back the light tracing algorithm incorporating
Russian roulette. Then, a new mixed continuous and
finite-element based iteration method is proposed, which uses
ray-bundles to transfer the radiance in a single random
direction. The resulting algorithm is fast, it provides initial
results in seconds and accurate solutions in minutes and does
not suffer from the error accumulation problem and the high
memory demand of other finite-element and hierarchical
approaches. },
}
@article{Heugebauer:1999:TTM,
   author = {Peter J. Heugebauer and Konrad Klein},
   title = {Texturing {3D} Models of Real World Objects from
Multiple Unregistered Photographic Views},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {245-256},
   note = {{ISSN} 1067-7055},
   annote = {As the efficiency of computer graphic rendering
methods is increasing, generating realistic models is now
becoming a limiting factor. In this paper we present a new
technique to enhance already existing geometry models of real
world objects with textures reconstructed from a sparse set of
unregistered still photographs. The aim of the proposed
technique is the generation of nearly photo-realistic models of
arbitrarily shaped objects with minimal effort. In our approach,
we require neither a prior calibration of the camera nor a high
precision of the user's interaction. Two main problems have to
be addressed of which the first is the recovery of the unknown
positions and parameters of the camera. An initial estimate of
the orientation is calculated from interactively selected point
correspondences. Subsequently, the unknown parameters are
accurately calculated by minimising a blend of objective
functions in a {3D-2D} projective registration approach. The key
point of the proposed method of registration is a novel
filtering approach which utilises the spatial information
provided by the geometry model. Second, the individual images
have to be combined yielding a set of consistent texture maps.
We present a robust method to recover the texture from the
photographs thereby preserving high spatial frequencies and
eliminating artifacts, particularly specular highlights. Parts
of the object not seen in any of the photographs are
interpolated in the textured model. Results are shown for three
complex example objects with different materials and numerous
self-occlusions. },
}
@article{Lutz:1999:VDA,
   author = {B. Lutz and M. Weintke},
   title = {Virtual Dunhuang Art Cave: A Cave within a {CAVE}},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {257-264},
   note = {{ISSN} 1067-7055},
   annote = {Virtual Reality can present historical places in a
three-dimensional and interactive way, giving visitors a
photorealistic impression of objects. Not only existing
scenarios can be shown, but {VR} can also be used to rebuild
scenarios that were damaged or destroyed a long time ago, giving
new life to the cultural heritage. We used Virtual Reality to
present the Mogao Grottos in Dunhuang. This cave site is one of
the most important cultural and religious places by the ancient
Silk Road. The presentation is to give visitors the impression
of visiting the cave site and provide information about the
caves, paintings and statues in an interesting way. To achieve
this, we developed a new, intuitive interaction paradigm, which
enables the user to explore the caves. To give observers a
photorealistic impression of the caves and to create a feeling
of immersion, innovative rendering techniques were
integrated.\\The resulting presentation combines Virtual Reality
and archaeology to give tourists a realistic experience of this
cave site and to support scientists in their research work. },
}
@article{Cortelazzo:1999:ANM,
   author = {G. M. Cortelazzo and L. Lucchese},
   title = {A New Method of Image Mosaicking and Its Application
to Cultural Heritage Representation},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {265-276},
   note = {{ISSN} 1067-7055},
   annote = {This paper presents an original two-step procedure
for estimating projective transformations between pairs of
images: first, the transformation between the images is
approximated as an affine transformation; second, this estimate
is refined into that of a projective transformation. This
strategy for matching projective views is computationally very
efficient. The proposed method can be applied both to mosaicking
of high resolution images of planar textured objects (e.g.,
frescoes and paintings), with subpixel accuracy, and to
construction of panoramic images. Practical examples of
mosaicking of cultural heritage imagery obtained by using the
presented procedure are discussed in the paper. },
}
@article{Encarnacao:1999:ATS,
   author = {L. M. Encarna{\c{c}}{\~{a}}o and G. Bimber and
Dieter Schmalsteig and S. D. Chandler},
   title = {A Translucent Sketchpad for the Virtual Table
Exploring Motion-based Gesture Recognition},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {277-286},
   note = {{ISSN} 1067-7055},
   annote = {The Virtual Table presents stereoscopic graphics to
a user in a workbench-like setting. For this device, a user
interface and new interaction techniques have been developed
based on transparent props -- a tracked hand-held pen and a pad.
These props, particularly the pad, are augmented with {3D}
graphics from the Virtual Table's display that can serve as a
palette for tools and controls as well as a window-like
see-through interface, a plane-shaped and through-the-plane
tool, supporting a variety of new interaction techniques. This
paper reports on an extension of this user-interface design
space which uses gestural input to create and control solid
geometries for {CAD} and conceptual design. The application of
gestural interfaces is a common method for interacting with
virtual environments on a habitual and natural basis. The
motion-based gesture recognition presented here uses Fuzzy Logic
to support a predictable, flexible, and efficient learning
process. This new interaction paradigm greatly increases the
Virtual Table's suitability for design tasks. Traditional {CAD}
dialogue can be combined with intuitive rapid sketching of
geometry on the pad. Additionally, the resulting events and
objects can be associated with scene details below the
translucent tablet. },
}
@article{Nelson:1999:IMD,
   author = {Donald D. Nelson and Elaine Cohen},
   title = {Interactive Mechanical Design Variation for Haptics and {CAD}},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {287-296},
   note = {{ISSN} 1067-7055},
   annote = {A fast design variation technique for mechanical
systems is presented. It is used to interactively optimize
mechanical characteristics while "self-assembling" or satisfying
large systems of mechanical constraints. The high speed method
is central to providing inverse dynamics force feedback in
haptics and control applications. Performance advantages with
the use of augmented coordinates for inverse dynamics of closed
loop topologies are also noted. The interaction framework allows
manipulation of complex assemblies while maintaining
kinematically admissible configurations though linkage and joint
limit constraints. Furthermore, design variables such as link
length can be treated as free variables and optimized to meet
design criteria such as assembly dexterity. Assemblies with
flexible bodies fit naturally within this framework. Thus, the
contribution of this paper is the advancement of techniques in
augmented coordinates for the kinematic and force feedback
interaction with virtual mechanical assembly design optimization
at force control rates. },
}
@article{Smith:1999:THW,
   author = {Shamus Smith and David Duke and Meike Massink},
   title = {The Hybrid World of Virtual Environments},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {297-308},
   note = {{ISSN} 1067-7055},
   annote = {Much of the work concerned with virtual
environments has addressed the development of new rendering
technologies or interaction techniques. As the technology
matures and becomes adopted in a wider range of applications,
there is, however, a need to better understand how this
technology can be accommodated in software engineering practice.
A particular challenge presented by virtual environments is the
complexity of the interaction that is supported, and sometimes
necessary, for a particular task. Methods such as finite-state
automata which are used to represent and design dialogue
components for more conventional interfaces, e.g. using direct
manipulation within a desktop model, do not seem to capture
adequately the style of interaction that is afforded by richer
input devices and graphical models. In this paper, we suggest
that virtual environments are, fundamentally, what are known as
"hybrid" systems. Building on this insight, we demonstrate how
techniques developed for modelling hybrid systems can be used to
represent and understand virtual interaction in a way that can
be used in the specification and design phases of software
development, and which have the potential to support prototyping
and analysis of virtual interfaces. },
}
@article{Farenc:1999:AIE,
   author = {Nathalie Farenc and Ronan Boulic and Daniel
Thalmann},
   title = {An Informed Environment Dedicated to the Simulation
of Virtual Humans in Urban Context},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {309-318},
   note = {{ISSN} 1067-7055},
   annote = {In this paper, we outline the creation of an
Informed Environment, dedicated to urban life simulation. We
propose methods and tools for creating and providing the
information necessary for animating virtual humans in a city
using an Informed Environment. The Informed Environment is based
on a hierarchical decomposition of a urban scene into
Environment Entities providing geometrical information as well
as semantic notions, thus allowing a more realistic simulation
of human behaviour. In this manner, virtual humans can integrate
with a certain kind of urban knowledge. },
}
@article{Wilson:1999:PAH,
   author = {A. Wilson and E. Larsen and Dinesh Manocha and Ming
C. Lin},
   title = {Partitioning and Handling Massive Models for
Interactive Collision Detection},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {319-330},
   note = {{ISSN} 1067-7055},
   annote = {We describe an approach for interactive collision
detection and proximity computations on massive models composed
of millions of geometric primitives. We address issues related
to interactive data access and processing in a large geometric
database, which may not fit into main memory of typical desktop
workstations or computers. We present a new algorithm using
overlap graphs for localizing the "regions of interest" within a
massive model, thereby reducing runtime memory requirements. The
overlap graph is computed off-line, pre-processed using graph
partitioning algorithms, and modified on the fly as needed. At
run time, we traverse localized sub-graphs to check the
corresponding geometry for proximity and pre-fetch geometry and
auxiliary data structures. To perform interactive proximity
queries, we use bounding-volume hierarchies and take advantage
of spatial and temporal coherence. Based on the proposed
algorithms, we have developed a system called {IMMPACT} and used
it for interaction with a {CAD} model of a power plant consisting
of over 15 million triangles. We are able to perform a number of
proximity queries in real-time on such a model. In terms of
model complexity and application to large models, we have
improved the performance of interactive collision detection and
proximity computation algorithms by an order of magnitude. },
}
@article{Soetebier:1999:SIO,
   author = {Ingo Soetebier and Ralf D{\"{o}}rner and Norbert
Braun},
   title = {Seamless Integration of Databases in {VR} for
Constructing Virtual Environments},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {331-338},
   note = {{ISSN} 1067-7055},
   annote = {An approach for authoring virtual environments
within the virtual environments themselves is presented,
integrating a database containing arbitrary components that are
used to construct the {3D} scene. The issues important to a
seamless integration of the database, such as multimedia data
storage and database linkage are discussed, with the focus on
the human-computer interaction component. A concept for a {3D}
database interface is described for query, presentation and
usage of query results in the virtual environment. Finally, an
implementation of the concept using {VRML} and Java is presented.
},
}
@article{Tal:1999:IMW,
   author = {Ayellet Tal and Gershon Elber},
   title = {Image Morphing with Feature Preserving Texture},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {339-348},
   note = {{ISSN} 1067-7055},
   annote = {Image metamorphosis as an animation tool has mostly
been employed in the context of the entire image. This work
explores the use of isolated and focused image based
metamorphosis between two-dimensional objects, while capturing
the features, colors, and textures of the objects. This
pinpointed approach allows one to independently overlay several
such dynamic shapes, without any bleeding of one shape into
another. Hence, shape blending and metamorphosis of
two-dimensional objects can be exploited as animated sequences
of clip arts. },
}
@article{Matsushita:1999:EAH,
   author = {Kenji Matsushita and Toyohisa Kaneko},
   title = {Efficient and Handy Texture Mapping on {3D} Surfaces},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {349-358},
   note = {{ISSN} 1067-7055},
   annote = {There has been a rapid technical progress in
three-dimensional (3D) computer graphics. But gathering surface
and texture data is yet a laborious task. This paper addresses
the problem of mapping photographic images on the surface of a
3D object whose geometric data are already known. We propose an
efficient and handy method for acquiring textures and mapping
them precisely on the surface, employing a digital camera alone.
We describe an algorithm for selecting a minimal number of
camera positions that can cover the entire surface of a given
object and also an algorithm to determine camera's position and
direction for each photograph taken so as to paste it to the
corresponding surfaces precisely. We obtained a matching
accuracy within a pixel on a surface through three experimental
examples, by which the practicability of our method is
demonstrated. },
}
@article{Cai:1999:DIA,
   author = {Wenli Cai and Georgios Sakas},
   title = {Data Intermixing and Multi-volume Rendering},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {359-368},
   note = {{ISSN} 1067-7055},
   annote = {The main difference between multi-volume rendering
and mono-volume rendering is data intermixing. In this paper, we
present three levels of data intermixing and their rendering
pipelines in direct multi-volume rendering, which discriminate
image level intensity intermixing, accumulation level opacity
intermixing, and illumination model level parameter intermixing.
In the context of radiotherapy treatment planning, different
data intermixing methods are applied to three volumes, including
CT volume, Dose volume, and Segmentation volume, to compare the
features of different data intermixing methods. },
}
@article{Comba:1999:FPC,
   author = {Jo{\~{a}}o Comba and James T. Klosowski and Nelson
Max and Joseph S. B. Mitchell and Cl{\'{a}}udio T. Silva and
Peter L. Williams},
   title = {Fast Polyhedral Cell Sorting for Interactive
Rendering of Unstructured Grids},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {369-376},
   note = {{ISSN} 1067-7055},
   annote = {Direct volume rendering based on projective methods
works by projecting, in visibility order, the polyhedral cells
of a mesh onto the image plane, and incrementally compositing
the cell's color and opacity into the final image. Crucial to
this method is the computation of a visibility ordering of the
cells. If the mesh is "well-behaved" (acyclic and convex), then
the {MPVO} method of Williams provides a very fast sorting
algorithm; however, this method only computes an approximate
ordering in general datasets, resulting in visual artifacts when
rendered. A recent method of Silva et al. removed the assumption
that the mesh is convex, by means of a sweep algorithm used in
conjunction with the {MPVO} method; their algorithm is
substantially faster than previous exact methods for general
meshes.\\In this paper we propose a new technique, which we call
BSP-XMPVO, which is based on a fast and simple way of using
binary space partitions on the boundary elements of the mesh to
augment the ordering produced by {MPVO}. Our results are shown to
be orders of magnitude better than previous exact methods of
sorting cells. },
}
@article{Boyer:1999:FLA,
   author = {V. Boyer and J. J. Bourdin},
   title = {Fast Lines: A Span by Span Method},
   volume = {18},
   number = {3},
   journal = {Computer Graphics Forum},
   month = {September}, year = {1999},
   publisher = {Blackwell Publishers},
   pages = {377-384},
   note = {{ISSN} 1067-7055},
   annote = {Straight line's scan conversion and drawing is a
major field in computer graphics. Algorithm's time computation
is very important. Nowadays, most of research papers suggest
improvements of the {DDA} method that was first presented by J.
Bresenham. But other approaches exist as well like combinatory
analysis and linguistic methods. Both of them use multiple
string copies that slow down the efficiency of the algorithms.
This paper proposes a new algorithm based on a careful analysis
of the line segments' properties some of them previously unused.
Our algorithm is proved significantly faster than previously
published ones. },
}